| /* AddressSanitizer, a fast memory error detector. |
| Copyright (C) 2012-2017 Free Software Foundation, Inc. |
| Contributed by Kostya Serebryany <kcc@google.com> |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify it under |
| the terms of the GNU General Public License as published by the Free |
| Software Foundation; either version 3, or (at your option) any later |
| version. |
| |
| GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GCC; see the file COPYING3. If not see |
| <http://www.gnu.org/licenses/>. */ |
| |
| |
| #include "config.h" |
| #include "system.h" |
| #include "coretypes.h" |
| #include "backend.h" |
| #include "target.h" |
| #include "rtl.h" |
| #include "tree.h" |
| #include "gimple.h" |
| #include "cfghooks.h" |
| #include "alloc-pool.h" |
| #include "tree-pass.h" |
| #include "memmodel.h" |
| #include "tm_p.h" |
| #include "ssa.h" |
| #include "stringpool.h" |
| #include "tree-ssanames.h" |
| #include "optabs.h" |
| #include "emit-rtl.h" |
| #include "cgraph.h" |
| #include "gimple-pretty-print.h" |
| #include "alias.h" |
| #include "fold-const.h" |
| #include "cfganal.h" |
| #include "gimplify.h" |
| #include "gimple-iterator.h" |
| #include "varasm.h" |
| #include "stor-layout.h" |
| #include "tree-iterator.h" |
| #include "asan.h" |
| #include "dojump.h" |
| #include "explow.h" |
| #include "expr.h" |
| #include "output.h" |
| #include "langhooks.h" |
| #include "cfgloop.h" |
| #include "gimple-builder.h" |
| #include "ubsan.h" |
| #include "params.h" |
| #include "builtins.h" |
| #include "fnmatch.h" |
| #include "tree-inline.h" |
| |
| /* AddressSanitizer finds out-of-bounds and use-after-free bugs |
| with <2x slowdown on average. |
| |
| The tool consists of two parts: |
| instrumentation module (this file) and a run-time library. |
| The instrumentation module adds a run-time check before every memory insn. |
| For a 8- or 16- byte load accessing address X: |
| ShadowAddr = (X >> 3) + Offset |
| ShadowValue = *(char*)ShadowAddr; // *(short*) for 16-byte access. |
| if (ShadowValue) |
| __asan_report_load8(X); |
| For a load of N bytes (N=1, 2 or 4) from address X: |
| ShadowAddr = (X >> 3) + Offset |
| ShadowValue = *(char*)ShadowAddr; |
| if (ShadowValue) |
| if ((X & 7) + N - 1 > ShadowValue) |
| __asan_report_loadN(X); |
| Stores are instrumented similarly, but using __asan_report_storeN functions. |
| A call too __asan_init_vN() is inserted to the list of module CTORs. |
| N is the version number of the AddressSanitizer API. The changes between the |
| API versions are listed in libsanitizer/asan/asan_interface_internal.h. |
| |
| The run-time library redefines malloc (so that redzone are inserted around |
| the allocated memory) and free (so that reuse of free-ed memory is delayed), |
| provides __asan_report* and __asan_init_vN functions. |
| |
| Read more: |
| http://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm |
| |
| The current implementation supports detection of out-of-bounds and |
| use-after-free in the heap, on the stack and for global variables. |
| |
| [Protection of stack variables] |
| |
| To understand how detection of out-of-bounds and use-after-free works |
| for stack variables, lets look at this example on x86_64 where the |
| stack grows downward: |
| |
| int |
| foo () |
| { |
| char a[23] = {0}; |
| int b[2] = {0}; |
| |
| a[5] = 1; |
| b[1] = 2; |
| |
| return a[5] + b[1]; |
| } |
| |
| For this function, the stack protected by asan will be organized as |
| follows, from the top of the stack to the bottom: |
| |
| Slot 1/ [red zone of 32 bytes called 'RIGHT RedZone'] |
| |
| Slot 2/ [8 bytes of red zone, that adds up to the space of 'a' to make |
| the next slot be 32 bytes aligned; this one is called Partial |
| Redzone; this 32 bytes alignment is an asan constraint] |
| |
| Slot 3/ [24 bytes for variable 'a'] |
| |
| Slot 4/ [red zone of 32 bytes called 'Middle RedZone'] |
| |
| Slot 5/ [24 bytes of Partial Red Zone (similar to slot 2] |
| |
| Slot 6/ [8 bytes for variable 'b'] |
| |
| Slot 7/ [32 bytes of Red Zone at the bottom of the stack, called |
| 'LEFT RedZone'] |
| |
| The 32 bytes of LEFT red zone at the bottom of the stack can be |
| decomposed as such: |
| |
| 1/ The first 8 bytes contain a magical asan number that is always |
| 0x41B58AB3. |
| |
| 2/ The following 8 bytes contains a pointer to a string (to be |
| parsed at runtime by the runtime asan library), which format is |
| the following: |
| |
| "<function-name> <space> <num-of-variables-on-the-stack> |
| (<32-bytes-aligned-offset-in-bytes-of-variable> <space> |
| <length-of-var-in-bytes> ){n} " |
| |
| where '(...){n}' means the content inside the parenthesis occurs 'n' |
| times, with 'n' being the number of variables on the stack. |
| |
| 3/ The following 8 bytes contain the PC of the current function which |
| will be used by the run-time library to print an error message. |
| |
| 4/ The following 8 bytes are reserved for internal use by the run-time. |
| |
| The shadow memory for that stack layout is going to look like this: |
| |
| - content of shadow memory 8 bytes for slot 7: 0xF1F1F1F1. |
| The F1 byte pattern is a magic number called |
| ASAN_STACK_MAGIC_LEFT and is a way for the runtime to know that |
| the memory for that shadow byte is part of a the LEFT red zone |
| intended to seat at the bottom of the variables on the stack. |
| |
| - content of shadow memory 8 bytes for slots 6 and 5: |
| 0xF4F4F400. The F4 byte pattern is a magic number |
| called ASAN_STACK_MAGIC_PARTIAL. It flags the fact that the |
| memory region for this shadow byte is a PARTIAL red zone |
| intended to pad a variable A, so that the slot following |
| {A,padding} is 32 bytes aligned. |
| |
| Note that the fact that the least significant byte of this |
| shadow memory content is 00 means that 8 bytes of its |
| corresponding memory (which corresponds to the memory of |
| variable 'b') is addressable. |
| |
| - content of shadow memory 8 bytes for slot 4: 0xF2F2F2F2. |
| The F2 byte pattern is a magic number called |
| ASAN_STACK_MAGIC_MIDDLE. It flags the fact that the memory |
| region for this shadow byte is a MIDDLE red zone intended to |
| seat between two 32 aligned slots of {variable,padding}. |
| |
| - content of shadow memory 8 bytes for slot 3 and 2: |
| 0xF4000000. This represents is the concatenation of |
| variable 'a' and the partial red zone following it, like what we |
| had for variable 'b'. The least significant 3 bytes being 00 |
| means that the 3 bytes of variable 'a' are addressable. |
| |
| - content of shadow memory 8 bytes for slot 1: 0xF3F3F3F3. |
| The F3 byte pattern is a magic number called |
| ASAN_STACK_MAGIC_RIGHT. It flags the fact that the memory |
| region for this shadow byte is a RIGHT red zone intended to seat |
| at the top of the variables of the stack. |
| |
| Note that the real variable layout is done in expand_used_vars in |
| cfgexpand.c. As far as Address Sanitizer is concerned, it lays out |
| stack variables as well as the different red zones, emits some |
| prologue code to populate the shadow memory as to poison (mark as |
| non-accessible) the regions of the red zones and mark the regions of |
| stack variables as accessible, and emit some epilogue code to |
| un-poison (mark as accessible) the regions of red zones right before |
| the function exits. |
| |
| [Protection of global variables] |
| |
| The basic idea is to insert a red zone between two global variables |
| and install a constructor function that calls the asan runtime to do |
| the populating of the relevant shadow memory regions at load time. |
| |
| So the global variables are laid out as to insert a red zone between |
| them. The size of the red zones is so that each variable starts on a |
| 32 bytes boundary. |
| |
| Then a constructor function is installed so that, for each global |
| variable, it calls the runtime asan library function |
| __asan_register_globals_with an instance of this type: |
| |
| struct __asan_global |
| { |
| // Address of the beginning of the global variable. |
| const void *__beg; |
| |
| // Initial size of the global variable. |
| uptr __size; |
| |
| // Size of the global variable + size of the red zone. This |
| // size is 32 bytes aligned. |
| uptr __size_with_redzone; |
| |
| // Name of the global variable. |
| const void *__name; |
| |
| // Name of the module where the global variable is declared. |
| const void *__module_name; |
| |
| // 1 if it has dynamic initialization, 0 otherwise. |
| uptr __has_dynamic_init; |
| |
| // A pointer to struct that contains source location, could be NULL. |
| __asan_global_source_location *__location; |
| } |
| |
| A destructor function that calls the runtime asan library function |
| _asan_unregister_globals is also installed. */ |
| |
| static unsigned HOST_WIDE_INT asan_shadow_offset_value; |
| static bool asan_shadow_offset_computed; |
| static vec<char *> sanitized_sections; |
| |
| /* Set of variable declarations that are going to be guarded by |
| use-after-scope sanitizer. */ |
| |
| static hash_set<tree> *asan_handled_variables = NULL; |
| |
| hash_set <tree> *asan_used_labels = NULL; |
| |
| /* Sets shadow offset to value in string VAL. */ |
| |
| bool |
| set_asan_shadow_offset (const char *val) |
| { |
| char *endp; |
| |
| errno = 0; |
| #ifdef HAVE_LONG_LONG |
| asan_shadow_offset_value = strtoull (val, &endp, 0); |
| #else |
| asan_shadow_offset_value = strtoul (val, &endp, 0); |
| #endif |
| if (!(*val != '\0' && *endp == '\0' && errno == 0)) |
| return false; |
| |
| asan_shadow_offset_computed = true; |
| |
| return true; |
| } |
| |
| /* Set list of user-defined sections that need to be sanitized. */ |
| |
| void |
| set_sanitized_sections (const char *sections) |
| { |
| char *pat; |
| unsigned i; |
| FOR_EACH_VEC_ELT (sanitized_sections, i, pat) |
| free (pat); |
| sanitized_sections.truncate (0); |
| |
| for (const char *s = sections; *s; ) |
| { |
| const char *end; |
| for (end = s; *end && *end != ','; ++end); |
| size_t len = end - s; |
| sanitized_sections.safe_push (xstrndup (s, len)); |
| s = *end ? end + 1 : end; |
| } |
| } |
| |
| bool |
| asan_mark_p (gimple *stmt, enum asan_mark_flags flag) |
| { |
| return (gimple_call_internal_p (stmt, IFN_ASAN_MARK) |
| && tree_to_uhwi (gimple_call_arg (stmt, 0)) == flag); |
| } |
| |
| bool |
| asan_sanitize_stack_p (void) |
| { |
| return ((flag_sanitize & SANITIZE_ADDRESS) |
| && ASAN_STACK |
| && !asan_no_sanitize_address_p ()); |
| } |
| |
| /* Checks whether section SEC should be sanitized. */ |
| |
| static bool |
| section_sanitized_p (const char *sec) |
| { |
| char *pat; |
| unsigned i; |
| FOR_EACH_VEC_ELT (sanitized_sections, i, pat) |
| if (fnmatch (pat, sec, FNM_PERIOD) == 0) |
| return true; |
| return false; |
| } |
| |
| /* Returns Asan shadow offset. */ |
| |
| static unsigned HOST_WIDE_INT |
| asan_shadow_offset () |
| { |
| if (!asan_shadow_offset_computed) |
| { |
| asan_shadow_offset_computed = true; |
| asan_shadow_offset_value = targetm.asan_shadow_offset (); |
| } |
| return asan_shadow_offset_value; |
| } |
| |
| alias_set_type asan_shadow_set = -1; |
| |
| /* Pointer types to 1, 2 or 4 byte integers in shadow memory. A separate |
| alias set is used for all shadow memory accesses. */ |
| static GTY(()) tree shadow_ptr_types[3]; |
| |
| /* Decl for __asan_option_detect_stack_use_after_return. */ |
| static GTY(()) tree asan_detect_stack_use_after_return; |
| |
| /* Hashtable support for memory references used by gimple |
| statements. */ |
| |
| /* This type represents a reference to a memory region. */ |
| struct asan_mem_ref |
| { |
| /* The expression of the beginning of the memory region. */ |
| tree start; |
| |
| /* The size of the access. */ |
| HOST_WIDE_INT access_size; |
| }; |
| |
| object_allocator <asan_mem_ref> asan_mem_ref_pool ("asan_mem_ref"); |
| |
| /* Initializes an instance of asan_mem_ref. */ |
| |
| static void |
| asan_mem_ref_init (asan_mem_ref *ref, tree start, HOST_WIDE_INT access_size) |
| { |
| ref->start = start; |
| ref->access_size = access_size; |
| } |
| |
| /* Allocates memory for an instance of asan_mem_ref into the memory |
| pool returned by asan_mem_ref_get_alloc_pool and initialize it. |
| START is the address of (or the expression pointing to) the |
| beginning of memory reference. ACCESS_SIZE is the size of the |
| access to the referenced memory. */ |
| |
| static asan_mem_ref* |
| asan_mem_ref_new (tree start, HOST_WIDE_INT access_size) |
| { |
| asan_mem_ref *ref = asan_mem_ref_pool.allocate (); |
| |
| asan_mem_ref_init (ref, start, access_size); |
| return ref; |
| } |
| |
| /* This builds and returns a pointer to the end of the memory region |
| that starts at START and of length LEN. */ |
| |
| tree |
| asan_mem_ref_get_end (tree start, tree len) |
| { |
| if (len == NULL_TREE || integer_zerop (len)) |
| return start; |
| |
| if (!ptrofftype_p (len)) |
| len = convert_to_ptrofftype (len); |
| |
| return fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (start), start, len); |
| } |
| |
| /* Return a tree expression that represents the end of the referenced |
| memory region. Beware that this function can actually build a new |
| tree expression. */ |
| |
| tree |
