linux-stable/tools/perf/util/dwarf-aux.h
Masami Hiramatsu (Google) dc9a5d2ccd perf probe: Fix to get declared file name from clang DWARF5
Fix to get the declared file name even if it uses file index 0
in DWARF5, using custom die_get_decl_file() function.

Actually, the DWARF5 standard says file index 0 of the DW_AT_decl_file
is invalid(1), but there is a discussion and maybe this will be updated
[2].

Anyway, clang generates such DWARF5 file for the linux kernel. Thus it
must be handled.

Without this, 'perf probe' returns an error:

   $ ./perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10
   Debuginfo analysis failed.
     Error: Failed to show lines.

With this, it can handle the case correctly:

  $ ./perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10
  <vfs_read@$SRC_PATH/fs/read_write.c:10>

       11         ret = rw_verify_area(READ, file, pos, count);
       12         if (ret)
                           return ret;

[1] DWARF5 specification 2.14 says "The value 0 indicates that no source file has been specified.")
[2] http://wiki.dwarfstd.org/index.php?title=DWARF5_Line_Table_File_Numbers)

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/166731052936.2100653.13380621874859467731.stgit@devnote3
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-11-03 09:28:46 -03:00

133 lines
4.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _DWARF_AUX_H
#define _DWARF_AUX_H
/*
* dwarf-aux.h : libdw auxiliary interfaces
*/
#include <dwarf.h>
#include <elfutils/libdw.h>
#include <elfutils/libdwfl.h>
#include <elfutils/version.h>
struct strbuf;
/* Find the realpath of the target file */
const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname);
/* Get DW_AT_comp_dir (should be NULL with older gcc) */
const char *cu_get_comp_dir(Dwarf_Die *cu_die);
/* Get a line number and file name for given address */
int cu_find_lineinfo(Dwarf_Die *cudie, Dwarf_Addr addr,
const char **fname, int *lineno);
/* Walk on functions at given address */
int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
int (*callback)(Dwarf_Die *, void *), void *data);
/* Get DW_AT_linkage_name (should be NULL for C binary) */
const char *die_get_linkage_name(Dwarf_Die *dw_die);
/* Get the lowest PC in DIE (including range list) */
int die_entrypc(Dwarf_Die *dw_die, Dwarf_Addr *addr);
/* Ensure that this DIE is a subprogram and definition (not declaration) */
bool die_is_func_def(Dwarf_Die *dw_die);
/* Ensure that this DIE is an instance of a subprogram */
bool die_is_func_instance(Dwarf_Die *dw_die);
/* Compare diename and tname */
bool die_compare_name(Dwarf_Die *dw_die, const char *tname);
/* Matching diename with glob pattern */
bool die_match_name(Dwarf_Die *dw_die, const char *glob);
/* Get callsite line number of inline-function instance */
int die_get_call_lineno(Dwarf_Die *in_die);
/* Get callsite file name of inlined function instance */
const char *die_get_call_file(Dwarf_Die *in_die);
/* Get declared file name of a DIE */
const char *die_get_decl_file(Dwarf_Die *dw_die);
/* Get type die */
Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem);
/* Get a type die, but skip qualifiers and typedef */
Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem);
/* Check whether the DIE is signed or not */
bool die_is_signed_type(Dwarf_Die *tp_die);
/* Get data_member_location offset */
int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs);
/* Return values for die_find_child() callbacks */
enum {
DIE_FIND_CB_END = 0, /* End of Search */
DIE_FIND_CB_CHILD = 1, /* Search only children */
DIE_FIND_CB_SIBLING = 2, /* Search only siblings */
DIE_FIND_CB_CONTINUE = 3, /* Search children and siblings */
};
/* Search child DIEs */
Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
int (*callback)(Dwarf_Die *, void *),
void *data, Dwarf_Die *die_mem);
/* Search a non-inlined function including given address */
Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
Dwarf_Die *die_mem);
/* Search a non-inlined function with tail call at given address */
Dwarf_Die *die_find_tailfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
Dwarf_Die *die_mem);
/* Search the top inlined function including given address */
Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
Dwarf_Die *die_mem);
/* Search the deepest inlined function including given address */
Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
Dwarf_Die *die_mem);
/* Walk on the instances of given DIE */
int die_walk_instances(Dwarf_Die *in_die,
int (*callback)(Dwarf_Die *, void *), void *data);
/* Walker on lines (Note: line number will not be sorted) */
typedef int (* line_walk_callback_t) (const char *fname, int lineno,
Dwarf_Addr addr, void *data);
/*
* Walk on lines inside given DIE. If the DIE is a subprogram, walk only on
* the lines inside the subprogram, otherwise the DIE must be a CU DIE.
*/
int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data);
/* Find a variable called 'name' at given address */
Dwarf_Die *die_find_variable_at(Dwarf_Die *sp_die, const char *name,
Dwarf_Addr addr, Dwarf_Die *die_mem);
/* Find a member called 'name' */
Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name,
Dwarf_Die *die_mem);
/* Get the name of given variable DIE */
int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf);
/* Get the name and type of given variable DIE, stored as "type\tname" */
int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf);
int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf);
/* Check if target program is compiled with optimization */
bool die_is_optimized_target(Dwarf_Die *cu_die);
/* Use next address after prologue as probe location */
void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
Dwarf_Addr *entrypc);
#endif