diff options
Diffstat (limited to 'tools/testing/selftests/proc')
| -rw-r--r-- | tools/testing/selftests/proc/.gitignore | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/proc/Makefile | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/proc/proc-maps-race.c | 806 | ||||
| -rw-r--r-- | tools/testing/selftests/proc/proc-net-dev-lseek.c | 68 | ||||
| -rw-r--r-- | tools/testing/selftests/proc/proc-pid-vm.c | 14 | ||||
| -rw-r--r-- | tools/testing/selftests/proc/proc-pidns.c | 211 |
6 files changed, 1100 insertions, 5 deletions
diff --git a/tools/testing/selftests/proc/.gitignore b/tools/testing/selftests/proc/.gitignore index 973968f45bba..9c9735570abf 100644 --- a/tools/testing/selftests/proc/.gitignore +++ b/tools/testing/selftests/proc/.gitignore @@ -5,7 +5,9 @@ /proc-2-is-kthread /proc-fsconfig-hidepid /proc-loadavg-001 +/proc-maps-race /proc-multiple-procfs +/proc-net-dev-lseek /proc-empty-vm /proc-pid-vm /proc-self-map-files-001 @@ -17,6 +19,7 @@ /proc-tid0 /proc-uptime-001 /proc-uptime-002 +/proc-pidns /read /self /setns-dcache diff --git a/tools/testing/selftests/proc/Makefile b/tools/testing/selftests/proc/Makefile index b12921b9794b..a7de2bb6d8be 100644 --- a/tools/testing/selftests/proc/Makefile +++ b/tools/testing/selftests/proc/Makefile @@ -9,6 +9,8 @@ TEST_GEN_PROGS += fd-002-posix-eq TEST_GEN_PROGS += fd-003-kthread TEST_GEN_PROGS += proc-2-is-kthread TEST_GEN_PROGS += proc-loadavg-001 +TEST_GEN_PROGS += proc-maps-race +TEST_GEN_PROGS += proc-net-dev-lseek TEST_GEN_PROGS += proc-empty-vm TEST_GEN_PROGS += proc-pid-vm TEST_GEN_PROGS += proc-self-map-files-001 @@ -27,5 +29,6 @@ TEST_GEN_PROGS += setns-sysvipc TEST_GEN_PROGS += thread-self TEST_GEN_PROGS += proc-multiple-procfs TEST_GEN_PROGS += proc-fsconfig-hidepid +TEST_GEN_PROGS += proc-pidns include ../lib.mk diff --git a/tools/testing/selftests/proc/proc-maps-race.c b/tools/testing/selftests/proc/proc-maps-race.c new file mode 100644 index 000000000000..a734553718da --- /dev/null +++ b/tools/testing/selftests/proc/proc-maps-race.c @@ -0,0 +1,806 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2022 Google LLC. + * Author: Suren Baghdasaryan <surenb@google.com> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ +/* + * Fork a child that concurrently modifies address space while the main + * process is reading /proc/$PID/maps and verifying the results. Address + * space modifications include: + * VMA splitting and merging + * + */ +#define _GNU_SOURCE +#include "kselftest_harness.h" +#include <errno.h> +#include <fcntl.h> +#include <pthread.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <linux/fs.h> +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/wait.h> + +/* /proc/pid/maps parsing routines */ +struct page_content { + char *data; + ssize_t size; +}; + +#define LINE_MAX_SIZE 256 + +struct line_content { + char text[LINE_MAX_SIZE]; + unsigned long start_addr; + unsigned long end_addr; +}; + +enum test_state { + INIT, + CHILD_READY, + PARENT_READY, + SETUP_READY, + SETUP_MODIFY_MAPS, + SETUP_MAPS_MODIFIED, + SETUP_RESTORE_MAPS, + SETUP_MAPS_RESTORED, + TEST_READY, + TEST_DONE, +}; + +struct vma_modifier_info; + +FIXTURE(proc_maps_race) +{ + struct vma_modifier_info *mod_info; + struct page_content page1; + struct page_content page2; + struct line_content last_line; + struct line_content first_line; + unsigned long duration_sec; + int shared_mem_size; + int page_size; + int vma_count; + bool verbose; + int maps_fd; + pid_t pid; +}; + +typedef bool (*vma_modifier_op)(FIXTURE_DATA(proc_maps_race) *self); +typedef bool (*vma_mod_result_check_op)(struct line_content *mod_last_line, + struct line_content *mod_first_line, + struct line_content *restored_last_line, + struct line_content *restored_first_line); + +struct vma_modifier_info { + int vma_count; + void *addr; + int prot; + void *next_addr; + vma_modifier_op vma_modify; + vma_modifier_op vma_restore; + vma_mod_result_check_op vma_mod_check; + pthread_mutex_t sync_lock; + pthread_cond_t sync_cond; + enum test_state curr_state; + bool exit; + void *child_mapped_addr[]; +}; + + +static bool read_two_pages(FIXTURE_DATA(proc_maps_race) *self) +{ + ssize_t bytes_read; + + if (lseek(self->maps_fd, 0, SEEK_SET) < 0) + return false; + + bytes_read = read(self->maps_fd, self->page1.data, self->page_size); + if (bytes_read <= 0) + return false; + + self->page1.size = bytes_read; + + bytes_read = read(self->maps_fd, self->page2.data, self->page_size); + if (bytes_read <= 0) + return