From 22098763a10d9c1340827fcf6edab66f153b27f0 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 13 Sep 2026 12:27:00 -0700 Subject: Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Don't destroy user event fields when removal fails User event fields are destroyed before the event is removed from visibility. But that can fail leaving the still visible event with no fields. Move the destroying of the fields to after the event is successfully removed from visibility. - Initialize function graph state is fork before calling copy_exec_state() For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, ftrace_graph_exit_task() will free the tasks ret_stack pointer. Since that pointer is still using the parent's ret_stack, it mistakenly frees the parent's pointer too. Call ftrace_graph_init() on the task first which will NULL out the new tasks's ret_stack and if the copy fails, it will not free anything. - Remove FGRAPH_MAX_INDEX The macro FGRAPH_MAX_INDEX was added but never used. Remove it. - Save ent_size in function graph printing of nested functions The function graph tracer needs to look at the next event to see if the next event is the return of the current function entry. If it is, it prints a single line: ktime_get(); Otherwise it prints it like a nested function: tick_nohz_irq_exit() { ktime_get(); kcpustat_irq_exit(); } In order to look at the next event, it must save the current event so that it has the information to print from it. It saves the event in the iterator descriptor called "ent". What it doesn't save is the ent_size of the event which is now used to know if the function graph arguments are to be printed. The peek doesn't save the size so the size used happens to be that of the size of the last event that was seen. Save the entry event size in the iterator descriptor so that the correct size is used. - Fix several errors with freeing data in the histogram code The histogram code had a lot of leaked or or incorrect accounting when failures happen. Correct them. - Fix histogram regression of .percent and .graph modifiers Up until 6.3 histogram values could have "percent" or "graph" modifiers that changed how they were printed. But a change that added restricting histograms values from being strings, stack traces and other modifiers inadvertently prevented them from using the percent and graph modifiers, which were legal use cases for values. Put back the percent and graph modifiers. - Fix various typos in the comments - Set the trace_clock before initializing a histogram with clock argument The histogram API allows the user to specific which trace clock to use via a "clock=" string. The histogram is set up first before the clock is checked. If the passed in clock is not valid, it exits without fully fixing up the histogram leaving it on the list and a use-after-free can trigger. Update the clock argument first and if it fails then exit gracefully before the histogram trigger is placed on any lists. - Restore :mod: trailer after parsing in ftrace_set_clr_event The function ftrace_set_clr_event() modifies the parse string and needs to put it back to what was passed in. It searches for ":mod:" via a strsep() but fails to put back the first ':' in the string. Add back the ':' in the passed in string. - Take trace_array reference when opening a tracer options file The options files are dynamically created and some tracers add their own options. When a tracer adds their own list of options, the trace_array holding them has an array to hold the list of options for each tracer. This array increases in size via a krealloc(), and the new entry gets a newly allocated array to hold the options of the new tracer being added. The element in each entry of the tracer's option array holds a pointer back to the trace_array, a pointer to the tracer it is associated to, a pointer to the flags of the option. The issue is that these arrays are freed when the trace_array is freed when its instance it represents is removed from the instances directory. There's a race that an open of one of these options files can happen when the instance is being removed. Add a new helper function to be called by the open function of the options file to iterate all existing trace_arrays under a lock and find the one that has the given option element in one of it's tracer arrays. If found, then update the associated trace_array's reference counter to keep it from being freed. If not found, have the open call return -ENODEV. - Disable interrupts when acquiring the lock in rb_wake_up_waiters() The function rb_wake_up_waiters() assumes it will be called in interrupt context and does not disable irqs when taking cpu_buffer->reader_lock, which can be called in hard interrupt context. The issue is in PREEMPT_RT, this function is called in thread context leaving this lock open to a deadlock. Take the lock with interrupts disabled. - Use rcu_assign_pointer() for tmp_ops filter hash The tmp_ops used in update_ftrace_direct_mod() assigns its filter_hash field directly, but that field is annotated as __rcu and sparse complains. Assign it with rcu_assign_pointer() - Fix use-after-free in enable_trigger_private_data_free() The trace_event_call is accessed through the event_trigger_data's trace_event_file pointer to put the trace_event_call on freeing. The issue is that the trace_event_file data may have been freed already causing a use-after-free. Add a field to the event_trigger_data that points directly to the trace_event_call so that it can decrement its reference directly without needing to go through the trace_event_file. - Fix accounting of buffer data remote headers trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the number of pages is needed for the asked for size as it doesn't take into account the meta data on each page. Add a helper function to do the calculation properly and use that in these functions. - Catch nr_page_va overflow in ring_buffer_desc sizing The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. - Do not resize the subbuf order if any per_cpu buffer is disabled The mmapping of ring buffers disables resizing the subbuffers, but it is done per-cpu whereas the subbuf size change is done for all the per_cpu buffers under the buffer->mutex. It could change the size of some while the mapping is happening on others. Have the resize of the subbuf order check all the per_cpu buffers under the lock to see if any of them is disabled before starting and causing an inconsistency between buffers that are being mapped. * tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits) ring-buffer: Check resize_disabled before publishing the new subbuf order tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing tracing/remotes: Account for ring buffer page header in size calculation tracing: Don't dereference trace_event_file in deferred trigger free ftrace: Use rcu_assign_pointer() for tmp_ops filter hash ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters() tracing: Take trace_array reference when opening a tracer options file tracing: Fix ring_buffer_read_page_size() kernel-doc tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event() tracing: Fix memory corruption from a "STACKTRACE" histogram key tracing: Fix memory corruption from the histogram stacktrace modifier tracing: Undo the registration when enabling the histogram trigger fails tracing: Take the reference before publishing the named histogram trigger tracing: Set the trace clock before registering the histogram trigger tracing: Fix typo "preceeded" in comment tracing: Fix typo "availabe" in comment tracing: Let histogram values keep the percent and graph modifiers tracing: Keep the entry count when the histogram stats allocation fails tracing: Free histogram the field rejected for a bad modifier tracing: Free histogram the var ref when its initialization fails ... --- tools/testing/selftests/clone3/.gitignore | 5 + tools/testing/selftests/clone3/Makefile | 8 + tools/testing/selftests/clone3/clone3.c | 342 +++++++++++++++++ .../clone3/clone3_cap_checkpoint_restore.c | 164 ++++++++ .../selftests/clone3/clone3_clear_sighand.c | 124 ++++++ tools/testing/selftests/clone3/clone3_selftests.h | 69 ++++ tools/testing/selftests/clone3/clone3_set_tid.c | 418 +++++++++++++++++++++ 7 files changed, 1130 insertions(+) create mode 100644 tools/testing/selftests/clone3/.gitignore create mode 100644 tools/testing/selftests/clone3/Makefile create mode 100644 tools/testing/selftests/clone3/clone3.c create mode 100644 tools/testing/selftests/clone3/clone3_cap_checkpoint_restore.c create mode 100644 tools/testing/selftests/clone3/clone3_clear_sighand.c create mode 100644 tools/testing/selftests/clone3/clone3_selftests.h create mode 100644 tools/testing/selftests/clone3/clone3_set_tid.c (limited to 'tools/testing/selftests/clone3') diff --git a/tools/testing/selftests/clone3/.gitignore b/tools/testing/selftests/clone3/.gitignore new file mode 100644 index 