[PATCH 2/4] softmmu: remove useless condition in watchpoint check

Pavel Dovgalyuk posted 4 patches 4 years, 3 months ago
Maintainers: Paolo Bonzini <pbonzini@redhat.com>, Peter Xu <peterx@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, David Hildenbrand <david@redhat.com>, "Philippe Mathieu-Daudé" <philmd@redhat.com>
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[PATCH 2/4] softmmu: remove useless condition in watchpoint check
Posted by Pavel Dovgalyuk 4 years, 3 months ago
cpu_check_watchpoint function checks cpu->watchpoint_hit at the entry.
But then it also does the same in the middle of the function,
while this field can't change.
That is why this patch removes this useless condition.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
---
 softmmu/physmem.c |   41 ++++++++++++++++++++---------------------
 1 file changed, 20 insertions(+), 21 deletions(-)

diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index fd1b3b2088..94eda44459 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -929,27 +929,26 @@ void cpu_check_watchpoint(CPUState *cpu, vaddr addr, vaddr len,
             }
             wp->hitaddr = MAX(addr, wp->vaddr);
             wp->hitattrs = attrs;
-            if (!cpu->watchpoint_hit) {
-                if (wp->flags & BP_CPU && cc->tcg_ops->debug_check_watchpoint &&
-                    !cc->tcg_ops->debug_check_watchpoint(cpu, wp)) {
-                    wp->flags &= ~BP_WATCHPOINT_HIT;
-                    continue;
-                }
-                cpu->watchpoint_hit = wp;
-
-                mmap_lock();
-                /* This call also restores vCPU state */
-                tb_check_watchpoint(cpu, ra);
-                if (wp->flags & BP_STOP_BEFORE_ACCESS) {
-                    cpu->exception_index = EXCP_DEBUG;
-                    mmap_unlock();
-                    cpu_loop_exit(cpu);
-                } else {
-                    /* Force execution of one insn next time.  */
-                    cpu->cflags_next_tb = 1 | curr_cflags(cpu);
-                    mmap_unlock();
-                    cpu_loop_exit_noexc(cpu);
-                }
+
+            if (wp->flags & BP_CPU && cc->tcg_ops->debug_check_watchpoint &&
+                !cc->tcg_ops->debug_check_watchpoint(cpu, wp)) {
+                wp->flags &= ~BP_WATCHPOINT_HIT;
+                continue;
+            }
+            cpu->watchpoint_hit = wp;
+
+            mmap_lock();
+            /* This call also restores vCPU state */
+            tb_check_watchpoint(cpu, ra);
+            if (wp->flags & BP_STOP_BEFORE_ACCESS) {
+                cpu->exception_index = EXCP_DEBUG;
+                mmap_unlock();
+                cpu_loop_exit(cpu);
+            } else {
+                /* Force execution of one insn next time.  */
+                cpu->cflags_next_tb = 1 | curr_cflags(cpu);
+                mmap_unlock();
+                cpu_loop_exit_noexc(cpu);
             }
         } else {
             wp->flags &= ~BP_WATCHPOINT_HIT;


Re: [PATCH 2/4] softmmu: remove useless condition in watchpoint check
Posted by Richard Henderson 4 years, 3 months ago
On 10/28/21 4:48 AM, Pavel Dovgalyuk wrote:
> cpu_check_watchpoint function checks cpu->watchpoint_hit at the entry.
> But then it also does the same in the middle of the function,
> while this field can't change.
> That is why this patch removes this useless condition.
> 
> Signed-off-by: Pavel Dovgalyuk<Pavel.Dovgalyuk@ispras.ru>
> ---
>   softmmu/physmem.c |   41 ++++++++++++++++++++---------------------
>   1 file changed, 20 insertions(+), 21 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~