| /* Handle JIT code generation in the inferior for GDB, the GNU Debugger. |
| |
| Copyright (C) 2009-2024 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program 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 of the License, or |
| (at your option) any later version. |
| |
| This program 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 this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| |
| #include "jit.h" |
| #include "extract-store-integer.h" |
| #include "jit-reader.h" |
| #include "block.h" |
| #include "breakpoint.h" |
| #include "command.h" |
| #include "dictionary.h" |
| #include "filenames.h" |
| #include "frame-unwind.h" |
| #include "cli/cli-cmds.h" |
| #include "gdbcore.h" |
| #include "inferior.h" |
| #include "observable.h" |
| #include "objfiles.h" |
| #include "regcache.h" |
| #include "symfile.h" |
| #include "symtab.h" |
| #include "target.h" |
| #include "gdbsupport/gdb-dlfcn.h" |
| #include <sys/stat.h> |
| #include "gdb_bfd.h" |
| #include "readline/tilde.h" |
| #include "completer.h" |
| #include <forward_list> |
| |
| static std::string jit_reader_dir; |
| |
| static const char jit_break_name[] = "__jit_debug_register_code"; |
| |
| static const char jit_descriptor_name[] = "__jit_debug_descriptor"; |
| |
| static void jit_inferior_created_hook (inferior *inf); |
| static void jit_inferior_exit_hook (struct inferior *inf); |
| |
| /* True if we want to see trace of jit level stuff. */ |
| |
| static bool jit_debug = false; |
| |
| /* Print a "jit" debug statement. */ |
| |
| #define jit_debug_printf(fmt, ...) \ |
| debug_prefixed_printf_cond (jit_debug, "jit", fmt, ##__VA_ARGS__) |
| |
| static void |
| show_jit_debug (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| gdb_printf (file, _("JIT debugging is %s.\n"), value); |
| } |
| |
| /* Implementation of the "maintenance info jit" command. */ |
| |
| static void |
| maint_info_jit_cmd (const char *args, int from_tty) |
| { |
| inferior *inf = current_inferior (); |
| bool printed_header = false; |
| |
| std::optional<ui_out_emit_table> table_emitter; |
| |
| /* Print a line for each JIT-ed objfile. */ |
| for (objfile *obj : inf->pspace->objfiles ()) |
| { |
| if (obj->jited_data == nullptr) |
| continue; |
| |
| if (!printed_header) |
| { |
| table_emitter.emplace (current_uiout, 3, -1, "jit-created-objfiles"); |
| |
| /* The +2 allows for the leading '0x', then one character for |
| every 4-bits. */ |
| int addr_width = 2 + (gdbarch_ptr_bit (obj->arch ()) / 4); |
| |
| /* The std::max here selects between the width of an address (as |
| a string) and the width of the column header string. */ |
| current_uiout->table_header (std::max (addr_width, 22), ui_left, |
| "jit_code_entry-address", |
| "jit_code_entry address"); |
| current_uiout->table_header (std::max (addr_width, 15), ui_left, |
| "symfile-address", "symfile address"); |
| current_uiout->table_header (20, ui_left, |
| "symfile-size", "symfile size"); |
| current_uiout->table_body (); |
| |
| printed_header = true; |
| } |
| |
| ui_out_emit_tuple tuple_emitter (current_uiout, "jit-objfile"); |
| |
| current_uiout->field_core_addr ("jit_code_entry-address", obj->arch (), |
| obj->jited_data->addr); |
| current_uiout->field_core_addr ("symfile-address", obj->arch (), |
| obj->jited_data->symfile_addr); |
| current_uiout->field_unsigned ("symfile-size", |
| obj->jited_data->symfile_size); |
| current_uiout->text ("\n"); |
| } |
| } |
| |
| struct jit_reader |
| { |
| jit_reader (struct gdb_reader_funcs *f, gdb_dlhandle_up &&h) |
| : functions (f), handle (std::move (h)) |
| { |
| } |
| |
| ~jit_reader () |
| { |
| functions->destroy (functions); |
| } |
| |
| DISABLE_COPY_AND_ASSIGN (jit_reader); |
| |
| struct gdb_reader_funcs *functions; |
| gdb_dlhandle_up handle; |
| }; |
| |
| /* One reader that has been loaded successfully, and can potentially be used to |
| parse debug info. */ |
| |
| static struct jit_reader *loaded_jit_reader = NULL; |
| |
| typedef struct gdb_reader_funcs * (reader_init_fn_type) (void); |
| static const char reader_init_fn_sym[] = "gdb_init_reader"; |
| |
| /* Try to load FILE_NAME as a JIT debug info reader. */ |
| |
| static struct jit_reader * |
| jit_reader_load (const char *file_name) |
| { |
| reader_init_fn_type *init_fn; |
| struct gdb_reader_funcs *funcs = NULL; |
| |
| jit_debug_printf ("Opening shared object %s", file_name); |
| |
| gdb_dlhandle_up so = gdb_dlopen (file_name); |
| |
| init_fn = (reader_init_fn_type *) gdb_dlsym (so, reader_init_fn_sym); |
| if (!init_fn) |
| error (_("Could not locate initialization function: %s."), |
| reader_init_fn_sym); |
| |
| if (gdb_dlsym (so, "plugin_is_GPL_compatible") == NULL) |
| error (_("Reader not GPL compatible.")); |
| |
| funcs = init_fn (); |
| if (funcs->reader_version != GDB_READER_INTERFACE_VERSION) |
| error (_("Reader version does not match GDB version.")); |
| |
| return new jit_reader (funcs, std::move (so)); |
| } |
| |
| /* Provides the jit-reader-load command. */ |
| |
| static void |
| jit_reader_load_command (const char *args, int from_tty) |
| { |
