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1// SPDX-License-Identifier: GPL-2.02/*3 * A ptrace test for testing PTRACE_SYSEMU, PTRACE_SETREGS and4 * PTRACE_GETREG. This test basically create a child process that executes5 * syscalls and the parent process check if it is being traced appropriated.6 *7 * This test is heavily based on tools/testing/selftests/x86/ptrace_syscall.c8 * test, and it was adapted to run on Powerpc by9 * Breno Leitao <leitao@debian.org>10 */11#define _GNU_SOURCE12 13#include <sys/ptrace.h>14#include <sys/types.h>15#include <sys/wait.h>16#include <sys/syscall.h>17#include <sys/user.h>18#include <unistd.h>19#include <errno.h>20#include <stddef.h>21#include <stdio.h>22#include <err.h>23#include <string.h>24#include <sys/auxv.h>25#include "utils.h"26 27/* Bitness-agnostic defines for user_regs_struct fields. */28#define user_syscall_nr gpr[0]29#define user_arg0 gpr[3]30#define user_arg1 gpr[4]31#define user_arg2 gpr[5]32#define user_arg3 gpr[6]33#define user_arg4 gpr[7]34#define user_arg5 gpr[8]35#define user_ip nip36 37#define PTRACE_SYSEMU 0x1d38 39static int nerrs;40 41static void wait_trap(pid_t chld)42{43 siginfo_t si;44 45 if (waitid(P_PID, chld, &si, WEXITED|WSTOPPED) != 0)46 err(1, "waitid");47 if (si.si_pid != chld)48 errx(1, "got unexpected pid in event\n");49 if (si.si_code != CLD_TRAPPED)50 errx(1, "got unexpected event type %d\n", si.si_code);51}52 53static void test_ptrace_syscall_restart(void)54{55 int status;56 struct pt_regs regs;57 pid_t chld;58 59 printf("[RUN]\tptrace-induced syscall restart\n");60 61 chld = fork();62 if (chld < 0)63 err(1, "fork");64 65 /*66 * Child process is running 4 syscalls after ptrace.67 *68 * 1) getpid()69 * 2) gettid()70 * 3) tgkill() -> Send SIGSTOP71 * 4) gettid() -> Where the tests will happen essentially72 */73 if (chld == 0) {74 if (ptrace(PTRACE_TRACEME, 0, 0, 0) != 0)75 err(1, "PTRACE_TRACEME");76 77 pid_t pid = getpid(), tid = syscall(SYS_gettid);78 79 printf("\tChild will make one syscall\n");80 syscall(SYS_tgkill, pid, tid, SIGSTOP);81 82 syscall(SYS_gettid, 10, 11, 12, 13, 14, 15);83 _exit(0);84 }85 /* Parent process below */86 87 /* Wait for SIGSTOP sent by tgkill above. */88 if (waitpid(chld, &status, 0) != chld || !WIFSTOPPED(status))89 err(1, "waitpid");90 91 printf("[RUN]\tSYSEMU\n");92 if (ptrace(PTRACE_SYSEMU, chld, 0, 0) != 0)93 err(1, "PTRACE_SYSEMU");94 wait_trap(chld);95 96 if (ptrace(PTRACE_GETREGS, chld, 0, ®s) != 0)97 err(1, "PTRACE_GETREGS");98 99 /*100 * Ptrace trapped prior to executing the syscall, thus r3 still has101 * the syscall number instead of the sys_gettid() result102 */103 if (regs.user_syscall_nr != SYS_gettid ||104 regs.user_arg0 != 10 || regs.user_arg1 != 11 ||105 regs.user_arg2 != 12 || regs.user_arg3 != 13 ||106 regs.user_arg4 != 14 || regs.user_arg5 != 15) {107 printf("[FAIL]\tInitial args are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n",108 (unsigned long)regs.user_syscall_nr,109 (unsigned long)regs.user_arg0,110 (unsigned long)regs.user_arg1,111 (unsigned long)regs.user_arg2,112 (unsigned long)regs.user_arg3,113 (unsigned long)regs.user_arg4,114 (unsigned long)regs.user_arg5);115 nerrs++;116 } else {117 printf("[OK]\tInitial nr and args are correct\n"); }118 119 printf("[RUN]\tRestart