November 2025 - Linux-kselftest-mirror

[PATCH v4 00/35] sparc64: vdso: Switch to the generic vDSO library

by Thomas Weißschuh

The generic vDSO provides a lot common functionality shared between different architectures. SPARC is the last architecture not using it, preventing some necessary code cleanup. Make use of the generic infrastructure. Follow-up to and replacement for Arnd's SPARC vDSO removal patches: https://lore.kernel.org/lkml/20250707144726.4008707-1-arnd@kernel.org/ SPARC64 can not map .bss into userspace, so the vDSO datapages are switched over to be allocated dynamically. This requires changes to the s390 and random subsystem vDSO initialization as preparation. The random subsystem changes in turn require some cleanup of the vDSO headers to not end up as ugly #ifdef mess. Tested on a Niagara T4 and QEMU. This has a semantic conflict with my series "vdso: Reject absolute relocations during build" [0]. The last patch of this series expects all users of the generic vDSO library to use the vdsocheck tool. This is not the case (yet) for SPARC64. I do have the patches for the integration, the specifics will depend on which series is applied first. Based on v6.18-rc1. [0] https://lore.kernel.org/lkml/20250812-vdso-absolute-reloc-v4-0-61a8b615e5ec… Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> --- Changes in v4: - Rebase on v6.18-rc1. - Keep inclusion of asm/clocksource.h from linux/clocksource.h - Reword description of "s390/time: Set up vDSO datapage later" - Link to v3: https://lore.kernel.org/r/20250917-vdso-sparc64-generic-2-v3-0-3679b1bc8ee8… Changes in v3: - Allocate vDSO data pages dynamically (and lots of preparations for that) - Drop clock_getres() - Fix 32bit clock_gettime() syscall fallback - Link to v2: https://lore.kernel.org/r/20250815-vdso-sparc64-generic-2-v2-0-b5ff80672347… Changes in v2: - Rebase on v6.17-rc1 - Drop RFC state - Fix typo in commit message - Drop duplicate 'select GENERIC_TIME_VSYSCALL' - Merge "sparc64: time: Remove architecture-specific clocksource data" into the main conversion patch. It violated the check in __clocksource_register_scale() - Link to v1: https://lore.kernel.org/r/20250724-vdso-sparc64-generic-2-v1-0-e376a3bd24d1… --- Arnd Bergmann (1): clocksource: remove ARCH_CLOCKSOURCE_DATA Thomas Weißschuh (34): selftests: vDSO: vdso_test_correctness: Handle different tv_usec types arm64: vDSO: getrandom: Explicitly include asm/alternative.h arm64: vDSO: gettimeofday: Explicitly include vdso/clocksource.h arm64: vDSO: compat_gettimeofday: Add explicit includes ARM: vdso: gettimeofday: Add explicit includes powerpc/vdso/gettimeofday: Explicitly include vdso/time32.h powerpc/vdso: Explicitly include asm/cputable.h and asm/feature-fixups.h LoongArch: vDSO: Explicitly include asm/vdso/vdso.h MIPS: vdso: Add include guard to asm/vdso/vdso.h MIPS: vdso: Explicitly include asm/vdso/vdso.h random: vDSO: Add explicit includes vdso/gettimeofday: Add explicit includes vdso/helpers: Explicitly include