false; + + self->page2.size = bytes_read; + + return true; +} + +static void copy_first_line(struct page_content *page, char *first_line) +{ + char *pos = strchr(page->data, '\n'); + + strncpy(first_line, page->data, pos - page->data); + first_line[pos - page->data] = '\0'; +} + +static void copy_last_line(struct page_content *page, char *last_line) +{ + /* Get the last line in the first page */ + const char *end = page->data + page->size - 1; + /* skip last newline */ + const char *pos = end - 1; + + /* search previous newline */ + while (pos[-1] != '\n') + pos--; + strncpy(last_line, pos, end - pos); + last_line[end - pos] = '\0'; +} + +/* Read the last line of the first page and the first line of the second page */ +static bool read_boundary_lines(FIXTURE_DATA(proc_maps_race) *self, + struct line_content *last_line, + struct line_content *first_line) +{ + if (!read_two_pages(self)) + return false; + + copy_last_line(&self->page1, last_line->text); + copy_first_line(&self->page2, first_line->text); + + return sscanf(last_line->text, "%lx-%lx", &last_line->start_addr, + &last_line->end_addr) == 2 && + sscanf(first_line->text, "%lx-%lx", &first_line->start_addr, + &first_line->end_addr) == 2; +} + +/* Thread synchronization routines */ +static void wait_for_state(struct vma_modifier_info *mod_info, enum test_state state) +{ + pthread_mutex_lock(&mod_info->sync_lock); + while (mod_info->curr_state != state) + pthread_cond_wait(&mod_info->sync_cond, &mod_info->sync_lock); + pthread_mutex_unlock(&mod_info->sync_lock); +} + +static void signal_state(struct vma_modifier_info *mod_info, enum test_state state) +{ + pthread_mutex_lock(&mod_info->sync_lock); + mod_info->curr_state = state; + pthread_cond_signal(&mod_info->sync_cond); + pthread_mutex_unlock(&mod_info->sync_lock); +} + +static void stop_vma_modifier(struct vma_modifier_info *mod_info) +{ + wait_for_state(mod_info, SETUP_READY); + mod_info->exit = true; + signal_state(mod_info, SETUP_MODIFY_MAPS); +} + +static void print_first_lines(char *text, int nr) +{ + const char *end = text; + + while (nr && (end = strchr(end, '\n')) != NULL) { + nr--; + end++; + } + + if (end) { + int offs = end - text; + + text[offs] = '\0'; + printf("%s", text); + text[offs] = '\n'; + printf("\n"); + } else { + printf("%s", text); + } +} + +static void print_last_lines(char *text, int nr) +{ + const char *start = text + strlen(text); + + nr++; /* to ignore the last newline */ + while (nr) { + while (start > text && *start != '\n') + start--; + nr--; + start--; + } + printf("%s", start); +} + +static void print_boundaries(const char *title, FIXTURE_DATA(proc_maps_race) *self) +{ + if (!self->verbose) + return; + + printf("%s", title); + /* Print 3 boundary lines from each page */ + print_last_lines(self->page1.data, 3); + printf("-----------------page boundary-----------------\n"); + print_first_lines(self->page2.data, 3); +} + +static bool print_boundaries_on(bool condition, const char *title, + FIXTURE_DATA(proc_maps_race) *self) +{ + if (self->verbose && condition) + print_boundaries(title, self); + + return condition; +} + +static void report_test_start(const char *name, bool verbose) +{ + if (verbose) + printf("==== %s ====\n", name); +} + +static struct timespec print_ts; + +static void start_test_loop(struct timespec *ts, bool verbose) +{ + if (verbose) + print_ts.tv_sec = ts->tv_sec; +} + +static void end_test_iteration(struct timespec *ts, bool verbose) +{ + if (!verbose) + return; + + /* Update every second */ + if (print_ts.tv_sec == ts->tv_sec) + return; + + printf("."); + fflush(stdout); + print_ts.tv_sec = ts->tv_sec; +} + +static void end_test_loop(bool verbose) +{ + if (verbose) + printf("\n"); +} + +static bool capture_mod_pattern(FIXTURE_DATA(proc_maps_race) *self, + struct line_content *mod_last_line, + struct line_content *mod_first_line, + struct line_content *restored_last_line, + struct line_content *restored_first_line) +{ + print_boundaries("Before modification", self); + + signal_state(self->mod_info, SETUP_MODIFY_MAPS); + wait_for_state(self->mod_info, SETUP_MAPS_MODIFIED); + + /* Copy last line of the first page and first line of the last page */ + if (!read_boundary_lines(self, mod_last_line, mod_first_line)) + return false; + + print_boundaries("After modification", self); + + signal_state(self->mod_info, SETUP_RESTORE_MAPS); + wait_for_state(self->mod_info, SETUP_MAPS_RESTORED); + + /* Copy last line of the first page and first line of the last