| if (args == NULL) |
| error (_("No reader name provided.")); |
| gdb::unique_xmalloc_ptr<char> file (tilde_expand (args)); |
| |
| if (loaded_jit_reader != NULL) |
| error (_("JIT reader already loaded. Run jit-reader-unload first.")); |
| |
| if (!IS_ABSOLUTE_PATH (file.get ())) |
| file = xstrprintf ("%s%s%s", jit_reader_dir.c_str (), |
| SLASH_STRING, file.get ()); |
| |
| loaded_jit_reader = jit_reader_load (file.get ()); |
| reinit_frame_cache (); |
| jit_inferior_created_hook (current_inferior ()); |
| } |
| |
| /* Provides the jit-reader-unload command. */ |
| |
| static void |
| jit_reader_unload_command (const char *args, int from_tty) |
| { |
| if (!loaded_jit_reader) |
| error (_("No JIT reader loaded.")); |
| |
| reinit_frame_cache (); |
| jit_inferior_exit_hook (current_inferior ()); |
| |
| delete loaded_jit_reader; |
| loaded_jit_reader = NULL; |
| } |
| |
| /* Destructor for jiter_objfile_data. */ |
| |
| jiter_objfile_data::~jiter_objfile_data () |
| { |
| if (this->jit_breakpoint != nullptr) |
| delete_breakpoint (this->jit_breakpoint); |
| } |
| |
| /* Fetch the jiter_objfile_data associated with OBJF. If no data exists |
| yet, make a new structure and attach it. */ |
| |
| static jiter_objfile_data * |
| get_jiter_objfile_data (objfile *objf) |
| { |
| if (objf->jiter_data == nullptr) |
| objf->jiter_data.reset (new jiter_objfile_data ()); |
| |
| return objf->jiter_data.get (); |
| } |
| |
| /* Remember OBJFILE has been created for struct jit_code_entry located |
| at inferior address ENTRY. */ |
| |
| static void |
| add_objfile_entry (struct objfile *objfile, CORE_ADDR entry, |
| CORE_ADDR symfile_addr, ULONGEST symfile_size) |
| { |
| gdb_assert (objfile->jited_data == nullptr); |
| |
| objfile->jited_data.reset (new jited_objfile_data (entry, symfile_addr, |
| symfile_size)); |
| } |
| |
| /* Helper function for reading the global JIT descriptor from remote |
| memory. Returns true if all went well, false otherwise. */ |
| |
| static bool |
| jit_read_descriptor (gdbarch *gdbarch, |
| jit_descriptor *descriptor, |
| objfile *jiter) |
| { |
| int err; |
| struct type *ptr_type; |
| int ptr_size; |
| int desc_size; |
| gdb_byte *desc_buf; |
| enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| |
| gdb_assert (jiter != nullptr); |
| jiter_objfile_data *objf_data = jiter->jiter_data.get (); |
| gdb_assert (objf_data != nullptr); |
| |
| CORE_ADDR addr = objf_data->descriptor->value_address (jiter); |
| |
| jit_debug_printf ("descriptor_addr = %s", paddress (gdbarch, addr)); |
| |
| /* Figure out how big the descriptor is on the remote and how to read it. */ |
| ptr_type = builtin_type (gdbarch)->builtin_data_ptr; |
| ptr_size = ptr_type->length (); |
| desc_size = 8 + 2 * ptr_size; /* Two 32-bit ints and two pointers. */ |
| desc_buf = (gdb_byte *) alloca (desc_size); |
| |
| /* Read the descriptor. */ |
| err = target_read_memory (addr, desc_buf, desc_size); |
| if (err) |
| { |
| gdb_printf (gdb_stderr, _("Unable to read JIT descriptor from " |
| "remote memory\n")); |
| return false; |
| } |
| |
| /* Fix the endianness to match the host. */ |
| descriptor->version = extract_unsigned_integer (&desc_buf[0], 4, byte_order); |
| descriptor->action_flag = |
| extract_unsigned_integer (&desc_buf[4], 4, byte_order); |
| descriptor->relevant_entry = extract_typed_address (&desc_buf[8], ptr_type); |
| descriptor->first_entry = |
| extract_typed_address (&desc_buf[8 + ptr_size], ptr_type); |
| |
| return true; |
| } |
| |
| /* Helper function for reading a JITed code entry from remote memory. */ |
| |
| static void |
| jit_read_code_entry (struct gdbarch *gdbarch, |
| CORE_ADDR code_addr, struct jit_code_entry *code_entry) |
| { |
| int err, off; |
| struct type *ptr_type; |
| int ptr_size; |
| int entry_size; |
| int align_bytes; |
| gdb_byte *entry_buf; |
| enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| |
| /* Figure out how big the entry is on the remote and how to read it. */ |
| ptr_type = builtin_type (gdbarch)->builtin_data_ptr; |
| ptr_size = ptr_type->length (); |
| |
| /* Figure out where the uint64_t value will be. */ |
| align_bytes = type_align (builtin_type (gdbarch)->builtin_uint64); |
| off = 3 * ptr_size; |
| off = (off + (align_bytes - 1)) & ~(align_bytes - 1); |
| |
| entry_size = off + 8; /* Three pointers and one 64-bit int. */ |
| entry_buf = (gdb_byte *) alloca (entry_size); |
| |
| /* Read the entry. */ |
| err = target_read_memory (code_addr, entry_buf, entry_size); |
| if (err) |
| error (_("Unable to read JIT code entry from remote memory!")); |
| |
| /* Fix the endianness to match the host. */ |
| ptr_type = builtin_type (gdbarch)->builtin_data_ptr; |
| code_entry->next_entry = extract_typed_address (&entry_buf[0], ptr_type); |
| code_entry->prev_entry = |
| extract_typed_address (&entry_buf[ptr_size], ptr_type); |
| code_entry->symfile_addr = |
| extract_typed_address (&entry_buf[2 * ptr_size], ptr_type); |
| code_entry->symfile_size = |
| extract_unsigned_integer (&entry_buf[off], 8, byte_order); |
| } |
| |
| /* Proxy object for building a block. */ |
| |
| struct gdb_block |
