tools/testing/selftests/ptrace/peeksiginfo.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #define _GNU_SOURCE
   3 #include <stdio.h>
   4 #include <signal.h>
   5 #include <unistd.h>
   6 #include <errno.h>
   7 #include <linux/types.h>
   8 #include <sys/wait.h>
   9 #include <sys/syscall.h>
  10 #include <sys/user.h>
  11 #include <sys/mman.h>
  12
  13 #include "linux/ptrace.h"
  14
  15 static int sys_rt_sigqueueinfo(pid_t tgid, int sig, siginfo_t *uinfo)
  16 {
  17         return syscall(SYS_rt_sigqueueinfo, tgid, sig, uinfo);
  18 }
  19
  20 static int sys_rt_tgsigqueueinfo(pid_t tgid, pid_t tid,
  21                                         int sig, siginfo_t *uinfo)
  22 {
  23         return syscall(SYS_rt_tgsigqueueinfo, tgid, tid, sig, uinfo);
  24 }
  25
  26 static int sys_ptrace(int request, pid_t pid, void *addr, void *data)
  27 {
  28         return syscall(SYS_ptrace, request, pid, addr, data);
  29 }
  30
  31 #define SIGNR 10
  32 #define TEST_SICODE_PRIV        -1
  33 #define TEST_SICODE_SHARE       -2
  34
  35 #ifndef PAGE_SIZE
  36 #define PAGE_SIZE sysconf(_SC_PAGESIZE)
  37 #endif
  38
  39 #define err(fmt, ...)                                           \
  40                 fprintf(stderr,                                 \
  41                         "Error (%s:%d): " fmt,                  \
  42                         __FILE__, __LINE__, ##__VA_ARGS__)
  43
  44 static int check_error_paths(pid_t child)
  45 {
  46         struct ptrace_peeksiginfo_args arg;
  47         int ret, exit_code = -1;
  48         void *addr_rw, *addr_ro;
  49
  50         /*
  51          * Allocate two contiguous pages. The first one is for read-write,
  52          * another is for read-only.
  53          */
  54         addr_rw = mmap(NULL, 2 * PAGE_SIZE, PROT_READ | PROT_WRITE,
  55                                 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  56         if (addr_rw == MAP_FAILED) {
  57                 err("mmap() failed: %m\n");
  58                 return 1;
  59         }
  60
  61         addr_ro = mmap(addr_rw + PAGE_SIZE, PAGE_SIZE, PROT_READ,
  62                         MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
  63         if (addr_ro == MAP_FAILED) {
  64                 err("mmap() failed: %m\n");
  65                 goto out;
  66         }
  67
  68         arg.nr = SIGNR;
  69         arg.off = 0;
  70
  71         /* Unsupported flags */
  72         arg.flags = ~0;
  73         ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg, addr_rw);
  74         if (ret != -1 || errno != EINVAL) {
  75                 err("sys_ptrace() returns %d (expected -1),"
  76                                 " errno %d (expected %d): %m\n",
  77                                 ret, errno, EINVAL);
  78                 goto out;
  79         }
  80         arg.flags = 0;
  81
  82         /* A part of the buffer is read-only */
  83         ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg,
  84                                         addr_ro - sizeof(siginfo_t) * 2);
  85         if (ret != 2) {
  86                 err("sys_ptrace() returns %d (expected 2): %m\n", ret);
  87                 goto out;
  88         }
  89
  90         /* Read-only buffer */
  91         ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg, addr_ro);
  92         if (ret != -1 && errno != EFAULT) {
  93                 err("sys_ptrace() returns %d (expected -1),"
  94                                 " errno %d (expected %d): %m\n",
  95                                 ret, errno, EFAULT);
  96                 goto out;
  97         }
  98
  99         exit_code = 0;
 100 out:
 101         munmap(addr_rw, 2 * PAGE_SIZE);
 102         return exit_code;
 103 }
 104
 105 int check_direct_path(pid_t child, int shared, int nr)