page */ + if (!read_boundary_lines(self, restored_last_line, restored_first_line)) + return false; + + print_boundaries("After restore", self); + + if (!self->mod_info->vma_mod_check(mod_last_line, mod_first_line, + restored_last_line, restored_first_line)) + return false; + + /* + * The content of these lines after modify+resore should be the same + * as the original. + */ + return strcmp(restored_last_line->text, self->last_line.text) == 0 && + strcmp(restored_first_line->text, self->first_line.text) == 0; +} + +static bool query_addr_at(int maps_fd, void *addr, + unsigned long *vma_start, unsigned long *vma_end) +{ + struct procmap_query q; + + memset(&q, 0, sizeof(q)); + q.size = sizeof(q); + /* Find the VMA at the split address */ + q.query_addr = (unsigned long long)addr; + q.query_flags = 0; + if (ioctl(maps_fd, PROCMAP_QUERY, &q)) + return false; + + *vma_start = q.vma_start; + *vma_end = q.vma_end; + + return true; +} + +static inline bool split_vma(FIXTURE_DATA(proc_maps_race) *self) +{ + return mmap(self->mod_info->addr, self->page_size, self->mod_info->prot | PROT_EXEC, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0) != MAP_FAILED; +} + +static inline bool merge_vma(FIXTURE_DATA(proc_maps_race) *self) +{ + return mmap(self->mod_info->addr, self->page_size, self->mod_info->prot, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0) != MAP_FAILED; +} + +static inline bool check_split_result(struct line_content *mod_last_line, + struct line_content *mod_first_line, + struct line_content *restored_last_line, + struct line_content *restored_first_line) +{ + /* Make sure vmas at the boundaries are changing */ + return strcmp(mod_last_line->text, restored_last_line->text) != 0 && + strcmp(mod_first_line->text, restored_first_line->text) != 0; +} + +static inline bool shrink_vma(FIXTURE_DATA(proc_maps_race) *self) +{ + return mremap(self->mod_info->addr, self->page_size * 3, + self->page_size, 0) != MAP_FAILED; +} + +static inline bool expand_vma(FIXTURE_DATA(proc_maps_race) *self) +{ + return mremap(self->mod_info->addr, self->page_size, + self->page_size * 3, 0) != MAP_FAILED; +} + +static inline bool check_shrink_result(struct line_content *mod_last_line, + struct line_content *mod_first_line, + struct line_content *restored_last_line, + struct line_content *restored_first_line) +{ + /* Make sure only the last vma of the first page is changing */ + return strcmp(mod_last_line->text, restored_last_line->text) != 0 && + strcmp(mod_first_line->text, restored_first_line->text) == 0; +} + +static inline bool remap_vma(FIXTURE_DATA(proc_maps_race) *self) +{ + /* + * Remap the last page of the next vma into the middle of the vma. + * This splits the current vma and the first and middle parts (the + * parts at lower addresses) become the last vma objserved in the + * first page and the first vma observed in the last page. + */ + return mremap(self->mod_info->next_addr + self->page_size * 2, self->page_size, + self->page_size, MREMAP_FIXED | MREMAP_MAYMOVE | MREMAP_DONTUNMAP, + self->mod_info->addr + self->page_size) != MAP_FAILED; +} + +static inline bool patch_vma(FIXTURE_DATA(proc_maps_race) *self) +{ + return mprotect(self->mod_info->addr + self->page_size, self->page_size, + self->mod_info->prot) == 0; +} + +static inline bool check_remap_result(struct line_content *mod_last_line, + struct line_content *mod_first_line, + struct line_content *restored_last_line, + struct line_content *restored_first_line) +{ + /* Make sure vmas at the boundaries are changing */ + return strcmp(mod_last_line->text, restored_last_line->text) != 0 && + strcmp(mod_first_line->text, restored_first_line->text) != 0; +} + +FIXTURE_SETUP(proc_maps_race) +{ + const char *verbose = getenv("VERBOSE"); + const char *duration = getenv("DURATION"); + struct vma_modifier_info *mod_info; + pthread_mutexattr_t mutex_attr; + pthread_condattr_t cond_attr; + unsigned long duration_sec; + char fname[32]; + + self->page_size = (unsigned long)sysconf(_SC_PAGESIZE); + self->verbose = verbose && !strncmp(verbose, "1", 1); + duration_sec = duration ? atol(duration) : 0; + self->duration_sec = duration_sec ? duration_sec : 5UL; + + /* + * Have to map enough vmas for /proc/pid/maps to contain more than one + * page worth of vmas. Assume at least 32 bytes per line in maps output + */ + self->vma_count = self->page_size / 32 + 1; + self->shared_mem_size = sizeof(struct vma_modifier_info) + self->vma_count * sizeof(void *); + + /* map shared memory