In order to provide accurate information about the triggering
instruction, this patch adds the required bits to restore the pc if the
access happened inside a TB. With the BP_STOP_BEFORE_ACCESS flag, the
watchpoint user can control if the debug trap should be issued on or
after the accessing instruction.
In contrast to the earlier posted version, this one makes use of
next_cflags to ensure that the next TB contains just a single
instruction.
Signed-off-by: Jan Kiszka <[EMAIL PROTECTED]>
---
qemu/cpu-all.h | 1 +
qemu/exec.c | 22 ++++++++++++++++++++--
2 files changed, 21 insertions(+), 2 deletions(-)
Index: b/qemu/exec.c
===================================================================
--- a/qemu/exec.c
+++ b/qemu/exec.c
@@ -2476,16 +2476,34 @@ static CPUWriteMemoryFunc *notdirty_mem_
static void check_watchpoint(int offset, int len_mask, int flags)
{
CPUState *env = cpu_single_env;
+ TranslationBlock *tb;
target_ulong vaddr;
CPUWatchpoint *wp;
+ if (env->watchpoint_hit) {
+ /* We re-entered the check after replacing the TB. Now raise
+ * the debug interrupt so that is will trigger after the
+ * current instruction. */
+ cpu_interrupt(env, CPU_INTERRUPT_DEBUG);
+ return;
+ }
vaddr = (env->mem_io_vaddr & TARGET_PAGE_MASK) + offset;
for (wp = env->watchpoints; wp != NULL; wp = wp->next) {
if ((vaddr == (wp->vaddr & len_mask) ||
(vaddr & wp->len_mask) == wp->vaddr) && (wp->flags & flags)) {
env->watchpoint_hit = wp;
- cpu_interrupt(env, CPU_INTERRUPT_DEBUG);
- break;
+ tb = tb_find_pc(env->mem_io_pc);
+ if (!tb) {
+ cpu_abort(env, "check_watchpoint: could not find TB for pc=%p",
+ (void *)env->mem_io_pc);
+ }
+ cpu_restore_state(tb, env, env->mem_io_pc, NULL);
+ tb_phys_invalidate(tb, -1);
+ if (wp->flags & BP_STOP_BEFORE_ACCESS)
+ env->exception_index = EXCP_DEBUG;
+ else
+ env->next_cflags = 1;
+ cpu_resume_from_signal(env, NULL);
}
}
}
Index: b/qemu/cpu-all.h
===================================================================
--- a/qemu/cpu-all.h
+++ b/qemu/cpu-all.h
@@ -765,6 +765,7 @@ void cpu_reset_interrupt(CPUState *env,
#define BP_MEM_READ 0x01
#define BP_MEM_WRITE 0x02
#define BP_MEM_ACCESS (BP_MEM_READ | BP_MEM_WRITE)
+#define BP_STOP_BEFORE_ACCESS 0x04
#define BP_GDB 0x10
int cpu_breakpoint_insert(CPUState *env, target_ulong pc, int flags,
--
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