| { |
| gdb_block (gdb_block *parent, CORE_ADDR begin, CORE_ADDR end, |
| const char *name) |
| : parent (parent), |
| begin (begin), |
| end (end), |
| name (name != nullptr ? xstrdup (name) : nullptr) |
| {} |
| |
| /* The parent of this block. */ |
| struct gdb_block *parent; |
| |
| /* Points to the "real" block that is being built out of this |
| instance. This block will be added to a blockvector, which will |
| then be added to a symtab. */ |
| struct block *real_block = nullptr; |
| |
| /* The first and last code address corresponding to this block. */ |
| CORE_ADDR begin, end; |
| |
| /* The name of this block (if any). If this is non-NULL, the |
| FUNCTION symbol symbol is set to this value. */ |
| gdb::unique_xmalloc_ptr<char> name; |
| }; |
| |
| /* Proxy object for building a symtab. */ |
| |
| struct gdb_symtab |
| { |
| explicit gdb_symtab (const char *file_name) |
| : file_name (file_name != nullptr ? file_name : "") |
| {} |
| |
| /* The list of blocks in this symtab. These will eventually be |
| converted to real blocks. |
| |
| This is specifically a linked list, instead of, for example, a vector, |
| because the pointers are returned to the user's debug info reader. So |
| it's important that the objects don't change location during their |
| lifetime (which would happen with a vector of objects getting resized). */ |
| std::forward_list<gdb_block> blocks; |
| |
| /* The number of blocks inserted. */ |
| int nblocks = 0; |
| |
| /* A mapping between line numbers to PC. */ |
| gdb::unique_xmalloc_ptr<struct linetable> linetable; |
| |
| /* The source file for this symtab. */ |
| std::string file_name; |
| }; |
| |
| /* Proxy object for building an object. */ |
| |
| struct gdb_object |
| { |
| /* Symtabs of this object. |
| |
| This is specifically a linked list, instead of, for example, a vector, |
| because the pointers are returned to the user's debug info reader. So |
| it's important that the objects don't change location during their |
| lifetime (which would happen with a vector of objects getting resized). */ |
| std::forward_list<gdb_symtab> symtabs; |
| }; |
| |
| /* The type of the `private' data passed around by the callback |
| functions. */ |
| |
| struct jit_dbg_reader_data |
| { |
| /* Address of the jit_code_entry in the inferior's address space. */ |
| CORE_ADDR entry_addr; |
| |
| /* The code entry, copied in our address space. */ |
| const jit_code_entry &entry; |
| |
| struct gdbarch *gdbarch; |
| }; |
| |
| /* The reader calls into this function to read data off the targets |
| address space. */ |
| |
| static enum gdb_status |
| jit_target_read_impl (GDB_CORE_ADDR target_mem, void *gdb_buf, int len) |
| { |
| int result = target_read_memory ((CORE_ADDR) target_mem, |
| (gdb_byte *) gdb_buf, len); |
| if (result == 0) |
| return GDB_SUCCESS; |
| else |
| return GDB_FAIL; |
| } |
| |
| /* The reader calls into this function to create a new gdb_object |
| which it can then pass around to the other callbacks. Right now, |
| all that is required is allocating the memory. */ |
| |
| static struct gdb_object * |
| jit_object_open_impl (struct gdb_symbol_callbacks *cb) |
| { |
| /* CB is not required right now, but sometime in the future we might |
| need a handle to it, and we'd like to do that without breaking |
| the ABI. */ |
| return new gdb_object; |
| } |
| |
| /* Readers call into this function to open a new gdb_symtab, which, |
| again, is passed around to other callbacks. */ |
| |
| static struct gdb_symtab * |
| jit_symtab_open_impl (struct gdb_symbol_callbacks *cb, |
| struct gdb_object *object, |
| const char *file_name) |
| { |
| /* CB stays unused. See comment in jit_object_open_impl. */ |
| |
| object->symtabs.emplace_front (file_name); |
| return &object->symtabs.front (); |
| } |
| |
| /* Called by readers to open a new gdb_block. This function also |
| inserts the new gdb_block in the correct place in the corresponding |
| gdb_symtab. */ |
| |
| static struct gdb_block * |
| jit_block_open_impl (struct gdb_symbol_callbacks *cb, |
| struct gdb_symtab *symtab, struct gdb_block *parent, |
| GDB_CORE_ADDR begin, GDB_CORE_ADDR end, const char *name) |
| { |
| /* Place the block at the beginning of the list, it will be sorted when the |
| symtab is finalized. */ |
| symtab->blocks.emplace_front (parent, begin, end, name); |
| symtab->nblocks++; |
| |
| return &symtab->blocks.front (); |
| } |
| |
| /* Readers call this to add a line mapping (from PC to line number) to |
| a gdb_symtab. */ |
| |
| static void |
| jit_symtab_line_mapping_add_impl (struct gdb_symbol_callbacks *cb, |
| struct gdb_symtab *stab, int nlines, |
| struct gdb_line_mapping *map) |
| { |
| int i; |
| int alloc_len; |
| |
| if (nlines < 1) |
| return; |
| |
| alloc_len = sizeof (struct linetable) |
| + (nlines - 1) * sizeof (struct linetable_entry); |
| stab->linetable.reset (XNEWVAR (struct linetable, alloc_len)); |
| stab->linetable->nitems = nlines; |
| for (i = 0; i < nlines; i++) |
| { |
| stab->linetable->item[i].set_unrelocated_pc |
| (unrelocated_addr (map[i].pc)); |