| asan_mem_ref_get_end (const asan_mem_ref *ref, tree len) |
| { |
| return asan_mem_ref_get_end (ref->start, len); |
| } |
| |
| struct asan_mem_ref_hasher : nofree_ptr_hash <asan_mem_ref> |
| { |
| static inline hashval_t hash (const asan_mem_ref *); |
| static inline bool equal (const asan_mem_ref *, const asan_mem_ref *); |
| }; |
| |
| /* Hash a memory reference. */ |
| |
| inline hashval_t |
| asan_mem_ref_hasher::hash (const asan_mem_ref *mem_ref) |
| { |
| return iterative_hash_expr (mem_ref->start, 0); |
| } |
| |
| /* Compare two memory references. We accept the length of either |
| memory references to be NULL_TREE. */ |
| |
| inline bool |
| asan_mem_ref_hasher::equal (const asan_mem_ref *m1, |
| const asan_mem_ref *m2) |
| { |
| return operand_equal_p (m1->start, m2->start, 0); |
| } |
| |
| static hash_table<asan_mem_ref_hasher> *asan_mem_ref_ht; |
| |
| /* Returns a reference to the hash table containing memory references. |
| This function ensures that the hash table is created. Note that |
| this hash table is updated by the function |
| update_mem_ref_hash_table. */ |
| |
| static hash_table<asan_mem_ref_hasher> * |
| get_mem_ref_hash_table () |
| { |
| if (!asan_mem_ref_ht) |
| asan_mem_ref_ht = new hash_table<asan_mem_ref_hasher> (10); |
| |
| return asan_mem_ref_ht; |
| } |
| |
| /* Clear all entries from the memory references hash table. */ |
| |
| static void |
| empty_mem_ref_hash_table () |
| { |
| if (asan_mem_ref_ht) |
| asan_mem_ref_ht->empty (); |
| } |
| |
| /* Free the memory references hash table. */ |
| |
| static void |
| free_mem_ref_resources () |
| { |
| delete asan_mem_ref_ht; |
| asan_mem_ref_ht = NULL; |
| |
| asan_mem_ref_pool.release (); |
| } |
| |
| /* Return true iff the memory reference REF has been instrumented. */ |
| |
| static bool |
| has_mem_ref_been_instrumented (tree ref, HOST_WIDE_INT access_size) |
| { |
| asan_mem_ref r; |
| asan_mem_ref_init (&r, ref, access_size); |
| |
| asan_mem_ref *saved_ref = get_mem_ref_hash_table ()->find (&r); |
| return saved_ref && saved_ref->access_size >= access_size; |
| } |
| |
| /* Return true iff the memory reference REF has been instrumented. */ |
| |
| static bool |
| has_mem_ref_been_instrumented (const asan_mem_ref *ref) |
| { |
| return has_mem_ref_been_instrumented (ref->start, ref->access_size); |
| } |
| |
| /* Return true iff access to memory region starting at REF and of |
| length LEN has been instrumented. */ |
| |
| static bool |
| has_mem_ref_been_instrumented (const asan_mem_ref *ref, tree len) |
| { |
| HOST_WIDE_INT size_in_bytes |
| = tree_fits_shwi_p (len) ? tree_to_shwi (len) : -1; |
| |
| return size_in_bytes != -1 |
| && has_mem_ref_been_instrumented (ref->start, size_in_bytes); |
| } |
| |
| /* Set REF to the memory reference present in a gimple assignment |
| ASSIGNMENT. Return true upon successful completion, false |
| otherwise. */ |
| |
| static bool |
| get_mem_ref_of_assignment (const gassign *assignment, |
| asan_mem_ref *ref, |
| bool *ref_is_store) |
| { |
| gcc_assert (gimple_assign_single_p (assignment)); |
| |
| if (gimple_store_p (assignment) |
| && !gimple_clobber_p (assignment)) |
| { |
| ref->start = gimple_assign_lhs (assignment); |
| *ref_is_store = true; |
| } |
| else if (gimple_assign_load_p (assignment)) |
| { |
| ref->start = gimple_assign_rhs1 (assignment); |
| *ref_is_store = false; |
| } |
| else |
| return false; |
| |
| ref->access_size = int_size_in_bytes (TREE_TYPE (ref->start)); |
| return true; |
| } |
| |
| /* Return the memory references contained in a gimple statement |
| representing a builtin call that has to do with memory access. */ |
| |
| static bool |
| get_mem_refs_of_builtin_call (const gcall *call, |
| asan_mem_ref *src0, |
| tree *src0_len, |
| bool *src0_is_store, |
| asan_mem_ref *src1, |
| tree *src1_len, |
| bool *src1_is_store, |
| asan_mem_ref *dst, |
| tree *dst_len, |
| bool *dst_is_store, |
| bool *dest_is_deref, |
| bool *intercepted_p) |
| { |
| gcc_checking_assert (gimple_call_builtin_p (call, BUILT_IN_NORMAL)); |
| |
| tree callee = gimple_call_fndecl (call); |
| tree source0 = NULL_TREE, source1 = NULL_TREE, |
| dest = NULL_TREE, len = NULL_TREE; |
| bool is_store = true, got_reference_p = false; |
| HOST_WIDE_INT access_size = 1; |
| |
| *intercepted_p = asan_intercepted_p ((DECL_FUNCTION_CODE (callee))); |
| |
| switch (DECL_FUNCTION_CODE (callee)) |
| { |
| /* (s, s, n) style memops. */ |
| case BUILT_IN_BCMP: |
| case BUILT_IN_MEMCMP: |
| source0 = gimple_call_arg (call, 0); |
| source1 = gimple_call_arg (call, 1); |
| len = gimple_call_arg (call, 2); |
| break; |
| |
| /* (src, dest, n) style memops. */ |
| case BUILT_IN_BCOPY: |
| source0 = gimple_call_arg (call, 0); |
| dest = gimple_call_arg (call, 1); |
| len = gimple_call_arg (call, 2); |
| break; |
| |
| /* (dest, src, n) style memops. */ |
| case BUILT_IN_MEMCPY: |
| case BUILT_IN_MEMCPY_CHK: |
| case BUILT_IN_MEMMOVE: |
| case BUILT_IN_MEMMOVE_CHK: |
| case BUILT_IN_MEMPCPY: |
| case BUILT_IN_MEMPCPY_CHK: |
| dest = gimple_call_arg (call, 0); |
| source0 = gimple_call_arg (call, 1); |
| len = gimple_call_arg (call, 2); |
| break; |
| |
| /* (dest, n) style memops. */ |
| case BUILT_IN_BZERO: |
| dest = gimple_call_arg (call, 0); |
| len = gimple_call_arg (call, 1); |
| break; |
| |
| /* (dest, x, n) style memops*/ |
| case BUILT_IN_MEMSET: |
| case BUILT_IN_MEMSET_CHK: |
| dest = gimple_call_arg (call, 0); |
| len = gimple_call_arg (call, 2); |
| break; |
| |
| case BUILT_IN_STRLEN: |
| source0 = gimple_call_arg (call, 0); |
| len = gimple_call_lhs (call); |
| break; |
| |
| /* And now the __atomic* and __sync builtins. |
| These are handled differently from the classical memory memory |
| access builtins above. */ |
| |
| case BUILT_IN_ATOMIC_LOAD_1: |
| is_store = false; |
| /* FALLTHRU */ |
| case BUILT_IN_SYNC_FETCH_AND_ADD_1: |
| case BUILT_IN_SYNC_FETCH_AND_SUB_1: |
| case BUILT_IN_SYNC_FETCH_AND_OR_1: |
| case BUILT_IN_SYNC_FETCH_AND_AND_1: |
| case BUILT_IN_SYNC_FETCH_AND_XOR_1: |
| case BUILT_IN_SYNC_FETCH_AND_NAND_1: |
| case BUILT_IN_SYNC_ADD_AND_FETCH_1: |
| case BUILT_IN_SYNC_SUB_AND_FETCH_1: |
| case BUILT_IN_SYNC_OR_AND_FETCH_1: |
| case BUILT_IN_SYNC_AND_AND_FETCH_1: |
| case BUILT_IN_SYNC_XOR_AND_FETCH_1: |
| case BUILT_IN_SYNC_NAND_AND_FETCH_1: |
| case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_1: |
| case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_1: |
| case BUILT_IN_SYNC_LOCK_TEST_AND_SET_1: |
| case BUILT_IN_SYNC_LOCK_RELEASE_1: |
| case BUILT_IN_ATOMIC_EXCHANGE_1: |
| case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_1: |
| case BUILT_IN_ATOMIC_STORE_1: |
| case BUILT_IN_ATOMIC_ADD_FETCH_1: |
| case BUILT_IN_ATOMIC_SUB_FETCH_1: |
| case BUILT_IN_ATOMIC_AND_FETCH_1: |
| case BUILT_IN_ATOMIC_NAND_FETCH_1: |
| case BUILT_IN_ATOMIC_XOR_FETCH_1: |
| case BUILT_IN_ATOMIC_OR_FETCH_1: |
| case BUILT_IN_ATOMIC_FETCH_ADD_1: |
| case BUILT_IN_ATOMIC_FETCH_SUB_1: |
| case BUILT_IN_ATOMIC_FETCH_AND_1: |
| case BUILT_IN_ATOMIC_FETCH_NAND_1: |
| case BUILT_IN_ATOMIC_FETCH_XOR_1: |
| case BUILT_IN_ATOMIC_FETCH_OR_1: |
| access_size = 1; |
| goto do_atomic; |
| |
| case BUILT_IN_ATOMIC_LOAD_2: |
| is_store = false; |
| /* FALLTHRU */ |
| case BUILT_IN_SYNC_FETCH_AND_ADD_2: |
| case BUILT_IN_SYNC_FETCH_AND_SUB_2: |
| case BUILT_IN_SYNC_FETCH_AND_OR_2: |
| case BUILT_IN_SYNC_FETCH_AND_AND_2: |
| case BUILT_IN_SYNC_FETCH_AND_XOR_2: |
| case BUILT_IN_SYNC_FETCH_AND_NAND_2: |
| case BUILT_IN_SYNC_ADD_AND_FETCH_2: |
| case BUILT_IN_SYNC_SUB_AND_FETCH_2: |
| case BUILT_IN_SYNC_OR_AND_FETCH_2: |
| case BUILT_IN_SYNC_AND_AND_FETCH_2: |
| case BUILT_IN_SYNC_XOR_AND_FETCH_2: |
| case BUILT_IN_SYNC_NAND_AND_FETCH_2: |
| case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_2: |
| case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_2: |
| case BUILT_IN_SYNC_LOCK_TEST_AND_SET_2: |
| case BUILT_IN_SYNC_LOCK_RELEASE_2: |
| case BUILT_IN_ATOMIC_EXCHANGE_2: |
| case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_2: |
| case BUILT_IN_ATOMIC_STORE_2: |
| case BUILT_IN_ATOMIC_ADD_FETCH_2: |
| case BUILT_IN_ATOMIC_SUB_FETCH_2: |
| case BUILT_IN_ATOMIC_AND_FETCH_2: |
| case BUILT_IN_ATOMIC_NAND_FETCH_2: |
| case BUILT_IN_ATOMIC_XOR_FETCH_2: |
| case BUILT_IN_ATOMIC_OR_FETCH_2: |
| case BUILT_IN_ATOMIC_FETCH_ADD_2: |
| case BUILT_IN_ATOMIC_FETCH_SUB_2: |
| case BUILT_IN_ATOMIC_FETCH_AND_2: |
| case BUILT_IN_ATOMIC_FETCH_NAND_2: |
| case BUILT_IN_ATOMIC_FETCH_XOR_2: |
| case BUILT_IN_ATOMIC_FETCH_OR_2: |
| access_size = 2; |
| goto do_atomic; |
| |
| case BUILT_IN_ATOMIC_LOAD_4: |
| is_store = false; |
| /* FALLTHRU */ |
| case BUILT_IN_SYNC_FETCH_AND_ADD_4: |
| case BUILT_IN_SYNC_FETCH_AND_SUB_4: |
| case BUILT_IN_SYNC_FETCH_AND_OR_4: |
| case BUILT_IN_SYNC_FETCH_AND_AND_4: |
| case BUILT_IN_SYNC_FETCH_AND_XOR_4: |
| case BUILT_IN_SYNC_FETCH_AND_NAND_4: |
| case BUILT_IN_SYNC_ADD_AND_FETCH_4: |
| case BUILT_IN_SYNC_SUB_AND_FETCH_4: |
| case BUILT_IN_SYNC_OR_AND_FETCH_4: |
| case BUILT_IN_SYNC_AND_AND_FETCH_4: |
| case BUILT_IN_SYNC_XOR_AND_FETCH_4: |
| case BUILT_IN_SYNC_NAND_AND_FETCH_4: |
| case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_4: |
| case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_4: |
| case BUILT_IN_SYNC_LOCK_TEST_AND_SET_4: |
| case BUILT_IN_SYNC_LOCK_RELEASE_4: |
| case BUILT_IN_ATOMIC_EXCHANGE_4: |
| case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_4: |
| case BUILT_IN_ATOMIC_STORE_4: |
| case BUILT_IN_ATOMIC_ADD_FETCH_4: |
| case BUILT_IN_ATOMIC_SUB_FETCH_4: |
| case BUILT_IN_ATOMIC_AND_FETCH_4: |
| case BUILT_IN_ATOMIC_NAND_FETCH_4: |
| case BUILT_IN_ATOMIC_XOR_FETCH_4: |
| case BUILT_IN_ATOMIC_OR_FETCH_4: |
| case BUILT_IN_ATOMIC_FETCH_ADD_4: |
| case BUILT_IN_ATOMIC_FETCH_SUB_4: |
| case BUILT_IN_ATOMIC_FETCH_AND_4: |
| case BUILT_IN_ATOMIC_FETCH_NAND_4: |
| case BUILT_IN_ATOMIC_FETCH_XOR_4: |
| case BUILT_IN_ATOMIC_FETCH_OR_4: |
| access_size = 4; |
| goto do_atomic; |
| |
| case BUILT_IN_ATOMIC_LOAD_8: |
| is_store = false; |
| /* FALLTHRU */ |
| case BUILT_IN_SYNC_FETCH_AND_ADD_8: |
| case BUILT_IN_SYNC_FETCH_AND_SUB_8: |
| case BUILT_IN_SYNC_FETCH_AND_OR_8: |
| case BUILT_IN_SYNC_FETCH_AND_AND_8: |
| case BUILT_IN_SYNC_FETCH_AND_XOR_8: |
| case BUILT_IN_SYNC_FETCH_AND_NAND_8: |
| case BUILT_IN_SYNC_ADD_AND_FETCH_8: |
| case BUILT_IN_SYNC_SUB_AND_FETCH_8: |
| case BUILT_IN_SYNC_OR_AND_FETCH_8: |
| case BUILT_IN_SYNC_AND_AND_FETCH_8: |
| case BUILT_IN_SYNC_XOR_AND_FETCH_8: |
| case BUILT_IN_SYNC_NAND_AND_FETCH_8: |
| case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_8: |
| case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_8: |
| case BUILT_IN_SYNC_LOCK_TEST_AND_SET_8: |
| case BUILT_IN_SYNC_LOCK_RELEASE_8: |
| case BUILT_IN_ATOMIC_EXCHANGE_8: |
| case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_8: |
| case BUILT_IN_ATOMIC_STORE_8: |
| case BUILT_IN_ATOMIC_ADD_FETCH_8: |
| case BUILT_IN_ATOMIC_SUB_FETCH_8: |
| case BUILT_IN_ATOMIC_AND_FETCH_8: |
| case BUILT_IN_ATOMIC_NAND_FETCH_8: |
| case BUILT_IN_ATOMIC_XOR_FETCH_8: |
| case BUILT_IN_ATOMIC_OR_FETCH_8: |
| case BUILT_IN_ATOMIC_FETCH_ADD_8: |
| case BUILT_IN_ATOMIC_FETCH_SUB_8: |
| case BUILT_IN_ATOMIC_FETCH_AND_8: |
| case BUILT_IN_ATOMIC_FETCH_NAND_8: |
| case BUILT_IN_ATOMIC_FETCH_XOR_8: |
| case BUILT_IN_ATOMIC_FETCH_OR_8: |
| access_size = 8; |
| goto do_atomic; |
| |
| case BUILT_IN_ATOMIC_LOAD_16: |
| is_store = false; |
| /* FALLTHRU */ |
| case BUILT_IN_SYNC_FETCH_AND_ADD_16: |
| case BUILT_IN_SYNC_FETCH_AND_SUB_16: |
| case BUILT_IN_SYNC_FETCH_AND_OR_16: |
| case BUILT_IN_SYNC_FETCH_AND_AND_16: |
| case BUILT_IN_SYNC_FETCH_AND_XOR_16: |
| case BUILT_IN_SYNC_FETCH_AND_NAND_16: |
| case BUILT_IN_SYNC_ADD_AND_FETCH_16: |
| case BUILT_IN_SYNC_SUB_AND_FETCH_16: |
| case BUILT_IN_SYNC_OR_AND_FETCH_16: |
| case BUILT_IN_SYNC_AND_AND_FETCH_16: |
| case BUILT_IN_SYNC_XOR_AND_FETCH_16: |
| case BUILT_IN_SYNC_NAND_AND_FETCH_16: |
| case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_16: |
| case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_16: |
| case BUILT_IN_SYNC_LOCK_TEST_AND_SET_16: |
| case BUILT_IN_SYNC_LOCK_RELEASE_16: |
| case BUILT_IN_ATOMIC_EXCHANGE_16: |
| case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_16: |
| case BUILT_IN_ATOMIC_STORE_16: |
| case BUILT_IN_ATOMIC_ADD_FETCH_16: |
| case BUILT_IN_ATOMIC_SUB_FETCH_16: |
| case BUILT_IN_ATOMIC_AND_FETCH_16: |
| case BUILT_IN_ATOMIC_NAND_FETCH_16: |
| case BUILT_IN_ATOMIC_XOR_FETCH_16: |
| case BUILT_IN_ATOMIC_OR_FETCH_16: |
| case BUILT_IN_ATOMIC_FETCH_ADD_16: |
| case BUILT_IN_ATOMIC_FETCH_SUB_16: |
| case BUILT_IN_ATOMIC_FETCH_AND_16: |
| case BUILT_IN_ATOMIC_FETCH_NAND_16: |
| case BUILT_IN_ATOMIC_FETCH_XOR_16: |
| case BUILT_IN_ATOMIC_FETCH_OR_16: |
| access_size = 16; |
| /* FALLTHRU */ |
| do_atomic: |
| { |
| dest = gimple_call_arg (call, 0); |
| /* DEST represents the address of a memory location. |
| instrument_derefs wants the memory location, so lets |
| dereference the address DEST before handing it to |
| instrument_derefs. */ |
| tree type = build_nonstandard_integer_type (access_size |
| * BITS_PER_UNIT, 1); |
| dest = build2 (MEM_REF, type, dest, |
| build_int_cst (build_pointer_type (char_type_node), 0)); |
| break; |
| } |
| |
| default: |
| /* The other builtins memory access are not instrumented in this |