vdso/processor.h vdso/datapage: Remove inclusion of gettimeofday.h vdso/datapage: Trim down unnecessary includes random: vDSO: trim vDSO includes random: vDSO: remove ifdeffery random: vDSO: split out datapage update into helper functions random: vDSO: only access vDSO datapage after random_init() s390/time: Set up vDSO datapage later vdso/datastore: Reduce scope of some variables in vvar_fault() vdso/datastore: Drop inclusion of linux/mmap_lock.h vdso/datastore: Map pages through struct page vdso/datastore: Allocate data pages dynamically sparc64: vdso: Link with -z noexecstack sparc64: vdso: Remove obsolete "fake section table" reservation sparc64: vdso: Replace code patching with runtime conditional sparc64: vdso: Move hardware counter read into header sparc64: vdso: Move syscall fallbacks into header sparc64: vdso: Introduce vdso/processor.h sparc64: vdso: Switch to the generic vDSO library sparc64: vdso2c: Drop sym_vvar_start handling sparc64: vdso2c: Remove symbol handling sparc64: vdso: Implement clock_gettime64() arch/arm/include/asm/vdso/gettimeofday.h | 2 + arch/arm64/include/asm/vdso/compat_gettimeofday.h | 3 + arch/arm64/include/asm/vdso/gettimeofday.h | 2 + arch/arm64/kernel/vdso/vgetrandom.c | 2 + arch/loongarch/kernel/process.c | 1 + arch/loongarch/kernel/vdso.c | 1 + arch/mips/include/asm/vdso/vdso.h | 5 + arch/mips/kernel/vdso.c | 1 + arch/powerpc/include/asm/vdso/gettimeofday.h | 1 + arch/powerpc/include/asm/vdso/processor.h | 3 + arch/s390/kernel/time.c | 4 +- arch/sparc/Kconfig | 3 +- arch/sparc/include/asm/clocksource.h | 9 - arch/sparc/include/asm/processor.h | 3 + arch/sparc/include/asm/processor_32.h | 2 - arch/sparc/include/asm/processor_64.h | 25 -- arch/sparc/include/asm/vdso.h | 2 - arch/sparc/include/asm/vdso/clocksource.h | 10 + arch/sparc/include/asm/vdso/gettimeofday.h | 184 ++++++++++ arch/sparc/include/asm/vdso/processor.h | 41 +++ arch/sparc/include/asm/vdso/vsyscall.h | 10 + arch/sparc/include/asm/vvar.h | 75 ---- arch/sparc/kernel/Makefile | 1 - arch/sparc/kernel/time_64.c | 6 +- arch/sparc/kernel/vdso.c | 69 ---- arch/sparc/vdso/Makefile | 8 +- arch/sparc/vdso/vclock_gettime.c | 380 ++------------------- arch/sparc/vdso/vdso-layout.lds.S | 26 +- arch/sparc/vdso/vdso.lds.S | 2 - arch/sparc/vdso/vdso2c.c | 24 -- arch/sparc/vdso/vdso2c.h | 45 +-- arch/sparc/vdso/vdso32/vdso32.lds.S | 4 +- arch/sparc/vdso/vma.c | 274 +-------------- drivers/char/random.c | 71 ++-- include/linux/clocksource.h | 6 +- include/linux/vdso_datastore.h | 6 + include/vdso/datapage.h | 23 +- include/vdso/helpers.h | 1 + init/main.c | 2 + kernel/time/Kconfig | 4 - lib/vdso/datastore.c | 73 ++-- lib/vdso/getrandom.c | 3 + lib/vdso/gettimeofday.c | 17 + .../testing/selftests/vDSO/vdso_test_correctness.c | 8 +- 44 files changed, 448 insertions(+), 994 deletions(-) --- base-commit: 28b1ac5ccd8d4900a8f53f0e6e84d517a7ccc71f change-id: 20250722-vdso-sparc64-generic-2-25f2e058e92c Best regards, -- Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>