| stab->linetable->item[i].line = map[i].line; |
| stab->linetable->item[i].is_stmt = true; |
| } |
| } |
| |
| /* Called by readers to close a gdb_symtab. Does not need to do |
| anything as of now. */ |
| |
| static void |
| jit_symtab_close_impl (struct gdb_symbol_callbacks *cb, |
| struct gdb_symtab *stab) |
| { |
| /* Right now nothing needs to be done here. We may need to do some |
| cleanup here in the future (again, without breaking the plugin |
| ABI). */ |
| } |
| |
| /* Transform STAB to a proper symtab, and add it it OBJFILE. */ |
| |
| static void |
| finalize_symtab (struct gdb_symtab *stab, struct objfile *objfile) |
| { |
| struct compunit_symtab *cust; |
| size_t blockvector_size; |
| CORE_ADDR begin, end; |
| struct blockvector *bv; |
| |
| int actual_nblocks = FIRST_LOCAL_BLOCK + stab->nblocks; |
| |
| /* Sort the blocks in the order they should appear in the blockvector. */ |
| stab->blocks.sort([] (const gdb_block &a, const gdb_block &b) |
| { |
| if (a.begin != b.begin) |
| return a.begin < b.begin; |
| |
| return a.end > b.end; |
| }); |
| |
| cust = allocate_compunit_symtab (objfile, stab->file_name.c_str ()); |
| symtab *filetab = allocate_symtab (cust, stab->file_name.c_str ()); |
| add_compunit_symtab_to_objfile (cust); |
| |
| /* JIT compilers compile in memory. */ |
| cust->set_dirname (nullptr); |
| |
| /* Copy over the linetable entry if one was provided. */ |
| if (stab->linetable) |
| { |
| size_t size = ((stab->linetable->nitems - 1) |
| * sizeof (struct linetable_entry) |
| + sizeof (struct linetable)); |
| struct linetable *new_table |
| = (struct linetable *) obstack_alloc (&objfile->objfile_obstack, |
| size); |
| memcpy (new_table, stab->linetable.get (), size); |
| filetab->set_linetable (new_table); |
| } |
| |
| blockvector_size = (sizeof (struct blockvector) |
| + (actual_nblocks - 1) * sizeof (struct block *)); |
| bv = (struct blockvector *) obstack_alloc (&objfile->objfile_obstack, |
| blockvector_size); |
| cust->set_blockvector (bv); |
| |
| /* At the end of this function, (begin, end) will contain the PC range this |
| entire blockvector spans. */ |
| bv->set_map (nullptr); |
| begin = stab->blocks.front ().begin; |
| end = stab->blocks.front ().end; |
| bv->set_num_blocks (actual_nblocks); |
| |
| /* First run over all the gdb_block objects, creating a real block |
| object for each. Simultaneously, keep setting the real_block |
| fields. */ |
| int block_idx = FIRST_LOCAL_BLOCK; |
| for (gdb_block &gdb_block_iter : stab->blocks) |
| { |
| struct block *new_block = new (&objfile->objfile_obstack) block; |
| struct symbol *block_name = new (&objfile->objfile_obstack) symbol; |
| struct type *block_type = builtin_type (objfile->arch ())->builtin_void; |
| |
| new_block->set_multidict |
| (mdict_create_linear (&objfile->objfile_obstack, NULL)); |
| /* The address range. */ |
| new_block->set_start (gdb_block_iter.begin); |
| new_block->set_end (gdb_block_iter.end); |
| |
| /* The name. */ |
| block_name->set_domain (FUNCTION_DOMAIN); |
| block_name->set_aclass_index (LOC_BLOCK); |
| block_name->set_symtab (filetab); |
| block_name->set_type (lookup_function_type (block_type)); |
| block_name->set_value_block (new_block); |
| |
| block_name->m_name = obstack_strdup (&objfile->objfile_obstack, |
| gdb_block_iter.name.get ()); |
| |
| new_block->set_function (block_name); |
| |
| bv->set_block (block_idx, new_block); |
| if (begin > new_block->start ()) |
| begin = new_block->start (); |
| if (end < new_block->end ()) |
| end = new_block->end (); |
| |
| gdb_block_iter.real_block = new_block; |
| |
| block_idx++; |
| } |
| |
| /* Now add the special blocks. */ |
| struct block *block_iter = NULL; |
| for (enum block_enum i : { GLOBAL_BLOCK, STATIC_BLOCK }) |
| { |
| struct block *new_block; |
| |
| if (i == GLOBAL_BLOCK) |
| new_block = new (&objfile->objfile_obstack) global_block; |
| else |
| new_block = new (&objfile->objfile_obstack) block; |
| |
| new_block->set_multidict |
| (mdict_create_linear (&objfile->objfile_obstack, NULL)); |
| new_block->set_superblock (block_iter); |
| block_iter = new_block; |
| |
| new_block->set_start (begin); |
| new_block->set_end (end); |
| |
| bv->set_block (i, new_block); |
| |
| if (i == GLOBAL_BLOCK) |
| new_block->as_global_block ()->set_compunit (cust); |
| } |
| |
| /* Fill up the superblock fields for the real blocks, using the |
| real_block fields populated earlier. */ |
| for (gdb_block &gdb_block_iter : stab->blocks) |
| { |
| if (gdb_block_iter.parent != NULL) |
| { |
| /* If the plugin specifically mentioned a parent block, we |
| use that. */ |
| gdb_block_iter.real_block->set_superblock |
| (gdb_block_iter.parent->real_block); |
| |
| } |
| else |
| { |
| /* And if not, we set a default parent block. */ |
| gdb_block_iter.real_block->set_superblock (bv->static_block ()); |
| } |
| } |
| } |
| |
| /* Called when closing a gdb_objfile. Converts OBJ to a proper |
| objfile. */ |
| |
| static void |
| jit_object_close_impl (struct gdb_symbol_callbacks *cb, |
| struct gdb_object *obj) |
| { |
| jit_dbg_reader_data *priv_data = (jit_dbg_reader_data *) cb->priv_data; |
