[Qemu-devel] [PATCH] linux-user: Fix register used for 6th and 7th syscall argument on aarch64

[Qemu-devel] [PATCH] linux-user: Fix register used for 6th and 7th syscall argument on aarch64

[Guido Günther]

Unbreaks the testcase from

    http://lists.nongnu.org/archive/html/qemu-arm/2018-01/msg00514.html

Thanks to Laurent Vivier for spotting the 7th one.
Signed-off-by: Guido Günther <agx@sigxcpu.org>
---
 linux-user/host/aarch64/safe-syscall.inc.S | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/linux-user/host/aarch64/safe-syscall.inc.S b/linux-user/host/aarch64/safe-syscall.inc.S
index 58a2329b37..bc1f5a9792 100644
--- a/linux-user/host/aarch64/safe-syscall.inc.S
+++ b/linux-user/host/aarch64/safe-syscall.inc.S
@@ -36,7 +36,7 @@ safe_syscall_base:
 	 *               and return the result in x0
 	 * and the syscall instruction needs
 	 *               x8 == syscall number
-	 *               x0 ... x7 == syscall arguments
+	 *               x0 ... x6 == syscall arguments
 	 *               and returns the result in x0
 	 * Shuffle everything around appropriately.
 	 */
@@ -47,8 +47,8 @@ safe_syscall_base:
 	mov	x2, x4
 	mov	x3, x5
 	mov	x4, x6
-	mov	x6, x7
-	ldr	x7, [sp]
+	mov	x5, x7
+	ldr	x6, [sp]
 
 	/* This next sequence of code works in conjunction with the
 	 * rewind_if_safe_syscall_function(). If a signal is taken
-- 
2.15.1

Re: [Qemu-devel] [PATCH] linux-user: Fix register used for 6th and 7th syscall argument on aarch64

[Philippe Mathieu-Daudé]

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I spent the night studying linux-user end figured out the same correct
fix. Just checking morning ML before sending the patch :)

Mine had "Suggested-by: Laurent Vivier <laurent@vivier.eu>" since he
said on IRC "gdb will help" and indeed single stepping before the
syscall the bug was obvious.

On 01/24/2018 07:13 AM, Guido Günther wrote:
> Unbreaks the testcase from
> 
>     http://lists.nongnu.org/archive/html/qemu-arm/2018-01/msg00514.html
> 
> Thanks to Laurent Vivier for spotting the 7th one.
> Signed-off-by: Guido Günther <agx@sigxcpu.org>

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> ---
>  linux-user/host/aarch64/safe-syscall.inc.S | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/linux-user/host/aarch64/safe-syscall.inc.S b/linux-user/host/aarch64/safe-syscall.inc.S
> index 58a2329b37..bc1f5a9792 100644
> --- a/linux-user/host/aarch64/safe-syscall.inc.S
> +++ b/linux-user/host/aarch64/safe-syscall.inc.S
> @@ -36,7 +36,7 @@ safe_syscall_base:
>  	 *               and return the result in x0
>  	 * and the syscall instruction needs
>  	 *               x8 == syscall number
> -	 *               x0 ... x7 == syscall arguments
> +	 *               x0 ... x6 == syscall arguments
>  	 *               and returns the result in x0
>  	 * Shuffle everything around appropriately.
>  	 */
> @@ -47,8 +47,8 @@ safe_syscall_base:
>  	mov	x2, x4
>  	mov	x3, x5
>  	mov	x4, x6
> -	mov	x6, x7
> -	ldr	x7, [sp]
> +	mov	x5, x7
> +	ldr	x6, [sp]
>  
>  	/* This next sequence of code works in conjunction with the
>  	 * rewind_if_safe_syscall_function(). If a signal is taken
> 


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Re: [Qemu-devel] [PATCH] linux-user: Fix register used for 6th and 7th syscall argument on aarch64

[Laurent Vivier]