3 weeks, 4 days

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[PATCH v3 0/2] Print map ID on successful creation

by Harshit Mogalapalli

Hi all, I have tried looking at an issue from the bpftool repository: https://github.com/libbpf/bpftool/issues/121 and this patch series tries to add that enhancement. Summary: Currently when a map creation is successful there is no message on the terminal, printing IDs on successful creation of maps can help notify the user and can be used in CI/CD. The first patch adds the logic for printing and the second patch adds a simple selftest for the same. Thank you very much. V1 --> V2: PATCH 1 updated [Thanks Yonghong for suggesting better way of error handling with a new label for close(fd); instead of calling multiple times] V2 --> V3: Thanks to Quentin. PATCH1: drop \n in p_err statement PATCH2: Remove messages in cases of successful ID printing. Also remove message with a "FAIL:" prefix to make it more consistent. Regards, Harshit Harshit Mogalapalli (2): bpftool: Print map ID upon creation and support JSON output selftests/bpf: Add test for bpftool map ID printing tools/bpf/bpftool/map.c | 21 +++++++++--- .../testing/selftests/bpf/test_bpftool_map.sh | 32 +++++++++++++++++++ 2 files changed, 49 insertions(+), 4 deletions(-) -- 2.50.1

3 weeks, 4 days

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[PATCH] selftests/seccomp: Fix pointer type mismatch in uprobe function declarations

by WangYuli

From: WangYuli <wangyl5933(a)chinaunicom.cn> Add __nocf_check attribute to probed_uretprobe on x86_64 to match probed_uprobe's function signature. [ Fix follow error with gcc-15: ] CC seccomp_bpf seccomp_bpf.c: In function ‘UPROBE_setup’: seccomp_bpf.c:5175:74: error: pointer type mismatch in conditional expression [-Wincompatible-pointer-types] 5175 | offset = get_uprobe_offset(variant->uretprobe ? probed_uretprobe : probed_uprobe); | ^ seccomp_bpf.c:5175:57: note: first expression has type ‘int (*)(void)’ 5175 | offset = get_uprobe_offset(variant->uretprobe ? probed_uretprobe : probed_uprobe); | ^~~~~~~~~~~~~~~~ seccomp_bpf.c:5175:76: note: second expression has type ‘int (__attribute__((nocf_check)) *)(void)’ 5175 | offset = get_uprobe_offset(variant->uretprobe ? probed_uretprobe : probed_uprobe); | ^~~~~~~~~~~~~ Signed-off-by: WangYuli <wangyl5933(a)chinaunicom.cn> Signed-off-by: WangYuli <wangyuli(a)aosc.io> --- tools/testing/selftests/seccomp/seccomp_bpf.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index 874f17763536..19df80d18619 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -5057,17 +5057,23 @@ __naked __nocf_check noinline int probed_uprobe(void) } #pragma GCC diagnostic pop -#else +int __nocf_check noinline probed_uretprobe(void) +{ + return 1; +} + +#else /* !__x86_64__ */ + noinline int probed_uprobe(void) { return 1; } -#endif noinline int probed_uretprobe(void) { return 1; } +#endif /* __x86_64__ */ static int parse_uint_from_file(const char *file, const char *fmt) { -- 2.51.0

3 weeks, 4 days

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[PATCH][next] selftests/bpf: Fix spelling mistake "clien" -> "client"

by Colin Ian King

There are spelling mistakes in ASSERT_OK_PTR messages. Fix them. Signed-off-by: Colin Ian King <coking(a)nvidia.com> --- tools/testing/selftests/bpf/prog_tests/test_tc_tunnel.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/test_tc_tunnel.c b/tools/testing/selftests/bpf/prog_tests/test_tc_tunnel.c index deea90aaefad..f74fb50e3f9f 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_tc_tunnel.c +++ b/tools/testing/selftests/bpf/prog_tests/test_tc_tunnel.c @@ -516,13 +516,13 @@ static void subtest_cleanup(struct subtest_cfg *cfg) struct nstoken *nstoken; nstoken = open_netns(CLIENT_NS); - if (ASSERT_OK_PTR(nstoken, "open clien ns")) { + if (ASSERT_OK_PTR(nstoken, "open client ns")) { SYS_NOFAIL("tc qdisc delete dev veth1 parent ffff:fff1"); SYS_NOFAIL("ip a flush veth1"); close_netns(nstoken); } nstoken = open_netns(SERVER_NS); - if (ASSERT_OK_PTR(nstoken, "open clien ns")) { + if (ASSERT_OK_PTR(nstoken, "open client ns")) { SYS_NOFAIL("tc qdisc delete dev veth2 parent ffff:fff1"); SYS_NOFAIL("ip a flush veth2"); if (!cfg->expect_kern_decap_failure) -- 2.51.0

