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

[PATCH bpf-next 1/2] bpf: Add bpf_task_cwd_from_pid() kfunc

by Rong Tao

From: Rong Tao <rongtao(a)cestc.cn> It is a bit troublesome to get cwd based on pid in bpf program, such as bpftrace example [1]. This patch therefore adds a new bpf_task_cwd_from_pid() kfunc which allows BPF programs to get cwd from a pid. [1] https://github.com/bpftrace/bpftrace/issues/3314 Signed-off-by: Rong Tao <rongtao(a)cestc.cn> --- kernel/bpf/helpers.c | 45 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index b71e428ad936..0f32fbc997bb 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -24,6 +24,10 @@ #include <linux/bpf_mem_alloc.h> #include <linux/kasan.h> #include <linux/bpf_verifier.h> +#include <linux/fs.h> +#include <linux/fs_struct.h> +#include <linux/path.h> +#include <linux/string.h> #include "../../lib/kstrtox.h" @@ -2643,6 +2647,46 @@ __bpf_kfunc struct task_struct *bpf_task_from_vpid(s32 vpid) return p; } +/** + * bpf_task_cwd_from_pid - Get a task's absolute pathname of the current + * working directory from its pid. + * @pid: The pid of the task being looked up. + * @buf: The array pointed to by buf. + * @buf_len: buf length. + */ +__bpf_kfunc int bpf_task_cwd_from_pid(s32 pid, char *buf, u32 buf_len) +{ + struct path pwd; + char kpath[256], *path; + struct task_struct *task; + + if (!buf || buf_len == 0) + return -EINVAL; + + rcu_read_lock(); + task = pid_task(find_vpid(pid), PIDTYPE_PID); + if (!task) { + rcu_read_unlock(); + return -ESRCH; + } + task_lock(task); + if (!task->fs) { + task_unlock(task); + return -ENOENT; + } + get_fs_pwd(task->fs, &pwd); + task_unlock(task); + rcu_read_unlock(); + + path = d_path(&pwd, kpath, sizeof(kpath)); + path_put(&pwd); + if (IS_ERR(path)) + return PTR_ERR(path); + + strncpy(buf, path, buf_len); + return 0; +} + /** * bpf_dynptr_slice() - Obtain a read-only pointer to the dynptr data. * @p: The dynptr whose data slice to retrieve @@ -3314,6 +3358,7 @@ BTF_ID_FLAGS(func, bpf_task_get_cgroup1, KF_ACQUIRE | KF_RCU | KF_RET_NULL) #endif BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_task_from_vpid, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_task_cwd_from_pid, KF_RET_NULL) BTF_ID_FLAGS(func, bpf_throw) #ifdef CONFIG_BPF_EVENTS BTF_ID_FLAGS(func, bpf_send_signal_task, KF_TRUSTED_ARGS) -- 2.49.0

4 weeks, 1 day

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[PATCH AUTOSEL 6.12 69/93] selftests: harness: Mark functions without prototypes static

