From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from picard.linux.it (picard.linux.it [213.254.12.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E9B15C5DF81 for ; Thu, 20 Aug 2026 18:48:33 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id 785413CF202 for ; Thu, 20 Aug 2026 20:48:31 +0200 (CEST) Received: from in-2.smtp.seeweb.it (in-2.smtp.seeweb.it [217.194.8.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1)) (No client certificate requested) by picard.linux.it (Postfix) with ESMTPS id C6D613C2953 for ; Thu, 20 Aug 2026 20:48:13 +0200 (CEST) Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2a07:de40:b251:101:10:150:64:1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by in-2.smtp.seeweb.it (Postfix) with ESMTPS id 10027600691 for ; Thu, 20 Aug 2026 20:48:12 +0200 (CEST) Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 863F485249; Thu, 20 Aug 2026 18:48:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1787251687; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=AzPgemSCxMH58gfNHK17m2YM51jRSznE3YStoWeGSBQ=; b=X3oeyZ9zwxsa4BhJJIZULHKgzT8CryD7FgdRdtI5SO6SneQmmD1dmwIWKM05M04qB2EfXy zeQG9lBP2gpSVOPVpII40u7BGWAwM/VgdOHUy5PImTrLJFE6Yx0AxOGE95NKOp7VXfijfb 8qRLBq+w8DAOVfzH9cQRWY3xswDBnWk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1787251687; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=AzPgemSCxMH58gfNHK17m2YM51jRSznE3YStoWeGSBQ=; b=Ode6c+QXlIgpL043RMCWXZ4mdPVjDPlH0L/GcL6ofYrGa/6Ul29MgrMpmqIEzn+vuqTyQj 6SiZYxIt6V/IApDA== Authentication-Results: smtp-out1.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1787251683; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=AzPgemSCxMH58gfNHK17m2YM51jRSznE3YStoWeGSBQ=; b=HXoFf6HwrdnWZyqudpLHpjBR6+8Yx4EnglLv4hgF3ygfx7Ns1OsRW0rf69mDkII/CSZ/rM wHMXvYq8tlWBLxrcBbulgAbNfHPgrZYnn5PZkqEO/2TBpCEg4zVGquRQgo0eVJC1OZp/z+ doqQARjZ9ogT+sOT4u3vO4rrr4jvEGA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1787251683; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=AzPgemSCxMH58gfNHK17m2YM51jRSznE3YStoWeGSBQ=; b=F6nvuk7+6vpAyWse4H2M0KXKtSXk725PCNuMV1Dlrms/fxpmmx2miLfhbBz4cSY2FQ7pVU 9h7OIlagoKU0gpAQ== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 3121C27A8; Thu, 20 Aug 2026 18:48:03 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id lpziBeNLh2pGaQAAD6G6ig (envelope-from ); Thu, 20 Aug 2026 18:48:03 +0000 From: Andrea Cervesato Date: Thu, 20 Aug 2026 20:47:47 +0200 MIME-Version: 1.0 Message-Id: <20260820-coredump-v1-1-7ce51603cefb@suse.com> X-B4-Tracking: v=1; b=H4sIANJLh2oC/yXM0QpAMBTG8VfRubaao1heRS7YzjgKa0NqeXfD5 a/+3xchkGcK0GQRPJ0ceFsTijwDPfXrSIJNMqDESiqUQm+ezLE4gWh1XRaDIakg5c6T5eu7arv f4Rhm0vu7h/t+AF+djQRsAAAA X-Change-ID: 20260820-coredump-22fc731bde08 To: Linux Test Project X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1787251683; l=9020; i=andrea.cervesato@suse.com; s=20251210; h=from:subject:message-id; bh=817rpfO6sX85r82fonYuKSXspuPiYrexQOx3vb5PW3I=; b=JpfINRTXXmPOKA/9+4Ouziu269WMTwLsQFozKBVoIdMgBmK2Voqb2BPiymnvY2cTgRq0/j6Dn fba2GBcYF7vAL3J7SuJXGD9TSO6uikaP/hjDJNGX9TfG+46RGy8CCx3 X-Developer-Key: i=andrea.cervesato@suse.com; a=ed25519; pk=zKY+6GCauOiuHNZ//d8PQ/UL4jFCTKbXrzXAOQSLevI= X-Spamd-Result: default: False [-4.30 / 50.00]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-0.996]; MIME_GOOD(-0.10)[text/plain]; RCPT_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; TO_DN_ALL(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; MIME_TRACE(0.00)[0:+]; FROM_EQ_ENVFROM(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:mid,suse.com:email] X-Virus-Scanned: clamav-milter 1.0.9 at in-2.smtp.seeweb.it X-Virus-Status: Clean Subject: [LTP] [PATCH] coredump01: New core_pattern specifiers test X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" From: Andrea Cervesato LTP has no coverage for the core_pattern specifiers expansion, neither for the pipe flavor of core_pattern, where the kernel spawns a user space helper and writes the core dump into its standard input. The new test verifies that %e, %p and %s are expanded both in the core