| std::string objfile_name |
| = string_printf ("<< JIT compiled code at %s >>", |
| paddress (priv_data->gdbarch, |
| priv_data->entry.symfile_addr)); |
| |
| objfile *objfile = objfile::make (nullptr, current_program_space, |
| objfile_name.c_str (), OBJF_NOT_FILENAME); |
| objfile->per_bfd->gdbarch = priv_data->gdbarch; |
| |
| for (gdb_symtab &symtab : obj->symtabs) |
| finalize_symtab (&symtab, objfile); |
| |
| add_objfile_entry (objfile, priv_data->entry_addr, |
| priv_data->entry.symfile_addr, |
| priv_data->entry.symfile_size); |
| |
| delete obj; |
| } |
| |
| /* Try to read CODE_ENTRY using the loaded jit reader (if any). |
| ENTRY_ADDR is the address of the struct jit_code_entry in the |
| inferior address space. */ |
| |
| static int |
| jit_reader_try_read_symtab (gdbarch *gdbarch, jit_code_entry *code_entry, |
| CORE_ADDR entry_addr) |
| { |
| int status; |
| jit_dbg_reader_data priv_data |
| { |
| entry_addr, |
| *code_entry, |
| gdbarch |
| }; |
| struct gdb_reader_funcs *funcs; |
| struct gdb_symbol_callbacks callbacks = |
| { |
| jit_object_open_impl, |
| jit_symtab_open_impl, |
| jit_block_open_impl, |
| jit_symtab_close_impl, |
| jit_object_close_impl, |
| |
| jit_symtab_line_mapping_add_impl, |
| jit_target_read_impl, |
| |
| &priv_data |
| }; |
| |
| if (!loaded_jit_reader) |
| return 0; |
| |
| gdb::byte_vector gdb_mem (code_entry->symfile_size); |
| |
| status = 1; |
| try |
| { |
| if (target_read_memory (code_entry->symfile_addr, gdb_mem.data (), |
| code_entry->symfile_size)) |
| status = 0; |
| } |
| catch (const gdb_exception_error &e) |
| { |
| status = 0; |
| } |
| |
| if (status) |
| { |
| funcs = loaded_jit_reader->functions; |
| if (funcs->read (funcs, &callbacks, gdb_mem.data (), |
| code_entry->symfile_size) |
| != GDB_SUCCESS) |
| status = 0; |
| } |
| |
| if (status == 0) |
| jit_debug_printf ("Could not read symtab using the loaded JIT reader."); |
| |
| return status; |
| } |
| |
| /* Try to read CODE_ENTRY using BFD. ENTRY_ADDR is the address of the |
| struct jit_code_entry in the inferior address space. */ |
| |
| static void |
| jit_bfd_try_read_symtab (struct jit_code_entry *code_entry, |
| CORE_ADDR entry_addr, |
| struct gdbarch *gdbarch) |
| { |
| struct bfd_section *sec; |
| struct objfile *objfile; |
| const struct bfd_arch_info *b; |
| |
| jit_debug_printf ("symfile_addr = %s, symfile_size = %s", |
| paddress (gdbarch, code_entry->symfile_addr), |
| pulongest (code_entry->symfile_size)); |
| |
| gdb_bfd_ref_ptr nbfd (gdb_bfd_open_from_target_memory |
| (code_entry->symfile_addr, code_entry->symfile_size, gnutarget)); |
| if (nbfd == NULL) |
| { |
| gdb_puts (_("Error opening JITed symbol file, ignoring it.\n"), |
| gdb_stderr); |
| return; |
| } |
| |
| /* Check the format. NOTE: This initializes important data that GDB uses! |
| We would segfault later without this line. */ |
| if (!bfd_check_format (nbfd.get (), bfd_object)) |
| { |
| gdb_printf (gdb_stderr, _("\ |
| JITed symbol file is not an object file, ignoring it.\n")); |
| return; |
| } |
| |
| /* Check bfd arch. */ |
| b = gdbarch_bfd_arch_info (gdbarch); |
| if (b->compatible (b, bfd_get_arch_info (nbfd.get ())) != b) |
| warning (_("JITed object file architecture %s is not compatible " |
| "with target architecture %s."), |
| bfd_get_arch_info (nbfd.get ())->printable_name, |
| b->printable_name); |
| |
| /* Read the section address information out of the symbol file. Since the |
| file is generated by the JIT at runtime, it should contain all of the |
| absolute addresses that we care about. */ |
| section_addr_info sai; |
| for (sec = nbfd->sections; sec != NULL; sec = sec->next) |
| if ((bfd_section_flags (sec) & (SEC_ALLOC|SEC_LOAD)) != 0) |
| { |
| /* We assume that these virtual addresses are absolute, and do not |
| treat them as offsets. */ |
| sai.emplace_back (bfd_section_vma (sec), |
| bfd_section_name (sec), |
| sec->index); |
| } |
| |
| /* This call does not take ownership of SAI. */ |
| objfile = symbol_file_add_from_bfd (nbfd, |
| bfd_get_filename (nbfd.get ()), 0, |
| &sai, |
| OBJF_SHARED | OBJF_NOT_FILENAME, NULL); |
| |
| add_objfile_entry (objfile, entry_addr, code_entry->symfile_addr, |
| code_entry->symfile_size); |
| } |
| |
| /* This function registers code associated with a JIT code entry. It uses the |
| pointer and size pair in the entry to read the symbol file from the remote |
| and then calls symbol_file_add_from_local_memory to add it as though it were |
| a symbol file added by the user. */ |
| |
| static void |
| jit_register_code (struct gdbarch *gdbarch, |
| CORE_ADDR entry_addr, struct jit_code_entry *code_entry) |
| { |
| int success; |
| |
| jit_debug_printf ("symfile_addr = %s, symfile_size = %s", |
| paddress (gdbarch, code_entry->symfile_addr), |
| pulongest (code_entry->symfile_size)); |
| |
| success = jit_reader_try_read_symtab (gdbarch, code_entry, entry_addr); |
| |
| if (!success) |
| jit_bfd_try_read_symtab (code_entry, entry_addr, gdbarch); |
| } |
| |
| /* Look up the objfile with this code entry address. */ |
| |
| static struct objfile * |