by Sasha Levin

From: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> [ Upstream commit c2bcc8e9577a35f9cf4707f8bb0b58bce30991aa ] With -Wmissing-prototypes the compiler will warn about non-static functions which don't have a prototype defined. As they are not used from a different compilation unit they don't need to be defined globally. Avoid the issue by marking the functions static. Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> Reviewed-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com> Acked-by: Shuah Khan <skhan(a)linuxfoundation.org> Link: https://lore.kernel.org/r/20250505-nolibc-kselftest-harness-v4-4-ee4dd52571… Signed-off-by: Thomas Weißschuh <linux(a)weissschuh.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- **YES** This commit should be backported to stable kernel trees. **Rationale:** 1. **Legitimate Build Fix**: The commit addresses a real compiler warning issue (`-Wmissing-prototypes`) that affects build cleanliness and code quality. Modern build systems increasingly use stricter warning flags, making this fix valuable for stable trees. 2. **Zero Functional Risk**: The changes are purely cosmetic from a runtime perspective. Adding `static` to functions that were already internal has no impact on functionality, memory layout, or behavior - it only affects compiler symbol visibility and warnings. 3. **Minimal and Contained**: The diff is extremely small (4 function signatures with `static` added) and isolated to the kselftest harness framework. There are no complex logic changes or cross-subsystem impacts. 4. **Testing Infrastructure Improvement**: While the kselftest framework isn't critical runtime code, it's important for kernel testing and validation. Improving build compliance in testing infrastructure benefits stable kernel maintenance. 5. **Standard Practice**: Compiler warning fixes of this nature (adding missing `static` keywords) are routinely backported to stable trees as they represent good coding practices without functional risk. 6. **Different from Similar Commits**: Unlike the referenced similar commits (all marked "NO") which involved feature additions, API changes, or structural modifications, this commit is purely a build compliance fix with no behavioral changes. The commit meets all stable tree criteria: it fixes an issue (compiler warnings), has minimal risk (no functional changes), and improves code quality without introducing new features or architectural changes. Tools like `kselftest_harness.h:241`, `kselftest_harness.h:290`, `kselftest_harness.h:970`, and `kselftest_harness.h:1188` are the specific locations where these low- risk improvements are made. tools/testing/selftests/kselftest_harness.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h index 666c9fde76da9..7c337b4fa054d 100644 --- a/tools/testing/selftests/kselftest_harness.h +++ b/tools/testing/selftests/kselftest_harness.h @@ -258,7 +258,7 @@ * A bare "return;" statement may be used to return early. */ #define FIXTURE_SETUP(fixture_name) \ - void fixture_name##_setup( \ + static void fixture_name##_setup( \ struct __test_metadata __attribute__((unused)) *_metadata, \ FIXTURE_DATA(fixture_name) __attribute__((unused)) *self, \ const FIXTURE_VARIANT(fixture_name) \ @@ -307,7 +307,7 @@ __FIXTURE_TEARDOWN(fixture_name) #define __FIXTURE_TEARDOWN(fixture_name) \ - void fixture_name##_teardown( \ + static void fixture_name##_teardown( \ struct __test_metadata __attribute__((unused)) *_metadata, \ FIXTURE_DATA(fixture_name) __attribute__((unused)) *self, \ const FIXTURE_VARIANT(fixture_name) \ @@ -987,7 +987,7 @@ static void __timeout_handler(int sig, siginfo_t *info, void *ucontext) kill(-(t->pid), SIGKILL); } -void __wait_for_test(struct __test_metadata *t) +static void __wait_for_test(struct __test_metadata *t) { struct sigaction action = { .sa_sigaction = __timeout_handler, @@ -1205,9 +1205,9 @@ static bool test_enabled(int argc, char **argv, return !has_positive; } -void __run_test(struct __fixture_metadata *f, - struct __fixture_variant_metadata *variant, - struct __test_metadata *t) +static void __run_test(struct __fixture_metadata *f, + struct __fixture_variant_metadata *variant, + struct __test_metadata *t) { struct __test_xfail *xfail; char test_name[1024]; -- 2.39.5

4 weeks, 1 day

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[PATCH AUTOSEL 6.14 076/102] selftests: harness: Mark functions without prototypes static

by Sasha Levin

From: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> [ Upstream commit c2bcc8e9577a35f9cf4707f8bb0b58bce30991aa ] With -Wmissing-prototypes the compiler will warn about non-static functions which don't have a prototype defined. As they are not used from a different compilation unit they don't need to be defined globally. Avoid the issue by marking the functions static. Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> Reviewed-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com> Acked-by: Shuah Khan <skhan(a)linuxfoundation.org> Link: https://lore.kernel.org/r/20250505-nolibc-kselftest-harness-v4-4-ee4dd52571… Signed-off-by: Thomas Weißschuh <linux(a)weissschuh.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- **YES** This commit should be backported to stable kernel trees. **Rationale:** 1. **Legitimate Build Fix**: The commit addresses a real compiler warning issue (`-Wmissing-prototypes`) that affects build cleanliness and code quality. Modern build systems increasingly use stricter warning flags, making this fix valuable for stable trees. 2. **Zero Functional Risk**: The changes are purely cosmetic from a runtime perspective. Adding `static` to functions that were already internal has no impact on functionality, memory layout, or behavior - it only affects compiler symbol visibility and warnings. 3. **Minimal and Contained**: The diff is extremely small (4 function signatures with `static` added) and isolated to the kselftest harness framework. There are no complex logic changes or cross-subsystem impacts. 4. **Testing Infrastructure Improvement**: While the kselftest framework isn't critical runtime code, it's important for kernel testing and validation. Improving build compliance in testing infrastructure benefits stable kernel maintenance. 5. **Standard Practice**: Compiler warning fixes of this nature (adding missing `static` keywords) are routinely backported to stable trees as they represent good coding practices without functional risk. 6. **Different from Similar Commits**: Unlike the referenced similar commits (all marked "NO") which involved feature additions, API changes, or structural modifications, this commit is purely a build compliance fix with no behavioral changes. The commit meets all stable tree criteria: it fixes an issue (compiler warnings), has minimal risk (no functional changes), and improves code quality without introducing new features or architectural changes. Tools like `kselftest_harness.h:241`, `kselftest_harness.h:290`, `kselftest_harness.h:970`, and `kselftest_harness.h:1188` are the specific locations where these low- risk improvements are made. tools/testing/selftests/kselftest_harness.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h index 666c9fde76da9..7c337b4fa054d 100644 --- a/tools/testing/selftests/kselftest_harness.h +++ b/tools/testing/selftests/kselftest_harness.h @@ -258,7 +258,7 @@ * A bare "return;" statement may be used to return early. */ #define FIXTURE_SETUP(fixture_name) \ - void fixture_name##_setup( \ + static void fixture_name##_setup( \ struct __test_metadata __attribute__((unused)) *_metadata, \ FIXTURE_DATA(fixture_name) __attribute__((unused)) *self, \ const FIXTURE_VARIANT(fixture_name) \ @@ -307,7 +307,7 @@ __FIXTURE_TEARDOWN(fixture_name) #define __FIXTURE_TEARDOWN(fixture_name) \ - void fixture_name##_teardown( \ + static void fixture_name##_teardown( \ struct __test_metadata __attribute__((unused)) *_metadata, \ FIXTURE_DATA(fixture_name) __attribute__((unused)) *self, \ const FIXTURE_VARIANT(fixture_name) \ @@ -987,7 +987,7 @@ static void __timeout_handler(int sig, siginfo_t *info, void *ucontext) kill(-(t->pid), SIGKILL); } -void __wait_for_test(struct __test_metadata *t) +static void __wait_for_test(struct __test_metadata *t) { struct sigaction action = { .sa_sigaction = __timeout_handler, @@ -1205,9 +1205,9 @@ static bool test_enabled(int argc, char **argv, return !has_positive; } -void __run_test(struct __fixture_metadata *f, - struct __fixture_variant_metadata *variant, - struct __test_metadata *t) +static void __run_test(struct __fixture_metadata *f, + struct __fixture_variant_metadata *variant, + struct __test_metadata *t) { struct __test_xfail *xfail; char test_name[1024]; -- 2.39.5

