diff options
Diffstat (limited to '')
-rw-r--r-- | tools/testing/selftests/ptrace/.gitignore | 4 | ||||
-rw-r--r-- | tools/testing/selftests/ptrace/Makefile | 6 | ||||
-rw-r--r-- | tools/testing/selftests/ptrace/get_syscall_info.c | 271 | ||||
-rw-r--r-- | tools/testing/selftests/ptrace/peeksiginfo.c | 219 | ||||
-rw-r--r-- | tools/testing/selftests/ptrace/vmaccess.c | 86 |
5 files changed, 586 insertions, 0 deletions
diff --git a/tools/testing/selftests/ptrace/.gitignore b/tools/testing/selftests/ptrace/.gitignore new file mode 100644 index 000000000..792318aaa --- /dev/null +++ b/tools/testing/selftests/ptrace/.gitignore @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +get_syscall_info +peeksiginfo +vmaccess diff --git a/tools/testing/selftests/ptrace/Makefile b/tools/testing/selftests/ptrace/Makefile new file mode 100644 index 000000000..2f1f532c3 --- /dev/null +++ b/tools/testing/selftests/ptrace/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0-only +CFLAGS += -std=c99 -pthread -iquote../../../../include/uapi -Wall + +TEST_GEN_PROGS := get_syscall_info peeksiginfo vmaccess + +include ../lib.mk diff --git a/tools/testing/selftests/ptrace/get_syscall_info.c b/tools/testing/selftests/ptrace/get_syscall_info.c new file mode 100644 index 000000000..5bcd1c7b5 --- /dev/null +++ b/tools/testing/selftests/ptrace/get_syscall_info.c @@ -0,0 +1,271 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2018 Dmitry V. Levin <ldv@altlinux.org> + * All rights reserved. + * + * Check whether PTRACE_GET_SYSCALL_INFO semantics implemented in the kernel + * matches userspace expectations. + */ + +#include "../kselftest_harness.h" +#include <err.h> +#include <signal.h> +#include <asm/unistd.h> +#include "linux/ptrace.h" + +static int +kill_tracee(pid_t pid) +{ + if (!pid) + return 0; + + int saved_errno = errno; + + int rc = kill(pid, SIGKILL); + + errno = saved_errno; + return rc; +} + +static long +sys_ptrace(int request, pid_t pid, unsigned long addr, unsigned long data) +{ + return syscall(__NR_ptrace, request, pid, addr, data); +} + +#define LOG_KILL_TRACEE(fmt, ...) \ + do { \ + kill_tracee(pid); \ + TH_LOG("wait #%d: " fmt, \ + ptrace_stop, ##__VA_ARGS__); \ + } while (0) + +TEST(get_syscall_info) +{ + static const unsigned long args[][7] = { + /* a sequence of architecture-agnostic syscalls */ + { + __NR_chdir, + (unsigned long) "", + 0xbad1fed1, + 0xbad2fed2, + 0xbad3fed3, + 0xbad4fed4, + 0xbad5fed5 + }, + { + __NR_gettid, + 0xcaf0bea0, + 0xcaf1bea1, + 0xcaf2bea2, + 0xcaf3bea3, + 0xcaf4bea4, + 0xcaf5bea5 + }, + { + __NR_exit_group, + 0, + 0xfac1c0d1, + 0xfac2c0d2, + 0xfac3c0d3, + 0xfac4c0d4, + 0xfac5c0d5 + } + }; + const unsigned long *exp_args; + + pid_t pid = fork(); + + ASSERT_LE(0, pid) { + TH_LOG("fork: %m"); + } + + if (pid == 0) { + /* get the pid before PTRACE_TRACEME */ + pid = getpid(); + ASSERT_EQ(0, sys_ptrace(PTRACE_TRACEME, 0, 0, 0)) { + TH_LOG("PTRACE_TRACEME: %m"); + } + ASSERT_EQ(0, kill(pid, SIGSTOP)) { + /* cannot happen */ + TH_LOG("kill SIGSTOP: %m"); + } + for (unsigned int i = 0; i < ARRAY_SIZE(args); ++i) { + syscall(args[i][0], + args[i][1], args[i][2], args[i][3], + args[i][4], args[i][5], args[i][6]); + } + /* unreachable */ + _exit(1); + } + + const struct { + unsigned int is_error; + int rval; + } *exp_param, exit_param[] = { + { 1, -ENOENT }, /* chdir */ + { 0, pid } /* gettid */ + }; + + unsigned int ptrace_stop; + + for (ptrace_stop = 0; ; ++ptrace_stop) { + struct ptrace_syscall_info info = { + .op = 0xff /* invalid PTRACE_SYSCALL_INFO_* op */ + }; + const size_t size = sizeof(info); + const int expected_none_size = + (void *) &info.entry - (void *) &info; + const int expected_entry_size = + (void *) &info.entry.args[6] - (void *) &info; + const int expected_exit_size = + (void *) (&info.exit.is_error + 1) - + (void *) &info; + int status; + long rc; + + ASSERT_EQ(pid, wait(&status)) { + /* cannot happen */ + LOG_KILL_TRACEE("wait: %m"); + } + if (WIFEXITED(status)) { + pid = 0; /* the tracee is no more */ + ASSERT_EQ(0, WEXITSTATUS(status)); + break; + } + ASSERT_FALSE(WIFSIGNALED(status)) { + pid = 0; /* the tracee is no more */ + LOG_KILL_TRACEE("unexpected signal %u", + WTERMSIG(status)); + } + ASSERT_TRUE(WIFSTOPPED(status)) { + /* cannot happen */ + LOG_KILL_TRACEE("unexpected wait status %#x", status); + } + + switch (WSTOPSIG(status)) { + case SIGSTOP: + ASSERT_EQ(0, ptrace_stop) { + LOG_KILL_TRACEE("unexpected signal stop"); + } + ASSERT_EQ(0, sys_ptrace(PTRACE_SETOPTIONS, pid, 0, + PTRACE_O_TRACESYSGOOD)) { + LOG_KILL_TRACEE("PTRACE_SETOPTIONS: %m"); + } + ASSERT_LT(0, (rc = sys_ptrace(PTRACE_GET_SYSCALL_INFO, + pid, size, + (unsigned long) &info))) { + LOG_KILL_TRACEE("PTRACE_GET_SYSCALL_INFO: %m"); + } + ASSERT_EQ(expected_none_size, rc) { + LOG_KILL_TRACEE("signal stop mismatch"); + } + ASSERT_EQ(PTRACE_SYSCALL_INFO_NONE, info.op) { + LOG_KILL_TRACEE("signal stop mismatch"); + } + ASSERT_TRUE(info.arch) { + LOG_KILL_TRACEE("signal stop mismatch"); + } + ASSERT_TRUE(info.instruction_pointer) { + LOG_KILL_TRACEE("signal stop mismatch"); + } + ASSERT_TRUE(info.stack_pointer) { + LOG_KILL_TRACEE("signal stop mismatch"); + } + break; + + case SIGTRAP | 0x80: + ASSERT_LT(0, (rc = sys_ptrace(PTRACE_GET_SYSCALL_INFO, + pid, size, + (unsigned long) &info))) { + LOG_KILL_TRACEE("PTRACE_GET_SYSCALL_INFO: %m"); + } + switch (ptrace_stop) { + case 1: /* entering chdir */ + case 3: /* entering gettid */ + case 5: /* entering exit_group */ + exp_args = args[ptrace_stop / 2]; + ASSERT_EQ(expected_entry_size, rc) { + LOG_KILL_TRACEE("entry stop mismatch"); + } + ASSERT_EQ(PTRACE_SYSCALL_INFO_ENTRY, info.op) { + LOG_KILL_TRACEE("entry stop mismatch"); + } + ASSERT_TRUE(info.arch) { + LOG_KILL_TRACEE("entry stop mismatch"); + } + ASSERT_TRUE(info.instruction_pointer) { + LOG_KILL_TRACEE("entry stop mismatch"); + } + ASSERT_TRUE(info.stack_pointer) { + LOG_KILL_TRACEE("entry