| jit_find_objf_with_entry_addr (CORE_ADDR entry_addr) |
| { |
| for (objfile *objf : current_program_space->objfiles ()) |
| { |
| if (objf->jited_data != nullptr && objf->jited_data->addr == entry_addr) |
| return objf; |
| } |
| |
| return NULL; |
| } |
| |
| /* This is called when a breakpoint is deleted. It updates the |
| inferior's cache, if needed. */ |
| |
| static void |
| jit_breakpoint_deleted (struct breakpoint *b) |
| { |
| if (b->type != bp_jit_event) |
| return; |
| |
| for (bp_location &iter : b->locations ()) |
| { |
| for (objfile *objf : iter.pspace->objfiles ()) |
| { |
| jiter_objfile_data *jiter_data = objf->jiter_data.get (); |
| |
| if (jiter_data != nullptr |
| && jiter_data->jit_breakpoint == iter.owner) |
| { |
| jiter_data->cached_code_address = 0; |
| jiter_data->jit_breakpoint = nullptr; |
| } |
| } |
| } |
| } |
| |
| /* (Re-)Initialize the jit breakpoints for JIT-producing objfiles in |
| PSPACE. */ |
| |
| static void |
| jit_breakpoint_re_set_internal (struct gdbarch *gdbarch, program_space *pspace) |
| { |
| for (objfile *the_objfile : pspace->objfiles ()) |
| { |
| /* Skip separate debug objects. */ |
| if (the_objfile->separate_debug_objfile_backlink != nullptr) |
| continue; |
| |
| if (the_objfile->skip_jit_symbol_lookup) |
| continue; |
| |
| /* Lookup the registration symbol. If it is missing, then we |
| assume we are not attached to a JIT. */ |
| bound_minimal_symbol reg_symbol |
| = lookup_minimal_symbol_text (pspace, jit_break_name, the_objfile); |
| if (reg_symbol.minsym == NULL |
| || reg_symbol.value_address () == 0) |
| { |
| /* No need to repeat the lookup the next time. */ |
| the_objfile->skip_jit_symbol_lookup = true; |
| continue; |
| } |
| |
| bound_minimal_symbol desc_symbol |
| = lookup_minimal_symbol_linkage (jit_descriptor_name, the_objfile); |
| if (desc_symbol.minsym == NULL |
| || desc_symbol.value_address () == 0) |
| { |
| /* No need to repeat the lookup the next time. */ |
| the_objfile->skip_jit_symbol_lookup = true; |
| continue; |
| } |
| |
| jiter_objfile_data *objf_data |
| = get_jiter_objfile_data (the_objfile); |
| objf_data->register_code = reg_symbol.minsym; |
| objf_data->descriptor = desc_symbol.minsym; |
| |
| CORE_ADDR addr = objf_data->register_code->value_address (the_objfile); |
| jit_debug_printf ("breakpoint_addr = %s", paddress (gdbarch, addr)); |
| |
| /* Check if we need to re-create the breakpoint. */ |
| if (objf_data->cached_code_address == addr) |
| continue; |
| |
| /* Delete the old breakpoint. */ |
| if (objf_data->jit_breakpoint != nullptr) |
| delete_breakpoint (objf_data->jit_breakpoint); |
| |
| /* Put a breakpoint in the registration symbol. */ |
| objf_data->cached_code_address = addr; |
| objf_data->jit_breakpoint = create_jit_event_breakpoint (gdbarch, addr); |
| } |
| } |
| |
| /* The private data passed around in the frame unwind callback |
| functions. */ |
| |
| struct jit_unwind_private |
| { |
| /* Cached register values. See jit_frame_sniffer to see how this |
| works. */ |
| std::unique_ptr<detached_regcache> regcache; |
| |
| /* The frame being unwound. */ |
| frame_info_ptr this_frame; |
| }; |
| |
| /* Sets the value of a particular register in this frame. */ |
| |
| static void |
| jit_unwind_reg_set_impl (struct gdb_unwind_callbacks *cb, int dwarf_regnum, |
| struct gdb_reg_value *value) |
| { |
| struct jit_unwind_private *priv; |
| int gdb_reg; |
| |
| priv = (struct jit_unwind_private *) cb->priv_data; |
| |
| gdb_reg = gdbarch_dwarf2_reg_to_regnum (get_frame_arch (priv->this_frame), |
| dwarf_regnum); |
| if (gdb_reg == -1) |
| { |
| jit_debug_printf ("Could not recognize DWARF regnum %d", dwarf_regnum); |
| value->free (value); |
| return; |
| } |
| |
| priv->regcache->raw_supply (gdb_reg, value->value); |
| value->free (value); |
| } |
| |
| static void |
| reg_value_free_impl (struct gdb_reg_value *value) |
| { |
| xfree (value); |
| } |
| |
| /* Get the value of register REGNUM in the previous frame. */ |
| |
| static struct gdb_reg_value * |
| jit_unwind_reg_get_impl (struct gdb_unwind_callbacks *cb, int regnum) |
| { |
| struct jit_unwind_private *priv; |
| struct gdb_reg_value *value; |
| int gdb_reg, size; |
| struct gdbarch *frame_arch; |
| |
| priv = (struct jit_unwind_private *) cb->priv_data; |
| frame_arch = get_frame_arch (priv->this_frame); |
| |
| gdb_reg = gdbarch_dwarf2_reg_to_regnum (frame_arch, regnum); |
| size = register_size (frame_arch, gdb_reg); |
| value = ((struct gdb_reg_value *) |
| xmalloc (sizeof (struct gdb_reg_value) + size - 1)); |
| value->defined = deprecated_frame_register_read (priv->this_frame, gdb_reg, |
| value->value); |
| value->size = size; |
| value->free = reg_value_free_impl; |
| return value; |
| } |
| |
| /* gdb_reg_value has a free function, which must be called on each |
| saved register value. */ |
| |
| static void |
| jit_dealloc_cache (frame_info *this_frame, void *cache) |
| { |
| struct jit_unwind_private *priv_data = (struct jit_unwind_private *) cache; |
| delete priv_data; |
| } |
| |
| /* The frame sniffer for the pseudo unwinder. |
| |