4 weeks, 1 day

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[PATCH AUTOSEL 6.15 082/110] selftests: harness: Mark functions without prototypes static

by Sasha Levin

From: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> [ Upstream commit c2bcc8e9577a35f9cf4707f8bb0b58bce30991aa ] With -Wmissing-prototypes the compiler will warn about non-static functions which don't have a prototype defined. As they are not used from a different compilation unit they don't need to be defined globally. Avoid the issue by marking the functions static. Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> Reviewed-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com> Acked-by: Shuah Khan <skhan(a)linuxfoundation.org> Link: https://lore.kernel.org/r/20250505-nolibc-kselftest-harness-v4-4-ee4dd52571… Signed-off-by: Thomas Weißschuh <linux(a)weissschuh.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- **YES** This commit should be backported to stable kernel trees. **Rationale:** 1. **Legitimate Build Fix**: The commit addresses a real compiler warning issue (`-Wmissing-prototypes`) that affects build cleanliness and code quality. Modern build systems increasingly use stricter warning flags, making this fix valuable for stable trees. 2. **Zero Functional Risk**: The changes are purely cosmetic from a runtime perspective. Adding `static` to functions that were already internal has no impact on functionality, memory layout, or behavior - it only affects compiler symbol visibility and warnings. 3. **Minimal and Contained**: The diff is extremely small (4 function signatures with `static` added) and isolated to the kselftest harness framework. There are no complex logic changes or cross-subsystem impacts. 4. **Testing Infrastructure Improvement**: While the kselftest framework isn't critical runtime code, it's important for kernel testing and validation. Improving build compliance in testing infrastructure benefits stable kernel maintenance. 5. **Standard Practice**: Compiler warning fixes of this nature (adding missing `static` keywords) are routinely backported to stable trees as they represent good coding practices without functional risk. 6. **Different from Similar Commits**: Unlike the referenced similar commits (all marked "NO") which involved feature additions, API changes, or structural modifications, this commit is purely a build compliance fix with no behavioral changes. The commit meets all stable tree criteria: it fixes an issue (compiler warnings), has minimal risk (no functional changes), and improves code quality without introducing new features or architectural changes. Tools like `kselftest_harness.h:241`, `kselftest_harness.h:290`, `kselftest_harness.h:970`, and `kselftest_harness.h:1188` are the specific locations where these low- risk improvements are made. tools/testing/selftests/kselftest_harness.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h index 666c9fde76da9..7c337b4fa054d 100644 --- a/tools/testing/selftests/kselftest_harness.h +++ b/tools/testing/selftests/kselftest_harness.h @@ -258,7 +258,7 @@ * A bare "return;" statement may be used to return early. */ #define FIXTURE_SETUP(fixture_name) \ - void fixture_name##_setup( \ + static void fixture_name##_setup( \ struct __test_metadata __attribute__((unused)) *_metadata, \ FIXTURE_DATA(fixture_name) __attribute__((unused)) *self, \ const FIXTURE_VARIANT(fixture_name) \ @@ -307,7 +307,7 @@ __FIXTURE_TEARDOWN(fixture_name) #define __FIXTURE_TEARDOWN(fixture_name) \ - void fixture_name##_teardown( \ + static void fixture_name##_teardown( \ struct __test_metadata __attribute__((unused)) *_metadata, \ FIXTURE_DATA(fixture_name) __attribute__((unused)) *self, \ const FIXTURE_VARIANT(fixture_name) \ @@ -987,7 +987,7 @@ static void __timeout_handler(int sig, siginfo_t *info, void *ucontext) kill(-(t->pid), SIGKILL); } -void __wait_for_test(struct __test_metadata *t) +static void __wait_for_test(struct __test_metadata *t) { struct sigaction action = { .sa_sigaction = __timeout_handler, @@ -1205,9 +1205,9 @@ static bool test_enabled(int argc, char **argv, return !has_positive; } -void __run_test(struct __fixture_metadata *f, - struct __fixture_variant_metadata *variant, - struct __test_metadata *t) +static void __run_test(struct __fixture_metadata *f, + struct __fixture_variant_metadata *variant, + struct __test_metadata *t) { struct __test_xfail *xfail; char test_name[1024]; -- 2.39.5