3 weeks, 5 days

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[PATCH] selftest/alsa: correct grammar in conf_get_bool error string

by Zhang Chujun

The phrase "an bool" is grammatically incorrect; it should be "a bool". Signed-off-by: Zhang Chujun <zhangchujun(a)cmss.chinamobile.com> diff --git a/tools/testing/selftests/alsa/conf.c b/tools/testing/selftests/alsa/conf.c index 5b7c83fe87b3..317212078e36 100644 --- a/tools/testing/selftests/alsa/conf.c +++ b/tools/testing/selftests/alsa/conf.c @@ -448,7 +448,7 @@ int conf_get_bool(snd_config_t *root, const char *key1, const char *key2, int de ksft_exit_fail_msg("key '%s'.'%s' search error: %s\n", key1, key2, snd_strerror(ret)); ret = snd_config_get_bool(cfg); if (ret < 0) - ksft_exit_fail_msg("key '%s'.'%s' is not an bool\n", key1, key2); + ksft_exit_fail_msg("key '%s'.'%s' is not a bool\n", key1, key2); return !!ret; } -- 2.50.1.windows.1

3 weeks, 5 days

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[PATCH v2] selftests/user_events: Fix type cast for write_index packed member in perf_test

by Ankit Khushwaha

Accessing 'reg.write_index' directly triggers a -Waddress-of-packed-member warning due to potential unaligned pointer access: perf_test.c:239:38: warning: taking address of packed member 'write_index' of class or structure 'user_reg' may result in an unaligned pointer value [-Waddress-of-packed-member] 239 | ASSERT_NE(-1, write(self->data_fd, &reg.write_index, | ^~~~~~~~~~~~~~~ Since write(2) works with any alignment. Casting '&reg.write_index' explicitly to 'void *' to suppress this warning. Signed-off-by: Ankit Khushwaha <ankitkhushwaha.linux(a)gmail.com> --- Changelog: v2: - typecast '&reg.write_index' to 'void *' & remove use of memcpy as suggested by Andrew. v1: https://lore.kernel.org/linux-kselftest/20251027113439.36059-1-ankitkhushwa… --- tools/testing/selftests/user_events/perf_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/user_events/perf_test.c b/tools/testing/selftests/user_events/perf_test.c index 201459d8094d..cafec0e52eb3 100644 --- a/tools/testing/selftests/user_events/perf_test.c +++ b/tools/testing/selftests/user_events/perf_test.c @@ -236,7 +236,7 @@ TEST_F(user, perf_empty_events) { ASSERT_EQ(1 << reg.enable_bit, self->check); /* Ensure write shows up at correct offset */ - ASSERT_NE(-1, write(self->data_fd, &reg.write_index, + ASSERT_NE(-1, write(self->data_fd, (void *)&reg.write_index, sizeof(reg.write_index))); val = (void *)(((char *)perf_page) + perf_page->data_offset); ASSERT_EQ(PERF_RECORD_SAMPLE, *val); -- 2.51.0

3 weeks, 5 days

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/Re,

by Harry Schofield ESQ

Re: Good day, Hope you are well, my first email returned undelivered, please can I provide you with more information through this email?. Best regards, Harry Schofield

3 weeks, 5 days

1
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[PATCH 0/3] introduce VM_MAYBE_GUARD and make it sticky

