[PATCH] mips: Fix argument passing for inlined syscalls on Linux [BZ #25523]

Adhemerval Zanella adhemerval.zanella@linaro.org
Mon Feb 10 16:07:00 GMT 2020



On 09/02/2020 15:57, WANG Xuerui wrote:
> According to [gcc documentation][1], temporary variables must be used for
> the desired content to not be call-clobbered.
> 
> Fix the Linux inline syscall templates by adding temporary variables,
> much like what x86 did before
> (commit 381a0c26d73e0f074c962e0ab53b99a6c327066d).
> 
> Tested with gcc 9.2.0, both cross-compiled and natively on Loongson
> 3A4000.
> 
> [1]: https://gcc.gnu.org/onlinedocs/gcc/Local-Register-Variables.html

LGTM, thanks.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

> ---
>  sysdeps/unix/sysv/linux/mips/mips32/sysdep.h  | 30 ++++++---
>  .../unix/sysv/linux/mips/mips64/n32/sysdep.h  | 63 ++++++++++++-------
>  .../unix/sysv/linux/mips/mips64/n64/sysdep.h  | 63 ++++++++++++-------
>  3 files changed, 104 insertions(+), 52 deletions(-)
> 
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h b/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
> index beefcf284b..c275d63f67 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
> @@ -178,10 +178,11 @@ union __mips_syscall_return
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long _arg1 = (long) (arg1);					\
>  	register long __s0 asm ("$16") __attribute__ ((unused))		\
>  	  = (number);							\
>  	register long __v0 asm ("$2");					\
> -	register long __a0 asm ("$4") = (long) (arg1);			\
> +	register long __a0 asm ("$4") = _arg1;				\
>  	register long __a3 asm ("$7");					\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\

Ok.

> @@ -202,11 +203,13 @@ union __mips_syscall_return
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long _arg1 = (long) (arg1);					\
> +	long _arg2 = (long) (arg2);					\
>  	register long __s0 asm ("$16") __attribute__ ((unused))		\
>  	  = (number);							\
>  	register long __v0 asm ("$2");					\
> -	register long __a0 asm ("$4") = (long) (arg1);			\
> -	register long __a1 asm ("$5") = (long) (arg2);			\
> +	register long __a0 asm ("$4") = _arg1;				\
> +	register long __a1 asm ("$5") = _arg2;				\
>  	register long __a3 asm ("$7");					\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\

Ok.

> @@ -228,12 +231,15 @@ union __mips_syscall_return
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long _arg1 = (long) (arg1);					\
> +	long _arg2 = (long) (arg2);					\
> +	long _arg3 = (long) (arg3);					\
>  	register long __s0 asm ("$16") __attribute__ ((unused))		\
>  	  = (number);							\
>  	register long __v0 asm ("$2");					\
> -	register long __a0 asm ("$4") = (long) (arg1);			\
> -	register long __a1 asm ("$5") = (long) (arg2);			\
> -	register long __a2 asm ("$6") = (long) (arg3);			\
> +	register long __a0 asm ("$4") = _arg1;				\
> +	register long __a1 asm ("$5") = _arg2;				\
> +	register long __a2 asm ("$6") = _arg3;				\
>  	register long __a3 asm ("$7");					\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\

Ok.

> @@ -255,13 +261,17 @@ union __mips_syscall_return
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long _arg1 = (long) (arg1);					\
> +	long _arg2 = (long) (arg2);					\
> +	long _arg3 = (long) (arg3);					\
> +	long _arg4 = (long) (arg4);					\
>  	register long __s0 asm ("$16") __attribute__ ((unused))		\
>  	  = (number);							\
>  	register long __v0 asm ("$2");					\
> -	register long __a0 asm ("$4") = (long) (arg1);			\
> -	register long __a1 asm ("$5") = (long) (arg2);			\
> -	register long __a2 asm ("$6") = (long) (arg3);			\
> -	register long __a3 asm ("$7") = (long) (arg4);			\
> +	register long __a0 asm ("$4") = _arg1;				\
> +	register long __a1 asm ("$5") = _arg2;				\
> +	register long __a2 asm ("$6") = _arg3;				\
> +	register long __a3 asm ("$7") = _arg4;				\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\
>  	v0_init								\

Ok.

> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h b/sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h
> index f96636538a..958a889147 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h
> @@ -138,10 +138,11 @@
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long long _arg1 = ARGIFY (arg1);				\
>  	register long long __s0 asm ("$16") __attribute__ ((unused))	\
>  	  = (number);							\
>  	register long long __v0 asm ("$2");				\
> -	register long long __a0 asm ("$4") = ARGIFY (arg1);		\
> +	register long long __a0 asm ("$4") = _arg1;			\
>  	register long long __a3 asm ("$7");				\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\

Ok.

> @@ -162,11 +163,13 @@
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long long _arg1 = ARGIFY (arg1);				\
> +	long long _arg2 = ARGIFY (arg2);				\
>  	register long long __s0 asm ("$16") __attribute__ ((unused))	\
>  	  = (number);							\
>  	register long long __v0 asm ("$2");				\
> -	register long long __a0 asm ("$4") = ARGIFY (arg1);		\
> -	register long long __a1 asm ("$5") = ARGIFY (arg2);		\
> +	register long long __a0 asm ("$4") = _arg1;			\
> +	register long long __a1 asm ("$5") = _arg2;			\
>  	register long long __a3 asm ("$7");				\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\

Ok.

> @@ -188,12 +191,15 @@
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long long _arg1 = ARGIFY (arg1);				\
> +	long long _arg2 = ARGIFY (arg2);				\
> +	long long _arg3 = ARGIFY (arg3);				\
>  	register long long __s0 asm ("$16") __attribute__ ((unused))	\
>  	  = (number);							\
>  	register long long __v0 asm ("$2");				\
> -	register long long __a0 asm ("$4") = ARGIFY (arg1);		\
> -	register long long __a1 asm ("$5") = ARGIFY (arg2);		\
> -	register long long __a2 asm ("$6") = ARGIFY (arg3);		\
> +	register long long __a0 asm ("$4") = _arg1;			\
> +	register long long __a1 asm ("$5") = _arg2;			\
> +	register long long __a2 asm ("$6") = _arg3;			\
>  	register long long __a3 asm ("$7");				\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\

Ok.

> @@ -215,13 +221,17 @@
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long long _arg1 = ARGIFY (arg1);				\
> +	long long _arg2 = ARGIFY (arg2);				\
> +	long long _arg3 = ARGIFY (arg3);				\
> +	long long _arg4 = ARGIFY (arg4);				\
>  	register long long __s0 asm ("$16") __attribute__ ((unused))	\
>  	  = (number);							\
>  	register long long __v0 asm ("$2");				\
> -	register long long __a0 asm ("$4") = ARGIFY (arg1);		\
> -	register long long __a1 asm ("$5") = ARGIFY (arg2);		\
> -	register long long __a2 asm ("$6") = ARGIFY (arg3);		\
> -	register long long __a3 asm ("$7") = ARGIFY (arg4);		\
> +	register long long __a0 asm ("$4") = _arg1;			\
> +	register long long __a1 asm ("$5") = _arg2;			\
> +	register long long __a2 asm ("$6") = _arg3;			\
> +	register long long __a3 asm ("$7") = _arg4;			\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\
>  	v0_init								\

Ok.

