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/* AddressSanitizer, a fast memory error detector.
Copyright (C) 2011-2020 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/>. */
#ifndef TREE_ASAN
#define TREE_ASAN
extern void asan_function_start (void);
extern void asan_finish_file (void);
extern rtx_insn *asan_emit_stack_protection (rtx, rtx, unsigned int,
HOST_WIDE_INT *, tree *, int);
extern rtx_insn *asan_emit_allocas_unpoison (rtx, rtx, rtx_insn *);
extern bool asan_protect_global (tree, bool ignore_decl_rtl_set_p = false);
extern void initialize_sanitizer_builtins (void);
extern tree asan_dynamic_init_call (bool);
extern bool asan_expand_check_ifn (gimple_stmt_iterator *, bool);
extern bool asan_expand_mark_ifn (gimple_stmt_iterator *);
extern bool asan_expand_poison_ifn (gimple_stmt_iterator *, bool *,
hash_map<tree, tree> &);
extern gimple_stmt_iterator create_cond_insert_point
(gimple_stmt_iterator *, bool, bool, bool, basic_block *, basic_block *);
/* Alias set for accessing the shadow memory. */
extern alias_set_type asan_shadow_set;
/* Hash set of labels that are either used in a goto, or their address
has been taken. */
extern hash_set <tree> *asan_used_labels;
/* Shadow memory is found at
(address >> ASAN_SHADOW_SHIFT) + asan_shadow_offset (). */
#define ASAN_SHADOW_SHIFT 3
#define ASAN_SHADOW_GRANULARITY (1UL << ASAN_SHADOW_SHIFT)
/* Red zone size, stack and global variables are padded by ASAN_RED_ZONE_SIZE
up to 2 * ASAN_RED_ZONE_SIZE - 1 bytes. */
#define ASAN_RED_ZONE_SIZE 32
/* Stack variable use more compact red zones. The size includes also
size of variable itself. */
#define ASAN_MIN_RED_ZONE_SIZE 16
/* Shadow memory values for stack protection. Left is below protected vars,
the first pointer in stack corresponding to that offset contains
ASAN_STACK_FRAME_MAGIC word, the second pointer to a string describing
the frame. Middle is for padding in between variables, right is
above the last protected variable and partial immediately after variables
up to ASAN_RED_ZONE_SIZE alignment. */
#define ASAN_STACK_MAGIC_LEFT 0xf1
#define ASAN_STACK_MAGIC_MIDDLE 0xf2
#define ASAN_STACK_MAGIC_RIGHT 0xf3
#define ASAN_STACK_MAGIC_USE_AFTER_RET 0xf5
#define ASAN_STACK_MAGIC_USE_AFTER_SCOPE 0xf8
#define ASAN_STACK_FRAME_MAGIC 0x41b58ab3
#define ASAN_STACK_RETIRED_MAGIC 0x45e0360e
#define ASAN_USE_AFTER_SCOPE_ATTRIBUTE "use after scope memory"
/* Various flags for Asan builtins. */
enum asan_check_flags
{
ASAN_CHECK_STORE = 1 << 0,
ASAN_CHECK_SCALAR_ACCESS = 1 << 1,
ASAN_CHECK_NON_ZERO_LEN = 1 << 2,
ASAN_CHECK_LAST = 1 << 3
};
/* Flags for Asan check builtins. */
#define IFN_ASAN_MARK_FLAGS DEF(POISON), DEF(UNPOISON)
enum asan_mark_flags
{
#define DEF(X) ASAN_MARK_##X
IFN_ASAN_MARK_FLAGS
#undef DEF
};
/* Return true if STMT is ASAN_MARK with FLAG as first argument. */
extern bool asan_mark_p (gimple *stmt, enum asan_mark_flags flag);
/* Return the size of padding needed to insert after a protected
decl of SIZE. */
static inline unsigned int
asan_red_zone_size (unsigned int size)
{
unsigned int c = size & (ASAN_RED_ZONE_SIZE - 1);
return c ? 2 * ASAN_RED_ZONE_SIZE - c : ASAN_RED_ZONE_SIZE;
}
/* Return how much a stack variable occupis on a stack
including a space for red zone. */
static inline unsigned HOST_WIDE_INT
asan_var_and_redzone_size (unsigned HOST_WIDE_INT size)
{
if (size <= 4)
return 16;
else if (size <= 16)
return 32;
else if (size <= 128)
return size + 32;
else if (size <= 512)
return size + 64;
else if (size <= 4096)
return size + 128;
else
return size + 256;
}
extern bool set_asan_shadow_offset (const char *);
extern bool asan_shadow_offset_set_p ();
extern void set_sanitized_sections (const char *);
extern bool asan_sanitize_stack_p (void);
extern bool asan_sanitize_allocas_p (void);
extern hash_set<tree> *asan_handled_variables;
/* Return TRUE if builtin with given FCODE will be intercepted by
libasan. */
static inline bool
asan_intercepted_p (enum built_in_function fcode)
{
return fcode == BUILT_IN_INDEX
|| fcode == BUILT_IN_MEMCHR
|| fcode == BUILT_IN_MEMCMP
|| fcode == BUILT_IN_MEMCPY
|| fcode == BUILT_IN_MEMMOVE
|| fcode == BUILT_IN_MEMSET
|| fcode == BUILT_IN_STRCASECMP
|| fcode == BUILT_IN_STRCAT
|| fcode == BUILT_IN_STRCHR
|| fcode == BUILT_IN_STRCMP
|| fcode == BUILT_IN_STRCPY
|| fcode == BUILT_IN_STRDUP
|| fcode == BUILT_IN_STRLEN
|| fcode == BUILT_IN_STRNCASECMP
|| fcode == BUILT_IN_STRNCAT
|| fcode == BUILT_IN_STRNCMP
|| fcode == BUILT_IN_STRCSPN
|| fcode == BUILT_IN_STRPBRK
|| fcode == BUILT_IN_STRSPN
|| fcode == BUILT_IN_STRSTR
|| fcode == BUILT_IN_STRNCPY;
}
/* Return TRUE if we should instrument for use-after-scope sanity checking. */
static inline bool
asan_sanitize_use_after_scope (void)
{
return (flag_sanitize_address_use_after_scope && asan_sanitize_stack_p ());
}
/* Return true if DECL should be guarded on the stack. */
static inline bool
asan_protect_stack_decl (tree decl)
{
return DECL_P (decl)
&& (!DECL_ARTIFICIAL (decl)
|| (asan_sanitize_use_after_scope () && TREE_ADDRESSABLE (decl)));
}
/* Return true when flag_sanitize & FLAG is non-zero. If FN is non-null,
remove all flags mentioned in "no_sanitize" of DECL_ATTRIBUTES. */
static inline bool
sanitize_flags_p (unsigned int flag, const_tree fn = current_function_decl)
{
unsigned int result_flags = flag_sanitize & flag;
if (result_flags == 0)
return false;
if (fn != NULL_TREE)
{
tree value = lookup_attribute ("no_sanitize", DECL_ATTRIBUTES (fn));
if (value)
result_flags &= ~tree_to_uhwi (TREE_VALUE (value));
}
return result_flags;
}
#endif /* TREE_ASAN */