the syscall (ip = 0x%lx)\n",120 (unsigned long)regs.user_ip);121 122 /*123 * Rewind to retry the same syscall again. This will basically test124 * the rewind process together with PTRACE_SETREGS and PTRACE_GETREGS.125 */126 regs.user_ip -= 4;127 if (ptrace(PTRACE_SETREGS, chld, 0, ®s) != 0)128 err(1, "PTRACE_SETREGS");129 130 if (ptrace(PTRACE_SYSEMU, chld, 0, 0) != 0)131 err(1, "PTRACE_SYSEMU");132 wait_trap(chld);133 134 if (ptrace(PTRACE_GETREGS, chld, 0, ®s) != 0)135 err(1, "PTRACE_GETREGS");136 137 if (regs.user_syscall_nr != SYS_gettid ||138 regs.user_arg0 != 10 || regs.user_arg1 != 11 ||139 regs.user_arg2 != 12 || regs.user_arg3 != 13 ||140 regs.user_arg4 != 14 || regs.user_arg5 != 15) {141 printf("[FAIL]\tRestart nr or args are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n",142 (unsigned long)regs.user_syscall_nr,143 (unsigned long)regs.user_arg0,144 (unsigned long)regs.user_arg1,145 (unsigned long)regs.user_arg2,146 (unsigned long)regs.user_arg3,147 (unsigned long)regs.user_arg4,148 (unsigned long)regs.user_arg5);149 nerrs++;150 } else {151 printf("[OK]\tRestarted nr and args are correct\n");152 }153 154 printf("[RUN]\tChange nr and args and restart the syscall (ip = 0x%lx)\n",155 (unsigned long)regs.user_ip);156 157 /*158 * Inject a new syscall (getpid) in the same place the previous159 * syscall (gettid), rewind and re-execute.160 */161 regs.user_syscall_nr = SYS_getpid;162 regs.user_arg0 = 20;163 regs.user_arg1 = 21;164 regs.user_arg2 = 22;165 regs.user_arg3 = 23;166 regs.user_arg4 = 24;167 regs.user_arg5 = 25;168 regs.user_ip -= 4;169 170 if (ptrace(PTRACE_SETREGS, chld, 0, ®s) != 0)171 err(1, "PTRACE_SETREGS");172 173 if (ptrace(PTRACE_SYSEMU, chld, 0, 0) != 0)174 err(1, "PTRACE_SYSEMU");175 wait_trap(chld);176 177 if (ptrace(PTRACE_GETREGS, chld, 0, ®s) != 0)178 err(1, "PTRACE_GETREGS");179 180 /* Check that ptrace stopped at the new syscall that was181 * injected, and guarantee that it haven't executed, i.e, user_args182 * contain the arguments and not the syscall return value, for183 * instance.184 */185 if (regs.user_syscall_nr != SYS_getpid186 || regs.user_arg0 != 20 || regs.user_arg1 != 21187 || regs.user_arg2 != 22 || regs.user_arg3 != 23188 || regs.user_arg4 != 24 || regs.user_arg5 != 25) {189 190 printf("[FAIL]\tRestart nr or args are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n",191 (unsigned long)regs.user_syscall_nr,192 (unsigned long)regs.user_arg0,193 (unsigned long)regs.user_arg1,194 (unsigned long)regs.user_arg2,195 (unsigned long)regs.user_arg3,196 (unsigned long)regs.user_arg4,197 (unsigned long)regs.user_arg5);198 nerrs++;199 } else {200 printf("[OK]\tReplacement nr and args are correct\n");201 }202 203 if (ptrace(PTRACE_CONT, chld, 0, 0) != 0)204 err(1, "PTRACE_CONT");205 206 if (waitpid(chld, &status, 0) != chld)207 err(1, "waitpid");208 209 /* Guarantee that the process executed properly, returning 0 */210 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {211 printf("[FAIL]\tChild failed\n");212 nerrs++;213 } else {214 printf("[OK]\tChild exited cleanly\n");215 }216}217 218int ptrace_syscall(void)219{220 test_ptrace_syscall_restart();221 222 return nerrs;223}224 225int main(void)226{227 return test_harness(ptrace_syscall, "ptrace_syscall");228}229