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

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Submitter YeongKyoon Lee
Date March 22, 2013, 11:56 a.m.
Message ID <1363953412-27847-1-git-send-email-yeongkyoon.lee@samsung.com>
Download mbox | patch
Permalink /patch/229973/
State New
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Comments

YeongKyoon Lee - March 22, 2013, 11:56 a.m.
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(-)
Peter Maydell - March 22, 2013, 11:58 a.m.
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
Andreas Färber - March 22, 2013, 12:35 p.m.
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
>  
>

Patch

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