- Linux-kselftest-mirror - lists.linaro.org

[PATCH 0/2] Add test to distinguish between thread's signal mask and ucontext_t

by Dev Jain

This patch series is motivated by the following observation: Raise a signal, jump to signal handler. The ucontext_t structure dumped by kernel to userspace has a uc_sigmask field having the mask of blocked signals. If you run a fresh minimalistic program doing this, this field is empty, even if you block some signals while registering the handler with sigaction(). Here is what the man-pages have to say: sigaction(2): "sa_mask specifies a mask of signals which should be blocked (i.e., added to the signal mask of the thread in which the signal handler is invoked) during execution of the signal handler. In addition, the signal which triggered the handler will be blocked, unless the SA_NODEFER flag is used." signal(7): Under "Execution of signal handlers", (1.3) implies: "The thread's current signal mask is accessible via the ucontext_t object that is pointed to by the third argument of the signal handler." But, (1.4) states: "Any signals specified in act->sa_mask when registering the handler with sigprocmask(2) are added to the thread's signal mask. The signal being delivered is also added to the signal mask, unless SA_NODEFER was specified when registering the handler. These signals are thus blocked while the handler executes." There clearly is no distinction being made in the man pages between "Thread's signal mask" and ucontext_t; this logically should imply that a signal blocked by populating struct sigaction should be visible in ucontext_t. Here is what the kernel code does (for Aarch64): do_signal() -> handle_signal() -> sigmask_to_save(), which returns &current->blocked, is passed to setup_rt_frame() -> setup_sigframe() -> __copy_to_user(). Hence, &current->blocked is copied to ucontext_t exposed to userspace. Returning back to handle_signal(), signal_setup_done() -> signal_delivered() -> sigorsets() and set_current_blocked() are responsible for using information from struct ksignal ksig, which was populated through the sigaction() system call in kernel/signal.c: copy_from_user(&new_sa.sa, act, sizeof(new_sa.sa)), to update &current->blocked; hence, the set of blocked signals for the current thread is updated AFTER the kernel dumps ucontext_t to userspace. Assuming that the above is indeed the intended behaviour, because it semantically makes sense, since the signals blocked using sigaction() remain blocked only till the execution of the handler, and not in the context present before jumping to the handler (but nothing can be confirmed from the man-pages), the series introduces a test for mangling with uc_sigmask. I will send a separate series to fix the man-pages. The proposed selftest has been tested out on Aarch32, Aarch64 and x86_64. Dev Jain (2): selftests: Rename sigaltstack to generic signal selftests: Add a test mangling with uc_sigmask tools/testing/selftests/Makefile | 2 +- .../{sigaltstack => signal}/.gitignore | 3 +- .../{sigaltstack => signal}/Makefile | 3 +- .../current_stack_pointer.h | 0 .../selftests/signal/mangle_uc_sigmask.c | 141 ++++++++++++++++++ .../sas.c => signal/sigaltstack.c} | 0 6 files changed, 146 insertions(+), 3 deletions(-) rename tools/testing/selftests/{sigaltstack => signal}/.gitignore (57%) rename tools/testing/selftests/{sigaltstack => signal}/Makefile (53%) rename tools/testing/selftests/{sigaltstack => signal}/current_stack_pointer.h (100%) create mode 100644 tools/testing/selftests/signal/mangle_uc_sigmask.c rename tools/testing/selftests/{sigaltstack/sas.c => signal/sigaltstack.c} (100%) -- 2.34.1

1 year, 6 months

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Kernel Testing & Dependability Micro-Conference at LPC 2024

by Guillaume Tucker

Hello, We're pleased to announce the return of the Kernel Testing & Dependability Micro-Conference at Linux Plumbers 2024: https://lpc.events/event/18/contributions/1665/ You can already submit proposals by selecting the micro-conf in the Track drop-down list: https://lpc.events/login/?next=/event/18/abstracts/%23submit-abstract Please note that the deadline for submissions is *Sunday 16th June* The event description contains a list of suggested topics inherited from past editions. Is there anything in particular you would like to see discussed this year? Knowing people's interests helps with triaging proposals and making the micro-conf as relevant as possible. See you there! Thanks, Guillaume & Shuah & Sasha