4 weeks, 1 day

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[PATCH] selftests/damon/_damon_sysfs: skip testcases if CONFIG_DAMON_SYSFS is disabled

by Enze Li

When CONFIG_DAMON_SYSFS is disabled, the selftests fail with the following outputs, not ok 2 selftests: damon: sysfs_update_schemes_tried_regions_wss_estimation.py # exit=1 not ok 3 selftests: damon: damos_quota.py # exit=1 not ok 4 selftests: damon: damos_quota_goal.py # exit=1 not ok 5 selftests: damon: damos_apply_interval.py # exit=1 not ok 6 selftests: damon: damos_tried_regions.py # exit=1 not ok 7 selftests: damon: damon_nr_regions.py # exit=1 not ok 11 selftests: damon: sysfs_update_schemes_tried_regions_hang.py # exit=1 The root cause of this issue is that all the testcases above do not check the sysfs interface of DAMON whether it exists or not. With this patch applied, all the testcases above now pass successfully. Signed-off-by: Enze Li <lienze(a)kylinos.cn> --- tools/testing/selftests/damon/_damon_sysfs.py | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/testing/selftests/damon/_damon_sysfs.py b/tools/testing/selftests/damon/_damon_sysfs.py index 6e136dc3df19..cab67addfb00 100644 --- a/tools/testing/selftests/damon/_damon_sysfs.py +++ b/tools/testing/selftests/damon/_damon_sysfs.py @@ -15,6 +15,10 @@ if sysfs_root is None: print('Seems sysfs not mounted?') exit(ksft_skip) +if not os.path.exists(sysfs_root): + print('Seems DAMON disabled?') + exit(ksft_skip) + def write_file(path, string): "Returns error string if failed, or None otherwise" string = '%s' % string base-commit: 0f70f5b08a47a3bc1a252e5f451a137cde7c98ce -- 2.43.0

1 month

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[PATCH net v2] selftests: net: build net/lib dependency in all target

by Bui Quang Minh

We have the logic to include net/lib automatically for net related selftests. However, currently, this logic is only in install target which means only `make install` will have net/lib included. This commit moves the logic to all target so that all `make`, `make run_tests` and `make install` will have net/lib included in net related selftests. Reviewed-by: Jakub Kicinski <kuba(a)kernel.org> Signed-off-by: Bui Quang Minh <minhquangbui99(a)gmail.com> --- Changes in v2: - Make the commit message clearer. tools/testing/selftests/Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 6aa11cd3db42..5b04d83ad9a1 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -205,7 +205,7 @@ export KHDR_INCLUDES all: @ret=1; \ - for TARGET in $(TARGETS); do \ + for TARGET in $(TARGETS) $(INSTALL_DEP_TARGETS); do \ BUILD_TARGET=$$BUILD/$$TARGET; \ mkdir $$BUILD_TARGET -p; \ $(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET \ @@ -270,7 +270,7 @@ ifdef INSTALL_PATH install -m 744 run_kselftest.sh $(INSTALL_PATH)/ rm -f $(TEST_LIST) @ret=1; \ - for TARGET in $(TARGETS) $(INSTALL_DEP_TARGETS); do \ + for TARGET in $(TARGETS); do \ BUILD_TARGET=$$BUILD/$$TARGET; \ $(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET install \ INSTALL_PATH=$(INSTALL_PATH)/$$TARGET \ -- 2.43.0

1 month

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[PATCH v1 1/1] selftests/x86: Add a test to detect infinite sigtrap handler loop

by Xin Li (Intel)

