mips: Fix argument passing for inlined syscalls on Linux [BZ #25523]
Commit Message
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
---
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(-)
Comments
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.
On Mon, 10 Feb 2020, WANG Xuerui wrote:
> 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); \
The glibc style is to use "long int" in place of "long", so I think the
new variables should do that throughout the patch (and likewise "long long
int").
Please post a revised patch, and say if you need someone to commit it for
you.
On Mon, 10 Feb 2020, WANG Xuerui wrote:
> According to [gcc documentation][1], temporary variables must be used for
> the desired content to not be call-clobbered.
Why does it specifically matter here?
> 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
[...]
> @@ -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" \
Can e.g. `(long) (arg1)' end up as a library call? Do you have a case,
even potential, where such clobbering actually happens?
Maciej
On 22/02/2020 19:40, Maciej W. Rozycki wrote:
> On Mon, 10 Feb 2020, WANG Xuerui wrote:
>
>> According to [gcc documentation][1], temporary variables must be used for
>> the desired content to not be call-clobbered.
>
> Why does it specifically matter here?
>
>> 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
> [...]
>> @@ -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" \
>
> Can e.g. `(long) (arg1)' end up as a library call? Do you have a case,
> even potential, where such clobbering actually happens?
On sysdeps/unix/sysv/linux/spawni.c:
188 if ((attr->__flags & POSIX_SPAWN_RESETIDS) != 0
189 && (local_seteuid (__getuid ()) != 0
190 || local_setegid (__getgid ()) != 0))
191 goto fail;
And local_seteuid/local_setegid are defined as:
sysdeps/unix/sysv/linux/local-setxid.h:
5 #ifdef __NR_setresuid32
6 # define local_seteuid(id) INLINE_SYSCALL (setresuid32, 3, -1, id, -1)
7 #else
8 # define local_seteuid(id) INLINE_SYSCALL (setresuid, 3, -1, id, -1)
9 #endif
10
11
12 #ifdef __NR_setresgid32
13 # define local_setegid(id) INLINE_SYSCALL (setresgid32, 3, -1, id, -1)
14 #else
15 # define local_setegid(id) INLINE_SYSCALL (setresgid, 3, -1, id, -1)
16 #endif
In any case, the previous usage of inline syscall is indeed fragile
and subject to such potential breakage.
On Sat, Feb 22, 2020 at 2:40 PM Maciej W. Rozycki <macro@linux-mips.org> wrote:
>
> On Mon, 10 Feb 2020, WANG Xuerui wrote:
>
> > According to [gcc documentation][1], temporary variables must be used for
> > the desired content to not be call-clobbered.
>
> Why does it specifically matter here?
>
> > 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
> [...]
> > @@ -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" \
>
> Can e.g. `(long) (arg1)' end up as a library call? Do you have a case,
> even potential, where such clobbering actually happens?
We found that GNU make 4.3 fails to work on MIPS without this patch to
glibc. See https://bugs.gentoo.org/708758
On Thu, 27 Feb 2020, Matt Turner wrote:
> > > 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
> > [...]
> > > @@ -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" \
> >
> > Can e.g. `(long) (arg1)' end up as a library call? Do you have a case,
> > even potential, where such clobbering actually happens?
>
> We found that GNU make 4.3 fails to work on MIPS without this patch to
> glibc. See https://bugs.gentoo.org/708758
Ah, indeed it can then, when whatever is passed as `arg1' gets inlined.
Thanks for the pointer and sorry about the confusion.
Maciej
@@ -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" \
@@ -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" \
@@ -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" \
@@ -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 \
@@ -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" \
@@ -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" \
@@ -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" \
@@ -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 \
@@ -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 \
@@ -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 \
@@ -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" \
@@ -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" \
@@ -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" \
@@ -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 \
@@ -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 \
@@ -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 \