| function because they either don't have any length parameter, |
| or their length parameter is just a limit. */ |
| break; |
| } |
| |
| if (len != NULL_TREE) |
| { |
| if (source0 != NULL_TREE) |
| { |
| src0->start = source0; |
| src0->access_size = access_size; |
| *src0_len = len; |
| *src0_is_store = false; |
| } |
| |
| if (source1 != NULL_TREE) |
| { |
| src1->start = source1; |
| src1->access_size = access_size; |
| *src1_len = len; |
| *src1_is_store = false; |
| } |
| |
| if (dest != NULL_TREE) |
| { |
| dst->start = dest; |
| dst->access_size = access_size; |
| *dst_len = len; |
| *dst_is_store = true; |
| } |
| |
| got_reference_p = true; |
| } |
| else if (dest) |
| { |
| dst->start = dest; |
| dst->access_size = access_size; |
| *dst_len = NULL_TREE; |
| *dst_is_store = is_store; |
| *dest_is_deref = true; |
| got_reference_p = true; |
| } |
| |
| return got_reference_p; |
| } |
| |
| /* Return true iff a given gimple statement has been instrumented. |
| Note that the statement is "defined" by the memory references it |
| contains. */ |
| |
| static bool |
| has_stmt_been_instrumented_p (gimple *stmt) |
| { |
| if (gimple_assign_single_p (stmt)) |
| { |
| bool r_is_store; |
| asan_mem_ref r; |
| asan_mem_ref_init (&r, NULL, 1); |
| |
| if (get_mem_ref_of_assignment (as_a <gassign *> (stmt), &r, |
| &r_is_store)) |
| return has_mem_ref_been_instrumented (&r); |
| } |
| else if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) |
| { |
| asan_mem_ref src0, src1, dest; |
| asan_mem_ref_init (&src0, NULL, 1); |
| asan_mem_ref_init (&src1, NULL, 1); |
| asan_mem_ref_init (&dest, NULL, 1); |
| |
| tree src0_len = NULL_TREE, src1_len = NULL_TREE, dest_len = NULL_TREE; |
| bool src0_is_store = false, src1_is_store = false, |
| dest_is_store = false, dest_is_deref = false, intercepted_p = true; |
| if (get_mem_refs_of_builtin_call (as_a <gcall *> (stmt), |
| &src0, &src0_len, &src0_is_store, |
| &src1, &src1_len, &src1_is_store, |
| &dest, &dest_len, &dest_is_store, |
| &dest_is_deref, &intercepted_p)) |
| { |
| if (src0.start != NULL_TREE |
| && !has_mem_ref_been_instrumented (&src0, src0_len)) |
| return false; |
| |
| if (src1.start != NULL_TREE |
| && !has_mem_ref_been_instrumented (&src1, src1_len)) |
| return false; |
| |
| if (dest.start != NULL_TREE |
| && !has_mem_ref_been_instrumented (&dest, dest_len)) |
| return false; |
| |
| return true; |
| } |
| } |
| else if (is_gimple_call (stmt) && gimple_store_p (stmt)) |
| { |
| asan_mem_ref r; |
| asan_mem_ref_init (&r, NULL, 1); |
| |
| r.start = gimple_call_lhs (stmt); |
| r.access_size = int_size_in_bytes (TREE_TYPE (r.start)); |
| return has_mem_ref_been_instrumented (&r); |
| } |
| |
| return false; |
| } |
| |
| /* Insert a memory reference into the hash table. */ |
| |
| static void |
| update_mem_ref_hash_table (tree ref, HOST_WIDE_INT access_size) |
| { |
| hash_table<asan_mem_ref_hasher> *ht = get_mem_ref_hash_table (); |
| |
| asan_mem_ref r; |
| asan_mem_ref_init (&r, ref, access_size); |
| |
| asan_mem_ref **slot = ht->find_slot (&r, INSERT); |
| if (*slot == NULL || (*slot)->access_size < access_size) |
| *slot = asan_mem_ref_new (ref, access_size); |
| } |
| |
| /* Initialize shadow_ptr_types array. */ |
| |
| static void |
| asan_init_shadow_ptr_types (void) |
| { |
| asan_shadow_set = new_alias_set (); |
| tree types[3] = { signed_char_type_node, short_integer_type_node, |
| integer_type_node }; |
| |
| for (unsigned i = 0; i < 3; i++) |
| { |
| shadow_ptr_types[i] = build_distinct_type_copy (types[i]); |
| TYPE_ALIAS_SET (shadow_ptr_types[i]) = asan_shadow_set; |
| shadow_ptr_types[i] = build_pointer_type (shadow_ptr_types[i]); |
| } |
| |
| initialize_sanitizer_builtins (); |
| } |
| |
| /* Create ADDR_EXPR of STRING_CST with the PP pretty printer text. */ |
| |
| static tree |
| asan_pp_string (pretty_printer *pp) |
| { |
| const char *buf = pp_formatted_text (pp); |
| size_t len = strlen (buf); |
| tree ret = build_string (len + 1, buf); |
| TREE_TYPE (ret) |
| = build_array_type (TREE_TYPE (shadow_ptr_types[0]), |
| build_index_type (size_int (len))); |
| TREE_READONLY (ret) = 1; |
| TREE_STATIC (ret) = 1; |
| return build1 (ADDR_EXPR, shadow_ptr_types[0], ret); |
| } |
| |
| /* Return a CONST_INT representing 4 subsequent shadow memory bytes. */ |
| |
| static rtx |
| asan_shadow_cst (unsigned char shadow_bytes[4]) |
| { |
| int i; |
| unsigned HOST_WIDE_INT val = 0; |
| gcc_assert (WORDS_BIG_ENDIAN == BYTES_BIG_ENDIAN); |
| for (i = 0; i < 4; i++) |
| val |= (unsigned HOST_WIDE_INT) shadow_bytes[BYTES_BIG_ENDIAN ? 3 - i : i] |
| << (BITS_PER_UNIT * i); |
| return gen_int_mode (val, SImode); |
| } |
| |
| /* Clear shadow memory at SHADOW_MEM, LEN bytes. Can't call a library call here |
| though. */ |
| |
| static void |
| asan_clear_shadow (rtx shadow_mem, HOST_WIDE_INT len) |
| { |
| rtx_insn *insn, *insns, *jump; |
| rtx_code_label *top_label; |
| rtx end, addr, tmp; |
| |
| start_sequence (); |
| clear_storage (shadow_mem, GEN_INT (len), BLOCK_OP_NORMAL); |
| insns = get_insns (); |
| end_sequence (); |
| for (insn = insns; insn; insn = NEXT_INSN (insn)) |
| if (CALL_P (insn)) |
| break; |
| if (insn == NULL_RTX) |
| { |
| emit_insn (insns); |
| return; |
| } |
| |
| gcc_assert ((len & 3) == 0); |
| top_label = gen_label_rtx (); |
| addr = copy_to_mode_reg (Pmode, XEXP (shadow_mem, 0)); |
| shadow_mem = adjust_automodify_address (shadow_mem, SImode, addr, 0); |
| end = force_reg (Pmode, plus_constant (Pmode, addr, len)); |
| emit_label (top_label); |
| |
| emit_move_insn (shadow_mem, const0_rtx); |
| tmp = expand_simple_binop (Pmode, PLUS, addr, gen_int_mode (4, Pmode), addr, |
| true, OPTAB_LIB_WIDEN); |
| if (tmp != addr) |
| emit_move_insn (addr, tmp); |
| emit_cmp_and_jump_insns (addr, end, LT, NULL_RTX, Pmode, true, top_label); |
| jump = get_last_insn (); |
| gcc_assert (JUMP_P (jump)); |
| add_int_reg_note (jump, REG_BR_PROB, REG_BR_PROB_BASE * 80 / 100); |
| } |
| |
| void |
| asan_function_start (void) |
| { |
| section *fnsec = function_section (current_function_decl); |
| switch_to_section (fnsec); |
| ASM_OUTPUT_DEBUG_LABEL (asm_out_file, "LASANPC", |
| current_function_funcdef_no); |
| } |
| |
| /* Return number of shadow bytes that are occupied by a local variable |
| of SIZE bytes. */ |
| |
| static unsigned HOST_WIDE_INT |
| shadow_mem_size (unsigned HOST_WIDE_INT size) |
| { |
| return ROUND_UP (size, ASAN_SHADOW_GRANULARITY) / ASAN_SHADOW_GRANULARITY; |
| } |
| |
| /* Insert code to protect stack vars. The prologue sequence should be emitted |
| directly, epilogue sequence returned. BASE is the register holding the |
| stack base, against which OFFSETS array offsets are relative to, OFFSETS |
| array contains pairs of offsets in reverse order, always the end offset |
| of some gap that needs protection followed by starting offset, |
| and DECLS is an array of representative decls for each var partition. |
| LENGTH is the length of the OFFSETS array, DECLS array is LENGTH / 2 - 1 |
| elements long (OFFSETS include gap before the first variable as well |
| as gaps after each stack variable). PBASE is, if non-NULL, some pseudo |
| register which stack vars DECL_RTLs are based on. Either BASE should be |
| assigned to PBASE, when not doing use after return protection, or |
| corresponding address based on __asan_stack_malloc* return value. */ |
| |
| rtx_insn * |
| asan_emit_stack_protection (rtx base, rtx pbase, unsigned int alignb, |
| HOST_WIDE_INT *offsets, tree *decls, int length) |
| { |
| rtx shadow_base, shadow_mem, ret, mem, orig_base; |
| rtx_code_label *lab; |
| rtx_insn *insns; |
| char buf[32]; |
| unsigned char shadow_bytes[4]; |
| HOST_WIDE_INT base_offset = offsets[length - 1]; |
| HOST_WIDE_INT base_align_bias = 0, offset, prev_offset; |
| HOST_WIDE_INT asan_frame_size = offsets[0] - base_offset; |
| HOST_WIDE_INT last_offset; |
| int l; |
| unsigned char cur_shadow_byte = ASAN_STACK_MAGIC_LEFT; |
| tree str_cst, decl, id; |
| int use_after_return_class = -1; |
| |
| if (shadow_ptr_types[0] == NULL_TREE) |
| asan_init_shadow_ptr_types (); |
| |
| /* First of all, prepare the description string. */ |
| pretty_printer asan_pp; |
| |
| pp_decimal_int (&asan_pp, length / 2 - 1); |
| pp_space (&asan_pp); |
| for (l = length - 2; l; l -= 2) |
| { |
| tree decl = decls[l / 2 - 1]; |
| pp_wide_integer (&asan_pp, offsets[l] - base_offset); |
| pp_space (&asan_pp); |
| pp_wide_integer (&asan_pp, offsets[l - 1] - offsets[l]); |
| pp_space (&asan_pp); |
| if (DECL_P (decl) && DECL_NAME (decl)) |
| { |
| pp_decimal_int (&asan_pp, IDENTIFIER_LENGTH (DECL_NAME (decl))); |
| pp_space (&asan_pp); |
| pp_tree_identifier (&asan_pp, DECL_NAME (decl)); |
| } |
| else |
| pp_string (&asan_pp, "9 <unknown>"); |
| pp_space (&asan_pp); |
| } |
| str_cst = asan_pp_string (&asan_pp); |
| |
| /* Emit the prologue sequence. */ |
| if (asan_frame_size > 32 && asan_frame_size <= 65536 && pbase |
| && ASAN_USE_AFTER_RETURN) |
| { |
| use_after_return_class = floor_log2 (asan_frame_size - 1) - 5; |
| /* __asan_stack_malloc_N guarantees alignment |
| N < 6 ? (64 << N) : 4096 bytes. */ |
| if (alignb > (use_after_return_class < 6 |
| ? (64U << use_after_return_class) : 4096U)) |
| use_after_return_class = -1; |
| else if (alignb > ASAN_RED_ZONE_SIZE && (asan_frame_size & (alignb - 1))) |
| base_align_bias = ((asan_frame_size + alignb - 1) |
| & ~(alignb - HOST_WIDE_INT_1)) - asan_frame_size; |
| } |
| /* Align base if target is STRICT_ALIGNMENT. */ |
| if (STRICT_ALIGNMENT) |
| base = expand_binop (Pmode, and_optab, base, |
| gen_int_mode (-((GET_MODE_ALIGNMENT (SImode) |
| << ASAN_SHADOW_SHIFT) |
| / BITS_PER_UNIT), Pmode), NULL_RTX, |
| 1, OPTAB_DIRECT); |
| |
| if (use_after_return_class == -1 && pbase) |
| emit_move_insn (pbase, base); |
| |
| base = expand_binop (Pmode, add_optab, base, |
| gen_int_mode (base_offset - base_align_bias, Pmode), |
| NULL_RTX, 1, OPTAB_DIRECT); |
| orig_base = NULL_RTX; |
| if (use_after_return_class != -1) |
| { |
| if (asan_detect_stack_use_after_return == NULL_TREE) |
| { |
| id = get_identifier ("__asan_option_detect_stack_use_after_return"); |
| decl = build_decl (BUILTINS_LOCATION, VAR_DECL, id, |
| integer_type_node); |
| SET_DECL_ASSEMBLER_NAME (decl, id); |
| TREE_ADDRESSABLE (decl) = 1; |
| DECL_ARTIFICIAL (decl) = 1; |
| DECL_IGNORED_P (decl) = 1; |
| DECL_EXTERNAL (decl) = 1; |
| TREE_STATIC (decl) = 1; |
| TREE_PUBLIC (decl) = 1; |
| TREE_USED (decl) = 1; |
| asan_detect_stack_use_after_return = decl; |
| } |
| orig_base = gen_reg_rtx (Pmode); |
| emit_move_insn (orig_base, base); |
| ret = expand_normal (asan_detect_stack_use_after_return); |
| lab = gen_label_rtx (); |
| int very_likely = REG_BR_PROB_BASE - (REG_BR_PROB_BASE / 2000 - 1); |
| emit_cmp_and_jump_insns (ret, const0_rtx, EQ, NULL_RTX, |
| VOIDmode, 0, lab, very_likely); |
| snprintf (buf, sizeof buf, "__asan_stack_malloc_%d", |
| use_after_return_class); |
| ret = init_one_libfunc (buf); |
| ret = emit_library_call_value (ret, NULL_RTX, LCT_NORMAL, ptr_mode, 1, |
| GEN_INT (asan_frame_size |
| + base_align_bias), |
| TYPE_MODE (pointer_sized_int_node)); |
| /* __asan_stack_malloc_[n] returns a pointer to fake stack if succeeded |
| and NULL otherwise. Check RET value is NULL here and jump over the |
| BASE reassignment in this case. Otherwise, reassign BASE to RET. */ |
| int very_unlikely = REG_BR_PROB_BASE / 2000 - 1; |
| emit_cmp_and_jump_insns (ret, const0_rtx, EQ, NULL_RTX, |
| VOIDmode, 0, lab, very_unlikely); |
| ret = convert_memory_address (Pmode, ret); |
| emit_move_insn (base, ret); |
| emit_label (lab); |
| emit_move_insn (pbase, expand_binop (Pmode, add_optab, base, |
| gen_int_mode (base_align_bias |
| - base_offset, Pmode), |
| NULL_RTX, 1, OPTAB_DIRECT)); |
| } |
| mem = gen_rtx_MEM (ptr_mode, base); |
| mem = adjust_address (mem, VOIDmode, base_align_bias); |
| emit_move_insn (mem, gen_int_mode (ASAN_STACK_FRAME_MAGIC, ptr_mode)); |
| mem = adjust_address (mem, VOIDmode, GET_MODE_SIZE (ptr_mode)); |
| emit_move_insn (mem, expand_normal (str_cst)); |
| mem = adjust_address (mem, VOIDmode, GET_MODE_SIZE (ptr_mode)); |
| ASM_GENERATE_INTERNAL_LABEL (buf, "LASANPC", current_function_funcdef_no); |
| id = get_identifier (buf); |
| decl = build_decl (DECL_SOURCE_LOCATION (current_function_decl), |
| VAR_DECL, id, char_type_node); |
| SET_DECL_ASSEMBLER_NAME (decl, id); |
| TREE_ADDRESSABLE (decl) = 1; |
| TREE_READONLY (decl) = 1; |
| DECL_ARTIFICIAL (decl) = 1; |
| DECL_IGNORED_P (decl) = 1; |
| TREE_STATIC (decl) = 1; |
| TREE_PUBLIC (decl) = 0; |
| TREE_USED (decl) = 1; |
| DECL_INITIAL (decl) = decl; |
| TREE_ASM_WRITTEN (decl) = 1; |
| TREE_ASM_WRITTEN (id) = 1; |
| emit_move_insn (mem, expand_normal (build_fold_addr_expr (decl))); |
| shadow_base = expand_binop (Pmode, lshr_optab, base, |
| GEN_INT (ASAN_SHADOW_SHIFT), |
| NULL_RTX, 1, OPTAB_DIRECT); |
| shadow_base |
| = plus_constant (Pmode, shadow_base, |
| asan_shadow_offset () |
| + (base_align_bias >> ASAN_SHADOW_SHIFT)); |
| gcc_assert (asan_shadow_set != -1 |
| && (ASAN_RED_ZONE_SIZE >> ASAN_SHADOW_SHIFT) == 4); |
| shadow_mem = gen_rtx_MEM (SImode, shadow_base); |
| set_mem_alias_set (shadow_mem, asan_shadow_set); |
| if (STRICT_ALIGNMENT) |
| set_mem_align (shadow_mem, (GET_MODE_ALIGNMENT (SImode))); |