> @@ -242,14 +252,19 @@
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long long _arg1 = ARGIFY (arg1);				\
> +	long long _arg2 = ARGIFY (arg2);				\
> +	long long _arg3 = ARGIFY (arg3);				\
> +	long long _arg4 = ARGIFY (arg4);				\
> +	long long _arg5 = ARGIFY (arg5);				\
>  	register long long __s0 asm ("$16") __attribute__ ((unused))	\
>  	  = (number);							\
>  	register long long __v0 asm ("$2");				\
> -	register long long __a0 asm ("$4") = ARGIFY (arg1);		\
> -	register long long __a1 asm ("$5") = ARGIFY (arg2);		\
> -	register long long __a2 asm ("$6") = ARGIFY (arg3);		\
> -	register long long __a3 asm ("$7") = ARGIFY (arg4);		\
> -	register long long __a4 asm ("$8") = ARGIFY (arg5);		\
> +	register long long __a0 asm ("$4") = _arg1;			\
> +	register long long __a1 asm ("$5") = _arg2;			\
> +	register long long __a2 asm ("$6") = _arg3;			\
> +	register long long __a3 asm ("$7") = _arg4;			\
> +	register long long __a4 asm ("$8") = _arg5;			\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\
>  	v0_init								\

Ok.

> @@ -270,15 +285,21 @@
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long long _arg1 = ARGIFY (arg1);				\
> +	long long _arg2 = ARGIFY (arg2);				\
> +	long long _arg3 = ARGIFY (arg3);				\
> +	long long _arg4 = ARGIFY (arg4);				\
> +	long long _arg5 = ARGIFY (arg5);				\
> +	long long _arg6 = ARGIFY (arg6);				\
>  	register long long __s0 asm ("$16") __attribute__ ((unused))	\
>  	  = (number);							\
>  	register long long __v0 asm ("$2");				\
> -	register long long __a0 asm ("$4") = ARGIFY (arg1);		\
> -	register long long __a1 asm ("$5") = ARGIFY (arg2);		\
> -	register long long __a2 asm ("$6") = ARGIFY (arg3);		\
> -	register long long __a3 asm ("$7") = ARGIFY (arg4);		\
> -	register long long __a4 asm ("$8") = ARGIFY (arg5);		\
> -	register long long __a5 asm ("$9") = ARGIFY (arg6);		\
> +	register long long __a0 asm ("$4") = _arg1;			\
> +	register long long __a1 asm ("$5") = _arg2;			\
> +	register long long __a2 asm ("$6") = _arg3;			\
> +	register long long __a3 asm ("$7") = _arg4;			\
> +	register long long __a4 asm ("$8") = _arg5;			\
> +	register long long __a5 asm ("$9") = _arg6;			\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\
>  	v0_init								\

Ok.

> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h b/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h
> index 9d30291f84..f47613deaf 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h
> @@ -134,10 +134,11 @@
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long _arg1 = (long) (arg1);					\
>  	register long __s0 asm ("$16") __attribute__ ((unused))		\
>  	  = (number);							\
>  	register long __v0 asm ("$2");					\
> -	register long __a0 asm ("$4") = (long) (arg1);			\
> +	register long __a0 asm ("$4") = _arg1;				\
>  	register long __a3 asm ("$7");					\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\

Ok.

> @@ -158,11 +159,13 @@
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long _arg1 = (long) (arg1);					\
> +	long _arg2 = (long) (arg2);					\
>  	register long __s0 asm ("$16") __attribute__ ((unused))		\
>  	  = (number);							\
>  	register long __v0 asm ("$2");					\
> -	register long __a0 asm ("$4") = (long) (arg1);			\
> -	register long __a1 asm ("$5") = (long) (arg2);			\
> +	register long __a0 asm ("$4") = _arg1;				\
> +	register long __a1 asm ("$5") = _arg2;				\
>  	register long __a3 asm ("$7");					\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\

Ok.

> @@ -184,12 +187,15 @@
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long _arg1 = (long) (arg1);					\
> +	long _arg2 = (long) (arg2);					\
> +	long _arg3 = (long) (arg3);					\
>  	register long __s0 asm ("$16") __attribute__ ((unused))		\
>  	  = (number);							\
>  	register long __v0 asm ("$2");					\
> -	register long __a0 asm ("$4") = (long) (arg1);			\
> -	register long __a1 asm ("$5") = (long) (arg2);			\
> -	register long __a2 asm ("$6") = (long) (arg3);			\
> +	register long __a0 asm ("$4") = _arg1;				\
> +	register long __a1 asm ("$5") = _arg2;				\
> +	register long __a2 asm ("$6") = _arg3;				\
>  	register long __a3 asm ("$7");					\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\

Ok.