| While this is nominally a frame sniffer, in the case where the JIT |
| reader actually recognizes the frame, it does a lot more work -- it |
| unwinds the frame and saves the corresponding register values in |
| the cache. jit_frame_prev_register simply returns the saved |
| register values. */ |
| |
| static int |
| jit_frame_sniffer (const struct frame_unwind *self, |
| const frame_info_ptr &this_frame, void **cache) |
| { |
| struct jit_unwind_private *priv_data; |
| struct gdb_unwind_callbacks callbacks; |
| struct gdb_reader_funcs *funcs; |
| |
| callbacks.reg_get = jit_unwind_reg_get_impl; |
| callbacks.reg_set = jit_unwind_reg_set_impl; |
| callbacks.target_read = jit_target_read_impl; |
| |
| if (loaded_jit_reader == NULL) |
| return 0; |
| |
| funcs = loaded_jit_reader->functions; |
| |
| gdb_assert (!*cache); |
| |
| priv_data = new struct jit_unwind_private; |
| *cache = priv_data; |
| /* Take a snapshot of current regcache. */ |
| priv_data->regcache.reset |
| (new detached_regcache (get_frame_arch (this_frame), true)); |
| priv_data->this_frame = this_frame; |
| |
| callbacks.priv_data = priv_data; |
| |
| /* Try to coax the provided unwinder to unwind the stack */ |
| if (funcs->unwind (funcs, &callbacks) == GDB_SUCCESS) |
| { |
| jit_debug_printf ("Successfully unwound frame using JIT reader."); |
| return 1; |
| } |
| |
| jit_debug_printf ("Could not unwind frame using JIT reader."); |
| |
| jit_dealloc_cache (this_frame.get (), *cache); |
| *cache = NULL; |
| |
| return 0; |
| } |
| |
| |
| /* The frame_id function for the pseudo unwinder. Relays the call to |
| the loaded plugin. */ |
| |
| static void |
| jit_frame_this_id (const frame_info_ptr &this_frame, void **cache, |
| struct frame_id *this_id) |
| { |
| struct jit_unwind_private priv; |
| struct gdb_frame_id frame_id; |
| struct gdb_reader_funcs *funcs; |
| struct gdb_unwind_callbacks callbacks; |
| |
| priv.regcache.reset (); |
| priv.this_frame = this_frame; |
| |
| /* We don't expect the frame_id function to set any registers, so we |
| set reg_set to NULL. */ |
| callbacks.reg_get = jit_unwind_reg_get_impl; |
| callbacks.reg_set = NULL; |
| callbacks.target_read = jit_target_read_impl; |
| callbacks.priv_data = &priv; |
| |
| gdb_assert (loaded_jit_reader); |
| funcs = loaded_jit_reader->functions; |
| |
| frame_id = funcs->get_frame_id (funcs, &callbacks); |
| *this_id = frame_id_build (frame_id.stack_address, frame_id.code_address); |
| } |
| |
| /* Pseudo unwinder function. Reads the previously fetched value for |
| the register from the cache. */ |
| |
| static struct value * |
| jit_frame_prev_register (const frame_info_ptr &this_frame, void **cache, int reg) |
| { |
| struct jit_unwind_private *priv = (struct jit_unwind_private *) *cache; |
| struct gdbarch *gdbarch; |
| |
| if (priv == NULL) |
| return frame_unwind_got_optimized (this_frame, reg); |
| |
| gdbarch = priv->regcache->arch (); |
| gdb_byte *buf = (gdb_byte *) alloca (register_size (gdbarch, reg)); |
| enum register_status status = priv->regcache->cooked_read (reg, buf); |
| |
| if (status == REG_VALID) |
| return frame_unwind_got_bytes (this_frame, reg, buf); |
| else |
| return frame_unwind_got_optimized (this_frame, reg); |
| } |
| |
| /* Relay everything back to the unwinder registered by the JIT debug |
| info reader.*/ |
| |
| static const struct frame_unwind jit_frame_unwind = |
| { |
| "jit", |
| NORMAL_FRAME, |
| default_frame_unwind_stop_reason, |
| jit_frame_this_id, |
| jit_frame_prev_register, |
| NULL, |
| jit_frame_sniffer, |
| jit_dealloc_cache |
| }; |
| |
| |
| /* This is the information that is stored at jit_gdbarch_data for each |
| architecture. */ |
| |
| struct jit_gdbarch_data_type |
| { |
| /* Has the (pseudo) unwinder been pretended? */ |
| int unwinder_registered = 0; |
| }; |
| |
| /* An unwinder is registered for every gdbarch. This key is used to |
| remember if the unwinder has been registered for a particular |
| gdbarch. */ |
| |
| static const registry<gdbarch>::key<jit_gdbarch_data_type> jit_gdbarch_data; |
| |
| /* Check GDBARCH and prepend the pseudo JIT unwinder if needed. */ |
| |
| static void |
| jit_prepend_unwinder (struct gdbarch *gdbarch) |
| { |
| struct jit_gdbarch_data_type *data = jit_gdbarch_data.get (gdbarch); |
| if (data == nullptr) |
| data = jit_gdbarch_data.emplace (gdbarch); |
| |
| if (!data->unwinder_registered) |
| { |
| frame_unwind_prepend_unwinder (gdbarch, &jit_frame_unwind); |
| data->unwinder_registered = 1; |
| } |
| } |
| |
| /* Looks for the descriptor and registration symbols and breakpoints |
| the registration function. If it finds both, it registers all the |
| already JITed code. If it has already found the symbols, then it |
| doesn't try again. */ |
| |
| static void |
| jit_inferior_init (inferior *inf) |
| { |
| struct jit_descriptor descriptor; |
| struct jit_code_entry cur_entry; |
| CORE_ADDR cur_entry_addr; |
| struct gdbarch *gdbarch = inf->arch (); |
| program_space *pspace = inf->pspace; |
| |
| jit_debug_printf ("called"); |
| |
| jit_prepend_unwinder (gdbarch); |
| |