000000000..83c0f6246 --- /dev/null +++ b/tools/testing/selftests/clone3/.gitignore @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0-only +clone3 +clone3_clear_sighand +clone3_set_tid +clone3_cap_checkpoint_restore diff --git a/tools/testing/selftests/clone3/Makefile b/tools/testing/selftests/clone3/Makefile new file mode 100644 index 000000000..84832c369 --- /dev/null +++ b/tools/testing/selftests/clone3/Makefile @@ -0,0 +1,8 @@ +# SPDX-License-Identifier: GPL-2.0 +CFLAGS += -g -std=gnu99 $(KHDR_INCLUDES) +LDLIBS += -lcap + +TEST_GEN_PROGS := clone3 clone3_clear_sighand clone3_set_tid \ + clone3_cap_checkpoint_restore + +include ../lib.mk diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c new file mode 100644 index 000000000..289e0c7c1 --- /dev/null +++ b/tools/testing/selftests/clone3/clone3.c @@ -0,0 +1,342 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* Based on Christian Brauner's clone3() example */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "kselftest.h" +#include "clone3_selftests.h" + +enum test_mode { + CLONE3_ARGS_NO_TEST, + CLONE3_ARGS_ALL_0, + CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG, + CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG, + CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG, + CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG, +}; + +static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode) +{ + struct __clone_args args = { + .flags = flags, + .exit_signal = SIGCHLD, + }; + + struct clone_args_extended { + struct __clone_args args; + __aligned_u64 excess_space[2]; + } args_ext; + + pid_t pid = -1; + int status; + + memset(&args_ext, 0, sizeof(args_ext)); + if (size > sizeof(struct __clone_args)) + args_ext.excess_space[1] = 1; + + if (size == 0) + size = sizeof(struct __clone_args); + + switch (test_mode) { + case CLONE3_ARGS_NO_TEST: + /* + * Uses default 'flags' and 'SIGCHLD' + * assignment. + */ + break; + case CLONE3_ARGS_ALL_0: + args.flags = 0; + args.exit_signal = 0; + break; + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG: + args.exit_signal = 0xbadc0ded00000000ULL; + break; + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG: + args.exit_signal = 0x0000000080000000ULL; + break; + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG: + args.exit_signal = 0x0000000000000100ULL; + break; + case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG: + args.exit_signal = 0x00000000000000f0ULL; + break; + } + + memcpy(&args_ext.args, &args, sizeof(struct __clone_args)); + + pid = sys_clone3((struct __clone_args *)&args_ext, size); + if (pid < 0) { + ksft_print_msg("%s - Failed to create new process\n", + strerror(errno)); + return -errno; + } + + if (pid == 0) { + ksft_print_msg("I am the child, my PID is %d\n", getpid()); + _exit(EXIT_SUCCESS); + } + + ksft_print_msg("I am the parent (%d). My child's pid is %d\n", + getpid(), pid); + + if (waitpid(-1, &status, __WALL) < 0) { + ksft_print_msg("waitpid() returned %s\n", strerror(errno)); + return -errno; + } + if (!WIFEXITED(status)) { + ksft_print_msg("Child did not exit normally, status 0x%x\n", + status); + return EXIT_FAILURE; + } + if (WEXITSTATUS(status)) + return WEXITSTATUS(status); + + return 0; +} + +static bool test_clone3(uint64_t flags, size_t size, int expected, + enum test_mode test_mode) +{ + int ret; + + ksft_print_msg( + "[%d] Trying clone3() with flags %#" PRIx64 " (size %zu)\n", + getpid(), flags, size); + ret = call_clone3(flags, size, test_mode); + ksft_print_msg("[%d] clone3() with flags says: %d expected %d\n", + getpid(), ret, expected); + if (ret != expected) { + ksft_print_msg( + "[%d] Result (%d) is different than expected (%d)\n", + getpid(), ret, expected); + return false; + } + + return true; +} + +typedef bool (*filter_function)(void); +typedef size_t (*size_function)(void); + +static bool not_root(void) +{ + if (getuid() != 0) { + ksft_print_msg("Not running as root\n"); + return true; + } + + return false; +} + +static bool no_timenamespace(void) +{ + if (not_root()) + return true; + + if (!access("/proc/self/ns/time", F_OK)) + return false; + + ksft_print_msg("Time namespaces are not supported\n"); + return true; +} + +static size_t page_size_plus_8(void) +{ + return getpagesize() + 8; +} + +struct test { + const char *name; + uint64_t flags; + size_t size; + size_function size_function; + int expected; + enum test_mode test_mode; + filter_function filter; +}; + +static const struct test tests[] = { + { + .name = "simple