| prev_offset = base_offset; |
| for (l = length; l; l -= 2) |
| { |
| if (l == 2) |
| cur_shadow_byte = ASAN_STACK_MAGIC_RIGHT; |
| offset = offsets[l - 1]; |
| if ((offset - base_offset) & (ASAN_RED_ZONE_SIZE - 1)) |
| { |
| int i; |
| HOST_WIDE_INT aoff |
| = base_offset + ((offset - base_offset) |
| & ~(ASAN_RED_ZONE_SIZE - HOST_WIDE_INT_1)); |
| shadow_mem = adjust_address (shadow_mem, VOIDmode, |
| (aoff - prev_offset) |
| >> ASAN_SHADOW_SHIFT); |
| prev_offset = aoff; |
| for (i = 0; i < 4; i++, aoff += ASAN_SHADOW_GRANULARITY) |
| if (aoff < offset) |
| { |
| if (aoff < offset - (HOST_WIDE_INT)ASAN_SHADOW_GRANULARITY + 1) |
| shadow_bytes[i] = 0; |
| else |
| shadow_bytes[i] = offset - aoff; |
| } |
| else |
| shadow_bytes[i] = ASAN_STACK_MAGIC_MIDDLE; |
| emit_move_insn (shadow_mem, asan_shadow_cst (shadow_bytes)); |
| offset = aoff; |
| } |
| while (offset <= offsets[l - 2] - ASAN_RED_ZONE_SIZE) |
| { |
| shadow_mem = adjust_address (shadow_mem, VOIDmode, |
| (offset - prev_offset) |
| >> ASAN_SHADOW_SHIFT); |
| prev_offset = offset; |
| memset (shadow_bytes, cur_shadow_byte, 4); |
| emit_move_insn (shadow_mem, asan_shadow_cst (shadow_bytes)); |
| offset += ASAN_RED_ZONE_SIZE; |
| } |
| cur_shadow_byte = ASAN_STACK_MAGIC_MIDDLE; |
| } |
| do_pending_stack_adjust (); |
| |
| /* Construct epilogue sequence. */ |
| start_sequence (); |
| |
| lab = NULL; |
| if (use_after_return_class != -1) |
| { |
| rtx_code_label *lab2 = gen_label_rtx (); |
| char c = (char) ASAN_STACK_MAGIC_USE_AFTER_RET; |
| int very_likely = REG_BR_PROB_BASE - (REG_BR_PROB_BASE / 2000 - 1); |
| emit_cmp_and_jump_insns (orig_base, base, EQ, NULL_RTX, |
| VOIDmode, 0, lab2, very_likely); |
| shadow_mem = gen_rtx_MEM (BLKmode, shadow_base); |
| set_mem_alias_set (shadow_mem, asan_shadow_set); |
| mem = gen_rtx_MEM (ptr_mode, base); |
| mem = adjust_address (mem, VOIDmode, base_align_bias); |
| emit_move_insn (mem, gen_int_mode (ASAN_STACK_RETIRED_MAGIC, ptr_mode)); |
| unsigned HOST_WIDE_INT sz = asan_frame_size >> ASAN_SHADOW_SHIFT; |
| if (use_after_return_class < 5 |
| && can_store_by_pieces (sz, builtin_memset_read_str, &c, |
| BITS_PER_UNIT, true)) |
| store_by_pieces (shadow_mem, sz, builtin_memset_read_str, &c, |
| BITS_PER_UNIT, true, 0); |
| else if (use_after_return_class >= 5 |
| || !set_storage_via_setmem (shadow_mem, |
| GEN_INT (sz), |
| gen_int_mode (c, QImode), |
| BITS_PER_UNIT, BITS_PER_UNIT, |
| -1, sz, sz, sz)) |
| { |
| snprintf (buf, sizeof buf, "__asan_stack_free_%d", |
| use_after_return_class); |
| ret = init_one_libfunc (buf); |
| rtx addr = convert_memory_address (ptr_mode, base); |
| rtx orig_addr = convert_memory_address (ptr_mode, orig_base); |
| emit_library_call (ret, LCT_NORMAL, ptr_mode, 3, addr, ptr_mode, |
| GEN_INT (asan_frame_size + base_align_bias), |
| TYPE_MODE (pointer_sized_int_node), |
| orig_addr, ptr_mode); |
| } |
| lab = gen_label_rtx (); |
| emit_jump (lab); |
| emit_label (lab2); |
| } |
| |
| shadow_mem = gen_rtx_MEM (BLKmode, shadow_base); |
| set_mem_alias_set (shadow_mem, asan_shadow_set); |
| |
| if (STRICT_ALIGNMENT) |
| set_mem_align (shadow_mem, (GET_MODE_ALIGNMENT (SImode))); |
| |
| /* Unpoison shadow memory of a stack at the very end of a function. |
| As we're poisoning stack variables at the end of their scope, |
| shadow memory must be properly unpoisoned here. The easiest approach |
| would be to collect all variables that should not be unpoisoned and |
| we unpoison shadow memory of the whole stack except ranges |
| occupied by these variables. */ |
| last_offset = base_offset; |
| HOST_WIDE_INT current_offset = last_offset; |
| if (length) |
| { |
| HOST_WIDE_INT var_end_offset = 0; |
| HOST_WIDE_INT stack_start = offsets[length - 1]; |
| gcc_assert (last_offset == stack_start); |
| |
| for (int l = length - 2; l > 0; l -= 2) |
| { |
| HOST_WIDE_INT var_offset = offsets[l]; |
| current_offset = var_offset; |
| var_end_offset = offsets[l - 1]; |
| HOST_WIDE_INT rounded_size = ROUND_UP (var_end_offset - var_offset, |
| BITS_PER_UNIT); |
| |
| /* Should we unpoison the variable? */ |
| if (asan_handled_variables != NULL |
| && asan_handled_variables->contains (decl)) |
| { |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| const char *n = (DECL_NAME (decl) |
| ? IDENTIFIER_POINTER (DECL_NAME (decl)) |
| : "<unknown>"); |
| fprintf (dump_file, "Unpoisoning shadow stack for variable: " |
| "%s (%" PRId64 "B)\n", n, |
| var_end_offset - var_offset); |
| } |
| |
| unsigned HOST_WIDE_INT s |
| = shadow_mem_size (current_offset - last_offset); |
| asan_clear_shadow (shadow_mem, s); |
| HOST_WIDE_INT shift |
| = shadow_mem_size (current_offset - last_offset + rounded_size); |
| shadow_mem = adjust_address (shadow_mem, VOIDmode, shift); |
| last_offset = var_offset + rounded_size; |
| current_offset = last_offset; |
| } |
| |
| } |
| |
| /* Handle last redzone. */ |
| current_offset = offsets[0]; |
| asan_clear_shadow (shadow_mem, |
| shadow_mem_size (current_offset - last_offset)); |
| } |
| |
| /* Clean-up set with instrumented stack variables. */ |
| delete asan_handled_variables; |
| asan_handled_variables = NULL; |
| delete asan_used_labels; |
| asan_used_labels = NULL; |
| |
| do_pending_stack_adjust (); |
| if (lab) |
| emit_label (lab); |
| |
| insns = get_insns (); |
| end_sequence (); |
| return insns; |
| } |
| |
| /* Return true if DECL, a global var, might be overridden and needs |
| therefore a local alias. */ |
| |
| static bool |
| asan_needs_local_alias (tree decl) |
| { |
| return DECL_WEAK (decl) || !targetm.binds_local_p (decl); |
| } |
| |
| /* Return true if DECL, a global var, is an artificial ODR indicator symbol |
| therefore doesn't need protection. */ |
| |
| static bool |
| is_odr_indicator (tree decl) |
| { |
| return (DECL_ARTIFICIAL (decl) |
| && lookup_attribute ("asan odr indicator", DECL_ATTRIBUTES (decl))); |
| } |
| |
| /* Return true if DECL is a VAR_DECL that should be protected |
| by Address Sanitizer, by appending a red zone with protected |
| shadow memory after it and aligning it to at least |
| ASAN_RED_ZONE_SIZE bytes. */ |
| |
| bool |
| asan_protect_global (tree decl) |
| { |
| if (!ASAN_GLOBALS) |
| return false; |
| |
| rtx rtl, symbol; |
| |
| if (TREE_CODE (decl) == STRING_CST) |
| { |
| /* Instrument all STRING_CSTs except those created |
| by asan_pp_string here. */ |
| if (shadow_ptr_types[0] != NULL_TREE |
| && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE |
| && TREE_TYPE (TREE_TYPE (decl)) == TREE_TYPE (shadow_ptr_types[0])) |
| return false; |
| return true; |
| } |
| if (!VAR_P (decl) |
| /* TLS vars aren't statically protectable. */ |
| || DECL_THREAD_LOCAL_P (decl) |
| /* Externs will be protected elsewhere. */ |
| || DECL_EXTERNAL (decl) |
| || !DECL_RTL_SET_P (decl) |
| /* Comdat vars pose an ABI problem, we can't know if |
| the var that is selected by the linker will have |
| padding or not. */ |
| || DECL_ONE_ONLY (decl) |
| /* Similarly for common vars. People can use -fno-common. |
| Note: Linux kernel is built with -fno-common, so we do instrument |
| globals there even if it is C. */ |
| || (DECL_COMMON (decl) && TREE_PUBLIC (decl)) |
| /* Don't protect if using user section, often vars placed |
| into user section from multiple TUs are then assumed |
| to be an array of such vars, putting padding in there |
| breaks this assumption. */ |
| || (DECL_SECTION_NAME (decl) != NULL |
| && !symtab_node::get (decl)->implicit_section |
| && !section_sanitized_p (DECL_SECTION_NAME (decl))) |
| || DECL_SIZE (decl) == 0 |
| || ASAN_RED_ZONE_SIZE * BITS_PER_UNIT > MAX_OFILE_ALIGNMENT |
| || !valid_constant_size_p (DECL_SIZE_UNIT (decl)) |
| || DECL_ALIGN_UNIT (decl) > 2 * ASAN_RED_ZONE_SIZE |
| || TREE_TYPE (decl) == ubsan_get_source_location_type () |
| || is_odr_indicator (decl)) |
| return false; |
| |
| rtl = DECL_RTL (decl); |
| if (!MEM_P (rtl) || GET_CODE (XEXP (rtl, 0)) != SYMBOL_REF) |
| return false; |
| symbol = XEXP (rtl, 0); |
| |
| if (CONSTANT_POOL_ADDRESS_P (symbol) |
| || TREE_CONSTANT_POOL_ADDRESS_P (symbol)) |
| return false; |
| |
| if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))) |
| return false; |
| |
| #ifndef ASM_OUTPUT_DEF |
| if (asan_needs_local_alias (decl)) |
| return false; |
| #endif |
| |
| return true; |
| } |
| |
| /* Construct a function tree for __asan_report_{load,store}{1,2,4,8,16,_n}. |
| IS_STORE is either 1 (for a store) or 0 (for a load). */ |
| |
| static tree |
| report_error_func (bool is_store, bool recover_p, HOST_WIDE_INT size_in_bytes, |
| int *nargs) |
| { |
| static enum built_in_function report[2][2][6] |
| = { { { BUILT_IN_ASAN_REPORT_LOAD1, BUILT_IN_ASAN_REPORT_LOAD2, |
| BUILT_IN_ASAN_REPORT_LOAD4, BUILT_IN_ASAN_REPORT_LOAD8, |
| BUILT_IN_ASAN_REPORT_LOAD16, BUILT_IN_ASAN_REPORT_LOAD_N }, |
| { BUILT_IN_ASAN_REPORT_STORE1, BUILT_IN_ASAN_REPORT_STORE2, |
| BUILT_IN_ASAN_REPORT_STORE4, BUILT_IN_ASAN_REPORT_STORE8, |
| BUILT_IN_ASAN_REPORT_STORE16, BUILT_IN_ASAN_REPORT_STORE_N } }, |
| { { BUILT_IN_ASAN_REPORT_LOAD1_NOABORT, |
| BUILT_IN_ASAN_REPORT_LOAD2_NOABORT, |
| BUILT_IN_ASAN_REPORT_LOAD4_NOABORT, |
| BUILT_IN_ASAN_REPORT_LOAD8_NOABORT, |
| BUILT_IN_ASAN_REPORT_LOAD16_NOABORT, |
| BUILT_IN_ASAN_REPORT_LOAD_N_NOABORT }, |
| { BUILT_IN_ASAN_REPORT_STORE1_NOABORT, |
| BUILT_IN_ASAN_REPORT_STORE2_NOABORT, |
| BUILT_IN_ASAN_REPORT_STORE4_NOABORT, |
| BUILT_IN_ASAN_REPORT_STORE8_NOABORT, |
| BUILT_IN_ASAN_REPORT_STORE16_NOABORT, |
| BUILT_IN_ASAN_REPORT_STORE_N_NOABORT } } }; |
| if (size_in_bytes == -1) |
| { |
| *nargs = 2; |
| return builtin_decl_implicit (report[recover_p][is_store][5]); |
| } |
| *nargs = 1; |
| int size_log2 = exact_log2 (size_in_bytes); |
| return builtin_decl_implicit (report[recover_p][is_store][size_log2]); |
| } |
| |
| /* Construct a function tree for __asan_{load,store}{1,2,4,8,16,_n}. |
| IS_STORE is either 1 (for a store) or 0 (for a load). */ |
| |
| static tree |
| check_func (bool is_store, bool recover_p, HOST_WIDE_INT size_in_bytes, |
| int *nargs) |
| { |
| static enum built_in_function check[2][2][6] |
| = { { { BUILT_IN_ASAN_LOAD1, BUILT_IN_ASAN_LOAD2, |
| BUILT_IN_ASAN_LOAD4, BUILT_IN_ASAN_LOAD8, |
| BUILT_IN_ASAN_LOAD16, BUILT_IN_ASAN_LOADN }, |
| { BUILT_IN_ASAN_STORE1, BUILT_IN_ASAN_STORE2, |
| BUILT_IN_ASAN_STORE4, BUILT_IN_ASAN_STORE8, |
| BUILT_IN_ASAN_STORE16, BUILT_IN_ASAN_STOREN } }, |
| { { BUILT_IN_ASAN_LOAD1_NOABORT, |
| BUILT_IN_ASAN_LOAD2_NOABORT, |
| BUILT_IN_ASAN_LOAD4_NOABORT, |
| BUILT_IN_ASAN_LOAD8_NOABORT, |
| BUILT_IN_ASAN_LOAD16_NOABORT, |
| BUILT_IN_ASAN_LOADN_NOABORT }, |
| { BUILT_IN_ASAN_STORE1_NOABORT, |
| BUILT_IN_ASAN_STORE2_NOABORT, |
| BUILT_IN_ASAN_STORE4_NOABORT, |
| BUILT_IN_ASAN_STORE8_NOABORT, |
| BUILT_IN_ASAN_STORE16_NOABORT, |
| BUILT_IN_ASAN_STOREN_NOABORT } } }; |
| if (size_in_bytes == -1) |
| { |
| *nargs = 2; |
| return builtin_decl_implicit (check[recover_p][is_store][5]); |
| } |
| *nargs = 1; |
| int size_log2 = exact_log2 (size_in_bytes); |
| return builtin_decl_implicit (check[recover_p][is_store][size_log2]); |
| } |
| |
| /* Split the current basic block and create a condition statement |
| insertion point right before or after the statement pointed to by |
| ITER. Return an iterator to the point at which the caller might |
| safely insert the condition statement. |
| |
| THEN_BLOCK must be set to the address of an uninitialized instance |
| of basic_block. The function will then set *THEN_BLOCK to the |
| 'then block' of the condition statement to be inserted by the |
| caller. |
| |
| If CREATE_THEN_FALLTHRU_EDGE is false, no edge will be created from |
| *THEN_BLOCK to *FALLTHROUGH_BLOCK. |
| |
| Similarly, the function will set *FALLTRHOUGH_BLOCK to the 'else |
| block' of the condition statement to be inserted by the caller. |
| |
| Note that *FALLTHROUGH_BLOCK is a new block that contains the |
| statements starting from *ITER, and *THEN_BLOCK is a new empty |
| block. |
| |
| *ITER is adjusted to point to always point to the first statement |
| of the basic block * FALLTHROUGH_BLOCK. That statement is the |
| same as what ITER was pointing to prior to calling this function, |
| if BEFORE_P is true; otherwise, it is its following statement. */ |
| |
| gimple_stmt_iterator |
| create_cond_insert_point (gimple_stmt_iterator *iter, |
| bool before_p, |
| bool then_more_likely_p, |
| bool create_then_fallthru_edge, |
| basic_block *then_block, |
| basic_block *fallthrough_block) |
| { |
| gimple_stmt_iterator gsi = *iter; |
| |
| if (!gsi_end_p (gsi) && before_p) |
| gsi_prev (&gsi); |
| |
| basic_block cur_bb = gsi_bb (*iter); |
| |
| edge e = split_block (cur_bb, gsi_stmt (gsi)); |
| |
| /* Get a hold on the 'condition block', the 'then block' and the |
| 'else block'. */ |
| basic_block cond_bb = e->src; |
| basic_block fallthru_bb = e->dest; |
| basic_block then_bb = create_empty_bb (cond_bb); |
| if (current_loops) |
| { |
| add_bb_to_loop (then_bb, cond_bb->loop_father); |
| loops_state_set (LOOPS_NEED_FIXUP); |
| } |
| |
| /* Set up the newly created 'then block'. */ |
| e = make_edge (cond_bb, then_bb, EDGE_TRUE_VALUE); |
| int fallthrough_probability |
| = then_more_likely_p |
| ? PROB_VERY_UNLIKELY |
| : PROB_ALWAYS - PROB_VERY_UNLIKELY; |
| e->probability = PROB_ALWAYS - fallthrough_probability; |
