gdb/testsuite/gdb.arch/aarch64-dbreg-contents.c

   1 /* Test case for setting a memory-write unaligned watchpoint on aarch64.
   2
   3   This software is provided 'as-is', without any express or implied
   4   warranty.  In no event will the authors be held liable for any damages
   5   arising from the use of this software.
   6
   7   Permission is granted to anyone to use this software for any purpose,
   8   including commercial applications, and to alter it and redistribute it
   9   freely.  */
  10
  11 #define _GNU_SOURCE 1
  12 #include <stdlib.h>
  13 #include <unistd.h>
  14 #include <sys/ptrace.h>
  15 #include <asm/ptrace.h>
  16 #include <assert.h>
  17 #include <sys/wait.h>
  18 #include <stddef.h>
  19 #include <errno.h>
  20 #include <sys/uio.h>
  21 #include <elf.h>
  22 #include <error.h>
  23
  24 static pid_t child;
  25
  26 static void
  27 cleanup (void)
  28 {
  29   if (child > 0)
  30     kill (child, SIGKILL);
  31   child = 0;
  32 }
  33
  34 /* Macros to extract fields from the hardware debug information word.  */
  35 #define AARCH64_DEBUG_NUM_SLOTS(x) ((x) & 0xff)
  36 #define AARCH64_DEBUG_ARCH(x) (((x) >> 8) & 0xff)
  37 /* Macro for the expected version of the ARMv8-A debug architecture.  */
  38 #define AARCH64_DEBUG_ARCH_V8 0x6
  39 #define DR_CONTROL_ENABLED(ctrl)        (((ctrl) & 0x1) == 1)
  40 #define DR_CONTROL_LENGTH(ctrl)         (((ctrl) >> 5) & 0xff)
  41
  42 static void
  43 set_watchpoint (pid_t pid, volatile void *addr, unsigned len_mask)
  44 {
  45   struct user_hwdebug_state dreg_state;
  46   struct iovec iov;
  47   long l;
  48
  49   assert (len_mask >= 0x01);
  50   assert (len_mask <= 0xff);
  51
  52   iov.iov_base = &dreg_state;
  53   iov.iov_len = sizeof (dreg_state);
  54   errno = 0;
  55   l = ptrace (PTRACE_GETREGSET, pid, NT_ARM_HW_WATCH, &iov);
  56   assert (l == 0);
  57   assert (AARCH64_DEBUG_ARCH (dreg_state.dbg_info) >= AARCH64_DEBUG_ARCH_V8);
  58   assert (AARCH64_DEBUG_NUM_SLOTS (dreg_state.dbg_info) >= 1);
  59
  60   assert (!DR_CONTROL_ENABLED (dreg_state.dbg_regs[0].ctrl));
  61   dreg_state.dbg_regs[0].ctrl |= 1;
  62   assert ( DR_CONTROL_ENABLED (dreg_state.dbg_regs[0].ctrl));
  63
  64   assert (DR_CONTROL_LENGTH (dreg_state.dbg_regs[0].ctrl) == 0);
  65   dreg_state.dbg_regs[0].ctrl |= len_mask << 5;
  66   assert (DR_CONTROL_LENGTH (dreg_state.dbg_regs[0].ctrl) == len_mask);
  67
  68   dreg_state.dbg_regs[0].ctrl |= 2 << 3; // write
  69   dreg_state.dbg_regs[0].ctrl |= 2 << 1; // enabled at el0
  70   dreg_state.dbg_regs[0].addr = (uintptr_t) addr;
  71
  72   iov.iov_base = &dreg_state;
  73   iov.iov_len = (offsetof (struct user_hwdebug_state, dbg_regs)
  74                  + sizeof (dreg_state.dbg_regs[0]));
  75   errno = 0;
  76   l = ptrace (PTRACE_SETREGSET, pid, NT_ARM_HW_WATCH, &iov);
  77   if (errno != 0)
  78     error (1, errno, "PTRACE_SETREGSET: NT_ARM_HW_WATCH");
  79   assert (l == 0);
  80 }
  81
  82 static volatile long long check;
  83
  84 int
  85 main (void)
  86 {
  87   pid_t got_pid;
  88   int i, status;
  89   long l;
  90
  91   atexit (cleanup);
  92
  93   child = fork ();
  94   assert (child >= 0);
  95   if (child == 0)
  96     {
  97       l = ptrace (PTRACE_TRACEME, 0, NULL, NULL);
  98       assert (l == 0);
  99       i = raise (SIGUSR1);
 100       assert (i == 0);
 101       check = -1;
 102       i = raise (SIGUSR2);
 103       /* NOTREACHED */
 104       assert (0);
 105     }
 106
 107   got_pid = waitpid (child, &status, 0);
 108   assert (got_pid == child);
 109   assert (WIFSTOPPED (status));
 110   assert (WSTOPSIG (status) == SIGUSR1);
 111
 112   /* Add a watchpoint to check.
 113      Restart the child. It will write to check.
 114      Check child has stopped on the watchpoint.  */
 115   set_watchpoint (child, &check, 0x02);
 116
 117   errno = 0;
 118   l = ptrace (PTRACE_CONT, child, 0l, 0l);
 119   assert_perror (errno);
 120   assert (l == 0);
 121
 122   got_pid = waitpid (child, &status, 0);
 123   assert (got_pid == child);
 124   assert (WIFSTOPPED (status));
 125   if (WSTOPSIG (status) == SIGUSR2)
 126     {
 127       /* We missed the watchpoint - unsupported by hardware?  */
 128       cleanup ();
 129       return 2;
 130     }
 131   assert (WSTOPSIG (status) == SIGTRAP);
 132
 133   return 0;
 134 }