From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dy1-f202.google.com (mail-dy1-f202.google.com [74.125.82.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5464D3CF68D for ; Sun, 3 May 2026 17:10:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777828249; cv=none; b=nkAdkxMUygfw3XBIMGrhJFfOxcuAKpIFZQS69vCtc7XbHBct4OnZpkP7tcJoGVE2+ZUlKDKVXtsiFn9G1S/shdw11F1vQF9GJj543JdqcU9AvoHzDP8IFvKAv3zRtrwNO8rdgV4ZjxszFd3JeHWDg3r9a/Swnx1hmxiooCCWawA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777828249; c=relaxed/simple; bh=yjcs1D6pGw7KPynb26FlbUjS/OAEHH4cdgoxuoNVwLM=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=SW86Y6pmlrxyY4MIgENXc98c8gdUag0f1Q6ink2wGb0z0Cxh2CNAoaF8pudLl7WwEOI0eCnPHY9QCSEZquV7ZSkV+LPPrUxCiUIc66e+lY418Ypqk5/m+fQMThgRGG9lFPkgJ4F5AIz5czrEKW5KaLgFi89DZIaE1CfbmziSg8A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=cgKka/Iz; arc=none smtp.client-ip=74.125.82.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="cgKka/Iz" Received: by mail-dy1-f202.google.com with SMTP id 5a478bee46e88-2ef37c3f773so1559498eec.1 for ; Sun, 03 May 2026 10:10:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777828247; x=1778433047; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=n7qKK0k5c4yxl6VaFAc+LrAt0pI1jotb392xlOeZ7Wo=; b=cgKka/IzZQS6nNYL9/vSrn0Q4VdE901nUshVtR8mCJOUDZUJOj9iWq55oioU9rBjcL o21muNUCydCoxuZOGplz9gxaElVEaco3srTxPeNBpENWfRU/v2s3mOf/+EMP+XwAM2u/ qYddpQ8n8qSmTPwD6JEhIZQDzpzkAmkR6k+ISwh2lkeUWDDQ+fCCD19bt20+DoAQ9YTg pXVlyJlJM0NWv+fqoKW2+JQ96GqFv0mfg9fgFxizIILoRhSyhu4EFk/ThgzP2qLeWa5P Rztk8IRfcm1fIP1SyCCKriKcchtffMOSXorxvNT73E3PQhxw9zQ2QagDdyfddadxKmUl e45Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777828247; x=1778433047; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=n7qKK0k5c4yxl6VaFAc+LrAt0pI1jotb392xlOeZ7Wo=; b=D7wrJWchryFGPR7b0te6ABLCIoMTCXTQNNkeQSIb+D8hduNwZb6lIqigTaTH6IKRwj HHdqwTUFpK9+16Ep5ibIQBgJTycLArUCnGwBZI891ggg0Rzp1I3r+BdHovcb60esKRXo Wjko7YMzoYZnJ0R5by7LSZX81j19kdyfuKGeRyHgQodE8Urq48aqZnKoml4C1eaioPGK oRV0W1LsRp1bODyf3CRwEGau5bkjprRTVYuY/+30101/o5s7IFDzLxZj3O17wFyfUQK0 xz4hUqm1akEf/1+mG6sg9hFP6evTKc2Vu8cKSRjpiK2rHJfRHO3KFbB+FIs3GxZL1uNt 4Dpg== X-Forwarded-Encrypted: i=1; AFNElJ/S2ws9HSza6slKiRS+eDD/DXycM1knC/cedRwKT+DHmxJeN2KUmjXJHnOs2uEB1PrzeCVWCdYk31jh58c=@vger.kernel.org X-Gm-Message-State: AOJu0Yxam74oS+LiNkUShDdoaZVjIRxdvvKOQqVXujoXUK4RbN8iKajw S5DTVCs0ie7jW0e5Valu4Zysp/mbZDUcCpnWp9Mj+U3WsAyTKcnctUxvKbej6AirBxXJTifkL2e Vip93ijYSIg== X-Received: from dybmk34.prod.google.com ([2002:a05:7301:ea2:b0:2ed:a84e:18d3]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7300:e68b:b0:2ea:4228:ab11 with SMTP id 5a478bee46e88-2efb7ad867amr3108657eec.3.1777828247156; Sun, 03 May 2026 10:10:47 -0700 (PDT) Date: Sun, 3 May 2026 10:10:28 -0700 In-Reply-To: <20260503171032.1559338-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260503003552.1063540-1-irogers@google.com> <20260503171032.1559338-1-irogers@google.com> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog Message-ID: <20260503171032.1559338-3-irogers@google.com> Subject: [PATCH v4 2/6] perf dwarf-aux: Fix libdw API contract violations From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Jiri Olsa , Adrian Hunter , James Clark , Zecheng Li , Masami Hiramatsu , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Ian Rogers Content-Type: text/plain; charset="UTF-8" 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. 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 --- v4: - Fix strcmp(NULL) risk and inherited member location fallbacks in dwarf-aux.c. --- tools/perf/util/dwarf-aux.c | 34 ++++++++++++++++------------------ tools/perf/util/dwarf-aux.h | 5 +++++ 2 files changed, 21 insertions(+), 18 deletions(-) diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index 109a166a6d19..a8ab1c30d0ac 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) { @@ -998,12 +993,11 @@ 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 (inl != decl || + if (dwarf_decl_line(&die_mem, &inl) != 0 || inl != decl || decf != die_get_decl_file(&die_mem)) continue; } @@ -1034,8 +1028,10 @@ int die_walk_lines(Dwarf_Die *rt_die, line_walk_callback_t callback, void *data) .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 +1935,12 @@ 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 */ -- 2.54.0.545.g6539524ca2-goog