| if (create_then_fallthru_edge) |
| make_single_succ_edge (then_bb, fallthru_bb, EDGE_FALLTHRU); |
| |
| /* Set up the fallthrough basic block. */ |
| e = find_edge (cond_bb, fallthru_bb); |
| e->flags = EDGE_FALSE_VALUE; |
| e->count = cond_bb->count; |
| e->probability = fallthrough_probability; |
| |
| /* Update dominance info for the newly created then_bb; note that |
| fallthru_bb's dominance info has already been updated by |
| split_bock. */ |
| if (dom_info_available_p (CDI_DOMINATORS)) |
| set_immediate_dominator (CDI_DOMINATORS, then_bb, cond_bb); |
| |
| *then_block = then_bb; |
| *fallthrough_block = fallthru_bb; |
| *iter = gsi_start_bb (fallthru_bb); |
| |
| return gsi_last_bb (cond_bb); |
| } |
| |
| /* Insert an if condition followed by a 'then block' right before the |
| statement pointed to by ITER. The fallthrough block -- which is the |
| else block of the condition as well as the destination of the |
| outcoming edge of the 'then block' -- starts with the statement |
| pointed to by ITER. |
| |
| COND is the condition of the if. |
| |
| If THEN_MORE_LIKELY_P is true, the probability of the edge to the |
| 'then block' is higher than the probability of the edge to the |
| fallthrough block. |
| |
| Upon completion of the function, *THEN_BB is set to the newly |
| inserted 'then block' and similarly, *FALLTHROUGH_BB is set to the |
| fallthrough block. |
| |
| *ITER is adjusted to still point to the same statement it was |
| pointing to initially. */ |
| |
| static void |
| insert_if_then_before_iter (gcond *cond, |
| gimple_stmt_iterator *iter, |
| bool then_more_likely_p, |
| basic_block *then_bb, |
| basic_block *fallthrough_bb) |
| { |
| gimple_stmt_iterator cond_insert_point = |
| create_cond_insert_point (iter, |
| /*before_p=*/true, |
| then_more_likely_p, |
| /*create_then_fallthru_edge=*/true, |
| then_bb, |
| fallthrough_bb); |
| gsi_insert_after (&cond_insert_point, cond, GSI_NEW_STMT); |
| } |
| |
| /* Build (base_addr >> ASAN_SHADOW_SHIFT) + asan_shadow_offset (). |
| If RETURN_ADDRESS is set to true, return memory location instread |
| of a value in the shadow memory. */ |
| |
| static tree |
| build_shadow_mem_access (gimple_stmt_iterator *gsi, location_t location, |
| tree base_addr, tree shadow_ptr_type, |
| bool return_address = false) |
| { |
| tree t, uintptr_type = TREE_TYPE (base_addr); |
| tree shadow_type = TREE_TYPE (shadow_ptr_type); |
| gimple *g; |
| |
| t = build_int_cst (uintptr_type, ASAN_SHADOW_SHIFT); |
| g = gimple_build_assign (make_ssa_name (uintptr_type), RSHIFT_EXPR, |
| base_addr, t); |
| gimple_set_location (g, location); |
| gsi_insert_after (gsi, g, GSI_NEW_STMT); |
| |
| t = build_int_cst (uintptr_type, asan_shadow_offset ()); |
| g = gimple_build_assign (make_ssa_name (uintptr_type), PLUS_EXPR, |
| gimple_assign_lhs (g), t); |
| gimple_set_location (g, location); |
| gsi_insert_after (gsi, g, GSI_NEW_STMT); |
| |
| g = gimple_build_assign (make_ssa_name (shadow_ptr_type), NOP_EXPR, |
| gimple_assign_lhs (g)); |
| gimple_set_location (g, location); |
| gsi_insert_after (gsi, g, GSI_NEW_STMT); |
| |
| if (!return_address) |
| { |
| t = build2 (MEM_REF, shadow_type, gimple_assign_lhs (g), |
| build_int_cst (shadow_ptr_type, 0)); |
| g = gimple_build_assign (make_ssa_name (shadow_type), MEM_REF, t); |
| gimple_set_location (g, location); |
| gsi_insert_after (gsi, g, GSI_NEW_STMT); |
| } |
| |
| return gimple_assign_lhs (g); |
| } |
| |
| /* BASE can already be an SSA_NAME; in that case, do not create a |
| new SSA_NAME for it. */ |
| |
| static tree |
| maybe_create_ssa_name (location_t loc, tree base, gimple_stmt_iterator *iter, |
| bool before_p) |
| { |
| if (TREE_CODE (base) == SSA_NAME) |
| return base; |
| gimple *g = gimple_build_assign (make_ssa_name (TREE_TYPE (base)), |
| TREE_CODE (base), base); |
| gimple_set_location (g, loc); |
| if (before_p) |
| gsi_insert_before (iter, g, GSI_SAME_STMT); |
| else |
| gsi_insert_after (iter, g, GSI_NEW_STMT); |
| return gimple_assign_lhs (g); |
| } |
| |
| /* LEN can already have necessary size and precision; |
| in that case, do not create a new variable. */ |
| |
| tree |
| maybe_cast_to_ptrmode (location_t loc, tree len, gimple_stmt_iterator *iter, |
| bool before_p) |
| { |
| if (ptrofftype_p (len)) |
| return len; |
| gimple *g = gimple_build_assign (make_ssa_name (pointer_sized_int_node), |
| NOP_EXPR, len); |
| gimple_set_location (g, loc); |
| if (before_p) |
| gsi_insert_before (iter, g, GSI_SAME_STMT); |
| else |
| gsi_insert_after (iter, g, GSI_NEW_STMT); |
| return gimple_assign_lhs (g); |
| } |
| |
| /* Instrument the memory access instruction BASE. Insert new |
| statements before or after ITER. |
| |
| Note that the memory access represented by BASE can be either an |
| SSA_NAME, or a non-SSA expression. LOCATION is the source code |
| location. IS_STORE is TRUE for a store, FALSE for a load. |
| BEFORE_P is TRUE for inserting the instrumentation code before |
| ITER, FALSE for inserting it after ITER. IS_SCALAR_ACCESS is TRUE |
| for a scalar memory access and FALSE for memory region access. |
| NON_ZERO_P is TRUE if memory region is guaranteed to have non-zero |
| length. ALIGN tells alignment of accessed memory object. |
| |
| START_INSTRUMENTED and END_INSTRUMENTED are TRUE if start/end of |
| memory region have already been instrumented. |
| |
| If BEFORE_P is TRUE, *ITER is arranged to still point to the |
| statement it was pointing to prior to calling this function, |
| otherwise, it points to the statement logically following it. */ |
| |
| static void |
| build_check_stmt (location_t loc, tree base, tree len, |
| HOST_WIDE_INT size_in_bytes, gimple_stmt_iterator *iter, |
| bool is_non_zero_len, bool before_p, bool is_store, |
| bool is_scalar_access, unsigned int align = 0) |
| { |
| gimple_stmt_iterator gsi = *iter; |
| gimple *g; |
| |
| gcc_assert (!(size_in_bytes > 0 && !is_non_zero_len)); |
| |
| gsi = *iter; |
| |
| base = unshare_expr (base); |
| base = maybe_create_ssa_name (loc, base, &gsi, before_p); |
| |
| if (len) |
| { |
| len = unshare_expr (len); |
| len = maybe_cast_to_ptrmode (loc, len, iter, before_p); |
| } |
| else |
| { |
| gcc_assert (size_in_bytes != -1); |
| len = build_int_cst (pointer_sized_int_node, size_in_bytes); |
| } |
| |
| if (size_in_bytes > 1) |
| { |
| if ((size_in_bytes & (size_in_bytes - 1)) != 0 |
| || size_in_bytes > 16) |
| is_scalar_access = false; |
| else if (align && align < size_in_bytes * BITS_PER_UNIT) |
| { |
| /* On non-strict alignment targets, if |
| 16-byte access is just 8-byte aligned, |
| this will result in misaligned shadow |
| memory 2 byte load, but otherwise can |
| be handled using one read. */ |
| if (size_in_bytes != 16 |
| || STRICT_ALIGNMENT |
| || align < 8 * BITS_PER_UNIT) |
| is_scalar_access = false; |
| } |
| } |
| |
| HOST_WIDE_INT flags = 0; |
| if (is_store) |
| flags |= ASAN_CHECK_STORE; |
| if (is_non_zero_len) |
| flags |= ASAN_CHECK_NON_ZERO_LEN; |
| if (is_scalar_access) |
| flags |= ASAN_CHECK_SCALAR_ACCESS; |
| |
| g = gimple_build_call_internal (IFN_ASAN_CHECK, 4, |
| build_int_cst (integer_type_node, flags), |
| base, len, |
| build_int_cst (integer_type_node, |
| align / BITS_PER_UNIT)); |
| gimple_set_location (g, loc); |
| if (before_p) |
| gsi_insert_before (&gsi, g, GSI_SAME_STMT); |
| else |
| { |
| gsi_insert_after (&gsi, g, GSI_NEW_STMT); |
| gsi_next (&gsi); |
| *iter = gsi; |
| } |
| } |
| |
| /* If T represents a memory access, add instrumentation code before ITER. |
| LOCATION is source code location. |
| IS_STORE is either TRUE (for a store) or FALSE (for a load). */ |
| |
| static void |
| instrument_derefs (gimple_stmt_iterator *iter, tree t, |
| location_t location, bool is_store) |
| { |
| if (is_store && !ASAN_INSTRUMENT_WRITES) |
| return; |
| if (!is_store && !ASAN_INSTRUMENT_READS) |
| return; |
| |
| tree type, base; |
| HOST_WIDE_INT size_in_bytes; |
| if (location == UNKNOWN_LOCATION) |
| location = EXPR_LOCATION (t); |
| |
| type = TREE_TYPE (t); |
| switch (TREE_CODE (t)) |
| { |
| case ARRAY_REF: |
| case COMPONENT_REF: |
| case INDIRECT_REF: |
| case MEM_REF: |
| case VAR_DECL: |
| case BIT_FIELD_REF: |
| break; |
| /* FALLTHRU */ |
| default: |
| return; |
| } |
| |
| size_in_bytes = int_size_in_bytes (type); |
| if (size_in_bytes <= 0) |
| return; |
| |
| HOST_WIDE_INT bitsize, bitpos; |
| tree offset; |
| machine_mode mode; |
| int unsignedp, reversep, volatilep = 0; |
| tree inner = get_inner_reference (t, &bitsize, &bitpos, &offset, &mode, |
| &unsignedp, &reversep, &volatilep); |
| |
| if (TREE_CODE (t) == COMPONENT_REF |
| && DECL_BIT_FIELD_REPRESENTATIVE (TREE_OPERAND (t, 1)) != NULL_TREE) |
| { |
| tree repr = DECL_BIT_FIELD_REPRESENTATIVE (TREE_OPERAND (t, 1)); |
| instrument_derefs (iter, build3 (COMPONENT_REF, TREE_TYPE (repr), |
| TREE_OPERAND (t, 0), repr, |
| TREE_OPERAND (t, 2)), |
| location, is_store); |
| return; |
| } |
| |
| if (bitpos % BITS_PER_UNIT |
| || bitsize != size_in_bytes * BITS_PER_UNIT) |
| return; |
| |
| if (VAR_P (inner) && DECL_HARD_REGISTER (inner)) |
| return; |
| |
| if (VAR_P (inner) |
| && offset == NULL_TREE |
| && bitpos >= 0 |
| && DECL_SIZE (inner) |
| && tree_fits_shwi_p (DECL_SIZE (inner)) |
| && bitpos + bitsize <= tree_to_shwi (DECL_SIZE (inner))) |
| { |
| if (DECL_THREAD_LOCAL_P (inner)) |
| return; |
| if (!ASAN_GLOBALS && is_global_var (inner)) |
| return; |
| if (!TREE_STATIC (inner)) |
| { |
| /* Automatic vars in the current function will be always |
| accessible. */ |
| if (decl_function_context (inner) == current_function_decl |
| && (!asan_sanitize_use_after_scope () |
| || !TREE_ADDRESSABLE (inner))) |
| return; |
| } |
| /* Always instrument external vars, they might be dynamically |
| initialized. */ |
| else if (!DECL_EXTERNAL (inner)) |
| { |
| /* For static vars if they are known not to be dynamically |
| initialized, they will be always accessible. */ |
| varpool_node *vnode = varpool_node::get (inner); |
| if (vnode && !vnode->dynamically_initialized) |
| return; |
| } |
| } |
| |
| base = build_fold_addr_expr (t); |
| if (!has_mem_ref_been_instrumented (base, size_in_bytes)) |
| { |
| unsigned int align = get_object_alignment (t); |
| build_check_stmt (location, base, NULL_TREE, size_in_bytes, iter, |
| /*is_non_zero_len*/size_in_bytes > 0, /*before_p=*/true, |
| is_store, /*is_scalar_access*/true, align); |
| update_mem_ref_hash_table (base, size_in_bytes); |
| update_mem_ref_hash_table (t, size_in_bytes); |
| } |
| |
| } |
| |
| /* Insert a memory reference into the hash table if access length |
| can be determined in compile time. */ |
| |
| static void |
| maybe_update_mem_ref_hash_table (tree base, tree len) |
| { |
| if (!POINTER_TYPE_P (TREE_TYPE (base)) |
| || !INTEGRAL_TYPE_P (TREE_TYPE (len))) |
| return; |
| |
| HOST_WIDE_INT size_in_bytes = tree_fits_shwi_p (len) ? tree_to_shwi (len) : -1; |
| |
| if (size_in_bytes != -1) |
| update_mem_ref_hash_table (base, size_in_bytes); |
| } |
| |
| /* Instrument an access to a contiguous memory region that starts at |
| the address pointed to by BASE, over a length of LEN (expressed in |
| the sizeof (*BASE) bytes). ITER points to the instruction before |
| which the instrumentation instructions must be inserted. LOCATION |
| is the source location that the instrumentation instructions must |
| have. If IS_STORE is true, then the memory access is a store; |
| otherwise, it's a load. */ |
| |
| static void |
| instrument_mem_region_access (tree base, tree len, |
| gimple_stmt_iterator *iter, |
| location_t location, bool is_store) |
| { |
| if (!POINTER_TYPE_P (TREE_TYPE (base)) |
| || !INTEGRAL_TYPE_P (TREE_TYPE (len)) |
| || integer_zerop (len)) |
| return; |
| |
| HOST_WIDE_INT size_in_bytes = tree_fits_shwi_p (len) ? tree_to_shwi (len) : -1; |
| |
| if ((size_in_bytes == -1) |
| || !has_mem_ref_been_instrumented (base, size_in_bytes)) |
| { |
| build_check_stmt (location, base, len, size_in_bytes, iter, |
| /*is_non_zero_len*/size_in_bytes > 0, /*before_p*/true, |
| is_store, /*is_scalar_access*/false, /*align*/0); |
| } |
| |
| maybe_update_mem_ref_hash_table (base, len); |
| *iter = gsi_for_stmt (gsi_stmt (*iter)); |
| } |
| |
| /* Instrument the call to a built-in memory access function that is |
| pointed to by the iterator ITER. |
| |
| Upon completion, return TRUE iff *ITER has been advanced to the |
| statement following the one it was originally pointing to. */ |
| |
| static bool |
| instrument_builtin_call (gimple_stmt_iterator *iter) |
| { |
| if (!ASAN_MEMINTRIN) |
| return false; |
| |
| bool iter_advanced_p = false; |
| gcall *call = as_a <gcall *> (gsi_stmt (*iter)); |
| |
| gcc_checking_assert (gimple_call_builtin_p (call, BUILT_IN_NORMAL)); |
| |
| location_t loc = gimple_location (call); |
| |
| asan_mem_ref src0, src1, dest; |
| asan_mem_ref_init (&src0, NULL, 1); |
| asan_mem_ref_init (&src1, NULL, 1); |
| asan_mem_ref_init (&dest, NULL, 1); |
| |
| tree src0_len = NULL_TREE, src1_len = NULL_TREE, dest_len = NULL_TREE; |
| bool src0_is_store = false, src1_is_store = false, dest_is_store = false, |
| dest_is_deref = false, intercepted_p = true; |
| |
| if (get_mem_refs_of_builtin_call (call, |
| &src0, &src0_len, &src0_is_store, |