clone3()", + .flags = 0, + .size = 0, + .expected = 0, + .test_mode = CLONE3_ARGS_NO_TEST, + }, + { + .name = "clone3() in a new PID_NS", + .flags = CLONE_NEWPID, + .size = 0, + .expected = 0, + .test_mode = CLONE3_ARGS_NO_TEST, + .filter = not_root, + }, + { + .name = "CLONE_ARGS_SIZE_VER0", + .flags = 0, + .size = CLONE_ARGS_SIZE_VER0, + .expected = 0, + .test_mode = CLONE3_ARGS_NO_TEST, + }, + { + .name = "CLONE_ARGS_SIZE_VER0 - 8", + .flags = 0, + .size = CLONE_ARGS_SIZE_VER0 - 8, + .expected = -EINVAL, + .test_mode = CLONE3_ARGS_NO_TEST, + }, + { + .name = "sizeof(struct clone_args) + 8", + .flags = 0, + .size = sizeof(struct __clone_args) + 8, + .expected = 0, + .test_mode = CLONE3_ARGS_NO_TEST, + }, + { + .name = "exit_signal with highest 32 bits non-zero", + .flags = 0, + .size = 0, + .expected = -EINVAL, + .test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG, + }, + { + .name = "negative 32-bit exit_signal", + .flags = 0, + .size = 0, + .expected = -EINVAL, + .test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG, + }, + { + .name = "exit_signal not fitting into CSIGNAL mask", + .flags = 0, + .size = 0, + .expected = -EINVAL, + .test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG, + }, + { + .name = "NSIG < exit_signal < CSIG", + .flags = 0, + .size = 0, + .expected = -EINVAL, + .test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG, + }, + { + .name = "Arguments sizeof(struct clone_args) + 8", + .flags = 0, + .size = sizeof(struct __clone_args) + 8, + .expected = 0, + .test_mode = CLONE3_ARGS_ALL_0, + }, + { + .name = "Arguments sizeof(struct clone_args) + 16", + .flags = 0, + .size = sizeof(struct __clone_args) + 16, + .expected = -E2BIG, + .test_mode = CLONE3_ARGS_ALL_0, + }, + { + .name = "Arguments sizeof(struct clone_arg) * 2", + .flags = 0, + .size = sizeof(struct __clone_args) + 16, + .expected = -E2BIG, + .test_mode = CLONE3_ARGS_ALL_0, + }, + { + .name = "Arguments > page size", + .flags = 0, + .size_function = page_size_plus_8, + .expected = -E2BIG, + .test_mode = CLONE3_ARGS_NO_TEST, + }, + { + .name = "CLONE_ARGS_SIZE_VER0 in a new PID NS", + .flags = CLONE_NEWPID, + .size = CLONE_ARGS_SIZE_VER0, + .expected = 0, + .test_mode = CLONE3_ARGS_NO_TEST, + .filter = not_root, + }, + { + .name = "CLONE_ARGS_SIZE_VER0 - 8 in a new PID NS", + .flags = CLONE_NEWPID, + .size = CLONE_ARGS_SIZE_VER0 - 8, + .expected = -EINVAL, + .test_mode = CLONE3_ARGS_NO_TEST, + }, + { + .name = "sizeof(struct clone_args) + 8 in a new PID NS", + .flags = CLONE_NEWPID, + .size = sizeof(struct __clone_args) + 8, + .expected = 0, + .test_mode = CLONE3_ARGS_NO_TEST, + .filter = not_root, + }, + { + .name = "Arguments > page size in a new PID NS", + .flags = CLONE_NEWPID, + .size_function = page_size_plus_8, + .expected = -E2BIG, + .test_mode = CLONE3_ARGS_NO_TEST, + }, + { + .name = "New time NS", + .flags = CLONE_NEWTIME, + .size = 0, + .expected = 0, + .test_mode = CLONE3_ARGS_NO_TEST, + .filter = no_timenamespace, + }, + { + .name = "exit signal (SIGCHLD) in flags", + .flags = SIGCHLD, + .size = 0, + .expected = -EINVAL, + .test_mode = CLONE3_ARGS_NO_TEST, + }, +}; + +int main(int argc, char *argv[]) +{ + size_t size; + int i; + + ksft_print_header(); + ksft_set_plan(ARRAY_SIZE(tests)); + test_clone3_supported(); + + for (i = 0; i < ARRAY_SIZE(tests); i++) { + if (tests[i].filter && tests[i].filter()) { + ksft_test_result_skip("%s\n", tests[i].name); + continue; + } + + if (tests[i].size_function) + size = tests[i].size_function(); + else + size = tests[i].size; + + ksft_print_msg("Running test '%s'\n", tests[i].name); + + ksft_test_result(test_clone3(tests[i].flags, size, + tests[i].expected, + tests[i].test_mode), + "%s\n", tests[i].name); + } + + ksft_finished(); +} diff --git a/tools/testing/selftests/clone3/clone3_cap_checkpoint_restore.c b/tools/testing/selftests/clone3/clone3_cap_checkpoint_restore.c new file mode 100644 index 000000000..ab62bcf41 --- /dev/null +++ b/tools/testing/selftests/clone3/clone3_cap_checkpoint_restore.c @@ -0,0 +1,164 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Based on Christian Brauner's clone3() example. + * These tests are assuming to be running in the host's + * PID namespace. + */ + +/* capabilities related code based on selftests/bpf/test_verifier.c */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "kselftest_harness.h" +#include "clone3_selftests.h" + +static void child_exit(int ret) +{ + fflush(stdout); + fflush(stderr); + _exit(ret); +} + +static