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From: Jan Kiszka <jan.kiszka@siemens.com>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] [PATCH 12/15] Introduce BP_WATCHPOINT_HIT flag
Date: Mon, 23 Jun 2008 16:32:02 +0200	[thread overview]
Message-ID: <485FB3E2.8080908@siemens.com> (raw)
In-Reply-To: <485FB18E.1090801@siemens.com>

When one watchpoint is hit, others might have triggered as well. To
support users of the watchpoint API which need to detect such cases,
the BP_WATCHPOINT_HIT flag is introduced and maintained.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 cpu-all.h  |    1 +
 cpu-exec.c |   11 +++++++++++
 exec.c     |   29 +++++++++++++++++------------
 3 files changed, 29 insertions(+), 12 deletions(-)

Index: b/cpu-all.h
===================================================================
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -802,6 +802,7 @@ void cpu_reset_interrupt(CPUState *env, 
 #define BP_MEM_WRITE          0x02
 #define BP_MEM_ACCESS         (BP_MEM_READ | BP_MEM_WRITE)
 #define BP_STOP_BEFORE_ACCESS 0x04
+#define BP_WATCHPOINT_HIT     0x08
 #define BP_GDB                0x10
 
 int cpu_breakpoint_insert(CPUState *env, target_ulong pc, int flags,
Index: b/cpu-exec.c
===================================================================
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -228,6 +228,15 @@ static inline TranslationBlock *tb_find_
     return tb;
 }
 
+static void cpu_handle_debug_exception(CPUState *env)
+{
+    CPUWatchpoint *wp;
+
+    if (!env->watchpoint_hit)
+        for (wp = env->watchpoints; wp != NULL; wp = wp->next)
+            wp->flags &= ~BP_WATCHPOINT_HIT;
+}
+
 /* main execution loop */
 
 int cpu_exec(CPUState *env1)
@@ -282,6 +291,8 @@ int cpu_exec(CPUState *env1)
                 if (env->exception_index >= EXCP_INTERRUPT) {
                     /* exit request from the cpu execution loop */
                     ret = env->exception_index;
+                    if (ret == EXCP_DEBUG)
+                        cpu_handle_debug_exception(env);
                     break;
                 } else if (env->user_mode_only) {
                     /* if user mode only, we simulate a fake exception
Index: b/exec.c
===================================================================
--- a/exec.c
+++ b/exec.c
@@ -1182,7 +1182,7 @@ int cpu_watchpoint_remove(CPUState *env,
 
     for (wp = env->watchpoints; wp != NULL; wp = wp->next) {
         if (addr == wp->vaddr && len_mask == wp->len_mask
-                && flags == wp->flags) {
+                && flags == (wp->flags & ~BP_WATCHPOINT_HIT)) {
             cpu_watchpoint_remove_by_ref(env, wp);
             return 0;
         }
@@ -2294,20 +2294,25 @@ static void check_watchpoint(int 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;
-            tb = tb_find_pc(env->mem_access_pc);
-            if (tb) {
-                cpu_restore_state(tb, env, env->mem_access_pc, NULL);
-                tb_phys_invalidate(tb, -1);
+            wp->flags |= BP_WATCHPOINT_HIT;
+            if (!env->watchpoint_hit) {
+                env->watchpoint_hit = wp;
+                tb = tb_find_pc(env->mem_access_pc);
+                if (tb) {
+                    cpu_restore_state(tb, env, env->mem_access_pc, NULL);
+                    tb_phys_invalidate(tb, -1);
+                }
+                if (wp->flags & BP_STOP_BEFORE_ACCESS)
+                    env->exception_index = EXCP_DEBUG;
+                else
+                    env->singlestep_enabled |= SSTEP_INTERNAL;
             }
-            if (wp->flags & BP_STOP_BEFORE_ACCESS)
-                env->exception_index = EXCP_DEBUG;
-            else
-                env->singlestep_enabled |= SSTEP_INTERNAL;
-            cpu_resume_from_signal(env, NULL);
-            break;
+        } else {
+            wp->flags &= ~BP_WATCHPOINT_HIT;
         }
     }
+    if (env->watchpoint_hit)
+        cpu_resume_from_signal(env, NULL);
 }
 
 /* Watchpoint access routines.  Watchpoints are inserted using TLB tricks,

  parent reply	other threads:[~2008-06-23 14:35 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-06-23 14:22 [Qemu-devel] [PATCH 0/15] Enhance debugging support Jan Kiszka
2008-06-23 14:23 ` [Qemu-devel] [PATCH 1/15] Convert remaining __builtin_expect to likely/unlikely Jan Kiszka
2008-06-23 14:24 ` [Qemu-devel] [PATCH 2/15] Introduce SSTEP_INTERNAL Jan Kiszka
2008-06-23 14:24 ` [Qemu-devel] [PATCH 3/15] Replace CF_SINGLE_INSN with SSTEP_INTERNAL - v2 Jan Kiszka
2008-06-23 14:25 ` [Qemu-devel] [PATCH 4/15] Remove unused TB cflags Jan Kiszka
2008-06-23 14:26 ` [Qemu-devel] [PATCH 5/15] Return appropriate watch message to gdb Jan Kiszka
2008-06-23 14:26 ` [Qemu-devel] [PATCH 6/15] Refactor and enhance break/watchpoint API - v5 Jan Kiszka
2008-06-23 14:27 ` [Qemu-devel] [PATCH 7/15] Extend mem_write_* to mem_access_* Jan Kiszka
2008-06-23 14:28 ` [Qemu-devel] [PATCH 8/15] Respect length of watchpoints Jan Kiszka
2008-06-23 14:29 ` [Qemu-devel] [PATCH 9/15] Restore pc on watchpoint hits Jan Kiszka
2008-06-23 14:30 ` [Qemu-devel] [PATCH 10/15] Remove premature memop TB terminations Jan Kiszka
2008-06-23 14:31 ` [Qemu-devel] [PATCH 11/15] Improve debugging of SMP guests - v2 Jan Kiszka
2008-06-23 14:32 ` Jan Kiszka [this message]
2008-06-23 14:32 ` [Qemu-devel] [PATCH 13/15] Add debug exception hook Jan Kiszka
2008-06-23 14:33 ` [Qemu-devel] [PATCH 14/15] Introduce BP_CPU as a breakpoint type Jan Kiszka
2008-06-23 14:33 ` [Qemu-devel] [PATCH 15/15] x86: Debug register emulation Jan Kiszka

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