| &src1, &src1_len, &src1_is_store, |
| &dest, &dest_len, &dest_is_store, |
| &dest_is_deref, &intercepted_p)) |
| { |
| if (dest_is_deref) |
| { |
| instrument_derefs (iter, dest.start, loc, dest_is_store); |
| gsi_next (iter); |
| iter_advanced_p = true; |
| } |
| else if (!intercepted_p |
| && (src0_len || src1_len || dest_len)) |
| { |
| if (src0.start != NULL_TREE) |
| instrument_mem_region_access (src0.start, src0_len, |
| iter, loc, /*is_store=*/false); |
| if (src1.start != NULL_TREE) |
| instrument_mem_region_access (src1.start, src1_len, |
| iter, loc, /*is_store=*/false); |
| if (dest.start != NULL_TREE) |
| instrument_mem_region_access (dest.start, dest_len, |
| iter, loc, /*is_store=*/true); |
| |
| *iter = gsi_for_stmt (call); |
| gsi_next (iter); |
| iter_advanced_p = true; |
| } |
| else |
| { |
| if (src0.start != NULL_TREE) |
| maybe_update_mem_ref_hash_table (src0.start, src0_len); |
| if (src1.start != NULL_TREE) |
| maybe_update_mem_ref_hash_table (src1.start, src1_len); |
| if (dest.start != NULL_TREE) |
| maybe_update_mem_ref_hash_table (dest.start, dest_len); |
| } |
| } |
| return iter_advanced_p; |
| } |
| |
| /* Instrument the assignment statement ITER if it is subject to |
| instrumentation. Return TRUE iff instrumentation actually |
| happened. In that case, the iterator ITER is advanced to the next |
| logical expression following the one initially pointed to by ITER, |
| and the relevant memory reference that which access has been |
| instrumented is added to the memory references hash table. */ |
| |
| static bool |
| maybe_instrument_assignment (gimple_stmt_iterator *iter) |
| { |
| gimple *s = gsi_stmt (*iter); |
| |
| gcc_assert (gimple_assign_single_p (s)); |
| |
| tree ref_expr = NULL_TREE; |
| bool is_store, is_instrumented = false; |
| |
| if (gimple_store_p (s)) |
| { |
| ref_expr = gimple_assign_lhs (s); |
| is_store = true; |
| instrument_derefs (iter, ref_expr, |
| gimple_location (s), |
| is_store); |
| is_instrumented = true; |
| } |
| |
| if (gimple_assign_load_p (s)) |
| { |
| ref_expr = gimple_assign_rhs1 (s); |
| is_store = false; |
| instrument_derefs (iter, ref_expr, |
| gimple_location (s), |
| is_store); |
| is_instrumented = true; |
| } |
| |
| if (is_instrumented) |
| gsi_next (iter); |
| |
| return is_instrumented; |
| } |
| |
| /* Instrument the function call pointed to by the iterator ITER, if it |
| is subject to instrumentation. At the moment, the only function |
| calls that are instrumented are some built-in functions that access |
| memory. Look at instrument_builtin_call to learn more. |
| |
| Upon completion return TRUE iff *ITER was advanced to the statement |
| following the one it was originally pointing to. */ |
| |
| static bool |
| maybe_instrument_call (gimple_stmt_iterator *iter) |
| { |
| gimple *stmt = gsi_stmt (*iter); |
| bool is_builtin = gimple_call_builtin_p (stmt, BUILT_IN_NORMAL); |
| |
| if (is_builtin && instrument_builtin_call (iter)) |
| return true; |
| |
| if (gimple_call_noreturn_p (stmt)) |
| { |
| if (is_builtin) |
| { |
| tree callee = gimple_call_fndecl (stmt); |
| switch (DECL_FUNCTION_CODE (callee)) |
| { |
| case BUILT_IN_UNREACHABLE: |
| case BUILT_IN_TRAP: |
| /* Don't instrument these. */ |
| return false; |
| default: |
| break; |
| } |
| } |
| tree decl = builtin_decl_implicit (BUILT_IN_ASAN_HANDLE_NO_RETURN); |
| gimple *g = gimple_build_call (decl, 0); |
| gimple_set_location (g, gimple_location (stmt)); |
| gsi_insert_before (iter, g, GSI_SAME_STMT); |
| } |
| |
| bool instrumented = false; |
| if (gimple_store_p (stmt)) |
| { |
| tree ref_expr = gimple_call_lhs (stmt); |
| instrument_derefs (iter, ref_expr, |
| gimple_location (stmt), |
| /*is_store=*/true); |
| |
| instrumented = true; |
| } |
| |
| /* Walk through gimple_call arguments and check them id needed. */ |
| unsigned args_num = gimple_call_num_args (stmt); |
| for (unsigned i = 0; i < args_num; ++i) |
| { |
| tree arg = gimple_call_arg (stmt, i); |
| /* If ARG is not a non-aggregate register variable, compiler in general |
| creates temporary for it and pass it as argument to gimple call. |
| But in some cases, e.g. when we pass by value a small structure that |
| fits to register, compiler can avoid extra overhead by pulling out |
| these temporaries. In this case, we should check the argument. */ |
| if (!is_gimple_reg (arg) && !is_gimple_min_invariant (arg)) |
| { |
| instrument_derefs (iter, arg, |
| gimple_location (stmt), |
| /*is_store=*/false); |
| instrumented = true; |
| } |
| } |
| if (instrumented) |
| gsi_next (iter); |
| return instrumented; |
| } |
| |
| /* Walk each instruction of all basic block and instrument those that |
| represent memory references: loads, stores, or function calls. |
| In a given basic block, this function avoids instrumenting memory |
| references that have already been instrumented. */ |
| |
| static void |
| transform_statements (void) |
| { |
| basic_block bb, last_bb = NULL; |
| gimple_stmt_iterator i; |
| int saved_last_basic_block = last_basic_block_for_fn (cfun); |
| |
| FOR_EACH_BB_FN (bb, cfun) |
| { |
| basic_block prev_bb = bb; |
| |
| if (bb->index >= saved_last_basic_block) continue; |
| |
| /* Flush the mem ref hash table, if current bb doesn't have |
| exactly one predecessor, or if that predecessor (skipping |
| over asan created basic blocks) isn't the last processed |
| basic block. Thus we effectively flush on extended basic |
| block boundaries. */ |
| while (single_pred_p (prev_bb)) |
| { |
| prev_bb = single_pred (prev_bb); |
| if (prev_bb->index < saved_last_basic_block) |
| break; |
| } |
| if (prev_bb != last_bb) |
| empty_mem_ref_hash_table (); |
| last_bb = bb; |
| |
| for (i = gsi_start_bb (bb); !gsi_end_p (i);) |
| { |
| gimple *s = gsi_stmt (i); |
| |
| if (has_stmt_been_instrumented_p (s)) |
| gsi_next (&i); |
| else if (gimple_assign_single_p (s) |
| && !gimple_clobber_p (s) |
| && maybe_instrument_assignment (&i)) |
| /* Nothing to do as maybe_instrument_assignment advanced |
| the iterator I. */; |
| else if (is_gimple_call (s) && maybe_instrument_call (&i)) |
| /* Nothing to do as maybe_instrument_call |
| advanced the iterator I. */; |
| else |
| { |
| /* No instrumentation happened. |
| |
| If the current instruction is a function call that |
| might free something, let's forget about the memory |
| references that got instrumented. Otherwise we might |
| miss some instrumentation opportunities. Do the same |
| for a ASAN_MARK poisoning internal function. */ |
| if (is_gimple_call (s) |
| && (!nonfreeing_call_p (s) |
| || asan_mark_p (s, ASAN_MARK_POISON))) |
| empty_mem_ref_hash_table (); |
| |
| gsi_next (&i); |
| } |
| } |
| } |
| free_mem_ref_resources (); |
| } |
| |
| /* Build |
| __asan_before_dynamic_init (module_name) |
| or |
| __asan_after_dynamic_init () |
| call. */ |
| |
| tree |
| asan_dynamic_init_call (bool after_p) |
| { |
| if (shadow_ptr_types[0] == NULL_TREE) |
| asan_init_shadow_ptr_types (); |
| |
| tree fn = builtin_decl_implicit (after_p |
| ? BUILT_IN_ASAN_AFTER_DYNAMIC_INIT |
| : BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT); |
| tree module_name_cst = NULL_TREE; |
| if (!after_p) |
| { |
| pretty_printer module_name_pp; |
| pp_string (&module_name_pp, main_input_filename); |
| |
| module_name_cst = asan_pp_string (&module_name_pp); |
| module_name_cst = fold_convert (const_ptr_type_node, |
| module_name_cst); |
| } |
| |
| return build_call_expr (fn, after_p ? 0 : 1, module_name_cst); |
| } |
| |
| /* Build |
| struct __asan_global |
| { |
| const void *__beg; |
| uptr __size; |
| uptr __size_with_redzone; |
| const void *__name; |
| const void *__module_name; |
| uptr __has_dynamic_init; |
| __asan_global_source_location *__location; |
| char *__odr_indicator; |
| } type. */ |
| |
| static tree |
| asan_global_struct (void) |
| { |
| static const char *field_names[] |
| = { "__beg", "__size", "__size_with_redzone", |
| "__name", "__module_name", "__has_dynamic_init", "__location", |
| "__odr_indicator" }; |
| tree fields[ARRAY_SIZE (field_names)], ret; |
| unsigned i; |
| |
| ret = make_node (RECORD_TYPE); |
| for (i = 0; i < ARRAY_SIZE (field_names); i++) |
| { |
| fields[i] |
| = build_decl (UNKNOWN_LOCATION, FIELD_DECL, |
| get_identifier (field_names[i]), |
| (i == 0 || i == 3) ? const_ptr_type_node |
| : pointer_sized_int_node); |
| DECL_CONTEXT (fields[i]) = ret; |
| if (i) |
| DECL_CHAIN (fields[i - 1]) = fields[i]; |
| } |
| tree type_decl = build_decl (input_location, TYPE_DECL, |
| get_identifier ("__asan_global"), ret); |
| DECL_IGNORED_P (type_decl) = 1; |
| DECL_ARTIFICIAL (type_decl) = 1; |
| TYPE_FIELDS (ret) = fields[0]; |
| TYPE_NAME (ret) = type_decl; |
| TYPE_STUB_DECL (ret) = type_decl; |
| layout_type (ret); |
| return ret; |
| } |
| |
| /* Create and return odr indicator symbol for DECL. |
| TYPE is __asan_global struct type as returned by asan_global_struct. */ |
| |
| static tree |
| create_odr_indicator (tree decl, tree type) |
| { |
| char *name; |
| tree uptr = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (type))); |
| tree decl_name |
| = (HAS_DECL_ASSEMBLER_NAME_P (decl) ? DECL_ASSEMBLER_NAME (decl) |
| : DECL_NAME (decl)); |
| /* DECL_NAME theoretically might be NULL. Bail out with 0 in this case. */ |
| if (decl_name == NULL_TREE) |
| return build_int_cst (uptr, 0); |
| const char *dname = IDENTIFIER_POINTER (decl_name); |
| if (HAS_DECL_ASSEMBLER_NAME_P (decl)) |
| dname = targetm.strip_name_encoding (dname); |
| size_t len = strlen (dname) + sizeof ("__odr_asan_"); |
| name = XALLOCAVEC (char, len); |
| snprintf (name, len, "__odr_asan_%s", dname); |
| #ifndef NO_DOT_IN_LABEL |
| name[sizeof ("__odr_asan") - 1] = '.'; |
| #elif !defined(NO_DOLLAR_IN_LABEL) |
| name[sizeof ("__odr_asan") - 1] = '$'; |
| #endif |
| tree var = build_decl (UNKNOWN_LOCATION, VAR_DECL, get_identifier (name), |
| char_type_node); |
| TREE_ADDRESSABLE (var) = 1; |
| TREE_READONLY (var) = 0; |
| TREE_THIS_VOLATILE (var) = 1; |
| DECL_GIMPLE_REG_P (var) = 0; |
| DECL_ARTIFICIAL (var) = 1; |
| DECL_IGNORED_P (var) = 1; |
| TREE_STATIC (var) = 1; |
| TREE_PUBLIC (var) = 1; |
| DECL_VISIBILITY (var) = DECL_VISIBILITY (decl); |
| DECL_VISIBILITY_SPECIFIED (var) = DECL_VISIBILITY_SPECIFIED (decl); |
| |
| TREE_USED (var) = 1; |
| tree ctor = build_constructor_va (TREE_TYPE (var), 1, NULL_TREE, |
| build_int_cst (unsigned_type_node, 0)); |
| TREE_CONSTANT (ctor) = 1; |
| TREE_STATIC (ctor) = 1; |
| DECL_INITIAL (var) = ctor; |
| DECL_ATTRIBUTES (var) = tree_cons (get_identifier ("asan odr indicator"), |
| NULL, DECL_ATTRIBUTES (var)); |
| make_decl_rtl (var); |
| varpool_node::finalize_decl (var); |
| return fold_convert (uptr, build_fold_addr_expr (var)); |
| } |
| |
| /* Return true if DECL, a global var, might be overridden and needs |
| an additional odr indicator symbol. */ |
| |
| static bool |
| asan_needs_odr_indicator_p (tree decl) |
| { |
| /* Don't emit ODR indicators for kernel because: |
| a) Kernel is written in C thus doesn't need ODR indicators. |
| b) Some kernel code may have assumptions about symbols containing specific |
| patterns in their names. Since ODR indicators contain original names |
| of symbols they are emitted for, these assumptions would be broken for |
| ODR indicator symbols. */ |
| return (!(flag_sanitize & SANITIZE_KERNEL_ADDRESS) |
| && !DECL_ARTIFICIAL (decl) |
| && !DECL_WEAK (decl) |
| && TREE_PUBLIC (decl)); |
| } |
| |
| /* Append description of a single global DECL into vector V. |
| TYPE is __asan_global struct type as returned by asan_global_struct. */ |
| |
| static void |
| asan_add_global (tree decl, tree type, vec<constructor_elt, va_gc> *v) |
| { |
| tree init, uptr = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (type))); |
| unsigned HOST_WIDE_INT size; |
| tree str_cst, module_name_cst, refdecl = decl; |
| vec<constructor_elt, va_gc> *vinner = NULL; |
| |
| pretty_printer asan_pp, module_name_pp; |
| |
| if (DECL_NAME (decl)) |
| pp_tree_identifier (&asan_pp, DECL_NAME (decl)); |
| else |
| pp_string (&asan_pp, "<unknown>"); |
| str_cst = asan_pp_string (&asan_pp); |
| |
| pp_string (&module_name_pp, main_input_filename); |
| module_name_cst = asan_pp_string (&module_name_pp); |
| |
| if (asan_needs_local_alias (decl)) |
| { |
| char buf[20]; |
| ASM_GENERATE_INTERNAL_LABEL (buf, "LASAN", vec_safe_length (v) + 1); |
| refdecl = build_decl (DECL_SOURCE_LOCATION (decl), |
| VAR_DECL, get_identifier (buf), TREE_TYPE (decl)); |
| TREE_ADDRESSABLE (refdecl) = TREE_ADDRESSABLE (decl); |
| TREE_READONLY (refdecl) = TREE_READONLY (decl); |
| TREE_THIS_VOLATILE (refdecl) = TREE_THIS_VOLATILE (decl); |
| DECL_GIMPLE_REG_P (refdecl) = DECL_GIMPLE_REG_P (decl); |
| DECL_ARTIFICIAL (refdecl) = DECL_ARTIFICIAL (decl); |
| DECL_IGNORED_P (refdecl) = DECL_IGNORED_P (decl); |
| TREE_STATIC (refdecl) = 1; |
| TREE_PUBLIC (refdecl) = 0; |
| TREE_USED (refdecl) = 1; |
| assemble_alias (refdecl, DECL_ASSEMBLER_NAME (decl)); |
| } |
| |
| tree odr_indicator_ptr |
| = (asan_needs_odr_indicator_p (decl) ? create_odr_indicator (decl, type) |
| : build_int_cst (uptr, 0)); |
| CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, |
| fold_convert (const_ptr_type_node, |
| build_fold_addr_expr (refdecl))); |
| size = tree_to_uhwi (DECL_SIZE_UNIT (decl)); |
| CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, build_int_cst (uptr, size)); |
| size += asan_red_zone_size (size); |
| CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, build_int_cst (uptr, size)); |
| CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, |
| fold_convert (const_ptr_type_node, str_cst)); |
| CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, |
| fold_convert (const_ptr_type_node, module_name_cst)); |
| varpool_node *vnode = varpool_node::get (decl); |
| int has_dynamic_init = 0; |
| /* FIXME: Enable initialization order fiasco detection in LTO mode once |
| proper fix for PR 79061 will be applied. */ |
| if (!in_lto_p) |
| has_dynamic_init = vnode ? vnode->dynamically_initialized : 0; |
| CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, |
| build_int_cst (uptr, has_dynamic_init)); |
| tree locptr = NULL_TREE; |
| location_t loc = DECL_SOURCE_LOCATION (decl); |
| expanded_location xloc = expand_location (loc); |
| if (xloc.file != NULL) |
| { |
| static int lasanloccnt = 0; |
| char buf[25]; |
| ASM_GENERATE_INTERNAL_LABEL (buf, "LASANLOC", ++lasanloccnt); |
| tree var = build_decl (UNKNOWN_LOCATION, VAR_DECL, get_identifier (buf), |
| ubsan_get_source_location_type ()); |
| TREE_STATIC (var) = 1; |
| TREE_PUBLIC (var) = 0; |
| DECL_ARTIFICIAL (var) = 1; |
| DECL_IGNORED_P (var) = 1; |
| pretty_printer filename_pp; |
| pp_string (&filename_pp, xloc.file); |
| tree str = asan_pp_string (&filename_pp); |
| tree ctor = build_constructor_va (TREE_TYPE (var), 3, |
| NULL_TREE, str, NULL_TREE, |
| build_int_cst (unsigned_type_node, |
| xloc.line), NULL_TREE, |
| build_int_cst (unsigned_type_node, |
| xloc.column)); |
| TREE_CONSTANT (ctor) = 1; |
| TREE_STATIC (ctor) = 1; |
| DECL_INITIAL (var) = ctor; |
| varpool_node::finalize_decl (var); |
| locptr = fold_convert (uptr, build_fold_addr_expr (var)); |
| } |
| else |
| locptr = build_int_cst (uptr, 0); |
| CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, locptr); |
| CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, odr_indicator_ptr); |
| init = build_constructor (type, vinner); |
| CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, init); |
| } |
| |
| /* Initialize sanitizer.def builtins if the FE hasn't initialized them. */ |
| void |
| initialize_sanitizer_builtins (void) |
| { |
| tree decl; |
| |
| if (builtin_decl_implicit_p (BUILT_IN_ASAN_INIT)) |
| return; |
| |
| tree BT_FN_VOID = build_function_type_list (void_type_node, NULL_TREE); |
| tree BT_FN_VOID_PTR |
| = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE); |
| tree BT_FN_VOID_CONST_PTR |
| = build_function_type_list (void_type_node, const_ptr_type_node, NULL_TREE); |
| tree BT_FN_VOID_PTR_PTR |
| = build_function_type_list (void_type_node, ptr_type_node, |
| ptr_type_node, NULL_TREE); |
| tree BT_FN_VOID_PTR_PTR_PTR |
| = build_function_type_list (void_type_node, ptr_type_node, |
| ptr_type_node, ptr_type_node, NULL_TREE); |
| tree BT_FN_VOID_PTR_PTRMODE |
| = build_function_type_list (void_type_node, ptr_type_node, |
| pointer_sized_int_node, NULL_TREE); |
| tree BT_FN_VOID_INT |
| = build_function_type_list (void_type_node, integer_type_node, NULL_TREE); |
| tree BT_FN_SIZE_CONST_PTR_INT |
| = build_function_type_list (size_type_node, const_ptr_type_node, |
| integer_type_node, NULL_TREE); |
| tree BT_FN_BOOL_VPTR_PTR_IX_INT_INT[5]; |
| tree BT_FN_IX_CONST_VPTR_INT[5]; |
| tree BT_FN_IX_VPTR_IX_INT[5]; |
| tree BT_FN_VOID_VPTR_IX_INT[5]; |
| tree vptr |
| = build_pointer_type (build_qualified_type (void_type_node, |
| TYPE_QUAL_VOLATILE)); |
| tree cvptr |
| = build_pointer_type (build_qualified_type (void_type_node, |
| TYPE_QUAL_VOLATILE |
| |TYPE_QUAL_CONST)); |
| tree boolt |
| = lang_hooks.types.type_for_size (BOOL_TYPE_SIZE, 1); |
| int i; |
| for (i = 0; i < 5; i++) |
| { |
| tree ix = build_nonstandard_integer_type (BITS_PER_UNIT * (1 << i), 1); |
| BT_FN_BOOL_VPTR_PTR_IX_INT_INT[i] |
| = build_function_type_list (boolt, vptr, ptr_type_node, ix, |
| integer_type_node, integer_type_node, |
| NULL_TREE); |
| BT_FN_IX_CONST_VPTR_INT[i] |
| = build_function_type_list (ix, cvptr, integer_type_node, NULL_TREE); |
| BT_FN_IX_VPTR_IX_INT[i] |
| = build_function_type_list (ix, vptr, ix, integer_type_node, |
| NULL_TREE); |
| BT_FN_VOID_VPTR_IX_INT[i] |
| = build_function_type_list (void_type_node, vptr, ix, |
| integer_type_node, NULL_TREE); |
| } |
| #define BT_FN_BOOL_VPTR_PTR_I1_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[0] |
| #define BT_FN_I1_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[0] |
| #define BT_FN_I1_VPTR_I1_INT BT_FN_IX_VPTR_IX_INT[0] |
| #define BT_FN_VOID_VPTR_I1_INT BT_FN_VOID_VPTR_IX_INT[0] |
| #define BT_FN_BOOL_VPTR_PTR_I2_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[1] |
| #define BT_FN_I2_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[1] |
| #define BT_FN_I2_VPTR_I2_INT BT_FN_IX_VPTR_IX_INT[1] |
| #define BT_FN_VOID_VPTR_I2_INT BT_FN_VOID_VPTR_IX_INT[1] |
| #define BT_FN_BOOL_VPTR_PTR_I4_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[2] |
| #define BT_FN_I4_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[2] |
| #define BT_FN_I4_VPTR_I4_INT BT_FN_IX_VPTR_IX_INT[2] |
| #define BT_FN_VOID_VPTR_I4_INT BT_FN_VOID_VPTR_IX_INT[2] |
| #define BT_FN_BOOL_VPTR_PTR_I8_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[3] |
| #define BT_FN_I8_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[3] |
| #define BT_FN_I8_VPTR_I8_INT BT_FN_IX_VPTR_IX_INT[3] |
| #define BT_FN_VOID_VPTR_I8_INT BT_FN_VOID_VPTR_IX_INT[3] |
| #define BT_FN_BOOL_VPTR_PTR_I16_INT_INT BT_FN_BOOL_VPTR_PTR_IX_INT_INT[4] |
| #define BT_FN_I16_CONST_VPTR_INT BT_FN_IX_CONST_VPTR_INT[4] |
| #define BT_FN_I16_VPTR_I16_INT BT_FN_IX_VPTR_IX_INT[4] |
| #define BT_FN_VOID_VPTR_I16_INT BT_FN_VOID_VPTR_IX_INT[4] |
| #undef ATTR_NOTHROW_LEAF_LIST |
| #define ATTR_NOTHROW_LEAF_LIST ECF_NOTHROW | ECF_LEAF |
| #undef ATTR_TMPURE_NOTHROW_LEAF_LIST |
| #define ATTR_TMPURE_NOTHROW_LEAF_LIST ECF_TM_PURE | ATTR_NOTHROW_LEAF_LIST |
| #undef ATTR_NORETURN_NOTHROW_LEAF_LIST |
| #define ATTR_NORETURN_NOTHROW_LEAF_LIST ECF_NORETURN | ATTR_NOTHROW_LEAF_LIST |
| #undef ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST |
| #define ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST \ |
| ECF_CONST | ATTR_NORETURN_NOTHROW_LEAF_LIST |
| #undef ATTR_TMPURE_NORETURN_NOTHROW_LEAF_LIST |
| #define ATTR_TMPURE_NORETURN_NOTHROW_LEAF_LIST \ |
| ECF_TM_PURE | ATTR_NORETURN_NOTHROW_LEAF_LIST |
| #undef ATTR_COLD_NOTHROW_LEAF_LIST |
| #define ATTR_COLD_NOTHROW_LEAF_LIST \ |
| /* ECF_COLD missing */ ATTR_NOTHROW_LEAF_LIST |
| #undef ATTR_COLD_NORETURN_NOTHROW_LEAF_LIST |
| #define ATTR_COLD_NORETURN_NOTHROW_LEAF_LIST \ |
| /* ECF_COLD missing */ ATTR_NORETURN_NOTHROW_LEAF_LIST |
| #undef ATTR_COLD_CONST_NORETURN_NOTHROW_LEAF_LIST |
| #define ATTR_COLD_CONST_NORETURN_NOTHROW_LEAF_LIST \ |
| /* ECF_COLD missing */ ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST |
| #undef ATTR_PURE_NOTHROW_LEAF_LIST |
| #define ATTR_PURE_NOTHROW_LEAF_LIST ECF_PURE | ATTR_NOTHROW_LEAF_LIST |
| #undef DEF_BUILTIN_STUB |
| #define DEF_BUILTIN_STUB(ENUM, NAME) |
| #undef DEF_SANITIZER_BUILTIN |
| #define DEF_SANITIZER_BUILTIN(ENUM, NAME, TYPE, ATTRS) \ |
| do { \ |
| decl = add_builtin_function ("__builtin_" NAME, TYPE, ENUM, \ |
| BUILT_IN_NORMAL, NAME, NULL_TREE); \ |
| set_call_expr_flags (decl, ATTRS); \ |
| set_builtin_decl (ENUM, decl, true); \ |
| } while (0); |
| |
| #include "sanitizer.def" |
| |
| /* -fsanitize=object-size uses __builtin_object_size, but that might |
| not be available for e.g. Fortran at this point. We use |
| DEF_SANITIZER_BUILTIN here only as a convenience macro. */ |
| if ((flag_sanitize & SANITIZE_OBJECT_SIZE) |
| && !builtin_decl_implicit_p (BUILT_IN_OBJECT_SIZE)) |
| DEF_SANITIZER_BUILTIN (BUILT_IN_OBJECT_SIZE, "object_size", |
| BT_FN_SIZE_CONST_PTR_INT, |
| ATTR_PURE_NOTHROW_LEAF_LIST) |
| |
| #undef DEF_SANITIZER_BUILTIN |
| #undef DEF_BUILTIN_STUB |
| } |
| |
| /* Called via htab_traverse. Count number of emitted |
| STRING_CSTs in the constant hash table. */ |
| |
| int |
| count_string_csts (constant_descriptor_tree **slot, |
| unsigned HOST_WIDE_INT *data) |
| { |
| struct constant_descriptor_tree *desc = *slot; |
| if (TREE_CODE (desc->value) == STRING_CST |
| && TREE_ASM_WRITTEN (desc->value) |
| && asan_protect_global (desc->value)) |
| ++*data; |
| return 1; |
| } |
| |
| /* Helper structure to pass two parameters to |
| add_string_csts. */ |
| |
| struct asan_add_string_csts_data |
| { |
| tree type; |
| vec<constructor_elt, va_gc> *v; |
| }; |
| |
| /* Called via hash_table::traverse. Call asan_add_global |
| on emitted STRING_CSTs from the constant hash table. */ |
| |
| int |
| add_string_csts (constant_descriptor_tree **slot, |
| asan_add_string_csts_data *aascd) |
| { |
| struct constant_descriptor_tree *desc = *slot; |
| if (TREE_CODE (desc->value) == STRING_CST |
| && TREE_ASM_WRITTEN (desc->value) |
| && asan_protect_global (desc->value)) |
| { |
| asan_add_global (SYMBOL_REF_DECL (XEXP (desc->rtl, 0)), |
| aascd->type, aascd->v); |
| } |
| return 1; |
| } |
| |
| /* Needs to be GTY(()), because cgraph_build_static_cdtor may |
| invoke ggc_collect. */ |
| static GTY(()) tree asan_ctor_statements; |
| |
| /* Module-level instrumentation. |
| - Insert __asan_init_vN() into the list of CTORs. |
| - TODO: insert redzones around globals. |
| */ |
| |
| void |
| asan_finish_file (void) |
| { |
| varpool_node *vnode; |
| unsigned HOST_WIDE_INT gcount = 0; |
| |
| if (shadow_ptr_types[0] == NULL_TREE) |
| asan_init_shadow_ptr_types (); |
| /* Avoid instrumenting code in the asan ctors/dtors. |
| We don't need to insert padding after the description strings, |
| nor after .LASAN* array. */ |
| flag_sanitize &= ~SANITIZE_ADDRESS; |
| |
| /* For user-space we want asan constructors to run first. |
| Linux kernel does not support priorities other than default, and the only |
| other user of constructors is coverage. So we run with the default |
| priority. */ |
| int priority = flag_sanitize & SANITIZE_USER_ADDRESS |
| ? MAX_RESERVED_INIT_PRIORITY - 1 : DEFAULT_INIT_PRIORITY; |
| |
| if (flag_sanitize & SANITIZE_USER_ADDRESS) |
| { |
| tree fn = builtin_decl_implicit (BUILT_IN_ASAN_INIT); |
| append_to_statement_list (build_call_expr (fn, 0), &asan_ctor_statements); |
| fn = builtin_decl_implicit (BUILT_IN_ASAN_VERSION_MISMATCH_CHECK); |
| append_to_statement_list (build_call_expr (fn, 0), &asan_ctor_statements); |
| } |
| FOR_EACH_DEFINED_VARIABLE (vnode) |
| if (TREE_ASM_WRITTEN (vnode->decl) |
| && asan_protect_global (vnode->decl)) |
| ++gcount; |
| hash_table<tree_descriptor_hasher> *const_desc_htab = constant_pool_htab (); |
| const_desc_htab->traverse<unsigned HOST_WIDE_INT *, count_string_csts> |
| (&gcount); |
| if (gcount) |
| { |
| tree type = asan_global_struct (), var, ctor; |
| tree dtor_statements = NULL_TREE; |
| vec<constructor_elt, va_gc> *v; |
| char buf[20]; |
| |
| type = build_array_type_nelts (type, gcount); |
| ASM_GENERATE_INTERNAL_LABEL (buf, "LASAN", 0); |
| var = build_decl (UNKNOWN_LOCATION, VAR_DECL, get_identifier (buf), |
| type); |
| TREE_STATIC (var) = 1; |
| TREE_PUBLIC (var) = 0; |
| DECL_ARTIFICIAL (var) = 1; |
| DECL_IGNORED_P (var) = 1; |
| vec_alloc (v, gcount); |
| FOR_EACH_DEFINED_VARIABLE (vnode) |
| if (TREE_ASM_WRITTEN (vnode->decl) |
| && asan_protect_global (vnode->decl)) |
| asan_add_global (vnode->decl, TREE_TYPE (type), v); |
| struct asan_add_string_csts_data aascd; |
| aascd.type = TREE_TYPE (type); |
| aascd.v = v; |
| const_desc_htab->traverse<asan_add_string_csts_data *, add_string_csts> |
| (&aascd); |
| ctor = build_constructor (type, v); |
| TREE_CONSTANT (ctor) = 1; |
| TREE_STATIC (ctor) = 1; |
| DECL_INITIAL (var) = ctor; |
| varpool_node::finalize_decl (var); |
| |
| tree fn = builtin_decl_implicit (BUILT_IN_ASAN_REGISTER_GLOBALS); |
| tree gcount_tree = build_int_cst (pointer_sized_int_node, gcount); |
| append_to_statement_list (build_call_expr (fn, 2, |
| build_fold_addr_expr (var), |
| gcount_tree), |
| &asan_ctor_statements); |
| |
| fn = builtin_decl_implicit (BUILT_IN_ASAN_UNREGISTER_GLOBALS); |
| append_to_statement_list (build_call_expr (fn, 2, |
| build_fold_addr_expr (var), |
| gcount_tree), |
| &dtor_statements); |
| cgraph_build_static_cdtor ('D', dtor_statements, priority); |
| } |
| if (asan_ctor_statements) |
| cgraph_build_static_cdtor ('I', asan_ctor_statements, priority); |
| flag_sanitize |= SANITIZE_ADDRESS; |
| } |
| |
| /* Poison or unpoison (depending on IS_CLOBBER variable) shadow memory based |
| on SHADOW address. Newly added statements will be added to ITER with |
| given location LOC. We mark SIZE bytes in shadow memory, where |
| LAST_CHUNK_SIZE is greater than zero in situation where we are at the |
| end of a variable. */ |
| |
| static void |
| asan_store_shadow_bytes (gimple_stmt_iterator *iter, location_t loc, |
| tree shadow, |
| unsigned HOST_WIDE_INT base_addr_offset, |
| bool is_clobber, unsigned size, |
| unsigned last_chunk_size) |
| { |
| tree shadow_ptr_type; |
| |
| switch (size) |
| { |
| case 1: |
| shadow_ptr_type = shadow_ptr_types[0]; |
| break; |
| case 2: |
| shadow_ptr_type = shadow_ptr_types[1]; |
| break; |
| case 4: |