When FRED is enabled, if the Trap Flag (TF) is set without an external debugger attached, it can lead to an infinite loop in the SIGTRAP handler. To avoid this, the software event flag in the augmented SS must be cleared, ensuring that no single-step trap remains pending when ERETU completes. This test checks for that specific scenario—verifying whether the kernel correctly prevents an infinite SIGTRAP loop in this edge case. Signed-off-by: Xin Li (Intel) <xin(a)zytor.com> --- tools/testing/selftests/x86/Makefile | 2 +- .../selftests/x86/test_sigtrap_handler.c | 80 +++++++++++++++++++ 2 files changed, 81 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/test_sigtrap_handler.c diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index f703fcfe9f7c..c486fd88ebb1 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -12,7 +12,7 @@ CAN_BUILD_WITH_NOPIE := $(shell ./check_cc.sh "$(CC)" trivial_program.c -no-pie) TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt test_mremap_vdso \ check_initial_reg_state sigreturn iopl ioperm \ - test_vsyscall mov_ss_trap \ + test_vsyscall mov_ss_trap test_sigtrap_handler \ syscall_arg_fault fsgsbase_restore sigaltstack TARGETS_C_BOTHBITS += nx_stack TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \ diff --git a/tools/testing/selftests/x86/test_sigtrap_handler.c b/tools/testing/selftests/x86/test_sigtrap_handler.c new file mode 100644 index 000000000000..9c5c2cf0cf88 --- /dev/null +++ b/tools/testing/selftests/x86/test_sigtrap_handler.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2025 Intel Corporation + */ +#define _GNU_SOURCE + +#include <err.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ucontext.h> + +#ifdef __x86_64__ +# define REG_IP REG_RIP +#else +# define REG_IP REG_EIP +#endif + +static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), int flags) +{ + struct sigaction sa; + + memset(&sa, 0, sizeof(sa)); + sa.sa_sigaction = handler; + sa.sa_flags = SA_SIGINFO | flags; + sigemptyset(&sa.sa_mask); + + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); + + return; +} + +static unsigned int loop_count_on_same_ip; + +static void sigtrap(int sig, siginfo_t *info, void *ctx_void) +{ + ucontext_t *ctx = (ucontext_t *)ctx_void; + static unsigned long last_trap_ip; + + if (last_trap_ip == ctx->uc_mcontext.gregs[REG_IP]) { + printf("trapped on %016lx\n", last_trap_ip); + + if (++loop_count_on_same_ip > 10) { + printf("trap loop detected, test failed\n"); + exit(2); + } + + return; + } + + loop_count_on_same_ip = 0; + last_trap_ip = ctx->uc_mcontext.gregs[REG_IP]; + printf("trapped on %016lx\n", last_trap_ip); +} + +int main(int argc, char *argv[]) +{ + sethandler(SIGTRAP, sigtrap, 0); + + asm volatile( +#ifdef __x86_64__ + /* Avoid clobbering the redzone */ + "sub $128, %rsp\n\t" +#endif + "push $0x302\n\t" + "popf\n\t" + "nop\n\t" + "nop\n\t" + "push $0x202\n\t" + "popf\n\t" +#ifdef __x86_64__ + "add $128, %rsp\n\t" +#endif + ); + + printf("test passed\n"); + return 0; +} base-commit: 485d11d84a2452ac16466cc7ae041c93d38929bc -- 2.49.0

1 month

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[PATCH v4 00/23] iommufd: Add vIOMMU infrastructure (Part-4 HW QUEUE)