by Lorenzo Stoakes

Currently, guard regions are not visible to users except through /proc/$pid/pagemap, with no explicit visibility at the VMA level. This makes the feature less useful, as it isn't entirely apparent which VMAs may have these entries present, especially when performing actions which walk through memory regions such as those performed by CRIU. This series addresses this issue by introducing the VM_MAYBE_GUARD flag which fulfils this role, updating the smaps logic to display an entry for these. The semantics of this flag are that a guard region MAY be present if set (we cannot be sure, as we can't efficiently track whether an MADV_GUARD_REMOVE finally removes all the guard regions in a VMA) - but if not set the VMA definitely does NOT have any guard regions present. It's problematic to establish this flag without further action, because that means that VMAs with guard regions in them become non-mergeable with adjacent VMAs for no especially good reason. To work around this, this series also introduces the concept of 'sticky' VMA flags - that is flags which: a. if set in one VMA and not in another still permit those VMAs to be merged (if otherwise compatible). b. When they are merged, the resultant VMA must have the flag set. The VMA logic is updated to propagate these flags correctly. Additionally, VM_MAYBE_GUARD being an explicit VMA flag allows us to solve an issue with file-backed guard regions - previously these established an anon_vma object for file-backed mappings solely to have vma_needs_copy() correctly propagate guard region mappings to child processes. We introduce a new flag alias VM_COPY_ON_FORK (which currently only specifies VM_MAYBE_GUARD) and update vma_needs_copy() to check explicitly for this flag and to copy page tables if it is present, which resolves this issue. Finally we introduce extensive VMA userland tests to assert that the sticky VMA logic behaves correctly as well as guard region self tests to assert that smaps visibility is correctly implemented. Lorenzo Stoakes (3): mm: introduce VM_MAYBE_GUARD and make visible for guard regions mm: implement sticky, copy on fork VMA flags selftests/mm/guard-regions: add smaps visibility test Documentation/filesystems/proc.rst | 1 + fs/proc/task_mmu.c | 1 + include/linux/mm.h | 33 ++++++ include/trace/events/mmflags.h | 1 + mm/madvise.c | 22 ++-- mm/memory.c | 3 + mm/vma.c | 22 ++-- tools/testing/selftests/mm/guard-regions.c | 120 +++++++++++++++++++++ tools/testing/selftests/mm/vm_util.c | 5 + tools/testing/selftests/mm/vm_util.h | 1 + tools/testing/vma/vma.c | 89 +++++++++++++-- tools/testing/vma/vma_internal.h | 33 ++++++ 12 files changed, 303 insertions(+), 28 deletions(-) -- 2.51.0

3 weeks, 5 days

5
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[bpf-next] selftests/bpf: refactor snprintf_btf test to use bpf_strncmp

by Hoyeon Lee

The netif_receive_skb BPF program used in snprintf_btf test still uses a custom __strncmp. This is unnecessary as the bpf_strncmp helper is available and provides the same functionality. This commit refactors the test to use the bpf_strncmp helper, removing the redundant custom implementation. Signed-off-by: Hoyeon Lee <hoyeon.lee(a)suse.com> --- .../selftests/bpf/progs/netif_receive_skb.c | 15 +-------------- 1 file changed, 1 insertion(+), 14 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/netif_receive_skb.c b/tools/testing/selftests/bpf/progs/netif_receive_skb.c index 9e067dcbf607..186b8c82b9e6 100644 --- a/tools/testing/selftests/bpf/progs/netif_receive_skb.c +++ b/tools/testing/selftests/bpf/progs/netif_receive_skb.c @@ -31,19 +31,6 @@ struct { __type(value, char[STRSIZE]); } strdata SEC(".maps"); -static int __strncmp(const void *m1, const void *m2, size_t len) -{ - const unsigned char *s1 = m1; - const unsigned char *s2 = m2; - int i, delta = 0; - - for (i = 0; i < len; i++) { - delta = s1[i] - s2[i]; - if (delta || s1[i] == 0 || s2[i] == 0) - break; - } - return delta; -} #if __has_builtin(__builtin_btf_type_id) #define TEST_BTF(_str, _type, _flags, _expected, ...) \ @@ -69,7 +56,7 @@ static int __strncmp(const void *m1, const void *m2, size_t len) &_ptr, sizeof(_ptr), _hflags); \ if (ret) \ break; \ - _cmp = __strncmp(_str, _expectedval, EXPECTED_STRSIZE); \ + _cmp = bpf_strncmp(_str, EXPECTED_STRSIZE, _expectedval); \ if (_cmp != 0) { \ bpf_printk("(%d) got %s", _cmp, _str); \ bpf_printk("(%d) expected %s", _cmp, \ -- 2.51.1