for communication with the child process */ + self->mod_info = (struct vma_modifier_info *)mmap(NULL, self->shared_mem_size, + PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); + ASSERT_NE(self->mod_info, MAP_FAILED); + mod_info = self->mod_info; + + /* Initialize shared members */ + pthread_mutexattr_init(&mutex_attr); + pthread_mutexattr_setpshared(&mutex_attr, PTHREAD_PROCESS_SHARED); + ASSERT_EQ(pthread_mutex_init(&mod_info->sync_lock, &mutex_attr), 0); + pthread_condattr_init(&cond_attr); + pthread_condattr_setpshared(&cond_attr, PTHREAD_PROCESS_SHARED); + ASSERT_EQ(pthread_cond_init(&mod_info->sync_cond, &cond_attr), 0); + mod_info->vma_count = self->vma_count; + mod_info->curr_state = INIT; + mod_info->exit = false; + + self->pid = fork(); + if (!self->pid) { + /* Child process modifying the address space */ + int prot = PROT_READ | PROT_WRITE; + int i; + + for (i = 0; i < mod_info->vma_count; i++) { + mod_info->child_mapped_addr[i] = mmap(NULL, self->page_size * 3, prot, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + ASSERT_NE(mod_info->child_mapped_addr[i], MAP_FAILED); + /* change protection in adjacent maps to prevent merging */ + prot ^= PROT_WRITE; + } + signal_state(mod_info, CHILD_READY); + wait_for_state(mod_info, PARENT_READY); + while (true) { + signal_state(mod_info, SETUP_READY); + wait_for_state(mod_info, SETUP_MODIFY_MAPS); + if (mod_info->exit) + break; + + ASSERT_TRUE(mod_info->vma_modify(self)); + signal_state(mod_info, SETUP_MAPS_MODIFIED); + wait_for_state(mod_info, SETUP_RESTORE_MAPS); + ASSERT_TRUE(mod_info->vma_restore(self)); + signal_state(mod_info, SETUP_MAPS_RESTORED); + + wait_for_state(mod_info, TEST_READY); + while (mod_info->curr_state != TEST_DONE) { + ASSERT_TRUE(mod_info->vma_modify(self)); + ASSERT_TRUE(mod_info->vma_restore(self)); + } + } + for (i = 0; i < mod_info->vma_count; i++) + munmap(mod_info->child_mapped_addr[i], self->page_size * 3); + + exit(0); + } + + sprintf(fname, "/proc/%d/maps", self->pid); + self->maps_fd = open(fname, O_RDONLY); + ASSERT_NE(self->maps_fd, -1); + + /* Wait for the child to map the VMAs */ + wait_for_state(mod_info, CHILD_READY); + + /* Read first two pages */ + self->page1.data = malloc(self->page_size); + ASSERT_NE(self->page1.data, NULL); + self->page2.data = malloc(self->page_size); + ASSERT_NE(self->page2.data, NULL); + + ASSERT_TRUE(read_boundary_lines(self, &self->last_line, &self->first_line)); + + /* + * Find the addresses corresponding to the last line in the first page + * and the first line in the last page. + */ + mod_info->addr = NULL; + mod_info->next_addr = NULL; + for (int i = 0; i < mod_info->vma_count; i++) { + if (mod_info->child_mapped_addr[i] == (void *)self->last_line.start_addr) { + mod_info->addr = mod_info->child_mapped_addr[i]; + mod_info->prot = PROT_READ; + /* Even VMAs have write permission */ + if ((i % 2) == 0) + mod_info->prot |= PROT_WRITE; + } else if (mod_info->child_mapped_addr[i] == (void *)self->first_line.start_addr) { + mod_info->next_addr = mod_info->child_mapped_addr[i]; + } + + if (mod_info->addr && mod_info->next_addr) + break; + } + ASSERT_TRUE(mod_info->addr && mod_info->next_addr); + + signal_state(mod_info, PARENT_READY); + +} + +FIXTURE_TEARDOWN(proc_maps_race) +{ + int status; + + stop_vma_modifier(self->mod_info); + + free(self->page2.data); + free(self->page1.data); + + for (int i = 0; i < self->vma_count; i++) + munmap(self->mod_info->child_mapped_addr[i], self->page_size); + close(self->maps_fd); + waitpid(self->pid, &status, 0); + munmap(self->mod_info, self->shared_mem_size); +} + +TEST_F(proc_maps_race, test_maps_tearing_from_split) +{ + struct vma_modifier_info *mod_info = self->mod_info; + + struct line_content split_last_line; + struct line_content split_first_line; + struct line_content restored_last_line; + struct line_content restored_first_line; + + wait_for_state(mod_info, SETUP_READY); + + /* re-read the file to avoid using stale data from previous test */ + ASSERT_TRUE(read_boundary_lines(self, &self->last_line, &self->first_line)); + + mod_info->vma_modify = split_vma; + mod_info->vma_restore = merge_vma; + mod_info->vma_mod_check = check_split_result; + + report_test_start("Tearing from split", self->verbose); + ASSERT_TRUE(capture_mod_pattern(self, &split_last_line, &split_first_line, + &restored_last_line, &restored_first_line)); + + /* Now start concurrent modifications for self->duration_sec */ + signal_state(mod_info, TEST_READY); + + struct