1 year, 6 months

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[PATCH v1 0/2] selftests/mm: thuge-gen defines

by Edward Liaw

When compiling with Android bionic, the MAP_HUGE_* and SHM_HUGE_* macros are redefined because they are included from the uapi by sys/mman.h and sys/shm.h: INFO: From Compiling common/tools/testing/selftests/mm/thuge-gen.c: common/tools/testing/selftests/mm/thuge-gen.c:32:9: warning: 'MAP_HUGE_2MB' macro redefined [-Wmacro-redefined] 32 | #define MAP_HUGE_2MB (21 << MAP_HUGE_SHIFT) | ^ external/_main~_repo_rules~prebuilt_ndk/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/include/linux/mman.h:38:9: note: previous definition is here 38 | #define MAP_HUGE_2MB HUGETLB_FLAG_ENCODE_2MB | ^ common/tools/testing/selftests/mm/thuge-gen.c:33:9: warning: 'MAP_HUGE_1GB' macro redefined [-Wmacro-redefined] 33 | #define MAP_HUGE_1GB (30 << MAP_HUGE_SHIFT) | ^ external/_main~_repo_rules~prebuilt_ndk/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/include/linux/mman.h:44:9: note: previous definition is here This test should probably use the uapi definitions instead of redefining them. However, glibc gets struct redefinitions when including sys/shm.h and linux/shm.h together. So, add guards for the SHM_HUGE_* macros instead. Edward Liaw (2): selftests/mm: Include linux/mman.h selftests/mm: Guard defines from shm tools/testing/selftests/mm/thuge-gen.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) -- 2.45.1.467.gbab1589fc0-goog

1 year, 6 months

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[PATCH] kunit: add missing MODULE_DESCRIPTION() macros to core modules

by Jeff Johnson

make allmodconfig && make W=1 C=1 reports in lib/kunit: WARNING: modpost: missing MODULE_DESCRIPTION() in lib/kunit/kunit.o WARNING: modpost: missing MODULE_DESCRIPTION() in lib/kunit/kunit-test.o WARNING: modpost: missing MODULE_DESCRIPTION() in lib/kunit/kunit-example-test.o Add the missing invocations of the MODULE_DESCRIPTION() macro. Signed-off-by: Jeff Johnson <quic_jjohnson(a)quicinc.com> --- lib/kunit/kunit-example-test.c | 1 + lib/kunit/kunit-test.c | 1 + lib/kunit/test.c | 1 + 3 files changed, 3 insertions(+) diff --git a/lib/kunit/kunit-example-test.c b/lib/kunit/kunit-example-test.c index 798924f7cc86..3056d6bc705d 100644 --- a/lib/kunit/kunit-example-test.c +++ b/lib/kunit/kunit-example-test.c @@ -374,4 +374,5 @@ static struct kunit_suite example_init_test_suite = { */ kunit_test_init_section_suites(&example_init_test_suite); +MODULE_DESCRIPTION("Example KUnit test suite"); MODULE_LICENSE("GPL v2"); diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c index e3412e0ca399..37e02be1e710 100644 --- a/lib/kunit/kunit-test.c +++ b/lib/kunit/kunit-test.c @@ -871,4 +871,5 @@ kunit_test_suites(&kunit_try_catch_test_suite, &kunit_resource_test_suite, &kunit_current_test_suite, &kunit_device_test_suite, &kunit_fault_test_suite); +MODULE_DESCRIPTION("KUnit test for core test infrastructure"); MODULE_LICENSE("GPL v2"); diff --git a/lib/kunit/test.c b/lib/kunit/test.c index b8514dbb337c..e8b1b52a19ab 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -938,4 +938,5 @@ static void __exit kunit_exit(void) } module_exit(kunit_exit); +MODULE_DESCRIPTION("Base unit test (KUnit) API"); MODULE_LICENSE("GPL v2"); --- base-commit: b050496579632f86ee1ef7e7501906db579f3457 change-id: 20240601-md-lib-kunit-framework-ed2d8b6f5e76

