From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- tools/testing/selftests/fchmodat2/.gitignore | 2 + tools/testing/selftests/fchmodat2/Makefile | 15 ++ tools/testing/selftests/fchmodat2/fchmodat2_test.c | 200 +++++++++++++++++++++ 3 files changed, 217 insertions(+) create mode 100644 tools/testing/selftests/fchmodat2/.gitignore create mode 100644 tools/testing/selftests/fchmodat2/Makefile create mode 100644 tools/testing/selftests/fchmodat2/fchmodat2_test.c (limited to 'tools/testing/selftests/fchmodat2') diff --git a/tools/testing/selftests/fchmodat2/.gitignore b/tools/testing/selftests/fchmodat2/.gitignore new file mode 100644 index 000000000..82a4846cb --- /dev/null +++ b/tools/testing/selftests/fchmodat2/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +/*_test diff --git a/tools/testing/selftests/fchmodat2/Makefile b/tools/testing/selftests/fchmodat2/Makefile new file mode 100644 index 000000000..4373cea79 --- /dev/null +++ b/tools/testing/selftests/fchmodat2/Makefile @@ -0,0 +1,15 @@ +# SPDX-License-Identifier: GPL-2.0-or-later + +CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined $(KHDR_INCLUDES) + +# gcc requires -static-libasan in order to ensure that Address Sanitizer's +# library is the first one loaded. However, clang already statically links the +# Address Sanitizer if -fsanitize is specified. Therefore, simply omit +# -static-libasan for clang builds. +ifeq ($(LLVM),) + CFLAGS += -static-libasan +endif + +TEST_GEN_PROGS := fchmodat2_test + +include ../lib.mk diff --git a/tools/testing/selftests/fchmodat2/fchmodat2_test.c b/tools/testing/selftests/fchmodat2/fchmodat2_test.c new file mode 100644 index 000000000..8e1b6384b --- /dev/null +++ b/tools/testing/selftests/fchmodat2/fchmodat2_test.c @@ -0,0 +1,200 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#define _GNU_SOURCE +#include +#include +#include +#include +#include + +#include "kselftest.h" + +struct testdir { + char *dirname; + int dfd; +}; + +int sys_fchmodat2(int dfd, const char *filename, mode_t mode, int flags) +{ + int ret = syscall(__NR_fchmodat2, dfd, filename, mode, flags); + + return ret >= 0 ? ret : -errno; +} + +static void setup_testdir(struct testdir *testdir) +{ + int ret, dfd; + char dirname[] = "/tmp/ksft-fchmodat2.XXXXXX"; + + /* Make the top-level directory. */ + if (!mkdtemp(dirname)) + ksft_exit_fail_msg("%s: failed to create tmpdir\n", __func__); + + dfd = open(dirname, O_PATH | O_DIRECTORY); + if (dfd < 0) { + ksft_perror("failed to open tmpdir"); + goto err; + } + + ret = openat(dfd, "regfile", O_CREAT | O_WRONLY | O_TRUNC, 0644); + if (ret < 0) { + ksft_perror("failed to create file in tmpdir"); + goto err; + } + close(ret); + + ret = symlinkat("regfile", dfd, "symlink"); + if (ret < 0) { + ksft_perror("symlinkat() failed"); + goto err_regfile; + } + + testdir->dirname = strdup(dirname); + if (!testdir->dirname) { + ksft_perror("Out of memory"); + goto err_symlink; + } + testdir->dfd = dfd; + + return; + +err_symlink: + unlinkat(testdir->dfd, "symlink", 0); +err_regfile: + unlinkat(testdir->dfd, "regfile", 0); +err: + unlink(dirname); + ksft_exit_fail(); +} + +static void cleanup_testdir(struct testdir *testdir) +{ + unlinkat(testdir->dfd, "regfile", 0); + unlinkat(testdir->dfd, "symlink", 0); + rmdir(testdir->dirname); + free(testdir->dirname); +} + +int expect_mode(int dfd, const char *filename, mode_t expect_mode) +{ + struct stat st; + int ret = fstatat(dfd, filename, &st, AT_SYMLINK_NOFOLLOW); + + if (ret) { + ksft_perror("fstatat() failed\n"); + return 0; + } + + return (st.st_mode == expect_mode); +} + +void test_regfile(void) +{ + struct testdir testdir; + int ret; + + setup_testdir(&testdir); + + ret = sys_fchmodat2(testdir.dfd, "regfile", 0640, 0); + + if (ret < 0) { + ksft_perror("fchmodat2(noflag) failed"); + goto out; + } + + if (!expect_mode(testdir.dfd, "regfile", 0100640)) { + ksft_print_msg("%s: wrong file mode bits after fchmodat2\n", + __func__); + ret = 1; + goto out; + } + + ret = sys_fchmodat2(testdir.dfd, "regfile", 0600, AT_SYMLINK_NOFOLLOW); + + if (ret < 0) { + ksft_perror("fchmodat2(AT_SYMLINK_NOFOLLOW) failed"); + goto out; + } + + if (!expect_mode(testdir.dfd, "regfile", 0100600)) { + ksft_print_msg("%s: wrong file mode bits after fchmodat2 with nofollow\n", + __func__); + ret = 1; + } + +out: + ksft_test_result(ret == 0, "fchmodat2(regfile)\n"); + cleanup_testdir(&testdir); +} + +void test_symlink(void) +{ + struct testdir testdir; + int ret; + + setup_testdir(&testdir); + + ret = sys_fchmodat2(testdir.dfd, "symlink", 0640, 0); + + if (ret < 0) { + ksft_perror("fchmodat2(noflag) failed"); + goto err; + } + + if (!expect_mode(testdir.dfd, "regfile", 0100640)) { + ksft_print_msg("%s: wrong file mode bits after fchmodat2\n", + __func__); + goto err; + } + + if (!expect_mode(testdir.dfd, "symlink", 0120777)) { + ksft_print_msg("%s: wrong symlink mode bits after fchmodat2\n", + __func__); + goto err; + } + + ret = sys_fchmodat2(testdir.dfd, "symlink", 0600, AT_SYMLINK_NOFOLLOW); + + /* + * On certain filesystems (xfs or btrfs), chmod operation fails. So we + * first check the symlink target but if the operation fails we mark the + * test as skipped. + * + * https://sourceware.org/legacy-ml/libc-alpha/2020-02/msg00467.html + */ + if (ret == 0 && !expect_mode(testdir.dfd, "symlink", 0120600)) { + ksft_print_msg("%s: wrong symlink mode bits after fchmodat2 with nofollow\n", + __func__); + ret = 1; + goto err; + } + + if (!expect_mode(testdir.dfd, "regfile", 0100640)) { + ksft_print_msg("%s: wrong file mode bits after fchmodat2 with nofollow\n", + __func__); + } + + if (ret != 0) + ksft_test_result_skip("fchmodat2(symlink)\n"); + else + ksft_test_result_pass("fchmodat2(symlink)\n"); + cleanup_testdir(&testdir); + return; + +err: + ksft_test_result_fail("fchmodat2(symlink)\n"); + cleanup_testdir(&testdir); +} + +#define NUM_TESTS 2 + +int main(int argc, char **argv) +{ + ksft_print_header(); + ksft_set_plan(NUM_TESTS); + + test_regfile(); + test_symlink(); + + ksft_finished(); +} -- cgit v1.3.1