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 <sys/ptrace.h>
  13 #include <assert.h>
  14 #include <sys/wait.h>
  15 #include <stddef.h>
  16 #include <errno.h>
  17 #include <sys/uio.h>
  18 #include <elf.h>
  19
  20 static pid_t child;
  21
  22 static void
  23 cleanup (void)
  24 {
  25   if (child > 0)
  26     kill (child, SIGKILL);
  27   child = 0;
  28 }
  29
  30 /* Macros to extract fields from the hardware debug information word.  */
  31 #define AARCH64_DEBUG_NUM_SLOTS(x) ((x) & 0xff)
  32 #define AARCH64_DEBUG_ARCH(x) (((x) >> 8) & 0xff)
  33 /* Macro for the expected version of the ARMv8-A debug architecture.  */
  34 #define AARCH64_DEBUG_ARCH_V8 0x6
  35 #define DR_CONTROL_ENABLED(ctrl)        (((ctrl) & 0x1) == 1)
  36 #define DR_CONTROL_LENGTH(ctrl)         (((ctrl) >> 5) & 0xff)
  37
  38 static void
  39 set_watchpoint (pid_t pid, volatile void *addr, unsigned len_mask)
  40 {
  41   struct user_hwdebug_state dreg_state;
  42   struct iovec iov;
  43   long l;
  44
  45   assert (len_mask >= 0x01);
  46   assert (len_mask <= 0xff);
  47
  48   iov.iov_base = &dreg_state;
  49   iov.iov_len = sizeof (dreg_state);
  50   errno = 0;
  51   l = ptrace (PTRACE_GETREGSET, pid, NT_ARM_HW_WATCH, &iov);
  52   assert (l == 0);
  53   assert (AARCH64_DEBUG_ARCH (dreg_state.dbg_info) == AARCH64_DEBUG_ARCH_V8);
  54   assert (AARCH64_DEBUG_NUM_SLOTS (dreg_state.dbg_info) >= 1);
  55
  56   assert (!DR_CONTROL_ENABLED (dreg_state.dbg_regs[0].ctrl));
  57   dreg_state.dbg_regs[0].ctrl |= 1;
  58   assert ( DR_CONTROL_ENABLED (dreg_state.dbg_regs[0].ctrl));
  59
  60   assert (DR_CONTROL_LENGTH (dreg_state.dbg_regs[0].ctrl) == 0);
  61   dreg_state.dbg_regs[0].ctrl |= len_mask << 5;
  62   assert (DR_CONTROL_LENGTH (dreg_state.dbg_regs[0].ctrl) == len_mask);
  63
  64   dreg_state.dbg_regs[0].ctrl |= 2 << 3; // write
  65   dreg_state.dbg_regs[0].ctrl |= 2 << 1; // enabled at el0
  66   dreg_state.dbg_regs[0].addr = (uintptr_t) addr;
  67
  68   iov.iov_base = &dreg_state;
  69   iov.iov_len = (offsetof (struct user_hwdebug_state, dbg_regs)
  70                  + sizeof (dreg_state.dbg_regs[0]));
  71   errno = 0;
  72   l = ptrace (PTRACE_SETREGSET, pid, NT_ARM_HW_WATCH, &iov);
  73   if (errno != 0)
  74     error (1, errno, "PTRACE_SETREGSET: NT_ARM_HW_WATCH");
  75   assert (l == 0);
  76 }
  77
  78 static volatile long long check;
  79
  80 int
  81 main (void)
  82 {
  83   pid_t got_pid;
  84   int i, status;
  85   long l;
  86
  87   atexit (cleanup);
  88
  89   child = fork ();
  90   assert (child >= 0);
  91   if (child == 0)
  92     {
  93       l = ptrace (PTRACE_TRACEME, 0, NULL, NULL);
  94       assert (l == 0);
  95       i = raise (SIGUSR1);
  96       assert (i == 0);
  97       check = -1;
  98       i = raise (SIGUSR2);
  99       /* NOTREACHED */
 100       assert (0);
 101     }
 102
 103   got_pid = waitpid (child, &status, 0);
 104   assert (got_pid == child);
 105   assert (WIFSTOPPED (status));
 106   assert (WSTOPSIG (status) == SIGUSR1);
 107
 108   /* Add a watchpoint to check.
 109      Restart the child. It will write to check.
 110      Check child has stopped on the watchpoint.  */
 111   set_watchpoint (child, &check, 0x02);
 112
 113   errno = 0;
 114   l = ptrace (PTRACE_CONT, child, 0l, 0l);
 115   assert_perror (errno);
 116   assert (l == 0);
 117
 118   got_pid = waitpid (child, &status, 0);
 119   assert (got_pid == child);
 120   assert (WIFSTOPPED (status));
 121   if (WSTOPSIG (status) == SIGUSR2)
 122     {
 123       /* We missed the watchpoint - unsupported by hardware?  */
 124       cleanup ();
 125       return 2;
 126     }
 127   assert (WSTOPSIG (status) == SIGTRAP);
 128
 129   return 0;
 130 }