> @@ -211,13 +217,17 @@
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long _arg1 = (long) (arg1);					\
> +	long _arg2 = (long) (arg2);					\
> +	long _arg3 = (long) (arg3);					\
> +	long _arg4 = (long) (arg4);					\
>  	register long __s0 asm ("$16") __attribute__ ((unused))		\
>  	  = (number);							\
>  	register long __v0 asm ("$2");					\
> -	register long __a0 asm ("$4") = (long) (arg1);			\
> -	register long __a1 asm ("$5") = (long) (arg2);			\
> -	register long __a2 asm ("$6") = (long) (arg3);			\
> -	register long __a3 asm ("$7") = (long) (arg4);			\
> +	register long __a0 asm ("$4") = _arg1;				\
> +	register long __a1 asm ("$5") = _arg2;				\
> +	register long __a2 asm ("$6") = _arg3;				\
> +	register long __a3 asm ("$7") = _arg4;				\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\
>  	v0_init								\

Ok.

> @@ -238,14 +248,19 @@
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long _arg1 = (long) (arg1);					\
> +	long _arg2 = (long) (arg2);					\
> +	long _arg3 = (long) (arg3);					\
> +	long _arg4 = (long) (arg4);					\
> +	long _arg5 = (long) (arg5);					\
>  	register long __s0 asm ("$16") __attribute__ ((unused))		\
>  	  = (number);							\
>  	register long __v0 asm ("$2");					\
> -	register long __a0 asm ("$4") = (long) (arg1);			\
> -	register long __a1 asm ("$5") = (long) (arg2);			\
> -	register long __a2 asm ("$6") = (long) (arg3);			\
> -	register long __a3 asm ("$7") = (long) (arg4);			\
> -	register long __a4 asm ("$8") = (long) (arg5);			\
> +	register long __a0 asm ("$4") = _arg1;				\
> +	register long __a1 asm ("$5") = _arg2;				\
> +	register long __a2 asm ("$6") = _arg3;				\
> +	register long __a3 asm ("$7") = _arg4;				\
> +	register long __a4 asm ("$8") = _arg5;				\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\
>  	v0_init								\

Ok.

> @@ -266,15 +281,21 @@
>  	long _sys_result;						\
>  									\
>  	{								\
> +	long _arg1 = (long) (arg1);					\
> +	long _arg2 = (long) (arg2);					\
> +	long _arg3 = (long) (arg3);					\
> +	long _arg4 = (long) (arg4);					\
> +	long _arg5 = (long) (arg5);					\
> +	long _arg6 = (long) (arg6);					\
>  	register long __s0 asm ("$16") __attribute__ ((unused))		\
>  	  = (number);							\
>  	register long __v0 asm ("$2");					\
> -	register long __a0 asm ("$4") = (long) (arg1);			\
> -	register long __a1 asm ("$5") = (long) (arg2);			\
> -	register long __a2 asm ("$6") = (long) (arg3);			\
> -	register long __a3 asm ("$7") = (long) (arg4);			\
> -	register long __a4 asm ("$8") = (long) (arg5);			\
> -	register long __a5 asm ("$9") = (long) (arg6);			\
> +	register long __a0 asm ("$4") = _arg1;				\
> +	register long __a1 asm ("$5") = _arg2;				\
> +	register long __a2 asm ("$6") = _arg3;				\
> +	register long __a3 asm ("$7") = _arg4;				\
> +	register long __a4 asm ("$8") = _arg5;				\
> +	register long __a5 asm ("$9") = _arg6;				\
>  	__asm__ volatile (						\
>  	".set\tnoreorder\n\t"						\
>  	v0_init								\
> 

Ok.



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