| shadow_ptr_type = shadow_ptr_types[2]; |
| break; |
| default: |
| gcc_unreachable (); |
| } |
| |
| unsigned char c = (char) is_clobber ? ASAN_STACK_MAGIC_USE_AFTER_SCOPE : 0; |
| unsigned HOST_WIDE_INT val = 0; |
| unsigned last_pos = size; |
| if (last_chunk_size && !is_clobber) |
| last_pos = BYTES_BIG_ENDIAN ? 0 : size - 1; |
| for (unsigned i = 0; i < size; ++i) |
| { |
| unsigned char shadow_c = c; |
| if (i == last_pos) |
| shadow_c = last_chunk_size; |
| val |= (unsigned HOST_WIDE_INT) shadow_c << (BITS_PER_UNIT * i); |
| } |
| |
| /* Handle last chunk in unpoisoning. */ |
| tree magic = build_int_cst (TREE_TYPE (shadow_ptr_type), val); |
| |
| tree dest = build2 (MEM_REF, TREE_TYPE (shadow_ptr_type), shadow, |
| build_int_cst (shadow_ptr_type, base_addr_offset)); |
| |
| gimple *g = gimple_build_assign (dest, magic); |
| gimple_set_location (g, loc); |
| gsi_insert_after (iter, g, GSI_NEW_STMT); |
| } |
| |
| /* Expand the ASAN_MARK builtins. */ |
| |
| bool |
| asan_expand_mark_ifn (gimple_stmt_iterator *iter) |
| { |
| gimple *g = gsi_stmt (*iter); |
| location_t loc = gimple_location (g); |
| HOST_WIDE_INT flag = tree_to_shwi (gimple_call_arg (g, 0)); |
| bool is_poison = ((asan_mark_flags)flag) == ASAN_MARK_POISON; |
| |
| tree base = gimple_call_arg (g, 1); |
| gcc_checking_assert (TREE_CODE (base) == ADDR_EXPR); |
| tree decl = TREE_OPERAND (base, 0); |
| |
| /* For a nested function, we can have: ASAN_MARK (2, &FRAME.2.fp_input, 4) */ |
| if (TREE_CODE (decl) == COMPONENT_REF |
| && DECL_NONLOCAL_FRAME (TREE_OPERAND (decl, 0))) |
| decl = TREE_OPERAND (decl, 0); |
| |
| gcc_checking_assert (TREE_CODE (decl) == VAR_DECL); |
| if (asan_handled_variables == NULL) |
| asan_handled_variables = new hash_set<tree> (16); |
| asan_handled_variables->add (decl); |
| tree len = gimple_call_arg (g, 2); |
| |
| gcc_assert (tree_fits_shwi_p (len)); |
| unsigned HOST_WIDE_INT size_in_bytes = tree_to_shwi (len); |
| gcc_assert (size_in_bytes); |
| |
| g = gimple_build_assign (make_ssa_name (pointer_sized_int_node), |
| NOP_EXPR, base); |
| gimple_set_location (g, loc); |
| gsi_replace (iter, g, false); |
| tree base_addr = gimple_assign_lhs (g); |
| |
| /* Generate direct emission if size_in_bytes is small. */ |
| if (size_in_bytes <= ASAN_PARAM_USE_AFTER_SCOPE_DIRECT_EMISSION_THRESHOLD) |
| { |
| unsigned HOST_WIDE_INT shadow_size = shadow_mem_size (size_in_bytes); |
| |
| tree shadow = build_shadow_mem_access (iter, loc, base_addr, |
| shadow_ptr_types[0], true); |
| |
| for (unsigned HOST_WIDE_INT offset = 0; offset < shadow_size;) |
| { |
| unsigned size = 1; |
| if (shadow_size - offset >= 4) |
| size = 4; |
| else if (shadow_size - offset >= 2) |
| size = 2; |
| |
| unsigned HOST_WIDE_INT last_chunk_size = 0; |
| unsigned HOST_WIDE_INT s = (offset + size) * ASAN_SHADOW_GRANULARITY; |
| if (s > size_in_bytes) |
| last_chunk_size = ASAN_SHADOW_GRANULARITY - (s - size_in_bytes); |
| |
| asan_store_shadow_bytes (iter, loc, shadow, offset, is_poison, |
| size, last_chunk_size); |
| offset += size; |
| } |
| } |
| else |
| { |
| g = gimple_build_assign (make_ssa_name (pointer_sized_int_node), |
| NOP_EXPR, len); |
| gimple_set_location (g, loc); |
| gsi_insert_before (iter, g, GSI_SAME_STMT); |
| tree sz_arg = gimple_assign_lhs (g); |
| |
| tree fun |
| = builtin_decl_implicit (is_poison ? BUILT_IN_ASAN_POISON_STACK_MEMORY |
| : BUILT_IN_ASAN_UNPOISON_STACK_MEMORY); |
| g = gimple_build_call (fun, 2, base_addr, sz_arg); |
| gimple_set_location (g, loc); |
| gsi_insert_after (iter, g, GSI_NEW_STMT); |
| } |
| |
| return false; |
| } |
| |
| /* Expand the ASAN_{LOAD,STORE} builtins. */ |
| |
| bool |
| asan_expand_check_ifn (gimple_stmt_iterator *iter, bool use_calls) |
| { |
| gimple *g = gsi_stmt (*iter); |
| location_t loc = gimple_location (g); |
| bool recover_p; |
| if (flag_sanitize & SANITIZE_USER_ADDRESS) |
| recover_p = (flag_sanitize_recover & SANITIZE_USER_ADDRESS) != 0; |
| else |
| recover_p = (flag_sanitize_recover & SANITIZE_KERNEL_ADDRESS) != 0; |
| |
| HOST_WIDE_INT flags = tree_to_shwi (gimple_call_arg (g, 0)); |
| gcc_assert (flags < ASAN_CHECK_LAST); |
| bool is_scalar_access = (flags & ASAN_CHECK_SCALAR_ACCESS) != 0; |
| bool is_store = (flags & ASAN_CHECK_STORE) != 0; |
| bool is_non_zero_len = (flags & ASAN_CHECK_NON_ZERO_LEN) != 0; |
| |
| tree base = gimple_call_arg (g, 1); |
| tree len = gimple_call_arg (g, 2); |
| HOST_WIDE_INT align = tree_to_shwi (gimple_call_arg (g, 3)); |
| |
| HOST_WIDE_INT size_in_bytes |
| = is_scalar_access && tree_fits_shwi_p (len) ? tree_to_shwi (len) : -1; |
| |
| if (use_calls) |
| { |
| /* Instrument using callbacks. */ |
| gimple *g = gimple_build_assign (make_ssa_name (pointer_sized_int_node), |
| NOP_EXPR, base); |
| gimple_set_location (g, loc); |
| gsi_insert_before (iter, g, GSI_SAME_STMT); |
| tree base_addr = gimple_assign_lhs (g); |
| |
| int nargs; |
| tree fun = check_func (is_store, recover_p, size_in_bytes, &nargs); |
| if (nargs == 1) |
| g = gimple_build_call (fun, 1, base_addr); |
| else |
| { |
| gcc_assert (nargs == 2); |
| g = gimple_build_assign (make_ssa_name (pointer_sized_int_node), |
| NOP_EXPR, len); |
| gimple_set_location (g, loc); |
| gsi_insert_before (iter, g, GSI_SAME_STMT); |
| tree sz_arg = gimple_assign_lhs (g); |
| g = gimple_build_call (fun, nargs, base_addr, sz_arg); |
| } |
| gimple_set_location (g, loc); |
| gsi_replace (iter, g, false); |
| return false; |
| } |
| |
| HOST_WIDE_INT real_size_in_bytes = size_in_bytes == -1 ? 1 : size_in_bytes; |
| |
| tree shadow_ptr_type = shadow_ptr_types[real_size_in_bytes == 16 ? 1 : 0]; |
| tree shadow_type = TREE_TYPE (shadow_ptr_type); |
| |
| gimple_stmt_iterator gsi = *iter; |
| |
| if (!is_non_zero_len) |
| { |
| /* So, the length of the memory area to asan-protect is |
| non-constant. Let's guard the generated instrumentation code |
| like: |
| |
| if (len != 0) |
| { |
| //asan instrumentation code goes here. |
| } |
| // falltrough instructions, starting with *ITER. */ |
| |
| g = gimple_build_cond (NE_EXPR, |
| len, |
| build_int_cst (TREE_TYPE (len), 0), |
| NULL_TREE, NULL_TREE); |
| gimple_set_location (g, loc); |
| |
| basic_block then_bb, fallthrough_bb; |
| insert_if_then_before_iter (as_a <gcond *> (g), iter, |
| /*then_more_likely_p=*/true, |
| &then_bb, &fallthrough_bb); |
| /* Note that fallthrough_bb starts with the statement that was |
| pointed to by ITER. */ |
| |
| /* The 'then block' of the 'if (len != 0) condition is where |
| we'll generate the asan instrumentation code now. */ |
| gsi = gsi_last_bb (then_bb); |
| } |
| |
| /* Get an iterator on the point where we can add the condition |
| statement for the instrumentation. */ |
| basic_block then_bb, else_bb; |
| gsi = create_cond_insert_point (&gsi, /*before_p*/false, |
| /*then_more_likely_p=*/false, |
| /*create_then_fallthru_edge*/recover_p, |
| &then_bb, |
| &else_bb); |
| |
| g = gimple_build_assign (make_ssa_name (pointer_sized_int_node), |
| NOP_EXPR, base); |
| gimple_set_location (g, loc); |
| gsi_insert_before (&gsi, g, GSI_NEW_STMT); |
| tree base_addr = gimple_assign_lhs (g); |
| |
| tree t = NULL_TREE; |
| if (real_size_in_bytes >= 8) |
| { |
| tree shadow = build_shadow_mem_access (&gsi, loc, base_addr, |
| shadow_ptr_type); |
| t = shadow; |
| } |
| else |
| { |
| /* Slow path for 1, 2 and 4 byte accesses. */ |
| /* Test (shadow != 0) |
| & ((base_addr & 7) + (real_size_in_bytes - 1)) >= shadow). */ |
| tree shadow = build_shadow_mem_access (&gsi, loc, base_addr, |
| shadow_ptr_type); |
| gimple *shadow_test = build_assign (NE_EXPR, shadow, 0); |
| gimple_seq seq = NULL; |
| gimple_seq_add_stmt (&seq, shadow_test); |
| /* Aligned (>= 8 bytes) can test just |
| (real_size_in_bytes - 1 >= shadow), as base_addr & 7 is known |
| to be 0. */ |
| if (align < 8) |
| { |
| gimple_seq_add_stmt (&seq, build_assign (BIT_AND_EXPR, |
| base_addr, 7)); |
| gimple_seq_add_stmt (&seq, |
| build_type_cast (shadow_type, |
| gimple_seq_last (seq))); |
| if (real_size_in_bytes > 1) |
| gimple_seq_add_stmt (&seq, |
| build_assign (PLUS_EXPR, |
| gimple_seq_last (seq), |
| real_size_in_bytes - 1)); |
| t = gimple_assign_lhs (gimple_seq_last_stmt (seq)); |
| } |
| else |
| t = build_int_cst (shadow_type, real_size_in_bytes - 1); |
| gimple_seq_add_stmt (&seq, build_assign (GE_EXPR, t, shadow)); |
| gimple_seq_add_stmt (&seq, build_assign (BIT_AND_EXPR, shadow_test, |
| gimple_seq_last (seq))); |
| t = gimple_assign_lhs (gimple_seq_last (seq)); |
| gimple_seq_set_location (seq, loc); |
| gsi_insert_seq_after (&gsi, seq, GSI_CONTINUE_LINKING); |
| |
| /* For non-constant, misaligned or otherwise weird access sizes, |
| check first and last byte. */ |
| if (size_in_bytes == -1) |
| { |
| g = gimple_build_assign (make_ssa_name (pointer_sized_int_node), |
| MINUS_EXPR, len, |
| build_int_cst (pointer_sized_int_node, 1)); |
| gimple_set_location (g, loc); |
| gsi_insert_after (&gsi, g, GSI_NEW_STMT); |
| tree last = gimple_assign_lhs (g); |
| g = gimple_build_assign (make_ssa_name (pointer_sized_int_node), |
| PLUS_EXPR, base_addr, last); |
| gimple_set_location (g, loc); |
| gsi_insert_after (&gsi, g, GSI_NEW_STMT); |
| tree base_end_addr = gimple_assign_lhs (g); |
| |
| tree shadow = build_shadow_mem_access (&gsi, loc, base_end_addr, |
| shadow_ptr_type); |
| gimple *shadow_test = build_assign (NE_EXPR, shadow, 0); |
| gimple_seq seq = NULL; |
| gimple_seq_add_stmt (&seq, shadow_test); |
| gimple_seq_add_stmt (&seq, build_assign (BIT_AND_EXPR, |
| base_end_addr, 7)); |
| gimple_seq_add_stmt (&seq, build_type_cast (shadow_type, |
| gimple_seq_last (seq))); |
| gimple_seq_add_stmt (&seq, build_assign (GE_EXPR, |
| gimple_seq_last (seq), |
| shadow)); |
| gimple_seq_add_stmt (&seq, build_assign (BIT_AND_EXPR, shadow_test, |
| gimple_seq_last (seq))); |
| gimple_seq_add_stmt (&seq, build_assign (BIT_IOR_EXPR, t, |
| gimple_seq_last (seq))); |
| t = gimple_assign_lhs (gimple_seq_last (seq)); |
| gimple_seq_set_location (seq, loc); |
| gsi_insert_seq_after (&gsi, seq, GSI_CONTINUE_LINKING); |
| } |
| } |
| |
| g = gimple_build_cond (NE_EXPR, t, build_int_cst (TREE_TYPE (t), 0), |
| NULL_TREE, NULL_TREE); |
| gimple_set_location (g, loc); |
| gsi_insert_after (&gsi, g, GSI_NEW_STMT); |
| |
| /* Generate call to the run-time library (e.g. __asan_report_load8). */ |
| gsi = gsi_start_bb (then_bb); |
| int nargs; |
| tree fun = report_error_func (is_store, recover_p, size_in_bytes, &nargs); |
| g = gimple_build_call (fun, nargs, base_addr, len); |
| gimple_set_location (g, loc); |
| gsi_insert_after (&gsi, g, GSI_NEW_STMT); |
| |
| gsi_remove (iter, true); |
| *iter = gsi_start_bb (else_bb); |
| |
| return true; |
| } |
| |
| /* Create ASAN shadow variable for a VAR_DECL which has been rewritten |
| into SSA. Already seen VAR_DECLs are stored in SHADOW_VARS_MAPPING. */ |
| |
| static tree |
| create_asan_shadow_var (tree var_decl, |
| hash_map<tree, tree> &shadow_vars_mapping) |
| { |
| tree *slot = shadow_vars_mapping.get (var_decl); |
| if (slot == NULL) |
| { |
| tree shadow_var = copy_node (var_decl); |
| |
| copy_body_data id; |
| memset (&id, 0, sizeof (copy_body_data)); |
| id.src_fn = id.dst_fn = current_function_decl; |
| copy_decl_for_dup_finish (&id, var_decl, shadow_var); |
| |
| DECL_ARTIFICIAL (shadow_var) = 1; |
| DECL_IGNORED_P (shadow_var) = 1; |
| DECL_SEEN_IN_BIND_EXPR_P (shadow_var) = 0; |
| gimple_add_tmp_var (shadow_var); |
| |
| shadow_vars_mapping.put (var_decl, shadow_var); |
| return shadow_var; |
| } |
| else |
| return *slot; |
| } |
| |
| /* Expand ASAN_POISON ifn. */ |
| |
| bool |
| asan_expand_poison_ifn (gimple_stmt_iterator *iter, |
| bool *need_commit_edge_insert, |
| hash_map<tree, tree> &shadow_vars_mapping) |
| { |
| gimple *g = gsi_stmt (*iter); |
| tree poisoned_var = gimple_call_lhs (g); |
| if (!poisoned_var || has_zero_uses (poisoned_var)) |
| { |
| gsi_remove (iter, true); |
| return true; |
| } |
| |
| if (SSA_NAME_VAR (poisoned_var) == NULL_TREE) |
| SET_SSA_NAME_VAR_OR_IDENTIFIER (poisoned_var, |
| create_tmp_var (TREE_TYPE (poisoned_var))); |
| |
| tree shadow_var = create_asan_shadow_var (SSA_NAME_VAR (poisoned_var), |
| shadow_vars_mapping); |
| |
| bool recover_p; |
| if (flag_sanitize & SANITIZE_USER_ADDRESS) |
| recover_p = (flag_sanitize_recover & SANITIZE_USER_ADDRESS) != 0; |
| else |
| recover_p = (flag_sanitize_recover & SANITIZE_KERNEL_ADDRESS) != 0; |
| tree size = DECL_SIZE_UNIT (shadow_var); |
| gimple *poison_call |
| = gimple_build_call_internal (IFN_ASAN_MARK, 3, |
| build_int_cst (integer_type_node, |
| ASAN_MARK_POISON), |
| build_fold_addr_expr (shadow_var), size); |
| |
| gimple *use; |
| imm_use_iterator imm_iter; |
| FOR_EACH_IMM_USE_STMT (use, imm_iter, poisoned_var) |
| { |
| if (is_gimple_debug (use)) |
| continue; |
| |
| int nargs; |
| bool store_p = gimple_call_internal_p (use, IFN_ASAN_POISON_USE); |
| tree fun = report_error_func (store_p, recover_p, tree_to_uhwi (size), |
| &nargs); |
| |
| gcall *call = gimple_build_call (fun, 1, |
| build_fold_addr_expr (shadow_var)); |
| gimple_set_location (call, gimple_location (use)); |
| gimple *call_to_insert = call; |
| |
| /* The USE can be a gimple PHI node. If so, insert the call on |
| all edges leading to the PHI node. */ |
| if (is_a <gphi *> (use)) |
| { |
|