tools/testing/selftests/ptrace/peeksiginfo.c

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