file name and in the arguments of a piped helper, checking also that the helper really receives an ELF core dump. Root is required to rewrite the system wide core_pattern, which is restored by the test library on all exit paths. Signed-off-by: Andrea Cervesato --- Add a simple coredump01 test that simulate a coredump and verify that it actually works. This is a small coverage that is missing inside LTP testing suite. --- runtest/kernel_misc | 1 + testcases/kernel/Makefile | 1 + testcases/kernel/coredump/.gitignore | 2 + testcases/kernel/coredump/Makefile | 7 ++ testcases/kernel/coredump/coredump01.c | 161 ++++++++++++++++++++++++++ testcases/kernel/coredump/coredump01_helper.c | 66 +++++++++++ 6 files changed, 238 insertions(+) diff --git a/runtest/kernel_misc b/runtest/kernel_misc index cc3562cb7..ecf9ee2a2 100644 --- a/runtest/kernel_misc +++ b/runtest/kernel_misc @@ -17,3 +17,4 @@ zram02 zram02.sh zram03 zram03 umip_basic_test umip_basic_test aslr01 aslr01 +coredump01 coredump01 diff --git a/testcases/kernel/Makefile b/testcases/kernel/Makefile index ac816e4e8..6b303c14b 100644 --- a/testcases/kernel/Makefile +++ b/testcases/kernel/Makefile @@ -19,6 +19,7 @@ SUBDIRS += lib SUBDIRS += connectors \ containers \ controllers \ + coredump \ crypto \ device-drivers \ firmware \ diff --git a/testcases/kernel/coredump/.gitignore b/testcases/kernel/coredump/.gitignore new file mode 100644 index 000000000..cd0b51700 --- /dev/null +++ b/testcases/kernel/coredump/.gitignore @@ -0,0 +1,2 @@ +/coredump01 +/coredump01_helper diff --git a/testcases/kernel/coredump/Makefile b/testcases/kernel/coredump/Makefile new file mode 100644 index 000000000..951a3e976 --- /dev/null +++ b/testcases/kernel/coredump/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0-or-later +# Copyright (c) 2026 Linux Test Project + +top_srcdir ?= ../../.. + +include $(top_srcdir)/include/mk/testcases.mk +include $(top_srcdir)/include/mk/generic_leaf_target.mk diff --git a/testcases/kernel/coredump/coredump01.c b/testcases/kernel/coredump/coredump01.c new file mode 100644 index 000000000..a6003ba10 --- /dev/null +++ b/testcases/kernel/coredump/coredump01.c @@ -0,0 +1,161 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2026 Linux Test Project + */ + +/*\ + * Verify that the kernel expands the :manpage:`core(5)` specifiers %e + * (executable name), %p (PID) and %s (signal number) when it creates a + * core dump. + * + * Both flavors of ``/proc/sys/kernel/core_pattern`` are tested: + * + * - a plain file name, where the specifiers become part of the core file + * name + * - a pipe to a user space helper, where the specifiers are expanded in + * the helper arguments and the core dump is written to the helper + * standard input + * + * The test needs root because it rewrites the system wide core_pattern. + * The original value is saved and restored by the test library on all + * exit paths. + * + * [Algorithm] + * + * - Point core_pattern into the test temporary directory + * - Fork a child which aborts itself to produce a core dump + * - For the file pattern check that ``core...`` was created + * - For the pipe pattern check the arguments the helper was called with + * and that it received an ELF core dump on its standard input + */ + +#include + +#include "tst_test.h" +#include "lapi/prctl.h" + +#define PATTERN_MAX 128 +#define HELPER "coredump01_helper" +#define HELPER_TIMEOUT 10 + +static char helper_dir[PATH_MAX]; +static char cwd[PATH_MAX]; + +static void set_pattern(const char *fmt, ...) +{ + char pattern[PATTERN_MAX]; + va_list va; + int len; + + va_start(va, fmt); + len = vsnprintf(pattern, sizeof(pattern), fmt, va); + va_end(va); + + if (len >= PATTERN_MAX) + tst_brk(TCONF, "core_pattern does not fit into %i bytes", PATTERN_MAX - 1); + + SAFE_FILE_PRINTF(PATH_KERN_CORE_PATTERN, "%s", pattern); + + tst_res(TINFO, "core_pattern is '%s'", pattern); +} + +static pid_t crash_child(void) +{ + int status; + pid_t pid; + + pid = SAFE_FORK(); + if (!pid) + abort(); + + SAFE_WAITPID(pid, &status, 0); + + if (!WIFSIGNALED(status) || !WCOREDUMP(status)) + tst_brk(TFAIL, "Child did not dump core"); + + return pid; +} + +static void verify_file_pattern(void) +{ + char dump[PATH_MAX + 32]; + pid_t pid; + + tst_res(TINFO, "Testing file core_pattern"); + + set_pattern("%s/core.