1 year, 6 months

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[PATCH] list: test: add the missing MODULE_DESCRIPTION() macro

by Jeff Johnson

make allmodconfig && make W=1 C=1 reports: WARNING: modpost: missing MODULE_DESCRIPTION() in lib/list-test.o Add the missing invocation of the MODULE_DESCRIPTION() macro. Signed-off-by: Jeff Johnson <quic_jjohnson(a)quicinc.com> --- lib/list-test.c | 1 + 1 file changed, 1 insertion(+) diff --git a/lib/list-test.c b/lib/list-test.c index 0cc27de9cec8..e87b9941206a 100644 --- a/lib/list-test.c +++ b/lib/list-test.c @@ -1499,4 +1499,5 @@ static struct kunit_suite klist_test_module = { kunit_test_suites(&list_test_module, &hlist_test_module, &klist_test_module); +MODULE_DESCRIPTION("KUnit test for the Kernel Linked-list structures"); MODULE_LICENSE("GPL v2"); --- base-commit: b050496579632f86ee1ef7e7501906db579f3457 change-id: 20240531-md-lib-list-test-679830e738cc

1 year, 6 months

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[PATCH bpf-next 0/5] use network helpers, part 6

by Geliang Tang

From: Geliang Tang <tanggeliang(a)kylinos.cn> For moving dctcp test dedicated code out of do_test() into test_dctcp(). This patchset adds a new helper start_test() in bpf_tcp_ca.c to refactor do_test(). Address Martin's comments for the previous series. Geliang Tang (5): selftests/bpf: Use connect_to_fd_opts in do_test in bpf_tcp_ca selftests/bpf: Add start_test helper in bpf_tcp_ca selftests/bpf: Use start_test in test_dctcp_fallback in bpf_tcp_ca selftests/bpf: Use start_test in test_dctcp in bpf_tcp_ca selftests/bpf: Drop useless arguments of do_test in bpf_tcp_ca .../selftests/bpf/prog_tests/bpf_tcp_ca.c | 140 +++++++++++------- 1 file changed, 85 insertions(+), 55 deletions(-) -- 2.43.0

1 year, 6 months

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[PATCH] selftests/mm: use volatile keyword to not optimize mmap read variable

by Pankaj Raghav (Samsung)

From: Pankaj Raghav <p.raghav(a)samsung.com> create_pagecache_thp_and_fd() in split_huge_page_test.c used the variable dummy to perform mmap read. However, this test was skipped even on XFS which has large folio support. The issue was compiler (gcc 13.2.0) was optimizing out the dummy variable, therefore, not creating huge page in the page cache. Add volatile keyword to force compiler not to optimize out the loop where we read from the mmaped addr. Signed-off-by: Pankaj Raghav <p.raghav(a)samsung.com> --- tools/testing/selftests/mm/split_huge_page_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c index d3c7f5fb3e7b..c573a58f80ab 100644 --- a/tools/testing/selftests/mm/split_huge_page_test.c +++ b/tools/testing/selftests/mm/split_huge_page_test.c @@ -300,7 +300,7 @@ int create_pagecache_thp_and_fd(const char *testfile, size_t fd_size, int *fd, char **addr) { size_t i; - int __attribute__((unused)) dummy = 0; + volatile int __attribute__((unused)) dummy = 0; srand(time(NULL)); base-commit: d97496ca23a2d4ee80b7302849404859d9058bcd -- 2.44.1

1 year, 6 months

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[PATCH v2] selftests/mm: use global variable to not optimize mmap read variable

by Pankaj Raghav (Samsung)

From: Pankaj Raghav <p.raghav(a)samsung.com> create_pagecache_thp_and_fd() in split_huge_page_test.c used the variable dummy to perform mmap read. However, this test was skipped even on XFS which has large folio support. The issue was compiler (gcc 13.2.0) was optimizing out the dummy variable, therefore, not creating huge page in the page cache. Make it as a global variable to force the compiler not to optimize out the loop where we read from the mmaped addr. Signed-off-by: Pankaj Raghav <p.raghav(a)samsung.com> --- Changes since v1: - Make the dummy variable as a global variable(willy). tools/testing/selftests/mm/split_huge_page_test.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c index d3c7f5fb3e7b..c4857de2c042 100644 --- a/tools/testing/selftests/mm/split_huge_page_test.c +++ b/tools/testing/selftests/mm/split_huge_page_test.c @@ -23,6 +23,11 @@ uint64_t pagesize; unsigned int pageshift; uint64_t pmd_pagesize; +/* + * Used by create_pagecache_thp_and_fd() to do mmap read. + * Made it as global to avoid compiler optimizing out the variable. + */ +int dummy; #define SPLIT_DEBUGFS "/sys/kernel/debug/split_huge_pages" #define SMAP_PATH "/proc/self/smaps" @@ -300,7 +305,6 @@ int create_pagecache_thp_and_fd(const char *testfile, size_t fd_size, int *fd, char **addr) { size_t i; - int __attribute__((unused)) dummy = 0; srand(time(NULL)); base-commit: d97496ca23a2d4ee80b7302849404859d9058bcd -- 2.44.1