3 weeks, 5 days

3
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[PATCH net v4 0/3] mptcp: Fix conflicts between MPTCP and sockmap

by Jiayuan Chen

Overall, we encountered a warning [1] that can be triggered by running the selftest I provided. sockmap works by replacing sk_data_ready, recvmsg, sendmsg operations and implementing fast socket-level forwarding logic: 1. Users can obtain file descriptors through userspace socket()/accept() interfaces, then call BPF syscall to perform these replacements. 2. Users can also use the bpf_sock_hash_update helper (in sockops programs) to replace handlers when TCP connections enter ESTABLISHED state (BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB/BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB) However, when combined with MPTCP, an issue arises: MPTCP creates subflow sk's and performs TCP handshakes, so the BPF program obtains subflow sk's and may incorrectly replace their sk_prot. We need to reject such operations. In patch 1, we set psock_update_sk_prot to NULL in the subflow's custom sk_prot. Additionally, if the server's listening socket has MPTCP enabled and the client's TCP also uses MPTCP, we should allow the combination of subflow and sockmap. This is because the latest Golang programs have enabled MPTCP for listening sockets by default [2]. For programs already using sockmap, upgrading Golang should not cause sockmap functionality to fail. Patch 2 prevents the WARNING from occurring. [1] truncated warning: ------------[ cut here ]------------ WARNING: CPU: 1 PID: 388 at net/mptcp/protocol.c:68 \ mptcp_stream_accept+0x34c/0x380 Modules linked in: RIP: 0010:mptcp_stream_accept+0x34c/0x380 RSP: 0018:ffffc90000cf3cf8 EFLAGS: 00010202 PKRU: 55555554 Call Trace: <TASK> do_accept+0xeb/0x190 ? __x64_sys_pselect6+0x61/0x80 ? _raw_spin_unlock+0x12/0x30 ? alloc_fd+0x11e/0x190 __sys_accept4+0x8c/0x100 __x64_sys_accept+0x1f/0x30 x64_sys_call+0x202f/0x20f0 do_syscall_64+0x72/0x9a0 ? switch_fpu_return+0x60/0xf0 ? irqentry_exit_to_user_mode+0xdb/0x1e0 ? irqentry_exit+0x3f/0x50 ? clear_bhb_loop+0x50/0xa0 ? clear_bhb_loop+0x50/0xa0 ? clear_bhb_loop+0x50/0xa0 entry_SYSCALL_64_after_hwframe+0x76/0x7e </TASK> ---[ end trace 0000000000000000 ]--- [2]: https://go-review.googlesource.com/c/go/+/607715 --- v3 -> v4: Addressed questions from Matthieu and Paolo, explained sockmap's operational mechanism, and finalized the changes v2 -> v3: Adopted Jakub Sitnicki's suggestions - atomic retrieval of sk_family is required v1 -> v2: Had initial discussion with Matthieu on sockmap and MPTCP technical details v3: https://lore.kernel.org/bpf/20251023125450.105859-1-jiayuan.chen@linux.dev/ v2: https://lore.kernel.org/bpf/20251020060503.325369-1-jiayuan.chen@linux.dev/… v1: https://lore.kernel.org/mptcp/a0a2b87119a06c5ffaa51427a0964a05534fe6f1@linu… Jiayuan Chen (3): mptcp: disallow MPTCP subflows from sockmap net,mptcp: fix proto fallback detection with BPF selftests/bpf: Add mptcp test with sockmap net/mptcp/protocol.c | 6 +- net/mptcp/subflow.c | 8 + .../testing/selftests/bpf/prog_tests/mptcp.c | 150 ++++++++++++++++++ .../selftests/bpf/progs/mptcp_sockmap.c | 43 +++++ 4 files changed, 205 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/mptcp_sockmap.c base-commit: 89aec171d9d1ab168e43fcf9754b82e4c0aef9b9 -- 2.43.0

3 weeks, 5 days

2
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