by Nicolin Chen

The vIOMMU object is designed to represent a slice of an IOMMU HW for its virtualization features shared with or passed to user space (a VM mostly) in a way of HW acceleration. This extended the HWPT-based design for more advanced virtualization feature. HW QUEUE introduced by this series as a part of the vIOMMU infrastructure represents a HW accelerated queue/buffer for VM to use exclusively, e.g. - NVIDIA's Virtual Command Queue - AMD vIOMMU's Command Buffer, Event Log Buffer, and PPR Log Buffer each of which allows its IOMMU HW to directly access a queue memory owned by a guest VM and allows a guest OS to control the HW queue direclty, to avoid VM Exit overheads to improve the performance. Introduce IOMMUFD_OBJ_HW_QUEUE and its pairing IOMMUFD_CMD_HW_QUEUE_ALLOC allowing VMM to forward the IOMMU-specific queue info, such as queue base address, size, and etc. Meanwhile, a guest-owned queue needs the guest kernel to control the queue by reading/writing its consumer and producer indexes, via MMIO acceses to the hardware MMIO registers. Introduce an mmap infrastructure for iommufd to support passing through a piece of MMIO region from the host physical address space to the guest physical address space. The mmap info (offset/ length) used by an mmap syscall must be pre-allocated and returned to the user space via an output driver-data during an IOMMUFD_CMD_HW_QUEUE_ALLOC call. Thus, it requires a driver-specific user data support in the vIOMMU allocation flow. As a real-world use case, this series implements a HW QUEUE support in the tegra241-cmdqv driver for VCMDQs on NVIDIA Grace CPU. In another word, it is also the Tegra CMDQV series Part-2 (user-space support), reworked from Previous RFCv1: https://lore.kernel.org/all/cover.1712978212.git.nicolinc@nvidia.com/ This enables the HW accelerated feature for NVIDIA Grace CPU. Compared to the standard SMMUv3 operating in the nested translation mode trapping CMDQ for TLBI and ATC_INV commands, this gives a huge performance improvement: 70% to 90% reductions of invalidation time were measured by various DMA unmap tests running in a guest OS. // Unmap latencies from "dma_map_benchmark -g @granule -t @threads", // by toggling "/sys/kernel/debug/iommu/tegra241_cmdqv/bypass_vcmdq" @granule | @threads | bypass_vcmdq=1 | bypass_vcmdq=0 4KB 1 35.7 us 5.3 us 16KB 1 41.8 us 6.8 us 64KB 1 68.9 us 9.9 us 128KB 1 109.0 us 12.6 us 256KB 1 187.1 us 18.0 us 4KB 2 96.9 us 6.8 us 16KB 2 97.8 us 7.5 us 64KB 2 151.5 us 10.7 us 128KB 2 257.8 us 12.7 us 256KB 2 443.0 us 17.9 us This is on Github: https://github.com/nicolinc/iommufd/commits/iommufd_hw_queue-v4 Paring QEMU branch for testing: https://github.com/nicolinc/qemu/commits/wip/for_iommufd_hw_queue-v4 Changelog v4 * Rebase on v6.15-rc5 * Add Reviewed-by from Vasant * Rename "vQUEUE" to "HW QUEUE" * Use "offset" and "length" for all mmap-related variables * [iommufd] Use u64 for guest PA * [iommufd] Fix typo in uAPI doc * [iommufd] Rename immap_id to offset * [iommufd] Drop the partial-size mmap support * [iommufd] Do not replace WARN_ON with WARN_ON_ONCE * [iommufd] Use "u64 base_addr" for queue base address * [iommufd] Use u64 base_pfn/num_pfns for immap structure * [iommufd] Correct the size passed in to mtree_alloc_range() * [iommufd] Add IOMMUFD_VIOMMU_FLAG_HW_QUEUE_READS_PA to viommu_ops v3 https://lore.kernel.org/all/cover.1746139811.git.nicolinc@nvidia.com/ * Add Reviewed-by from Baolu, Pranjal, and Alok * Revise kdocs, uAPI docs, and commit logs * Rename "vCMDQ" back to "vQUEUE" for AMD cases * [tegra] Add tegra241_vcmdq_hw_flush_timeout() * [tegra] Rename vsmmu_alloc to alloc_vintf_user * [tegra] Use writel for SID replacement registers * [tegra] Move mmap removal call to vsmmu_destroy op * [tegra] Fix revert in tegra241_vintf_alloc_lvcmdq_user() * [iommufd] Replace "& ~PAGE_MASK" with PAGE_ALIGNED() * [iommufd] Add an object-type "owner" to