From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) (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 48BBDA943 for ; Fri, 9 Jun 2023 23:54:31 +0000 (UTC) Received: by mail-yb1-f202.google.com with SMTP id 3f1490d57ef6-bb3cb542875so3244992276.1 for ; Fri, 09 Jun 2023 16:54:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1686354870; x=1688946870; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=oNyUS02eW/yXFIAlgFDfwEmFoe9Pd7uSEDgKLORvHjM=; b=V11apG9LHOwhutH46QHmQ0gFKrfNaC6p1CizyVW65E2n8EhG+rIvmW285qgxYWdy68 Am892SzAOwS/ktZ92R2Inm+9rHnmpjZH5EtYHOE9rLiXEl33z6EZLwsx3lkKfCfkYfNa dnpiTxRdkt2Aha2k3I1IdY+WUUBb6EnCjBrF+YbO1s2z1W1d4daY7/xMLd+PqX6c2ZN7 1l4pasEPgSopAcpHBehgcFW+gl/CqZK9N+iAoO9Xm2e0ZieeV+dpSeNsvOeXcKMNRuf4 /fEJf+7N7JW8da5CtMIl/WIre12zkDa/wtXnudrUI7oozutQxWyOqfMhHfJ4n0RSogMw bEDA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686354870; x=1688946870; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=oNyUS02eW/yXFIAlgFDfwEmFoe9Pd7uSEDgKLORvHjM=; b=cJk9RAExec69iC/VtVsvkV6qi0PKsC0MitC+94ELQGCHHh8TzUVxDpaeqnK3rmrLVx 5nMjXG/BoWoqr6Di18agvx5Ywq59Nd0NyZRQktzJsYainXhab6W5WQ/ElPc2Vt6CEyTF CQx/tA7+5EIIdIcJLAVP3nXn2kodjNhp3XevEzFvtYokizGNJKD0e6SWUSxe99M8RHsV hdOVvE8q/c5RwW3K+Xim+HxMMqJFTwaiUSce+fb7D+lvYeyLGnOxh1p+P73KqVSMi0zh Vo265torEzULj7QdKmVV3mDUxG24+C2Psy+wXJU0rce69F/X4UZh4ak1GtmIW4cXDpif 1GqA== X-Gm-Message-State: AC+VfDxHPVIf4bppXIj09uMXKzcmA6Vh1A1DYI3MFqHadnMCEIy9gmEB nc9UymsMlbiEp6e9+cHn3fEMSNsx35tA X-Google-Smtp-Source: ACHHUZ4PMyCkdCSyENQFYB0qETjtjOg/fcbawc434c4hu5aAPdXX7kCJC4yurstliqdU7VqpZ+H7i4hZQlWz X-Received: from irogers.svl.corp.google.com ([2620:15c:2d4:203:55f2:1922:c44b:472d]) (user=irogers job=sendgmr) by 2002:a25:da09:0:b0:bbe:8486:5895 with SMTP id n9-20020a25da09000000b00bbe84865895mr1408283ybf.1.1686354870144; Fri, 09 Jun 2023 16:54:30 -0700 (PDT) Date: Fri, 9 Jun 2023 16:54:19 -0700 In-Reply-To: <20230609235419.204624-1-irogers@google.com> Message-Id: <20230609235419.204624-2-irogers@google.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20230609235419.204624-1-irogers@google.com> X-Mailer: git-send-email 2.41.0.162.gfafddb0af9-goog Subject: [PATCH v1 2/2] perf srcline: Make sentinel reading for binutils addr2line more robust From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Nathan Chancellor , Nick Desaulniers , Tom Rix , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, Changbin Du Content-Type: text/plain; charset="UTF-8" The addr2line process is sent an address then multiple function, filename:line "records" are read. To detect the end of output a ',' is sent and for llvm-addr2line a ',' is then read back showing the end of addrline's output. For binutils addr2line the ',' translates to address 0 and we expect the bogus filename marker "??:0" (see filename_split) to be sent from addr2line. For some kernels address 0 may have a mapping and so a seemingly valid inline output is given and breaking the sentinel discovery: ``` $ addr2line -e vmlinux -f -i , __per_cpu_start ./arch/x86/kernel/cpu/common.c:1850 ``` To avoid this problem enable the address dumping for addr2line (the -a option). If an address of 0x0000000000000000 is read then this is the sentinel value working around the problem above. The filename_split still needs to check for "??:0" as bogus non-zero addresses also need handling. Reported-by: Changbin Du Signed-off-by: Ian Rogers --- tools/perf/util/srcline.c | 61 ++++++++++++++++++++++++++++++++++----- 1 file changed, 53 insertions(+), 8 deletions(-) diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c index fc85cdd6c8f9..c99a001453b4 100644 --- a/tools/perf/util/srcline.c +++ b/tools/perf/util/srcline.c @@ -406,7 +406,7 @@ static struct child_process *addr2line_subprocess_init(const char *addr2line_pat const char *argv[] = { addr2line_path ?: "addr2line", "-e", binary_path, - "-i", "-f", NULL + "-a", "-i", "-f", NULL }; struct child_process *a2l = zalloc(sizeof(*a2l)); int start_command_status = 0; @@ -461,10 +461,10 @@ static enum a2l_style addr2line_configure(struct child_process *a2l, const char style = LLVM; cached = true; lines = 1; - } else if (ch == '?') { + } else if (ch == '0') { style = GNU_BINUTILS; cached = true; - lines = 2; + lines = 3; } else { if (!symbol_conf.disable_add2line_warn) { char *output; @@ -516,20 +516,64 @@ static int read_addr2line_record(struct io *io, if (line_nr != NULL) *line_nr = 0; + /* + * Read the first line. Without an error this will be either an address + * like 0x1234 or for llvm-addr2line the sentinal ',' character. + */ if (io__getline(io, &line, &line_len) < 0 || !line_len) goto error; - if (style == LLVM && line_len == 2 && line[0] == ',') { - zfree(&line); - return 0; + if (style == LLVM) { + if (line_len == 2 && line[0] == ',') { + zfree(&line); + return 0; + } + } else { + int zero_count = 0, non_zero_count = 0; + + /* The address should always start 0x. */ + if (line_len < 2 || line[0] != '0' || line[1] != 'x') + goto error; + + for (size_t i = 2; i < line_len; i++) { + if (line[i] == '0') + zero_count++; + else + non_zero_count++; + } + if (!non_zero_count) { + int ch; + + if (!zero_count) { + /* Line was erroneous just '0x'. */ + goto error; + } + /* + * Line was 0x0..0, the sentinel for binutils. Remove + * the function and filename lines. + */ + zfree(&line); + do { + ch = io__get_char(io); + } while (ch > 0 && ch != '\n'); + do { + ch = io__get_char(io); + } while (ch > 0 && ch != '\n'); + return 0; + } } + /* Read the second function name line. */ + if (io__getline(io, &line, &line_len) < 0 || !line_len) + goto error; + if (function != NULL) *function = strdup(strim(line)); zfree(&line); line_len = 0; + /* Read the third filename and line number line. */ if (io__getline(io, &line, &line_len) < 0 || !line_len) goto error; @@ -633,8 +677,9 @@ static int addr2line(const char *dso_name, u64 addr, goto out; case 0: /* - * The first record was invalid, so return failure, but first read another - * record, since we asked a junk question and have to clear the answer out. + * The first record was invalid, so return failure, but first + * read another record, since we sent a sentinel ',' for the + * sake of detected the last inlined function. */ switch (read_addr2line_record(&io, a2l_style, NULL, NULL, NULL)) { case -1: -- 2.41.0.162.gfafddb0af9-goog