line_content new_last_line; + struct line_content new_first_line; + struct timespec start_ts, end_ts; + + clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts); + start_test_loop(&start_ts, self->verbose); + do { + bool last_line_changed; + bool first_line_changed; + unsigned long vma_start; + unsigned long vma_end; + + ASSERT_TRUE(read_boundary_lines(self, &new_last_line, &new_first_line)); + + /* Check if we read vmas after split */ + if (!strcmp(new_last_line.text, split_last_line.text)) { + /* + * The vmas should be consistent with split results, + * however if vma was concurrently restored after a + * split, it can be reported twice (first the original + * split one, then the same vma but extended after the + * merge) because we found it as the next vma again. + * In that case new first line will be the same as the + * last restored line. + */ + ASSERT_FALSE(print_boundaries_on( + strcmp(new_first_line.text, split_first_line.text) && + strcmp(new_first_line.text, restored_last_line.text), + "Split result invalid", self)); + } else { + /* The vmas should be consistent with merge results */ + ASSERT_FALSE(print_boundaries_on( + strcmp(new_last_line.text, restored_last_line.text), + "Merge result invalid", self)); + ASSERT_FALSE(print_boundaries_on( + strcmp(new_first_line.text, restored_first_line.text), + "Merge result invalid", self)); + } + /* + * First and last lines should change in unison. If the last + * line changed then the first line should change as well and + * vice versa. + */ + last_line_changed = strcmp(new_last_line.text, self->last_line.text) != 0; + first_line_changed = strcmp(new_first_line.text, self->first_line.text) != 0; + ASSERT_EQ(last_line_changed, first_line_changed); + + /* Check if PROCMAP_QUERY ioclt() finds the right VMA */ + ASSERT_TRUE(query_addr_at(self->maps_fd, mod_info->addr + self->page_size, + &vma_start, &vma_end)); + /* + * The vma at the split address can be either the same as + * original one (if read before the split) or the same as the + * first line in the second page (if read after the split). + */ + ASSERT_TRUE((vma_start == self->last_line.start_addr && + vma_end == self->last_line.end_addr) || + (vma_start == split_first_line.start_addr && + vma_end == split_first_line.end_addr)); + + clock_gettime(CLOCK_MONOTONIC_COARSE, &end_ts); + end_test_iteration(&end_ts, self->verbose); + } while (end_ts.tv_sec - start_ts.tv_sec < self->duration_sec); + end_test_loop(self->verbose); + + /* Signal the modifyer thread to stop and wait until it exits */ + signal_state(mod_info, TEST_DONE); +} + +TEST_F(proc_maps_race, test_maps_tearing_from_resize) +{ + struct vma_modifier_info *mod_info = self->mod_info; + + struct line_content shrunk_last_line; + struct line_content shrunk_first_line; + struct line_content restored_last_line; + struct line_content restored_first_line; + + wait_for_state(mod_info, SETUP_READY); + + /* re-read the file to avoid using stale data from previous test */ + ASSERT_TRUE(read_boundary_lines(self, &self->last_line, &self->first_line)); + + mod_info->vma_modify = shrink_vma; + mod_info->vma_restore = expand_vma; + mod_info->vma_mod_check = check_shrink_result; + + report_test_start("Tearing from resize", self->verbose); + ASSERT_TRUE(capture_mod_pattern(self, &shrunk_last_line, &shrunk_first_line, + &restored_last_line, &restored_first_line)); + + /* Now start concurrent modifications for self->duration_sec */ + signal_state(mod_info, TEST_READY); + + struct line_content new_last_line; + struct line_content new_first_line; + struct timespec start_ts, end_ts; + + clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts); + start_test_loop(&start_ts, self->verbose); + do { + unsigned long vma_start; + unsigned long vma_end; + + ASSERT_TRUE(read_boundary_lines(self, &new_last_line, &new_first_line)); + + /* Check if we read vmas after shrinking it */ + if (!strcmp(new_last_line.text, shrunk_last_line.text)) { + /* + * The vmas should be consistent with shrunk results, + * however if the vma was concurrently restored, it + * can be reported twice (first as shrunk one, then + * as restored one) because we found it as the next vma + * again. In that case new first line will be the same + * as the last restored line. + */ + ASSERT_FALSE(print_boundaries_on( + strcmp(new_first_line.text, shrunk_first_line.text) && + strcmp(new_first_line.text, restored_last_line.text), + "Shrink result invalid", self)); + } else { + /* The vmas should be consistent