immap structure * [iommufd] Drop the ictx input in the new for-driver APIs * [iommufd] Add iommufd_vma_ops to keep track of mmap lifecycle * [iommufd] Add viommu-based iommufd_viommu_alloc/destroy_mmap helpers * [iommufd] Rename iommufd_ctx_alloc/free_mmap to _iommufd_alloc/destroy_mmap v2 https://lore.kernel.org/all/cover.1745646960.git.nicolinc@nvidia.com/ * Add Reviewed-by from Jason * [smmu] Fix vsmmu initial value * [smmu] Support impl for hw_info * [tegra] Rename "slot" to "vsid" * [tegra] Update kdocs and commit logs * [tegra] Map/unmap LVCMDQ dynamically * [tegra] Refcount the previous LVCMDQ * [tegra] Return -EEXIST if LVCMDQ exists * [tegra] Simplify VINTF cleanup routine * [tegra] Use vmid and s2_domain in vsmmu * [tegra] Rename "mmap_pgoff" to "immap_id" * [tegra] Add more addr and length validation * [iommufd] Add more narrative to mmap's kdoc * [iommufd] Add iommufd_struct_depend/undepend() * [iommufd] Rename vcmdq_free op to vcmdq_destroy * [iommufd] Fix bug in iommu_copy_struct_to_user() * [iommufd] Drop is_io from iommufd_ctx_alloc_mmap() * [iommufd] Test the queue memory for its contiguity * [iommufd] Return -ENXIO if address or length fails * [iommufd] Do not change @min_last in mock_viommu_alloc() * [iommufd] Generalize TEGRA241_VCMDQ data in core structure * [iommufd] Add selftest coverage for IOMMUFD_CMD_VCMDQ_ALLOC * [iommufd] Add iopt_pin_pages() to prevent queue memory from unmapping v1 https://lore.kernel.org/all/cover.1744353300.git.nicolinc@nvidia.com/ Thanks Nicolin Nicolin Chen (23): iommufd/viommu: Add driver-allocated vDEVICE support iommu: Pass in a driver-level user data structure to viommu_alloc op iommufd/viommu: Allow driver-specific user data for a vIOMMU object iommu: Add iommu_copy_struct_to_user helper iommufd/driver: Let iommufd_viommu_alloc helper save ictx to viommu->ictx iommufd/driver: Add iommufd_struct_destroy to revert iommufd_viommu_alloc iommufd/selftest: Support user_data in mock_viommu_alloc iommufd/selftest: Add covearge for viommu data iommufd: Abstract iopt_pin_pages and iopt_unpin_pages helpers iommufd/viommu: Introduce IOMMUFD_OBJ_HW_QUEUE and its related struct iommufd/viommu: Add IOMMUFD_CMD_HW_QUEUE_ALLOC ioctl iommufd/driver: Add iommufd_hw_queue_depend/undepend() helpers iommufd/selftest: Add coverage for IOMMUFD_CMD_HW_QUEUE_ALLOC iommufd: Add mmap interface iommufd/selftest: Add coverage for the new mmap interface Documentation: userspace-api: iommufd: Update HW QUEUE iommu/arm-smmu-v3-iommufd: Add vsmmu_alloc impl op iommu/arm-smmu-v3-iommufd: Support implementation-defined hw_info iommu/tegra241-cmdqv: Use request_threaded_irq iommu/tegra241-cmdqv: Simplify deinit flow in tegra241_cmdqv_remove_vintf() iommu/tegra241-cmdqv: Do not statically map LVCMDQs iommu/tegra241-cmdqv: Add user-space use support iommu/tegra241-cmdqv: Add IOMMU_VEVENTQ_TYPE_TEGRA241_CMDQV support drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 25 +- drivers/iommu/iommufd/io_pagetable.h | 8 + drivers/iommu/iommufd/iommufd_private.h | 28 +- drivers/iommu/iommufd/iommufd_test.h | 20 + include/linux/iommu.h | 43 +- include/linux/iommufd.h | 186 ++++++- include/uapi/linux/iommufd.h | 116 ++++- tools/testing/selftests/iommu/iommufd_utils.h | 52 +- .../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 43 +- .../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 490 +++++++++++++++++- drivers/iommu/iommufd/device.c | 117 +---- drivers/iommu/iommufd/driver.c | 94 ++++ drivers/iommu/iommufd/io_pagetable.c | 95 ++++ drivers/iommu/iommufd/main.c | 80 ++- drivers/iommu/iommufd/selftest.c | 133 ++++- drivers/iommu/iommufd/viommu.c | 121 ++++- tools/testing/selftests/iommu/iommufd.c | 97 +++- .../selftests/iommu/iommufd_fail_nth.c | 11 +- Documentation/userspace-api/iommufd.rst | 12 + 19 files changed, 1577 insertions(+), 194 deletions(-) base-commit: 92a09c47464d040866cf2b4cd052bc60555185fb -- 2.43.0