int call_clone3_set_tid(struct __test_metadata *_metadata, + pid_t *set_tid, size_t set_tid_size) +{ + int status; + pid_t pid = -1; + + struct __clone_args args = { + .exit_signal = SIGCHLD, + .set_tid = ptr_to_u64(set_tid), + .set_tid_size = set_tid_size, + }; + + pid = sys_clone3(&args, sizeof(args)); + if (pid < 0) { + TH_LOG("%s - Failed to create new process", strerror(errno)); + return -errno; + } + + if (pid == 0) { + TH_LOG("I am the child, my PID is %d (expected %d)", getpid(), set_tid[0]); + + if (set_tid[0] != getpid()) + child_exit(EXIT_FAILURE); + child_exit(EXIT_SUCCESS); + } + + TH_LOG("I am the parent (%d). My child's pid is %d", getpid(), pid); + + if (waitpid(pid, &status, 0) < 0) { + TH_LOG("Child returned %s", strerror(errno)); + return -errno; + } + + if (!WIFEXITED(status)) + return -1; + + return WEXITSTATUS(status); +} + +static int test_clone3_set_tid(struct __test_metadata *_metadata, + pid_t *set_tid, size_t set_tid_size) +{ + int ret; + + TH_LOG("[%d] Trying clone3() with CLONE_SET_TID to %d", getpid(), set_tid[0]); + ret = call_clone3_set_tid(_metadata, set_tid, set_tid_size); + TH_LOG("[%d] clone3() with CLONE_SET_TID %d says:%d", getpid(), set_tid[0], ret); + return ret; +} + +static int set_capability(void) +{ + cap_value_t cap_values[] = { + CAP_SETUID, CAP_SETGID, CAP_CHECKPOINT_RESTORE + }; + int ret = -1; + cap_t caps; + + caps = cap_get_proc(); + if (!caps) { + perror("cap_get_proc"); + return -1; + } + + /* Drop all capabilities */ + if (cap_clear(caps)) { + perror("cap_clear"); + goto out; + } + + cap_set_flag(caps, CAP_EFFECTIVE, 3, cap_values, CAP_SET); + cap_set_flag(caps, CAP_PERMITTED, 3, cap_values, CAP_SET); + + if (cap_set_proc(caps)) { + perror("cap_set_proc"); + goto out; + } + ret = 0; +out: + if (cap_free(caps)) + perror("cap_free"); + return ret; +} + +TEST(clone3_cap_checkpoint_restore) +{ + pid_t pid; + int status; + pid_t set_tid[1]; + + test_clone3_supported(); + + EXPECT_EQ(getuid(), 0) + SKIP(return, "Skipping all tests as non-root"); + + memset(&set_tid, 0, sizeof(set_tid)); + + /* Find the current active PID */ + pid = fork(); + if (pid == 0) { + TH_LOG("Child has PID %d", getpid()); + child_exit(EXIT_SUCCESS); + } + ASSERT_GT(waitpid(pid, &status, 0), 0) + TH_LOG("Waiting for child %d failed", pid); + + /* After the child has finished, its PID should be free. */ + set_tid[0] = pid; + + ASSERT_EQ(set_capability(), 0) + TH_LOG("Could not set CAP_CHECKPOINT_RESTORE"); + + ASSERT_EQ(prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0), 0); + + EXPECT_EQ(setgid(65534), 0) + TH_LOG("Failed to setgid(65534)"); + ASSERT_EQ(setuid(65534), 0); + + set_tid[0] = pid; + /* This would fail without CAP_CHECKPOINT_RESTORE */ + ASSERT_EQ(test_clone3_set_tid(_metadata, set_tid, 1), -EPERM); + ASSERT_EQ(set_capability(), 0) + TH_LOG("Could not set CAP_CHECKPOINT_RESTORE"); + /* This should work as we have CAP_CHECKPOINT_RESTORE as non-root */ + ASSERT_EQ(test_clone3_set_tid(_metadata, set_tid, 1), 0); +} + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/clone3/clone3_clear_sighand.c b/tools/testing/selftests/clone3/clone3_clear_sighand.c new file mode 100644 index 000000000..de0c9d620 --- /dev/null +++ b/tools/testing/selftests/clone3/clone3_clear_sighand.c @@ -0,0 +1,124 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "kselftest.h" +#include "clone3_selftests.h" + +static void nop_handler(int signo) +{ +} + +static int wait_for_pid(pid_t pid) +{ + int status, ret; + +again: + ret = waitpid(pid, &status, 0); + if (ret == -1) { + if (errno == EINTR) + goto again; + + return -1; + } + + if (!WIFEXITED(status)) + return -1; + + return WEXITSTATUS(status); +} + +static void test_clone3_clear_sighand(void) +{ + int ret; + pid_t pid; + struct __clone_args args = {}; + struct sigaction act; + + /* + * Check that CLONE_CLEAR_SIGHAND and CLONE_SIGHAND are mutually + * exclusive. + */ + args.flags |= CLONE_CLEAR_SIGHAND | CLONE_SIGHAND; + args.exit_signal = SIGCHLD; + pid = sys_clone3(&args, sizeof(args)); + if (pid > 0) + ksft_exit_fail_msg( + "clone3(CLONE_CLEAR_SIGHAND | CLONE_SIGHAND) succeeded\n"); + + act.sa_handler = nop_handler; + ret = sigemptyset(&act.sa_mask); + if (ret < 0) + ksft_exit_fail_msg("%s - sigemptyset() failed\n", + strerror(errno)); + + act.sa_flags = 0; + + /* Register signal handler for SIGUSR1 */ + ret = sigaction(SIGUSR1, &act, NULL); + if (ret < 0) + ksft_exit_fail_msg( + "%s - sigaction(SIGUSR1, &act, NULL) failed\n", + strerror(errno)); + + /* Register signal handler for SIGUSR2 */ + ret = sigaction(SIGUSR2, &act, NULL); + if (ret < 0) + ksft_exit_fail_msg( + "%s - sigaction(SIGUSR2, &act, NULL) failed\n", + strerror(errno)); + + /* Check that CLONE_CLEAR_SIGHAND works. */ + args.flags = CLONE_CLEAR_SIGHAND; + pid = sys_clone3(&args, sizeof(args)); + if (pid < 0) + ksft_exit_fail_msg("%s - clone3(CLONE_CLEAR_SIGHAND) failed\n", + strerror(errno)); + + if (pid == 0) { + ret = sigaction(SIGUSR1, NULL, &act); + if (ret < 0) + exit(EXIT_FAILURE); + + if (act.sa_handler != SIG_DFL) + exit(EXIT_FAILURE); + + ret = sigaction(SIGUSR2, NULL, &act); + if (ret < 0) + exit(EXIT_FAILURE); + + if (act.sa_handler != SIG_DFL) + exit(EXIT_FAILURE); + + exit(EXIT_SUCCESS); + } + + ret = wait_for_pid(pid); + if (ret) + ksft_exit_fail_msg( + "Failed to clear signal handler for child process\n"); + + ksft_test_result_pass("Cleared signal handlers for child process\n"); +} + +int main(int argc, char **argv) +{ + ksft_print_header(); + ksft_set_plan(1); + test_clone3_supported(); + + test_clone3_clear_sighand(); + + ksft_exit_pass(); +} diff --git a/tools/testing/selftests/clone3/clone3_selftests.h b/tools/testing/selftests/clone3/clone3_selftests.h new file mode 100644 index 000000000..a0593e895 --- /dev/null +++ b/tools/testing/selftests/clone3/clone3_selftests.h @@ -0,0 +1,69 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _CLONE3_SELFTESTS_H +#define _CLONE3_SELFTESTS_H + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include + +#include "kselftest.h" + +#define ptr_to_u64(ptr) ((__u64)((uintptr_t)(ptr))) + +#ifndef __NR_clone3 +#define __NR_clone3 435 +#endif + +struct __clone_args { + __aligned_u64 flags; + __aligned_u64 pidfd; + __aligned_u64 child_tid; + __aligned_u64 parent_tid; + __aligned_u64 exit_signal; + __aligned_u64 stack; + __aligned_u64 stack_size; + __aligned_u64 tls; + __aligned_u64 set_tid; + __aligned_u64 set_tid_size; + __aligned_u64 cgroup; +}; + +static pid_t sys_clone3(struct __clone_args *args, size_t size) +{ + fflush(stdout); + fflush(stderr); + return syscall(__NR_clone3, args, size); +} + +static inline void test_clone3_supported(void) +{ + pid_t pid; + struct __clone_args args = {}; + + if (__NR_clone3 < 0) + ksft_exit_skip("clone3() syscall is not supported\n"); + + /* Set to something that will always cause EINVAL. */ + args.exit_signal = -1; + pid = sys_clone3(&args, sizeof(args)); + if (!pid) + exit(EXIT_SUCCESS); + + if (pid > 0) { + wait(NULL); + ksft_exit_fail_msg( + "Managed to create child process with invalid exit_signal\n"); + } + + if (errno == ENOSYS) + ksft_exit_skip("clone3() syscall is not supported\n"); + + ksft_print_msg("clone3() syscall supported\n"); +} + +#endif /* _CLONE3_SELFTESTS_H */ diff --git a/tools/testing/selftests/clone3/clone3_set_tid.c b/tools/testing/selftests/clone3/clone3_set_tid.c new file mode 100644 index 000000000..485efa7c9 --- /dev/null +++ b/tools/testing/selftests/clone3/clone3_set_tid.c @@ -0,0 +1,418 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Based on Christian Brauner's clone3() example. + * These tests are assuming to be running in the host's + * PID namespace. + */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "kselftest.h" +#include "clone3_selftests.h" + +#define MAX_PID_NS_LEVEL 32 + +static int pipe_1[2]; +static int pipe_2[2]; + +static void child_exit(int ret) +{ + fflush(stdout); + fflush(stderr); + _exit(ret); +} + +static int call_clone3_set_tid(pid_t *set_tid, + size_t set_tid_size, + int flags, + int expected_pid, + bool wait_for_it) +{ + int status; + pid_t pid = -1; + + struct __clone_args args = { + .flags = flags, + .exit_signal = SIGCHLD, + .set_tid = ptr_to_u64(set_tid), + .set_tid_size = set_tid_size, + }; + + pid = sys_clone3(&args, sizeof(args)); + if (pid < 0) { + ksft_print_msg("%s - Failed to create new process\n", + strerror(errno)); + return -errno; + } + + if (pid == 0) { + int ret; + char tmp = 0; + int exit_code = EXIT_SUCCESS; + + ksft_print_msg("I am the child, my PID is %d (expected %d)\n", + getpid(), set_tid[0]); + if (wait_for_it) { + ksft_print_msg("[%d] Child is ready and waiting\n", + getpid()); + + /* Signal the parent that the child is ready */ + close(pipe_1[0]); + ret = write(pipe_1[1], &tmp, 1); + if (ret != 1) { + ksft_print_msg( + "Writing to pipe returned %d", ret); + exit_code = EXIT_FAILURE; + } + close(pipe_1[1]); + close(pipe_2[1]); + ret = read(pipe_2[0], &tmp, 1); + if (ret != 1) { + ksft_print_msg( + "Reading from pipe returned %d", ret); + exit_code = EXIT_FAILURE; + } + close(pipe_2[0]); + } + + if (set_tid[0] != getpid()) + child_exit(EXIT_FAILURE); + child_exit(exit_code); + } + + if (expected_pid == 0 || expected_pid == pid) { + ksft_print_msg("I am the parent (%d). My child's pid is %d\n", + getpid(), pid); + } else { + ksft_print_msg( + "Expected child pid %d does not match actual pid %d\n", + expected_pid, pid); + return -1; + } + + if (waitpid(pid, &status, 0) < 0) { + ksft_print_msg("Child returned %s\n", strerror(errno)); + return -errno; + } + + if (!WIFEXITED(status)) + return -1; + + return WEXITSTATUS(status); +} + +static void test_clone3_set_tid(const char *desc, + pid_t *set_tid, + size_t set_tid_size, + int flags, + int expected, + int expected_pid, + bool wait_for_it) +{ + int ret; + + ksft_print_msg( + "[%d] Trying clone3() with CLONE_SET_TID to %d and 0x%x\n", + getpid(), set_tid[0], flags); + ret = call_clone3_set_tid(set_tid, set_tid_size, flags, expected_pid, + wait_for_it); + ksft_print_msg( + "[%d] clone3() with CLONE_SET_TID %d says: %d - expected %d\n", + getpid(), set_tid[0], ret, expected); + + ksft_test_result(ret == expected, "%s with %zu TIDs and flags 0x%x\n", + desc, set_tid_size, flags); +} + +int main(int argc, char *argv[]) +{ + FILE *f; + char buf; + char *line = NULL; + int status; + int ret = -1; + size_t len = 0; + int pid_max = 0; + uid_t uid = getuid(); + char proc_path[100] = {0}; + pid_t pid, ns1, ns2, ns3, ns_pid; + pid_t set_tid[MAX_PID_NS_LEVEL * 2]; + + ksft_print_header(); + ksft_set_plan(29); + test_clone3_supported(); + + if (pipe(pipe_1) < 0 || pipe(pipe_2) < 0) + ksft_exit_fail_msg("pipe() failed\n"); + + f = fopen("/proc/sys/kernel/pid_max", "r"); + if (f == NULL) + ksft_exit_fail_msg( + "%s - Could not open /proc/sys/kernel/pid_max\n", + strerror(errno)); + fscanf(f, "%d", &pid_max); + fclose(f); + ksft_print_msg("/proc/sys/kernel/pid_max %d\n", pid_max); + + /* Try invalid settings */ + memset(&set_tid, 0, sizeof(set_tid)); + test_clone3_set_tid("invalid size, 0 TID", + set_tid, MAX_PID_NS_LEVEL + 1, 0, -EINVAL, 0, 0); + + test_clone3_set_tid("invalid size, 0 TID", + set_tid, MAX_PID_NS_LEVEL * 2, 0, -EINVAL, 0, 0); + + test_clone3_set_tid("invalid size, 0 TID", + set_tid, MAX_PID_NS_LEVEL * 2 + 1, 0, + -EINVAL, 0, 0); + + test_clone3_set_tid("invalid size, 0 TID", + set_tid, MAX_PID_NS_LEVEL * 42, 0, -EINVAL, 0, 0); + + /* + * This can actually work if this test running in a MAX_PID_NS_LEVEL - 1 + * nested PID namespace. + */ + test_clone3_set_tid("invalid size, 0 TID", + set_tid, MAX_PID_NS_LEVEL - 1, 0, -EINVAL, 0, 0); + + memset(&set_tid, 0xff, sizeof(set_tid)); + test_clone3_set_tid("invalid size, TID all 1s", + set_tid, MAX_PID_NS_LEVEL + 1, 0, -EINVAL, 0, 0); + + test_clone3_set_tid("invalid size, TID all 1s", + set_tid, MAX_PID_NS_LEVEL * 2, 0, -EINVAL, 0, 0); + + test_clone3_set_tid("invalid size, TID all 1s", + set_tid, MAX_PID_NS_LEVEL * 2 + 1, 0, + -EINVAL, 0, 0); + + test_clone3_set_tid("invalid size, TID all 1s", + set_tid, MAX_PID_NS_LEVEL * 42, 0, -EINVAL, 0, 0); + + /* + * This can actually work if this test running in a MAX_PID_NS_LEVEL - 1 + * nested PID namespace. + */ + test_clone3_set_tid("invalid size, TID all 1s", + set_tid, MAX_PID_NS_LEVEL - 1, 0, -EINVAL, 0, 0); + + memset(&set_tid, 0, sizeof(set_tid)); + /* Try with an invalid PID */ + set_tid[0] = 0; + test_clone3_set_tid("valid size, 0 TID", + set_tid, 1, 0, -EINVAL, 0, 0); + + set_tid[0] = -1; + test_clone3_set_tid("valid size, -1 TID", + set_tid, 1, 0, -EINVAL, 0, 0); + + /* Claim that the set_tid array actually contains 2 elements. */ + test_clone3_set_tid("2 TIDs, -1 and 0", + set_tid, 2, 0, -EINVAL, 0, 0); + + /* Try it in a new PID namespace */ + if (uid == 0) + test_clone3_set_tid("valid size, -1 TID", + set_tid, 1, CLONE_NEWPID, -EINVAL, 0, 0); + else + ksft_test_result_skip("Clone3() with set_tid requires root\n"); + + /* Try with a valid PID (1) this should return -EEXIST. */ + set_tid[0] = 1; + if (uid == 0) + test_clone3_set_tid("duplicate PID 1", + set_tid, 1, 0, -EEXIST, 0, 0); + else + ksft_test_result_skip("Clone3() with set_tid requires root\n"); + + /* Try it in a new PID namespace */ + if (uid == 0) + test_clone3_set_tid("duplicate PID 1", + set_tid, 1, CLONE_NEWPID, 0, 0, 0); + else + ksft_test_result_skip("Clone3() with set_tid requires root\n"); + + /* pid_max should fail everywhere */ + set_tid[0] = pid_max; + test_clone3_set_tid("set TID to maximum", + set_tid, 1, 0, -EINVAL, 0, 0); + + if (uid == 0) + test_clone3_set_tid("set TID to maximum", + set_tid, 1, CLONE_NEWPID, -EINVAL, 0, 0); + else + ksft_test_result_skip("Clone3() with set_tid requires root\n"); + + if (uid != 0) { + /* + * All remaining tests require root. Tell the framework + * that all those tests are skipped as non-root. + */ + ksft_cnt.ksft_xskip += ksft_plan - ksft_test_num(); + goto out; + } + + /* Find the current active PID */ + pid = fork(); + if (pid == 0) { + ksft_print_msg("Child has PID %d\n", getpid()); + child_exit(EXIT_SUCCESS); + } + if (waitpid(pid, &status, 0) < 0) + ksft_exit_fail_msg("Waiting for child %d failed", pid); + + /* After the child has finished, its PID should be free. */ + set_tid[0] = pid; + test_clone3_set_tid("reallocate child TID", + set_tid, 1, 0, 0, 0, 0); + + /* This should fail as there is no PID 1 in that namespace */ + test_clone3_set_tid("duplicate child TID", + set_tid, 1, CLONE_NEWPID, -EINVAL, 0, 0); + + /* + * Creating a process with PID 1 in the newly created most nested + * PID namespace and PID 'pid' in the parent PID namespace. This + * needs to work. + */ + set_tid[0] = 1; + set_tid[1] = pid; + test_clone3_set_tid("create PID 1 in new NS", + set_tid, 2, CLONE_NEWPID, 0, pid, 0); + + ksft_print_msg("unshare PID namespace\n"); + if (unshare(CLONE_NEWPID) == -1) + ksft_exit_fail_msg("unshare(CLONE_NEWPID) failed: %s\n", + strerror(errno)); + + set_tid[0] = pid; + + /* This should fail as there is no PID 1 in that namespace */ + test_clone3_set_tid("duplicate PID 1", + set_tid, 1, 0, -EINVAL, 0, 0); + + /* Let's create a PID 1 */ + ns_pid = fork(); + if (ns_pid == 0) { + /* + * This and the next test cases check that all pid-s are + * released on error paths. + */ + set_tid[0] = 43; + set_tid[1] = -1; + test_clone3_set_tid("check leak on invalid TID -1", + set_tid, 2, 0, -EINVAL, 0, 0); + + set_tid[0] = 43; + set_tid[1] = pid; + test_clone3_set_tid("check leak on invalid specific TID", + set_tid, 2, 0, 0, 43, 0); + + ksft_print_msg("Child in PID namespace has PID %d\n", getpid()); + set_tid[0] = 2; + test_clone3_set_tid("create PID 2 in child NS", + set_tid, 1, 0, 0, 2, 0); + + set_tid[0] = 1; + set_tid[1] = -1; + set_tid[2] = pid; + /* This should fail as there is invalid PID at level '1'. */ + test_clone3_set_tid("fail due to invalid TID at level 1", + set_tid, 3, CLONE_NEWPID, -EINVAL, 0, 0); + + set_tid[0] = 1; + set_tid[1] = 42; + set_tid[2] = pid; + /* + * This should fail as there are not enough active PID + * namespaces. Again assuming this is running in the host's + * PID namespace. Not yet nested. + */ + test_clone3_set_tid("fail due to too few active PID NSs", + set_tid, 4, CLONE_NEWPID, -EINVAL, 0, 0); + + /* + * This should work and from the parent we should see + * something like 'NSpid: pid 42 1'. + */ + test_clone3_set_tid("verify that we have 3 PID NSs", + set_tid, 3, CLONE_NEWPID, 0, 42, true); + + child_exit(ksft_cnt.ksft_fail); + } + + close(pipe_1[1]); + close(pipe_2[0]); + while (read(pipe_1[0], &buf, 1) > 0) { + ksft_print_msg("[%d] Child is ready and waiting\n", getpid()); + break; + } + + snprintf(proc_path, sizeof(proc_path), "/proc/%d/status", pid); + f = fopen(proc_path, "r"); + if (f == NULL) + ksft_exit_fail_msg( + "%s - Could not open %s\n", + strerror(errno), proc_path); + + while (getline(&line, &len, f) != -1) { + if (strstr(line, "NSpid")) { + int i; + + /* Verify that all generated PIDs are as expected. */ + i = sscanf(line, "NSpid:\t%d\t%d\t%d", + &ns3, &ns2, &ns1); + if (i != 3) { + ksft_print_msg( + "Unexpected 'NSPid:' entry: %s", + line); + ns1 = ns2 = ns3 = 0; + } + break; + } + } + fclose(f); + free(line); + close(pipe_2[0]); + + /* Tell the clone3()'d child to finish. */ + write(pipe_2[1], &buf, 1); + close(pipe_2[1]); + + if (waitpid(ns_pid, &status, 0) < 0) { + ksft_print_msg("Child returned %s\n", strerror(errno)); + ret = -errno; + goto out; + } + + if (!WIFEXITED(status)) + ksft_test_result_fail("Child error\n"); + + ksft_cnt.ksft_pass += 6 - (ksft_cnt.ksft_fail - WEXITSTATUS(status)); + ksft_cnt.ksft_fail = WEXITSTATUS(status); + + ksft_print_msg("Expecting PIDs %d, 42, 1\n", pid); + ksft_print_msg("Have PIDs in namespaces: %d, %d, %d\n", ns3, ns2, ns1); + ksft_test_result(ns3 == pid && ns2 == 42 && ns1 == 1, + "PIDs in all namespaces as expected\n"); +out: + ret = 0; + + if (ret) + ksft_exit_fail(); + ksft_exit_pass(); +} -- cgit v1.3.1