%%e.%%p.%%s", cwd); + + pid = crash_child(); + + snprintf(dump, sizeof(dump), "%s/core.coredump01.%d.%d", cwd, pid, SIGABRT); + + TST_EXP_PASS(access(dump, F_OK), "core.%%e.%%p.%%s expanded to core.coredump01.%d.%d", + pid, SIGABRT); +} + +static void verify_pipe_pattern(void) +{ + char res[PATH_MAX + 32], exe[PATH_MAX]; + int pid_seen, sig_seen, elf; + long long bytes; + pid_t pid; + + tst_res(TINFO, "Testing pipe core_pattern"); + + set_pattern("|%s/%s %%e %%p %%s %s/res.%%p", helper_dir, HELPER, cwd); + + pid = crash_child(); + + snprintf(res, sizeof(res), "%s/res.%d", cwd, pid); + + /* the kernel spawns the helper asynchronously */ + if (TST_RETRY_FN_EXP_BACKOFF(access(res, F_OK), TST_RETVAL_EQ0, HELPER_TIMEOUT)) { + tst_res(TFAIL, "%s did not report any core dump", HELPER); + return; + } + + SAFE_FILE_SCANF(res, "exe=%15s pid=%d sig=%d bytes=%lld elf=%d", + exe, &pid_seen, &sig_seen, &bytes, &elf); + + TST_EXP_EQ_STR(exe, "coredump01"); + TST_EXP_EQ_LI(pid_seen, pid); + TST_EXP_EQ_LI(sig_seen, SIGABRT); + TST_EXP_EXPR(elf && bytes > 0, "%s read %lli bytes of ELF core dump", HELPER, bytes); +} + +static void run(unsigned int n) +{ + if (n) + verify_pipe_pattern(); + else + verify_file_pattern(); +} + +static void setup(void) +{ + struct rlimit rl = {RLIM_INFINITY, RLIM_INFINITY}; + ssize_t len; + + SAFE_SETRLIMIT(RLIMIT_CORE, &rl); + + SAFE_PRCTL(PR_GET_DUMPABLE, 1, 0, 0, 0); + + SAFE_GETCWD(cwd, sizeof(cwd)); + + len = SAFE_READLINK("/proc/self/exe", helper_dir, sizeof(helper_dir) - 1); + helper_dir[len] = '\0'; + *strrchr(helper_dir, '/') = '\0'; +} + +static struct tst_test test = { + .test = run, + .tcnt = 2, + .setup = setup, + .needs_root = 1, + .needs_tmpdir = 1, + .forks_child = 1, + .save_restore = (const struct tst_path_val[]) { + {PATH_KERN_CORE_PATTERN, NULL, TST_SR_TCONF}, + {} + }, +}; diff --git a/testcases/kernel/coredump/coredump01_helper.c b/testcases/kernel/coredump/coredump01_helper.c new file mode 100644 index 000000000..a993e2ef7 --- /dev/null +++ b/testcases/kernel/coredump/coredump01_helper.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2026 Linux Test Project + */ + +/* + * Core dump collector for the piped core_pattern tested by coredump01. + * + * Avoiding the LTP API here is correct, since the kernel spawns the helper + * through ``call_usermodehelper()`` without the LTP IPC environment. + * + * The helper is called as: + * + * coredump01_helper + * + * and stores what it received in the result file, which is published with + * :manpage:`rename()` so that the polling test never reads a partial line. + */ + +#include +#include +#include +#include +#include + +int main(int argc, char *argv[]) +{ + char buf[4096], tmp[PATH_MAX], magic[4]; + long long bytes = 0; + ssize_t rval, i; + int fd, elf; + + if (argc < 5) + return 1; + + /* + * A core dump embeds the ELF images it has mapped, so the magic is + * only meaningful at the very beginning of the stream. Collect it + * across reads, since a pipe read can return less than 4 bytes. + */ + while ((rval = read(STDIN_FILENO, buf, sizeof(buf))) > 0) { + for (i = 0; i < rval && bytes + i < 4; i++) + magic[bytes + i] = buf[i]; + + bytes += rval; + } + + if (rval < 0) + return 1; + + if (bytes >= 4 && !memcmp(magic, "\177ELF", 4)) + elf = 1; + + snprintf(tmp, sizeof(tmp), "%s.tmp", argv[4]); + + fd = open(tmp, O_WRONLY | O_CREAT | O_TRUNC, 0644); + if (fd < 0) + return 1; + + dprintf(fd, "exe=%s pid=%s sig=%s bytes=%lld elf=%d\n", + argv[1], argv[2], argv[3], bytes, elf); + + close(fd); + + return rename(tmp, argv[4]) ? 1 : 0; +} --- base-commit: e62b1a4731f9c458d65c2659d2f8bb58b93e6d6d change-id: 20260820-coredump-22fc731bde08 Best regards, -- Andrea Cervesato -- Mailing list info: https://lists.linux.it/listinfo/ltp