1 year, 6 months

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[PATCH net 0/3] selftests: net: lib: small fixes

by Matthieu Baerts (NGI0)

While looking at using 'lib.sh' for the MPTCP selftests [1], we found some small issues with 'lib.sh'. Here they are: - Patch 1: fix 'errexit' (set -e) support with busywait. 'errexit' is supported in some functions, not all. A fix for v6.8+. - Patch 2: avoid confusing error messages linked to the cleaning part when the netns setup fails. A fix for v6.8+. - Patch 3: set a variable as local to avoid accidentally changing the value of a another one with the same name on the caller side. A fix for v6.10-rc1+. Link: https://lore.kernel.org/mptcp/5f4615c3-0621-43c5-ad25-55747a4350ce@kernel.o… [1] Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org> --- Matthieu Baerts (NGI0) (3): selftests: net: lib: support errexit with busywait selftests: net: lib: avoid error removing empty netns name selftests: net: lib: set 'i' as local tools/testing/selftests/net/lib.sh | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) --- base-commit: a535d59432370343058755100ee75ab03c0e3f91 change-id: 20240605-upstream-net-20240605-selftests-net-lib-fixes-7a90a1a8d9d2 Best regards, -- Matthieu Baerts (NGI0) <matttbe(a)kernel.org>

1 year, 6 months

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[PATCH v2] selftest: mm: Test if hugepage does not get leaked during __bio_release_pages()

