[Qemu-devel] [Qemu-stable][PATCH v2] tcg: Fix occasional TCG broken problem when ldst optimization enabled

[Qemu-devel] [Qemu-stable][PATCH v2] tcg: Fix occasional TCG broken problem when ldst optimization enabled

[Yeongkyoon Lee]

is_tcg_gen_code() checks the upper limit of TCG generated code range wrong, so
that TCG could get broken occasionally only when CONFIG_QEMU_LDST_OPTIMIZATION
enabled. The reason is code_gen_buffer_max_size does not cover the upper range
up to (TCG_MAX_OP_SIZE * OPC_BUF_SIZE), thus code_gen_buffer_max_size should be
modified to code_gen_buffer_size.

Signed-off-by: Yeongkyoon Lee <yeongkyoon.lee@samsung.com>
---

Here's is the promised patch with Aurelien Jarno for TCG broken problem, which
is supposed to be applied to 1.3.x and 1.4.x releases as well as master.
Thanks to Aurelien Jarno and Stefan Weil.

 translate-all.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/translate-all.c b/translate-all.c
index 1f3237e..72bea9b 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -1308,11 +1308,11 @@ static void tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc,
 /* check whether the given addr is in TCG generated code buffer or not */
 bool is_tcg_gen_code(uintptr_t tc_ptr)
 {
-    /* This can be called during code generation, code_gen_buffer_max_size
+    /* This can be called during code generation, code_gen_buffer_size
        is used instead of code_gen_ptr for upper boundary checking */
     return (tc_ptr >= (uintptr_t)tcg_ctx.code_gen_buffer &&
             tc_ptr < (uintptr_t)(tcg_ctx.code_gen_buffer +
-                    tcg_ctx.code_gen_buffer_max_size));
+                    tcg_ctx.code_gen_buffer_size));
 }
 #endif
 
-- 
1.7.9.5

Re: [Qemu-devel] [Qemu-stable][PATCH v2] tcg: Fix occasional TCG broken problem when ldst optimization enabled

[Peter Maydell]

On 22 March 2013 11:56, Yeongkyoon Lee <yeongkyoon.lee@samsung.com> wrote:
> is_tcg_gen_code() checks the upper limit of TCG generated code range wrong, so
> that TCG could get broken occasionally only when CONFIG_QEMU_LDST_OPTIMIZATION
> enabled. The reason is code_gen_buffer_max_size does not cover the upper range
> up to (TCG_MAX_OP_SIZE * OPC_BUF_SIZE), thus code_gen_buffer_max_size should be
> modified to code_gen_buffer_size.
>
> Signed-off-by: Yeongkyoon Lee <yeongkyoon.lee@samsung.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

-- PMM

Re: [Qemu-devel] [Qemu-stable][PATCH v2] tcg: Fix occasional TCG broken problem when ldst optimization enabled

[Andreas Färber]

Am 22.03.2013 12:56, schrieb Yeongkyoon Lee:
> is_tcg_gen_code() checks the upper limit of TCG generated code range wrong, so
> that TCG could get broken occasionally only when CONFIG_QEMU_LDST_OPTIMIZATION
> enabled. The reason is code_gen_buffer_max_size does not cover the upper range
> up to (TCG_MAX_OP_SIZE * OPC_BUF_SIZE), thus code_gen_buffer_max_size should be
> modified to code_gen_buffer_size.
> 
> Signed-off-by: Yeongkyoon Lee <yeongkyoon.lee@samsung.com>
> ---
> 
> Here's is the promised patch with Aurelien Jarno for TCG broken problem, which
> is supposed to be applied to 1.3.x and 1.4.x releases as well as master.

In that case either the author or the committer should add
Cc: qemu-stable@nongnu.org
to the commit message please.

Andreas

> Thanks to Aurelien Jarno and Stefan Weil.
> 
>  translate-all.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/translate-all.c b/translate-all.c
> index 1f3237e..72bea9b 100644
> --- a/translate-all.c
> +++ b/translate-all.c
> @@ -1308,11 +1308,11 @@ static void tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc,
>  /* check whether the given addr is in TCG generated code buffer or not */
>  bool is_tcg_gen_code(uintptr_t tc_ptr)
>  {
> -    /* This can be called during code generation, code_gen_buffer_max_size
> +    /* This can be called during code generation, code_gen_buffer_size
>         is used instead of code_gen_ptr for upper boundary checking */
>      return (tc_ptr >= (uintptr_t)tcg_ctx.code_gen_buffer &&
>              tc_ptr < (uintptr_t)(tcg_ctx.code_gen_buffer +
> -                    tcg_ctx.code_gen_buffer_max_size));
> +                    tcg_ctx.code_gen_buffer_size));
>  }
>  #endif
>  
> 


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