| jit_breakpoint_re_set_internal (gdbarch, pspace); |
| |
| for (objfile *jiter : pspace->objfiles ()) |
| { |
| if (jiter->jiter_data == nullptr) |
| continue; |
| |
| /* Read the descriptor so we can check the version number and load |
| any already JITed functions. */ |
| if (!jit_read_descriptor (gdbarch, &descriptor, jiter)) |
| continue; |
| |
| /* Check that the version number agrees with that we support. */ |
| if (descriptor.version != 1) |
| { |
| gdb_printf (gdb_stderr, |
| _("Unsupported JIT protocol version %ld " |
| "in descriptor (expected 1)\n"), |
| (long) descriptor.version); |
| continue; |
| } |
| |
| /* If we've attached to a running program, we need to check the |
| descriptor to register any functions that were already |
| generated. */ |
| for (cur_entry_addr = descriptor.first_entry; |
| cur_entry_addr != 0; |
| cur_entry_addr = cur_entry.next_entry) |
| { |
| jit_read_code_entry (gdbarch, cur_entry_addr, &cur_entry); |
| |
| /* This hook may be called many times during setup, so make sure |
| we don't add the same symbol file twice. */ |
| if (jit_find_objf_with_entry_addr (cur_entry_addr) != NULL) |
| continue; |
| |
| jit_register_code (gdbarch, cur_entry_addr, &cur_entry); |
| } |
| } |
| } |
| |
| /* inferior_created observer. */ |
| |
| static void |
| jit_inferior_created_hook (inferior *inf) |
| { |
| jit_inferior_init (inf); |
| } |
| |
| /* inferior_execd observer. */ |
| |
| static void |
| jit_inferior_execd_hook (inferior *exec_inf, inferior *follow_inf) |
| { |
| jit_inferior_init (follow_inf); |
| } |
| |
| /* Exported routine to call to re-set the jit breakpoints, |
| e.g. when a program is rerun. */ |
| |
| void |
| jit_breakpoint_re_set (void) |
| { |
| jit_breakpoint_re_set_internal (current_inferior ()->arch (), |
| current_program_space); |
| } |
| |
| /* This function cleans up any code entries left over when the |
| inferior exits. We get left over code when the inferior exits |
| without unregistering its code, for example when it crashes. */ |
| |
| static void |
| jit_inferior_exit_hook (struct inferior *inf) |
| { |
| for (objfile *objf : current_program_space->objfiles_safe ()) |
| { |
| if (objf->jited_data != nullptr && objf->jited_data->addr != 0) |
| objf->unlink (); |
| } |
| } |
| |
| void |
| jit_event_handler (gdbarch *gdbarch, objfile *jiter) |
| { |
| struct jit_descriptor descriptor; |
| |
| /* If we get a JIT breakpoint event for this objfile, it is necessarily a |
| JITer. */ |
| gdb_assert (jiter->jiter_data != nullptr); |
| |
| /* Read the descriptor from remote memory. */ |
| if (!jit_read_descriptor (gdbarch, &descriptor, jiter)) |
| return; |
| CORE_ADDR entry_addr = descriptor.relevant_entry; |
| |
| /* Do the corresponding action. */ |
| switch (descriptor.action_flag) |
| { |
| case JIT_NOACTION: |
| break; |
| |
| case JIT_REGISTER: |
| { |
| jit_code_entry code_entry; |
| jit_read_code_entry (gdbarch, entry_addr, &code_entry); |
| jit_register_code (gdbarch, entry_addr, &code_entry); |
| break; |
| } |
| |
| case JIT_UNREGISTER: |
| { |
| objfile *jited = jit_find_objf_with_entry_addr (entry_addr); |
| if (jited == nullptr) |
| gdb_printf (gdb_stderr, |
| _("Unable to find JITed code " |
| "entry at address: %s\n"), |
| paddress (gdbarch, entry_addr)); |
| else |
| jited->unlink (); |
| |
| break; |
| } |
| |
| default: |
| error (_("Unknown action_flag value in JIT descriptor!")); |
| break; |
| } |
| } |
| |
| void _initialize_jit (); |
| void |
| _initialize_jit () |
| { |
| jit_reader_dir = relocate_gdb_directory (JIT_READER_DIR, |
| JIT_READER_DIR_RELOCATABLE); |
| add_setshow_boolean_cmd ("jit", class_maintenance, &jit_debug, |
| _("Set JIT debugging."), |
| _("Show JIT debugging."), |
| _("When set, JIT debugging is enabled."), |
| NULL, |
| show_jit_debug, |
| &setdebuglist, &showdebuglist); |
| |
| add_cmd ("jit", class_maintenance, maint_info_jit_cmd, |
| _("Print information about JIT-ed code objects."), |
| &maintenanceinfolist); |
| |
| gdb::observers::inferior_created.attach (jit_inferior_created_hook, "jit"); |
| gdb::observers::inferior_execd.attach (jit_inferior_execd_hook, "jit"); |
| gdb::observers::inferior_exit.attach (jit_inferior_exit_hook, "jit"); |
| gdb::observers::breakpoint_deleted.attach (jit_breakpoint_deleted, "jit"); |
| |
| if (is_dl_available ()) |
| { |
| struct cmd_list_element *c; |
| |
| c = add_com ("jit-reader-load", no_class, jit_reader_load_command, _("\ |
| Load FILE as debug info reader and unwinder for JIT compiled code.\n\ |
| Usage: jit-reader-load FILE\n\ |
| Try to load file FILE as a debug info reader (and unwinder) for\n\ |
| JIT compiled code. The file is loaded from " JIT_READER_DIR ",\n\ |
| relocated relative to the GDB executable if required.")); |
| set_cmd_completer (c, deprecated_filename_completer); |
| |
| c = add_com ("jit-reader-unload", no_class, |
| jit_reader_unload_command, _("\ |
| Unload the currently loaded JIT debug info reader.\n\ |
| Usage: jit-reader-unload\n\n\ |
| Do \"help jit-reader-load\" for info on loading debug info readers.")); |
| set_cmd_completer (c, noop_completer); |
| } |
| } |