by Donet Tom

Commit 1b151e2435fc ("block: Remove special-casing of compound pages") caused a change in behaviour when releasing the pages if the buffer does not start at the beginning of the page. This was because the calculation of the number of pages to release was incorrect. This was fixed by commit 38b43539d64b ("block: Fix page refcounts for unaligned buffers in __bio_release_pages()"). We pin the user buffer during direct I/O writes. If this buffer is a hugepage, bio_release_page() will unpin it and decrement all references and pin counts at ->bi_end_io. However, if any references to the hugepage remain post-I/O, the hugepage will not be freed upon unmap, leading to a memory leak. This patch verifies that a hugepage, used as a user buffer for DIO operations, is correctly freed upon unmapping, regardless of whether the offsets are aligned or unaligned w.r.t page boundary. Test Result Fail Scenario (Without the fix) -------------------------------------------------------- []# ./hugetlb_dio TAP version 13 1..4 No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 1 : Huge pages freed successfully ! No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 2 : Huge pages freed successfully ! No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 3 : Huge pages freed successfully ! No. Free pages before allocation : 7 No. Free pages after munmap : 6 not ok 4 : Huge pages not freed! Totals: pass:3 fail:1 xfail:0 xpass:0 skip:0 error:0 Test Result PASS Scenario (With the fix) --------------------------------------------------------- []#./hugetlb_dio TAP version 13 1..4 No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 1 : Huge pages freed successfully ! No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 2 : Huge pages freed successfully ! No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 3 : Huge pages freed successfully ! No. Free pages before allocation : 7 No. Free pages after munmap : 7 ok 4 : Huge pages freed successfully ! Totals: pass:4 fail:0 xfail:0 xpass:0 skip:0 error:0 V2: - Addressed all review commets from Muhammad Usama Anjum V1: https://lore.kernel.org/all/20240523063905.3173-1-donettom@linux.ibm.com/#t Signed-off-by: Donet Tom <donettom(a)linux.ibm.com> Co-developed-by: Ritesh Harjani (IBM) <ritesh.list(a)gmail.com> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list(a)gmail.com> --- tools/testing/selftests/mm/Makefile | 1 + tools/testing/selftests/mm/hugetlb_dio.c | 118 +++++++++++++++++++++++ 2 files changed, 119 insertions(+) create mode 100644 tools/testing/selftests/mm/hugetlb_dio.c diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile index 3b49bc3d0a3b..a1748a4c7df1 100644 --- a/tools/testing/selftests/mm/Makefile +++ b/tools/testing/selftests/mm/Makefile @@ -73,6 +73,7 @@ TEST_GEN_FILES += ksm_functional_tests TEST_GEN_FILES += mdwe_test TEST_GEN_FILES += hugetlb_fault_after_madv TEST_GEN_FILES += hugetlb_madv_vs_map +TEST_GEN_FILES += hugetlb_dio ifneq ($(ARCH),arm64) TEST_GEN_FILES += soft-dirty diff --git a/tools/testing/selftests/mm/hugetlb_dio.c b/tools/testing/selftests/mm/hugetlb_dio.c new file mode 100644 index 000000000000..e4f4924179c8 --- /dev/null +++ b/tools/testing/selftests/mm/hugetlb_dio.c @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This program tests for hugepage leaks after DIO writes to a file using a + * hugepage as the user buffer. During DIO, the user buffer is pinned and + * should be properly unpinned upon completion. This patch verifies that the + * kernel correctly unpins the buffer at DIO completion for both aligned and + * unaligned user buffer offsets (w.r.t page boundary), ensuring the hugepage + * is freed upon unmapping. + */ + +#define _GNU_SOURCE +#include <stdio.h> +#include <sys/stat.h> +#include <stdlib.h> +#include <fcntl.h> +#include <stdint.h> +#include <unistd.h> +#include <string.h> +#include <sys/mman.h> +#include "vm_util.h" +#include "../kselftest.h" + +void run_dio_using_hugetlb(unsigned int start_off, unsigned int end_off) +{ + int fd; + char *buffer = NULL; + char *orig_buffer = NULL; + size_t h_pagesize = 0; + size_t writesize; + int free_hpage_b = 0; + int free_hpage_a = 0; + const int mmap_flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB; + const int mmap_prot = PROT_READ | PROT_WRITE; + + writesize = end_off - start_off; + + /* Get the default huge page size */ + h_pagesize = default_huge_page_size(); + if (!h_pagesize) + ksft_exit_fail_msg("Unable to determine huge page size\n"); + + /* Open the file to DIO */ + fd = open("/tmp", O_TMPFILE | O_RDWR | O_DIRECT); + if (fd < 0) + ksft_exit_fail_perror("Error opening file\n"); + + /* Get the free huge pages before allocation */ + free_hpage_b = get_free_hugepages(); + if (free_hpage_b == 0) { + close(fd); + ksft_exit_skip("No free hugepage, exiting!\n"); + } + + /* Allocate a hugetlb page */ + orig_buffer = mmap(NULL, h_pagesize, mmap_prot, mmap_flags, -1, 0); + if (orig_buffer == MAP_FAILED) { + close(fd); + ksft_exit_fail_perror("Error mapping memory\n"); + } + buffer = orig_buffer; + buffer += start_off; + + memset(buffer, 'A', writesize); + + /* Write the buffer to the file */ + if (write(fd, buffer, writesize) != (writesize)) { + munmap(orig_buffer, h_pagesize); + close(fd); + ksft_exit_fail_perror("Error writing to file\n"); + } + + /* unmap the huge page */ + munmap(orig_buffer, h_pagesize); + close(fd); + + /* Get the free huge pages after unmap*/ + free_hpage_a = get_free_hugepages(); + + /* + * If the no. of free hugepages before allocation and after unmap does + * not match - that means there could still be a page which is pinned. + */ + if (free_hpage_a != free_hpage_b) { + ksft_print_msg("No. Free pages before allocation : %d\n", free_hpage_b); + ksft_print_msg("No. Free pages after munmap : %d\n", free_hpage_a); + ksft_test_result_fail(": Huge pages not freed!\n"); + } else { + ksft_print_msg("No. Free pages before allocation : %d\n", free_hpage_b); + ksft_print_msg("No. Free pages after munmap : %d\n", free_hpage_a); + ksft_test_result_pass(": Huge pages freed successfully !\n"); + } +} + +int main(void) +{ + size_t pagesize = 0; + + ksft_print_header(); + ksft_set_plan(4); + + /* Get base page size */ + pagesize = psize(); + + /* start and end is aligned to pagesize */ + run_dio_using_hugetlb(0, (pagesize * 3)); + + /* start is aligned but end is not aligned */ + run_dio_using_hugetlb(0, (pagesize * 3) - (pagesize / 2)); + + /* start is unaligned and end is aligned */ + run_dio_using_hugetlb(pagesize / 2, (pagesize * 3)); + + /* both start and end are unaligned */ + run_dio_using_hugetlb(pagesize / 2, (pagesize * 3) + (pagesize / 2)); + + ksft_finished(); +} + -- 2.43.0

1 year, 6 months

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