From: Ian Rogers Date: Mon, 4 May 2026 08:12:20 +0000 (-0700) Subject: perf dwarf-aux: Fix libdw API contract violations X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=17e9b4243e76f0a0fe951d30ce990d6081a8b426;p=thirdparty%2Fkernel%2Fstable.git perf dwarf-aux: Fix libdw API contract violations Check return values of `dwarf_decl_line` (where non-optional), `dwarf_getfuncs`, and `dwarf_lineaddr` to prevent using uninitialized stack variables or incorrectly reporting success on failure. For the root DIE in `die_walk_lines()`, `dwarf_decl_line` and `die_get_decl_file` are optional and their failures are handled gracefully to avoid breaking line walking on valid functions. Specifically, remove the strict `!decf` (declared file) check that would prematurely abort line walking on generated or artificial functions lacking this optional attribute. Additionally: - Add NULL pointer protection for `strcmp()` in `die_walk_lines()` when `inf` or `decf` are NULL to prevent crashes on generated code. - Use `dwarf_attr_integrate` in `die_get_data_member_location` to correctly resolve inherited member locations (e.g. via abstract origin or specification). Fixes: 57f95bf5f882 ("perf probe: Show correct statement line number by perf probe -l") Fixes: 3f4460a28fb2 ("perf probe: Filter out redundant inline-instances") Fixes: 75186a9b09e4 ("perf probe: Fix to show lines of sys_ functions correctly") Fixes: e0d153c69040 ("perf-probe: Move dwarf library routines to dwarf-aux.{c, h}") Fixes: 6243b9dc4c99 ("perf probe: Move dwarf specific functions to dwarf-aux.c") Assisted-by: Gemini-CLI:Google Gemini 3 Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Zecheng Li Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index 109a166a6d19..d7160f87ac7d 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -125,7 +125,8 @@ int cu_find_lineinfo(Dwarf_Die *cu_die, Dwarf_Addr addr, && die_entrypc(&die_mem, &faddr) == 0 && faddr == addr) { *fname = die_get_decl_file(&die_mem); - dwarf_decl_line(&die_mem, lineno); + if (dwarf_decl_line(&die_mem, lineno) != 0) + return -ENOENT; goto out; } @@ -459,7 +460,7 @@ int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs) size_t nexpr; int ret; - if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL) + if (dwarf_attr_integrate(mb_die, DW_AT_data_member_location, &attr) == NULL) return -ENOENT; if (dwarf_formudata(&attr, offs) != 0) { @@ -795,8 +796,7 @@ static int __die_walk_instances_cb(Dwarf_Die *inst, void *data) /* Ignore redundant instances */ if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) { - dwarf_decl_line(origin, &tmp); - if (die_get_call_lineno(inst) == tmp) { + if (dwarf_decl_line(origin, &tmp) == 0 && die_get_call_lineno(inst) == tmp) { tmp = die_get_decl_fileno(origin); if (die_get_call_fileno(inst) == tmp) return DIE_FIND_CB_CONTINUE; @@ -950,11 +950,6 @@ int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data) cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL); dwarf_decl_line(rt_die, &decl); decf = die_get_decl_file(rt_die); - if (!decf) { - pr_debug2("Failed to get the declared file name of %s\n", - dwarf_diename(rt_die)); - return -EINVAL; - } } else cu_die = rt_die; if (!cu_die) { @@ -998,11 +993,12 @@ int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data) if (die_find_inlinefunc(rt_die, addr, &die_mem)) { /* Call-site check */ inf = die_get_call_file(&die_mem); - if ((inf && !strcmp(inf, decf)) && + if ((inf == decf || (inf && decf && !strcmp(inf, decf))) && die_get_call_lineno(&die_mem) == lineno) goto found; - dwarf_decl_line(&die_mem, &inl); + if (dwarf_decl_line(&die_mem, &inl) != 0) + inl = 0; if (inl != decl || decf != die_get_decl_file(&die_mem)) continue; @@ -1034,8 +1030,10 @@ found: .data = data, .retval = 0, }; - dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0); - ret = param.retval; + if (dwarf_getfuncs(cu_die, __die_walk_culines_cb, ¶m, 0) < 0) + ret = -EINVAL; + else + ret = param.retval; } return ret; @@ -1939,10 +1937,12 @@ static bool die_get_postprologue_addr(unsigned long entrypc_idx, break; } - dwarf_lineaddr(line, postprologue_addr); - if (*postprologue_addr >= highpc) - dwarf_lineaddr(dwarf_onesrcline(lines, i - 1), - postprologue_addr); + if (dwarf_lineaddr(line, postprologue_addr) != 0) + return false; + if (*postprologue_addr >= highpc) { + if (dwarf_lineaddr(dwarf_onesrcline(lines, i - 1), postprologue_addr) != 0) + return false; + } return true; } diff --git a/tools/perf/util/dwarf-aux.h b/tools/perf/util/dwarf-aux.h index a79968a2e573..161f0bf980b6 100644 --- a/tools/perf/util/dwarf-aux.h +++ b/tools/perf/util/dwarf-aux.h @@ -10,6 +10,11 @@ #include #include +static inline const char *die_name(Dwarf_Die *die) +{ + return dwarf_diename(die) ?: ""; +} + struct strbuf; /* Find the realpath of the target file */