Le 24/01/2018 à 11:13, Guido Günther a écrit :
> Unbreaks the testcase from
> 
>     http://lists.nongnu.org/archive/html/qemu-arm/2018-01/msg00514.html
> 
> Thanks to Laurent Vivier for spotting the 7th one.
> Signed-off-by: Guido Günther <agx@sigxcpu.org>
> ---
>  linux-user/host/aarch64/safe-syscall.inc.S | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/linux-user/host/aarch64/safe-syscall.inc.S b/linux-user/host/aarch64/safe-syscall.inc.S
> index 58a2329b37..bc1f5a9792 100644
> --- a/linux-user/host/aarch64/safe-syscall.inc.S
> +++ b/linux-user/host/aarch64/safe-syscall.inc.S
> @@ -36,7 +36,7 @@ safe_syscall_base:
>  	 *               and return the result in x0
>  	 * and the syscall instruction needs
>  	 *               x8 == syscall number
> -	 *               x0 ... x7 == syscall arguments
> +	 *               x0 ... x6 == syscall arguments
>  	 *               and returns the result in x0
>  	 * Shuffle everything around appropriately.
>  	 */
> @@ -47,8 +47,8 @@ safe_syscall_base:
>  	mov	x2, x4
>  	mov	x3, x5
>  	mov	x4, x6
> -	mov	x6, x7
> -	ldr	x7, [sp]
> +	mov	x5, x7
> +	ldr	x6, [sp]
>  
>  	/* This next sequence of code works in conjunction with the
>  	 * rewind_if_safe_syscall_function(). If a signal is taken
> 

Reviewed-by: Laurent Vivier <laurent@vivier.eu>

for your future patches (I hope there will be), if there are several
versions, add the version number in the Subject (i.e. "[PATCH v2]") and
version history below the signature mark ("---"):

   ...

   Signed-off-by: Guido Günther <agx@sigxcpu.org>
   ---
   v2: fix also 7th arg

     linux-user/host/aarch64/safe-syscall.inc.S | 6 +++---
     1 file changed, 3 insertions(+), 3 deletions(-)

   ...

Thanks,
Laurent

Re: [Qemu-devel] [PATCH] linux-user: Fix register used for 6th and 7th syscall argument on aarch64

[Richard Henderson]

On 01/24/2018 02:13 AM, Guido Günther wrote:
> Unbreaks the testcase from
> 
>     http://lists.nongnu.org/archive/html/qemu-arm/2018-01/msg00514.html
> 
> Thanks to Laurent Vivier for spotting the 7th one.
> Signed-off-by: Guido Günther <agx@sigxcpu.org>
> ---
>  linux-user/host/aarch64/safe-syscall.inc.S | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

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

r~

[Qemu-devel] [PATCH v3] linux-user: Fix register used for 6th and 7th syscall argument on aarch64

[Guido Günther]

This unbreaks the testcase from

    http://lists.nongnu.org/archive/html/qemu-arm/2018-01/msg00514.html

Thanks to Laurent Vivier for spotting the 7th one.

Signed-off-by: Guido Günther <agx@sigxcpu.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Suggested-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
v3 collects *-by: replies. Anything else I can do to get this applied?

 linux-user/host/aarch64/safe-syscall.inc.S | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/linux-user/host/aarch64/safe-syscall.inc.S b/linux-user/host/aarch64/safe-syscall.inc.S
index 58a2329b37..bc1f5a9792 100644
--- a/linux-user/host/aarch64/safe-syscall.inc.S
+++ b/linux-user/host/aarch64/safe-syscall.inc.S
@@ -36,7 +36,7 @@ safe_syscall_base:
 	 *               and return the result in x0
 	 * and the syscall instruction needs
 	 *               x8 == syscall number
-	 *               x0 ... x7 == syscall arguments
+	 *               x0 ... x6 == syscall arguments
 	 *               and returns the result in x0
 	 * Shuffle everything around appropriately.
 	 */
@@ -47,8 +47,8 @@ safe_syscall_base:
 	mov	x2, x4
 	mov	x3, x5
 	mov	x4, x6
-	mov	x6, x7
-	ldr	x7, [sp]
+	mov	x5, x7
+	ldr	x6, [sp]
 
 	/* This next sequence of code works in conjunction with the
 	 * rewind_if_safe_syscall_function(). If a signal is taken
-- 
2.15.1

Re: [Qemu-devel] [PATCH v3] linux-user: Fix register used for 6th and 7th syscall argument on aarch64

[Laurent Vivier]

Le 02/02/2018 à 11:02, Guido Günther a écrit :
> This unbreaks the testcase from
> 
>     http://lists.nongnu.org/archive/html/qemu-arm/2018-01/msg00514.html
> 
> Thanks to Laurent Vivier for spotting the 7th one.
> 
> Signed-off-by: Guido Günther <agx@sigxcpu.org>
> Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> Suggested-by: Laurent Vivier <laurent@vivier.eu>
> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> v3 collects *-by: replies. Anything else I can do to get this applied?
> 
>  linux-user/host/aarch64/safe-syscall.inc.S | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

Applied to my 'linux-user-for-2.12' branch.

Thanks,
Laurent