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 99706317148 for ; Mon, 4 May 2026 08:12:37 +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=1777882360; cv=none; b=ge+c+Ny2miTZnjyb4ATN3RIpwPmVkgJDC/GYlPGY0jVd8LcacVQHeDPMtnRGt2zBjB8d6jUFJD5DLBSBohGiz19Zdl97N+hJci53VcePyZ5rIA/pNfSBeG3heFLKB2l1cW7A2rlhHdKgjZa8tHYvtkr6ZmtpIA2ZR34hpcF5iOI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777882360; c=relaxed/simple; bh=ezr8slRwH9n2ZV1JvOOFyTaI1PUIDpT5biKxWiOeQak=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=noejtGEWzrYF6XImMHJoo5NSGyN3X/59oOZUlmGjEpSFRWR0zcg43W4qlhmvZdfWxibws8mNDOy6p+xAS+tvsGZyzD8BjoyXDeEVNS90i7hR1HSIvWTHBffgEFpspbqHjM+4xZ2kKbS1DLuZQPMqhK8tIXu1xGOYu1vjjcwgRXw= 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=T7fRFx8x; 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="T7fRFx8x" Received: by mail-dy1-f202.google.com with SMTP id 5a478bee46e88-2eebb099efbso5408655eec.0 for ; Mon, 04 May 2026 01:12:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777882356; x=1778487156; 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=rAfUSIRolAH4G9771FLWXZbdPKkv4l0+2rHJCOKFAXw=; b=T7fRFx8xmJ4OqV6aYvmPw/0fVmDLkgOATqoy40OLol1/TUxbl7oJTj15vi75Eu+G6X ihCojoFVLQ4DYQiZsFIBdcHW0GpRA+R7Ge4Wmuo0AaECno3AoI4+zsK4UjY/YlZVK1SA qNM2IMojBNkaniJD+bIwHjFg6zUYtUuDk7PynO+QXWiikqKhn/PQ0j2HTP0D4Bv7AUAK Q+dNoIAU/mv3Tp7xOkkMJf3iGr697Rwz3/3Bvx1aTs5NI/71S+hVtb/Oj3FXaDAmby6A 6Tnrg1YEvLez53rfH7BORjptl9tBzyP2Qmi+sIVHq0NTlQUhaU4wgzVx8JLyxL+ufekW vRng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777882356; x=1778487156; 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=rAfUSIRolAH4G9771FLWXZbdPKkv4l0+2rHJCOKFAXw=; b=HkVHSg00PErXBZqX1Q6IDRd/YagP5Zi+rugkr0YfXOO8DSPiYMDYhtUibV2wrDIV6K vpWZBIErmPYZ3DSK8ZYPdFPoRlVXfoxlhrwyP8L64NusupmV+sJKBYRZjJkL5xxzjltS QvtxPP1NsrO7s5f6lJ7GJF8qwVi9juXs/IBzdlT6cBYgTuSzwcDUXkhYJX4kqN4Irk8X 6hhe745JyO6hxaJrtI1qYaQ0455htH7Nb3GYoBCq9LdgJ6Xan5i0L2HVCrJzhnpKlu5H lKAWG8KoY0RNmwkPciJY2FUegieAmH1ziAEmw7uOCcHzqvwpuiWEW2Ti7X1lfCs2cJW8 m2+A== X-Forwarded-Encrypted: i=1; AFNElJ/54Zpcn2TmGyx7dmPzxEmFqkmXEcSJP1mYJzfK2Z7WMBCYeXjLehBlBZRII3QjO1j2+EE/ga/+IKllOTtBVcIt@vger.kernel.org X-Gm-Message-State: AOJu0YzDudFE3hQoBp8Og9a9KwtQd+pwN2JqJFo1g5HRNyMmjC8ocoML 92VXTy2nPumifkTUjxVzlutlKd1q702nEfMhMhZKp1TRPe0BHCHijebNIlgtz2OmsVpuf8fpi9F QDHE1j0SDow== X-Received: from dyx13.prod.google.com ([2002:a05:693c:820d:b0:2ed:b77f:b02a]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7301:2b08:b0:2dd:c066:bf7 with SMTP id 5a478bee46e88-2efb80c0c41mr3580658eec.11.1777882356366; Mon, 04 May 2026 01:12:36 -0700 (PDT) Date: Mon, 4 May 2026 01:12:20 -0700 In-Reply-To: <20260504081227.2203848-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260503171032.1559338-1-irogers@google.com> <20260504081227.2203848-1-irogers@google.com> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog Message-ID: <20260504081227.2203848-3-irogers@google.com> Subject: [PATCH v5 2/9] 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. 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 --- v5: - Updated commit message to explain optional DWARF attributes and decf check removal. 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, 22 insertions(+), 17 deletions(-) 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 @@ 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 +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 */ -- 2.54.0.545.g6539524ca2-goog