stop mismatch"); + } + ASSERT_EQ(exp_args[0], info.entry.nr) { + LOG_KILL_TRACEE("entry stop mismatch"); + } + ASSERT_EQ(exp_args[1], info.entry.args[0]) { + LOG_KILL_TRACEE("entry stop mismatch"); + } + ASSERT_EQ(exp_args[2], info.entry.args[1]) { + LOG_KILL_TRACEE("entry stop mismatch"); + } + ASSERT_EQ(exp_args[3], info.entry.args[2]) { + LOG_KILL_TRACEE("entry stop mismatch"); + } + ASSERT_EQ(exp_args[4], info.entry.args[3]) { + LOG_KILL_TRACEE("entry stop mismatch"); + } + ASSERT_EQ(exp_args[5], info.entry.args[4]) { + LOG_KILL_TRACEE("entry stop mismatch"); + } + ASSERT_EQ(exp_args[6], info.entry.args[5]) { + LOG_KILL_TRACEE("entry stop mismatch"); + } + break; + case 2: /* exiting chdir */ + case 4: /* exiting gettid */ + exp_param = &exit_param[ptrace_stop / 2 - 1]; + ASSERT_EQ(expected_exit_size, rc) { + LOG_KILL_TRACEE("exit stop mismatch"); + } + ASSERT_EQ(PTRACE_SYSCALL_INFO_EXIT, info.op) { + LOG_KILL_TRACEE("exit stop mismatch"); + } + ASSERT_TRUE(info.arch) { + LOG_KILL_TRACEE("exit stop mismatch"); + } + ASSERT_TRUE(info.instruction_pointer) { + LOG_KILL_TRACEE("exit stop mismatch"); + } + ASSERT_TRUE(info.stack_pointer) { + LOG_KILL_TRACEE("exit stop mismatch"); + } + ASSERT_EQ(exp_param->is_error, + info.exit.is_error) { + LOG_KILL_TRACEE("exit stop mismatch"); + } + ASSERT_EQ(exp_param->rval, info.exit.rval) { + LOG_KILL_TRACEE("exit stop mismatch"); + } + break; + default: + LOG_KILL_TRACEE("unexpected syscall stop"); + abort(); + } + break; + + default: + LOG_KILL_TRACEE("unexpected stop signal %#x", + WSTOPSIG(status)); + abort(); + } + + ASSERT_EQ(0, sys_ptrace(PTRACE_SYSCALL, pid, 0, 0)) { + LOG_KILL_TRACEE("PTRACE_SYSCALL: %m"); + } + } + + ASSERT_EQ(ARRAY_SIZE(args) * 2, ptrace_stop); +} + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/ptrace/peeksiginfo.c b/tools/testing/selftests/ptrace/peeksiginfo.c new file mode 100644 index 000000000..54900657e --- /dev/null +++ b/tools/testing/selftests/ptrace/peeksiginfo.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE +#include <stdio.h> +#include <signal.h> +#include <unistd.h> +#include <errno.h> +#include <linux/types.h> +#include <sys/wait.h> +#include <sys/syscall.h> +#include <sys/user.h> +#include <sys/mman.h> + +#include "linux/ptrace.h" + +static int sys_rt_sigqueueinfo(pid_t tgid, int sig, siginfo_t *uinfo) +{ + return syscall(SYS_rt_sigqueueinfo, tgid, sig, uinfo); +} + +static int sys_rt_tgsigqueueinfo(pid_t tgid, pid_t tid, + int sig, siginfo_t *uinfo) +{ + return syscall(SYS_rt_tgsigqueueinfo, tgid, tid, sig, uinfo); +} + +static int sys_ptrace(int request, pid_t pid, void *addr, void *data) +{ + return syscall(SYS_ptrace, request, pid, addr, data); +} + +#define SIGNR 10 +#define TEST_SICODE_PRIV -1 +#define TEST_SICODE_SHARE -2 + +#ifndef PAGE_SIZE +#define PAGE_SIZE sysconf(_SC_PAGESIZE) +#endif + +#define err(fmt, ...) \ + fprintf(stderr, \ + "Error (%s:%d): " fmt, \ + __FILE__, __LINE__, ##__VA_ARGS__) + +static int check_error_paths(pid_t child) +{ + struct ptrace_peeksiginfo_args arg; + int ret, exit_code = -1; + void *addr_rw, *addr_ro; + + /* + * Allocate two contiguous pages. The first one is for read-write, + * another is for read-only. + */ + addr_rw = mmap(NULL, 2 * PAGE_SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (addr_rw == MAP_FAILED) { + err("mmap() failed: %m\n"); + return 1; + } + + addr_ro = mmap(addr_rw + PAGE_SIZE, PAGE_SIZE, PROT_READ, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); + if (addr_ro == MAP_FAILED) { + err("mmap() failed: %m\n"); + goto out; + } + + arg.nr = SIGNR; + arg.off = 0; + + /* Unsupported flags */ + arg.flags = ~0; + ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg, addr_rw); + if (ret != -1 || errno != EINVAL) { + err("sys_ptrace() returns %d (expected -1)," + " errno %d (expected %d): %m\n", + ret, errno, EINVAL); + goto out; + } + arg.flags = 0; + + /* A part of the buffer is read-only */ + ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg, + addr_ro - sizeof(siginfo_t) * 2); + if (ret != 2) { + err("sys_ptrace() returns %d (expected 2): %m\n", ret); + goto out; + } + + /* Read-only buffer */ + ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg, addr_ro); + if (ret != -1 && errno != EFAULT) { + err("sys_ptrace() returns %d (expected -1)," + " errno %d (expected %d): %m\n", + ret, errno, EFAULT); + goto out; + } + + exit_code = 0; +out: + munmap(addr_rw, 2 * PAGE_SIZE); + return exit_code; +} + +int check_direct_path(pid_t child, int shared, int nr) +{ + struct ptrace_peeksiginfo_args arg = {.flags = 0, .nr = nr, .off = 0}; + int i, j, ret, exit_code = -1; + siginfo_t siginfo[SIGNR]; + int si_code; + + if (shared == 1) { + arg.flags = PTRACE_PEEKSIGINFO_SHARED; + si_code = TEST_SICODE_SHARE; + } else { + arg.flags = 0; + si_code = TEST_SICODE_PRIV; + } + + for (i = 0; i < SIGNR; ) { + arg.off = i; + ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg, siginfo); + if (ret == -1) { + err("ptrace() failed: %m\n"); + goto out; + } + + if (ret == 0) + break; + + for (j = 0; j < ret; j++, i++) { + if (siginfo[j].si_code == si_code && + siginfo[j].si_int == i) + continue; + + err("%d: Wrong siginfo i=%d si_code=%d si_int=%d\n", + shared, i, siginfo[j].si_code, siginfo[j].si_int); + goto out; + } + } + + if (i != SIGNR) { + err("Only %d signals were read\n", i); + goto out; + } + + exit_code = 0; +out: + return exit_code; +} + +int main(int argc, char *argv[]) +{ + siginfo_t siginfo[SIGNR]; + int i, exit_code = 1; + sigset_t blockmask; + pid_t child; + + sigemptyset(&blockmask); + sigaddset(&blockmask, SIGRTMIN); + sigprocmask(SIG_BLOCK, &blockmask, NULL); + + child = fork(); + if (child == -1) { + err("fork() failed: %m"); + return 1; + } else if (child == 0) { + pid_t ppid = getppid(); + while (1) { + if (ppid != getppid()) + break; + sleep(1); + } + return 1; + } + + /* Send signals in process-wide and per-thread