 106 {
 107         struct ptrace_peeksiginfo_args arg = {.flags = 0, .nr = nr, .off = 0};
 108         int i, j, ret, exit_code = -1;
 109         siginfo_t siginfo[SIGNR];
 110         int si_code;
 111
 112         if (shared == 1) {
 113                 arg.flags = PTRACE_PEEKSIGINFO_SHARED;
 114                 si_code = TEST_SICODE_SHARE;
 115         } else {
 116                 arg.flags = 0;
 117                 si_code = TEST_SICODE_PRIV;
 118         }
 119
 120         for (i = 0; i < SIGNR; ) {
 121                 arg.off = i;
 122                 ret = sys_ptrace(PTRACE_PEEKSIGINFO, child, &arg, siginfo);
 123                 if (ret == -1) {
 124                         err("ptrace() failed: %m\n");
 125                         goto out;
 126                 }
 127
 128                 if (ret == 0)
 129                         break;
 130
 131                 for (j = 0; j < ret; j++, i++) {
 132                         if (siginfo[j].si_code == si_code &&
 133                             siginfo[j].si_int == i)
 134                                 continue;
 135
 136                         err("%d: Wrong siginfo i=%d si_code=%d si_int=%d\n",
 137                              shared, i, siginfo[j].si_code, siginfo[j].si_int);
 138                         goto out;
 139                 }
 140         }
 141
 142         if (i != SIGNR) {
 143                 err("Only %d signals were read\n", i);
 144                 goto out;
 145         }
 146
 147         exit_code = 0;
 148 out:
 149         return exit_code;
 150 }
 151
 152 int main(int argc, char *argv[])
 153 {
 154         siginfo_t siginfo[SIGNR];
 155         int i, exit_code = 1;
 156         sigset_t blockmask;
 157         pid_t child;
 158
 159         sigemptyset(&blockmask);
 160         sigaddset(&blockmask, SIGRTMIN);
 161         sigprocmask(SIG_BLOCK, &blockmask, NULL);
 162
 163         child = fork();
 164         if (child == -1) {
 165                 err("fork() failed: %m");
 166                 return 1;
 167         } else if (child == 0) {
 168                 pid_t ppid = getppid();
 169                 while (1) {
 170                         if (ppid != getppid())
 171                                 break;
 172                         sleep(1);
 173                 }
 174                 return 1;
 175         }
 176
 177         /* Send signals in process-wide and per-thread queues */
 178         for (i = 0; i < SIGNR; i++) {
 179                 siginfo->si_code = TEST_SICODE_SHARE;
 180                 siginfo->si_int = i;
 181                 sys_rt_sigqueueinfo(child, SIGRTMIN, siginfo);
 182
 183                 siginfo->si_code = TEST_SICODE_PRIV;
 184                 siginfo->si_int = i;
 185                 sys_rt_tgsigqueueinfo(child, child, SIGRTMIN, siginfo);
 186         }
 187
 188         if (sys_ptrace(PTRACE_ATTACH, child, NULL, NULL) == -1)
 189                 return 1;
 190
 191         waitpid(child, NULL, 0);
 192
 193         /* Dump signals one by one*/
 194         if (check_direct_path(child, 0, 1))
 195                 goto out;
 196         /* Dump all signals for one call */
 197         if (check_direct_path(child, 0, SIGNR))
 198                 goto out;
 199
 200         /*
 201          * Dump signal from the process-wide queue.
 202          * The number of signals is not multible to the buffer size
 203          */
 204         if (check_direct_path(child, 1, 3))
 205                 goto out;
 206
 207         if (check_error_paths(child))
 208                 goto out;
 209
 210         printf("PASS\n");
 211         exit_code = 0;
 212 out:
 213         if (sys_ptrace(PTRACE_KILL, child, NULL, NULL) == -1)
 214                 return 1;
 215
 216         waitpid(child, NULL, 0);
 217
 218         return exit_code;
 219 }