[Qemu-devel] [PATCH 1.1] exec: fix TB invalidation after breakpoint insertion/deletion

[Qemu-devel] [PATCH 1.1] exec: fix TB invalidation after breakpoint insertion/deletion

[Max Filippov]

tb_invalidate_phys_addr has to be called with the exact physical address of
the breakpoint we add/remove, not just the page's base address.
Otherwise we easily fail to flush the right TB.

This breakage was introduced by the commit f3705d5329 "memory: make
phys_page_find() return an unadjusted".

This appeared to work for some guest architectures because their
cpu_get_phys_page_debug implementation returns full translated physical
address, not just the base of the TARGET_PAGE_SIZE-sized page.

Reported-by: TeLeMan <geleman@gmail.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 exec.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/exec.c b/exec.c
index a0494c7..0a67f07 100644
--- a/exec.c
+++ b/exec.c
@@ -1492,7 +1492,8 @@ void tb_invalidate_phys_addr(target_phys_addr_t addr)
 
 static void breakpoint_invalidate(CPUArchState *env, target_ulong pc)
 {
-    tb_invalidate_phys_addr(cpu_get_phys_page_debug(env, pc));
+    tb_invalidate_phys_addr(cpu_get_phys_page_debug(env, pc) |
+            (pc & ~TARGET_PAGE_MASK));
 }
 #endif
 #endif /* TARGET_HAS_ICE */
-- 
1.7.7.6

Re: [Qemu-devel] [PATCH 1.1] exec: fix TB invalidation after breakpoint insertion/deletion

[Blue Swirl]

Thanks, applied.

On Sun, May 27, 2012 at 4:21 PM, Max Filippov <jcmvbkbc@gmail.com> wrote:
> tb_invalidate_phys_addr has to be called with the exact physical address of
> the breakpoint we add/remove, not just the page's base address.
> Otherwise we easily fail to flush the right TB.
>
> This breakage was introduced by the commit f3705d5329 "memory: make
> phys_page_find() return an unadjusted".
>
> This appeared to work for some guest architectures because their
> cpu_get_phys_page_debug implementation returns full translated physical
> address, not just the base of the TARGET_PAGE_SIZE-sized page.
>
> Reported-by: TeLeMan <geleman@gmail.com>
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
> ---
>  exec.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index a0494c7..0a67f07 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1492,7 +1492,8 @@ void tb_invalidate_phys_addr(target_phys_addr_t addr)
>
>  static void breakpoint_invalidate(CPUArchState *env, target_ulong pc)
>  {
> -    tb_invalidate_phys_addr(cpu_get_phys_page_debug(env, pc));
> +    tb_invalidate_phys_addr(cpu_get_phys_page_debug(env, pc) |
> +            (pc & ~TARGET_PAGE_MASK));
>  }
>  #endif
>  #endif /* TARGET_HAS_ICE */
> --
> 1.7.7.6
>