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[PATCH v1 0/6] VMM can handle guest SEA via KVM_EXIT_ARM_SEA

by Jiaqi Yan

Problem ======= When host APEI is unable to claim synchronous external abort (SEA) during stage-2 guest abort, today KVM directly injects an async SError into the VCPU then resumes it. The injected SError usually results in unpleasant guest kernel panic. One of the major situation of guest SEA is when VCPU consumes recoverable uncorrected memory error (UER), which is not uncommon at all in modern datacenter servers with large amounts of physical memory. Although SError and guest panic is sufficient to stop the propagation of corrupted memory there is still room to recover from memory UER in a more graceful manner. Proposed Solution ================= Alternatively KVM can replay the SEA to the faulting VCPU, via existing KVM_SET_VCPU_EVENTS API. If the memory poison consumption or the fault that cause SEA is not from guest kernel, the blast radius can be limited to the consuming or faulting guest userspace process, so the VM can keep running. In addition, instead of doing under the hood without involving userspace, there are benefits to redirect the SEA to VMM: - VM customers care about the disruptions caused by memory errors, and VMM usually has the responsibility to start the process of notifying the customers of memory error events in their VMs. For example some cloud provider emits a critical log in their observability UI [1], and provides playbook for customers on how to mitigate disruptions to their workloads. - VMM can protect future memory error consumption or faults by unmapping the poisoned pages from stage-2 page table with KVM userfault [2], which is more performant than splitting the memslot that contains the poisoned guest pages. - VMM can keep track SEA events in the VM. When VMM thinks the status on the host or the VM is bad enough, e.g. number of distinct SEAs exceeds a threshold, it can restart the VM on another healthy host. - Behavior parity with x86 architecture. When machine check exception (MCE) is caused by VCPU, kernel or KVM signals userspace SIGBUS to let VMM either recover from the MCE, or terminate itself with VM. The prior RFC proposes to implement SIGBUS on arm64 as well, but Marc preferred VCPU exit over signal [3]. However, implementation aside, returning SEA to VMM is on par with returning MCE to VMM. Once SEA is redirected to VMM, among other actions, VMM is encouraged to inject external aborts into the faulting VCPU, which is already supported by KVM on arm64, although not fully supported by KVM_SET_VCPU_EVENTS but complemented in this patchset. New UAPIs ========= This patchset introduces following userspace-visiable changes to empower VMM to control what happens next for guest SEA: - KVM_CAP_ARM_SEA_TO_USER. If userspace enables this new capability at VM creation, KVM will not inject SError while taking SEA, but VM exit to userspace. - KVM_EXIT_ARM_SEA. This is the VM exit reason VMM gets. The details about the SEA is provided in arm_sea as much as possible, including ESR value at EL2, if guest virtual and physical addresses (GPA and GVA) are available and the values if available. - KVM_CAP_ARM_INJECT_EXT_IABT. VMM today can inject external data abort to VCPU via KVM_SET_VCPU_EVENTS API. However, in case of instruction abort, VMM cannot inject it via KVM_SET_VCPU_EVENTS. KVM_CAP_ARM_INJECT_EXT_IABT is just a natural extend to KVM_CAP_ARM_INJECT_EXT_DABT that tells VMM KVM_SET_VCPU_EVENTS now supports external instruction abort. Patchset utilizes commit 26fbdf369227 ("KVM: arm64: Don't translate FAR if invalid/unsafe") from [4], available already in kvmarm/next. [4] makes KVM safely do address translation for HPFAR_EL2, including at the event of SEA, and indicate if HPFAR_EL2 is valid in NS bit. This patchset depends on [4] to tell userspace if GPA is valid and its value if valid. Patchset is based on commit 68ec8b4e84446 ("Merge branch kvm-arm64/pkvm-6.16 into kvmarm-master/next") [1] https://cloud.google.com/solutions/sap/docs/manage-host-errors [2] https://lpc.events/event/18/contributions/1757/attachments/1442/3073/LPC_%2… [3] https://lore.kernel.org/kvm/86pljbqqh0.wl-maz@kernel.org [4] https://lore.kernel.org/all/174369514508.3034362.13165690020799838042.b4-ty… Jiaqi Yan (5): KVM: arm64: VM exit to userspace to handle SEA KVM: arm64: Set FnV for VCPU when FAR_EL2 is invalid KVM: selftests: Test for KVM_EXIT_ARM_SEA and KVM_CAP_ARM_SEA_TO_USER KVM: selftests: Test for KVM_CAP_INJECT_EXT_IABT Documentation: kvm: new uAPI for handling SEA Raghavendra Rao Ananta (1): KVM: arm64: Allow userspace to inject external instruction aborts Documentation/virt/kvm/api.rst | 120 ++++++- arch/arm64/include/asm/kvm_emulate.h | 12 + arch/arm64/include/asm/kvm_host.h | 8 + arch/arm64/include/asm/kvm_ras.h | 21 +- arch/arm64/include/uapi/asm/kvm.h | 3 +- arch/arm64/kvm/Makefile | 3 +- arch/arm64/kvm/arm.c | 6 + arch/arm64/kvm/guest.c | 13 +- arch/arm64/kvm/inject_fault.c | 3 + arch/arm64/kvm/kvm_ras.c | 54 +++ arch/arm64/kvm/mmu.c | 12 +- include/uapi/linux/kvm.h | 12 + tools/arch/arm64/include/uapi/asm/kvm.h | 3 +- tools/testing/selftests/kvm/Makefile.kvm | 2 + .../testing/selftests/kvm/arm64/inject_iabt.c | 100 ++++++ .../testing/selftests/kvm/arm64/sea_to_user.c | 324 ++++++++++++++++++ tools/testing/selftests/kvm/lib/kvm_util.c | 1 + 17 files changed, 654 insertions(+), 43 deletions(-) create mode 100644 arch/arm64/kvm/kvm_ras.c create mode 100644 tools/testing/selftests/kvm/arm64/inject_iabt.c create mode 100644 tools/testing/selftests/kvm/arm64/sea_to_user.c -- 2.49.0.967.g6a0df3ecc3-goog

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[PATCH] kunit: configs: Enable CONFIG_INIT_STACK_ALL_PATTERN in all_tests

by Richard Fitzgerald

Enable CONFIG_INIT_STACK_ALL_PATTERN in all_tests.config. This helps to detect use of uninitialized local variables. This option found an uninitialized data bug in the cs_dsp test. Signed-off-by: Richard Fitzgerald <rf(a)opensource.cirrus.com> --- tools/testing/kunit/configs/all_tests.config | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/testing/kunit/configs/all_tests.config b/tools/testing/kunit/configs/all_tests.config index cdd9782f9646..4a60bb71fe72 100644 --- a/tools/testing/kunit/configs/all_tests.config +++ b/tools/testing/kunit/configs/all_tests.config @@ -10,6 +10,7 @@ CONFIG_KUNIT_EXAMPLE_TEST=y CONFIG_KUNIT_ALL_TESTS=y CONFIG_FORTIFY_SOURCE=y +CONFIG_INIT_STACK_ALL_PATTERN=y CONFIG_IIO=y -- 2.39.5

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