queues */ + for (i = 0; i < SIGNR; i++) { + siginfo->si_code = TEST_SICODE_SHARE; + siginfo->si_int = i; + sys_rt_sigqueueinfo(child, SIGRTMIN, siginfo); + + siginfo->si_code = TEST_SICODE_PRIV; + siginfo->si_int = i; + sys_rt_tgsigqueueinfo(child, child, SIGRTMIN, siginfo); + } + + if (sys_ptrace(PTRACE_ATTACH, child, NULL, NULL) == -1) + return 1; + + waitpid(child, NULL, 0); + + /* Dump signals one by one*/ + if (check_direct_path(child, 0, 1)) + goto out; + /* Dump all signals for one call */ + if (check_direct_path(child, 0, SIGNR)) + goto out; + + /* + * Dump signal from the process-wide queue. + * The number of signals is not multible to the buffer size + */ + if (check_direct_path(child, 1, 3)) + goto out; + + if (check_error_paths(child)) + goto out; + + printf("PASS\n"); + exit_code = 0; +out: + if (sys_ptrace(PTRACE_KILL, child, NULL, NULL) == -1) + return 1; + + waitpid(child, NULL, 0); + + return exit_code; +} diff --git a/tools/testing/selftests/ptrace/vmaccess.c b/tools/testing/selftests/ptrace/vmaccess.c new file mode 100644 index 000000000..4db327b44 --- /dev/null +++ b/tools/testing/selftests/ptrace/vmaccess.c @@ -0,0 +1,86 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2020 Bernd Edlinger <bernd.edlinger@hotmail.de> + * All rights reserved. + * + * Check whether /proc/$pid/mem can be accessed without causing deadlocks + * when de_thread is blocked with ->cred_guard_mutex held. + */ + +#include "../kselftest_harness.h" +#include <stdio.h> +#include <fcntl.h> +#include <pthread.h> +#include <signal.h> +#include <unistd.h> +#include <sys/ptrace.h> + +static void *thread(void *arg) +{ + ptrace(PTRACE_TRACEME, 0, 0L, 0L); + return NULL; +} + +TEST(vmaccess) +{ + int f, pid = fork(); + char mm[64]; + + if (!pid) { + pthread_t pt; + + pthread_create(&pt, NULL, thread, NULL); + pthread_join(pt, NULL); + execlp("true", "true", NULL); + } + + sleep(1); + sprintf(mm, "/proc/%d/mem", pid); + f = open(mm, O_RDONLY); + ASSERT_GE(f, 0); + close(f); + f = kill(pid, SIGCONT); + ASSERT_EQ(f, 0); +} + +TEST(attach) +{ + int s, k, pid = fork(); + + if (!pid) { + pthread_t pt; + + pthread_create(&pt, NULL, thread, NULL); + pthread_join(pt, NULL); + execlp("sleep", "sleep", "2", NULL); + } + + sleep(1); + k = ptrace(PTRACE_ATTACH, pid, 0L, 0L); + ASSERT_EQ(errno, EAGAIN); + ASSERT_EQ(k, -1); + k = waitpid(-1, &s, WNOHANG); + ASSERT_NE(k, -1); + ASSERT_NE(k, 0); + ASSERT_NE(k, pid); + ASSERT_EQ(WIFEXITED(s), 1); + ASSERT_EQ(WEXITSTATUS(s), 0); + sleep(1); + k = ptrace(PTRACE_ATTACH, pid, 0L, 0L); + ASSERT_EQ(k, 0); + k = waitpid(-1, &s, 0); + ASSERT_EQ(k, pid); + ASSERT_EQ(WIFSTOPPED(s), 1); + ASSERT_EQ(WSTOPSIG(s), SIGSTOP); + k = ptrace(PTRACE_DETACH, pid, 0L, 0L); + ASSERT_EQ(k, 0); + k = waitpid(-1, &s, 0); + ASSERT_EQ(k, pid); + ASSERT_EQ(WIFEXITED(s), 1); + ASSERT_EQ(WEXITSTATUS(s), 0); + k = waitpid(-1, NULL, 0); + ASSERT_EQ(k, -1); + ASSERT_EQ(errno, ECHILD); +} + +TEST_HARNESS_MAIN |