with the original/resored state */ + ASSERT_FALSE(print_boundaries_on( + strcmp(new_last_line.text, restored_last_line.text), + "Expand result invalid", self)); + ASSERT_FALSE(print_boundaries_on( + strcmp(new_first_line.text, restored_first_line.text), + "Expand result invalid", self)); + } + + /* Check if PROCMAP_QUERY ioclt() finds the right VMA */ + ASSERT_TRUE(query_addr_at(self->maps_fd, mod_info->addr, &vma_start, &vma_end)); + /* + * The vma should stay at the same address and have either the + * original size of 3 pages or 1 page if read after shrinking. + */ + ASSERT_TRUE(vma_start == self->last_line.start_addr && + (vma_end - vma_start == self->page_size * 3 || + vma_end - vma_start == self->page_size)); + + clock_gettime(CLOCK_MONOTONIC_COARSE, &end_ts); + end_test_iteration(&end_ts, self->verbose); + } while (end_ts.tv_sec - start_ts.tv_sec < self->duration_sec); + end_test_loop(self->verbose); + + /* Signal the modifyer thread to stop and wait until it exits */ + signal_state(mod_info, TEST_DONE); +} + +TEST_F(proc_maps_race, test_maps_tearing_from_remap) +{ + struct vma_modifier_info *mod_info = self->mod_info; + + struct line_content remapped_last_line; + struct line_content remapped_first_line; + struct line_content restored_last_line; + struct line_content restored_first_line; + + wait_for_state(mod_info, SETUP_READY); + + /* re-read the file to avoid using stale data from previous test */ + ASSERT_TRUE(read_boundary_lines(self, &self->last_line, &self->first_line)); + + mod_info->vma_modify = remap_vma; + mod_info->vma_restore = patch_vma; + mod_info->vma_mod_check = check_remap_result; + + report_test_start("Tearing from remap", self->verbose); + ASSERT_TRUE(capture_mod_pattern(self, &remapped_last_line, &remapped_first_line, + &restored_last_line, &restored_first_line)); + + /* Now start concurrent modifications for self->duration_sec */ + signal_state(mod_info, TEST_READY); + + struct line_content new_last_line; + struct line_content new_first_line; + struct timespec start_ts, end_ts; + + clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts); + start_test_loop(&start_ts, self->verbose); + do { + unsigned long vma_start; + unsigned long vma_end; + + ASSERT_TRUE(read_boundary_lines(self, &new_last_line, &new_first_line)); + + /* Check if we read vmas after remapping it */ + if (!strcmp(new_last_line.text, remapped_last_line.text)) { + /* + * The vmas should be consistent with remap results, + * however if the vma was concurrently restored, it + * can be reported twice (first as split one, then + * as restored one) because we found it as the next vma + * again. In that case new first line will be the same + * as the last restored line. + */ + ASSERT_FALSE(print_boundaries_on( + strcmp(new_first_line.text, remapped_first_line.text) && + strcmp(new_first_line.text, restored_last_line.text), + "Remap result invalid", self)); + } else { + /* The vmas should be consistent with the original/resored state */ + ASSERT_FALSE(print_boundaries_on( + strcmp(new_last_line.text, restored_last_line.text), + "Remap restore result invalid", self)); + ASSERT_FALSE(print_boundaries_on( + strcmp(new_first_line.text, restored_first_line.text), + "Remap restore result invalid", self)); + } + + /* Check if PROCMAP_QUERY ioclt() finds the right VMA */ + ASSERT_TRUE(query_addr_at(self->maps_fd, mod_info->addr + self->page_size, + &vma_start, &vma_end)); + /* + * The vma should either stay at the same address and have the + * original size of 3 pages or we should find the remapped vma + * at the remap destination address with size of 1 page. + */ + ASSERT_TRUE((vma_start == self->last_line.start_addr && + vma_end - vma_start == self->page_size * 3) || + (vma_start == self->last_line.start_addr + self->page_size && + vma_end - vma_start == self->page_size)); + + clock_gettime(CLOCK_MONOTONIC_COARSE, &end_ts); + end_test_iteration(&end_ts, self->verbose); + } while (end_ts.tv_sec - start_ts.tv_sec < self->duration_sec); + end_test_loop(self->verbose); + + /* Signal the modifyer thread to stop and wait until it exits */ + signal_state(mod_info, TEST_DONE); +} + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/proc/proc-net-dev-lseek.c b/tools/testing/selftests/proc/proc-net-dev-lseek.c new file mode 100644 index 000000000000..742a3e804451 --- /dev/null +++ b/tools/testing/selftests/proc/proc-net-dev-lseek.c @@ -0,0 +1,68 @@ +/* + * Copyright (c) 2025 Alexey Dobriyan <adobriyan@gmail.com> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ +#undef _GNU_SOURCE +#define _GNU_SOURCE +#undef NDEBUG +#include <assert.h> +#include <errno.h> +#include <fcntl.h> +#include <string.h> +#include <unistd.h> +#include <sched.h> +/* + * Test that lseek("/proc/net/dev/", 0, SEEK_SET) + * a) works, + * b) does what you think it does. + */ +int main(void) +{ + /* /proc/net/dev output is deterministic in fresh netns only. */ + if (unshare(CLONE_NEWNET) == -1) { + if (errno == ENOSYS || errno == EPERM) { + return 4; + } + return 1; + } + + const int fd = open("/proc/net/dev", O_RDONLY); + assert(fd >= 0); + + char buf1[4096]; + const ssize_t rv1 = read(fd, buf1, sizeof(buf1)); + /* + * Not "<=", this file can't be empty: + * there is header, "lo" interface with some zeroes. + */ + assert(0 < rv1); + assert(rv1 <= sizeof(buf1)); + + /* Believe it or not, this line broke one day. */ + assert(lseek(fd, 0, SEEK_SET) == 0); + + char buf2[4096]; + const ssize_t rv2 = read(fd, buf2, sizeof(buf2)); + /* Not "<=", see above. */ + assert(0 < rv2); + assert(rv2 <= sizeof(buf2)); + + /* Test that lseek rewinds to the beginning of the file. */ + assert(rv1 == rv2); + assert(memcmp(buf1, buf2, rv1) == 0); + + /* Contents of the file is not validated: this test is about lseek(). */ + + return 0; +} diff --git a/tools/testing/selftests/proc/proc-pid-vm.c b/tools/testing/selftests/proc/proc-pid-vm.c index d04685771952..4e6a3e53f975 100644 --- a/tools/testing/selftests/proc/proc-pid-vm.c +++ b/tools/testing/selftests/proc/proc-pid-vm.c @@ -47,7 +47,11 @@ #include <sys/resource.h> #include <linux/fs.h> -#include "../kselftest.h" +#ifndef __maybe_unused +#define __maybe_unused __attribute__((__unused__)) +#endif + +#include "kselftest.h" static inline long sys_execveat(int dirfd, const char *pathname, char **argv, char **envp, int flags) { @@ -218,12 +222,12 @@ static int make_exe(const uint8_t *payload, size_t len) * 2: vsyscall VMA is r-xp vsyscall=emulate */ static volatile int g_vsyscall; -static const char *str_vsyscall; +static const char *str_vsyscall __maybe_unused; -static const char str_vsyscall_0[] = ""; -static const char str_vsyscall_1[] = +static const char str_vsyscall_0[] __maybe_unused = ""; +static const char str_vsyscall_1[] __maybe_unused = "ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0 [vsyscall]\n"; -static const char str_vsyscall_2[] = +static const char str_vsyscall_2[] __maybe_unused = "ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]\n"; #ifdef __x86_64__ diff --git a/tools/testing/selftests/proc/proc-pidns.c b/tools/testing/selftests/proc/proc-pidns.c new file mode 100644 index 000000000000..25b9a2933c45 --- /dev/null +++ b/tools/testing/selftests/proc/proc-pidns.c @@ -0,0 +1,211 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Author: Aleksa Sarai <cyphar@cyphar.com> + * Copyright (C) 2025 SUSE LLC. + */ + +#include <assert.h> +#include <errno.h> +#include <sched.h> +#include <stdbool.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <stdio.h> +#include <sys/mount.h> +#include <sys/stat.h> +#include <sys/prctl.h> + +#include "kselftest_harness.h" + +#define ASSERT_ERRNO(expected, _t, seen) \ + __EXPECT(expected, #expected, \ + ({__typeof__(seen) _tmp_seen = (seen); \ + _tmp_seen >= 0 ? _tmp_seen : -errno; }), #seen, _t, 1) + +#define ASSERT_ERRNO_EQ(expected, seen) \ + ASSERT_ERRNO(expected, ==, seen) + +#define ASSERT_SUCCESS(seen) \ + ASSERT_ERRNO(0, <=, seen) + +static int touch(char *path) +{ + int fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC, 0644); + if (fd < 0) + return -1; + return close(fd); +} + +FIXTURE(ns) +{ + int host_mntns, host_pidns; + int dummy_pidns; +}; + +FIXTURE_SETUP(ns) +{ + /* Stash the old mntns. */ + self->host_mntns = open("/proc/self/ns/mnt", O_RDONLY|O_CLOEXEC); + ASSERT_SUCCESS(self->host_mntns); + + /* Create a new mount namespace and make it private. */ + ASSERT_SUCCESS(unshare(CLONE_NEWNS)); + ASSERT_SUCCESS(mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL)); + + /* + * Create a proper tmpfs that we can use and will disappear once we + * leave this mntns. + */ + ASSERT_SUCCESS(mount("tmpfs", "/tmp", "tmpfs", 0, NULL)); + + /* + * Create a pidns we can use for later tests. We need to fork off a + * child so that we get a usable nsfd that we can bind-mount and open. + */ + ASSERT_SUCCESS(mkdir("/tmp/dummy", 0755)); + ASSERT_SUCCESS(touch("/tmp/dummy/pidns")); + ASSERT_SUCCESS(mkdir("/tmp/dummy/proc", 0755)); + + self->host_pidns = open("/proc/self/ns/pid", O_RDONLY|O_CLOEXEC); + ASSERT_SUCCESS(self->host_pidns); + ASSERT_SUCCESS(unshare(CLONE_NEWPID)); + + pid_t pid = fork(); + ASSERT_SUCCESS(pid); + if (!pid) { + prctl(PR_SET_PDEATHSIG, SIGKILL); + ASSERT_SUCCESS(mount("/proc/self/ns/pid", "/tmp/dummy/pidns", NULL, MS_BIND, NULL)); + ASSERT_SUCCESS(mount("proc", "/tmp/dummy/proc", "proc", 0, NULL)); + exit(0); + } + + int wstatus; + ASSERT_EQ(waitpid(pid, &wstatus, 0), pid); + ASSERT_TRUE(WIFEXITED(wstatus)); + ASSERT_EQ(WEXITSTATUS(wstatus), 0); + + ASSERT_SUCCESS(setns(self->host_pidns, CLONE_NEWPID)); + + self->dummy_pidns = open("/tmp/dummy/pidns", O_RDONLY|O_CLOEXEC); + ASSERT_SUCCESS(self->dummy_pidns); +} + +FIXTURE_TEARDOWN(ns) +{ + ASSERT_SUCCESS(setns(self->host_mntns, CLONE_NEWNS)); + ASSERT_SUCCESS(close(self->host_mntns)); + + ASSERT_SUCCESS(close(self->host_pidns)); + ASSERT_SUCCESS(close(self->dummy_pidns)); +} + +TEST_F(ns, pidns_mount_string_path) +{ + ASSERT_SUCCESS(mkdir("/tmp/proc-host", 0755)); + ASSERT_SUCCESS(mount("proc", "/tmp/proc-host", "proc", 0, "pidns=/proc/self/ns/pid")); + ASSERT_SUCCESS(access("/tmp/proc-host/self/", X_OK)); + + ASSERT_SUCCESS(mkdir("/tmp/proc-dummy", 0755)); + ASSERT_SUCCESS(mount("proc", "/tmp/proc-dummy", "proc", 0, "pidns=/tmp/dummy/pidns")); + ASSERT_ERRNO_EQ(-ENOENT, access("/tmp/proc-dummy/1/", X_OK)); + ASSERT_ERRNO_EQ(-ENOENT, access("/tmp/proc-dummy/self/", X_OK)); +} + +TEST_F(ns, pidns_fsconfig_string_path) +{ + int fsfd = fsopen("proc", FSOPEN_CLOEXEC); + ASSERT_SUCCESS(fsfd); + + ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_SET_STRING, "pidns", "/tmp/dummy/pidns", 0)); + ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0)); + + int mountfd = fsmount(fsfd, FSMOUNT_CLOEXEC, 0); + ASSERT_SUCCESS(mountfd); + + ASSERT_ERRNO_EQ(-ENOENT, faccessat(mountfd, "1/", X_OK, 0)); + ASSERT_ERRNO_EQ(-ENOENT, faccessat(mountfd, "self/", X_OK, 0)); + + ASSERT_SUCCESS(close(fsfd)); + ASSERT_SUCCESS(close(mountfd)); +} + +TEST_F(ns, pidns_fsconfig_fd) +{ + int fsfd = fsopen("proc", FSOPEN_CLOEXEC); + ASSERT_SUCCESS(fsfd); + + ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_SET_FD, "pidns", NULL, self->dummy_pidns)); + ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0)); + + int mountfd = fsmount(fsfd, FSMOUNT_CLOEXEC, 0); + ASSERT_SUCCESS(mountfd); + + ASSERT_ERRNO_EQ(-ENOENT, faccessat(mountfd, "1/", X_OK, 0)); + ASSERT_ERRNO_EQ(-ENOENT, faccessat(mountfd, "self/", X_OK, 0)); + + ASSERT_SUCCESS(close(fsfd)); + ASSERT_SUCCESS(close(mountfd)); +} + +TEST_F(ns, pidns_reconfigure_remount) +{ + ASSERT_SUCCESS(mkdir("/tmp/proc", 0755)); + ASSERT_SUCCESS(mount("proc", "/tmp/proc", "proc", 0, "")); + + ASSERT_SUCCESS(access("/tmp/proc/1/", X_OK)); + ASSERT_SUCCESS(access("/tmp/proc/self/", X_OK)); + + ASSERT_ERRNO_EQ(-EBUSY, mount(NULL, "/tmp/proc", NULL, MS_REMOUNT, "pidns=/tmp/dummy/pidns")); + + ASSERT_SUCCESS(access("/tmp/proc/1/", X_OK)); + ASSERT_SUCCESS(access("/tmp/proc/self/", X_OK)); +} + +TEST_F(ns, pidns_reconfigure_fsconfig_string_path) +{ + int fsfd = fsopen("proc", FSOPEN_CLOEXEC); + ASSERT_SUCCESS(fsfd); + + ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0)); + + int mountfd = fsmount(fsfd, FSMOUNT_CLOEXEC, 0); + ASSERT_SUCCESS(mountfd); + + ASSERT_SUCCESS(faccessat(mountfd, "1/", X_OK, 0)); + ASSERT_SUCCESS(faccessat(mountfd, "self/", X_OK, 0)); + + ASSERT_ERRNO_EQ(-EBUSY, fsconfig(fsfd, FSCONFIG_SET_STRING, "pidns", "/tmp/dummy/pidns", 0)); + ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_CMD_RECONFIGURE, NULL, NULL, 0)); /* noop */ + + ASSERT_SUCCESS(faccessat(mountfd, "1/", X_OK, 0)); + ASSERT_SUCCESS(faccessat(mountfd, "self/", X_OK, 0)); + + ASSERT_SUCCESS(close(fsfd)); + ASSERT_SUCCESS(close(mountfd)); +} + +TEST_F(ns, pidns_reconfigure_fsconfig_fd) +{ + int fsfd = fsopen("proc", FSOPEN_CLOEXEC); + ASSERT_SUCCESS(fsfd); + + ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0)); + + int mountfd = fsmount(fsfd, FSMOUNT_CLOEXEC, 0); + ASSERT_SUCCESS(mountfd); + + ASSERT_SUCCESS(faccessat(mountfd, "1/", X_OK, 0)); + ASSERT_SUCCESS(faccessat(mountfd, "self/", X_OK, 0)); + + ASSERT_ERRNO_EQ(-EBUSY, fsconfig(fsfd, FSCONFIG_SET_FD, "pidns", NULL, self->dummy_pidns)); + ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_CMD_RECONFIGURE, NULL, NULL, 0)); /* noop */ + + ASSERT_SUCCESS(faccessat(mountfd, "1/", X_OK, 0)); + ASSERT_SUCCESS(faccessat(mountfd, "self/", X_OK, 0)); + + ASSERT_SUCCESS(close(fsfd)); + ASSERT_SUCCESS(close(mountfd)); +} + +TEST_HARNESS_MAIN |