This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH] mips/o32: fix internal_syscall5/6/7
On 17/08/2017 18:20, Aurelien Jarno wrote:
> On 2017-08-17 18:09, Adhemerval Zanella wrote:
>>
>>
>> On 17/08/2017 17:34, Maciej W. Rozycki wrote:
>>> On Thu, 17 Aug 2017, Adhemerval Zanella wrote:
>>>
>>>> My point is I think we should aim for compiler optimization safeness
>>>> (to avoid code breakage over compiler defined default flags) and taking
>>>> as base current approach to *avoid* VLA on GLIBC I do not think it is
>>>> good approach to use it as a bridge to force GCC to generate the expected
>>>> code.
>>>
>>> You certainly have a point here overall, although I don't think a VLA
>>> whose size is always 0 really hurts. And we've used the approach with
>>> `alloca' since forever with no adverse effects until we added a place
>>> where the caller invokes the syscall wrapper in a loop. So I wouldn't
>>> necessarily call it an issue. Mind that this is target-specific code, so
>>> we can rely on a target-specific execution model rather than limiting
>>> ourselves to what generic ISO C guarantees.
>>>
>>> Aurelien's figures indicating a clear size reduction certainly count as a
>>> pro though.
>>
>> Joseph pointed out another advantage of avoid VLAs (building with
>> -Werror=alloca -Werror=vla). My main problem here is we are betting that
>> compiler won't mess with our assumptions and generate the desirable code
>> without trying to adhere what it is suppose to provide. Target generic
>> ISO C give us a better guarantee and any deviation indicates a possible
>> compiler issue, not otherwise (such this case). My another point is we
>> can optimize if required later if this is the case and imho this is hardly
>> the case here (at least for latency).
>>
>> If I understood correctly Aurelien's suggestion of returning err in v1
>> is not ABI strictly so it will end up calling __libc_do_syscall with a
>> non-conformant ABI convention (similar to pipe implementation where requires
>> assembly specific implementation for a lot of architectures to get this
>> right). Again this is something I would really to avoid.
>>
>>>
>>>> I still thinking trying to optimize for 5/6/7 syscall argument is over
>>>> engineering in this *specific* case. As I put in my last message,
>>>> 5/6/7 argument syscalls are used for
>>>>
>>>> pread, pwrite, lseek, llseek, ppoll, posix_fadvice, posix_fallocate,
>>>> sync_file_range, fallocate, preadv, pwritev, preadv2, pwritev2, select,
>>>> pselect, mmap, readahead, epoll_pwait, splice, recvfrom, sendto, recvmmsg,
>>>> msgsnd, msgrcv, msgget, msgctl, semop, semget, semctl, semtimedop, shmat,
>>>> shmdt, shmget, and shmctl.
>>>>
>>>> Which are the one generated from C implementation (some are still auto
>>>> generated). The majority of them are blocking syscalls, so both context
>>>> switch plus the required work for syscall completion itself will taking
>>>> proportionally all the required time. So trying to squeeze some cycles
>>>> don't really pay off comparing to code maintainability (just all this
>>>> discussion of which C construct would be safe enough to generate the
>>>> correct stack spill plus the current issue should indicate we should
>>>> aim for correctness first).
>>>
>>> TBH, I find it questionable whether it's really the approach I proposed
>>> that requires more engineering (and long-term maintenance) effort rather
>>> than using a separate handwritten assembly-language call stub. Especially
>>> if a non-standard calling convention is used.
>>
>> IMHO I find the VLA suggestion more fragile in long term.
>>
>>>
>>> If everyone but me thinks there's a clear advantage in using such a
>>> handcoded stub though, then as I previously noted please adjust the
>>> affected MIPS16 stubs to avoid the extra indirection, i.e. you can call
>>> `__libc_do_syscall' directly from MIPS16 code as you'd do from regular
>>> MIPS or microMIPS code, as the lone reason for the existence of the MIPS16
>>> stubs is the inexistence of a MIPS16 SYSCALL instruction.
>>
>> Ok, I will try to at least check it on qemu. If you have any points on how
>> correctly build a mips16 glibc it could be helpful.
>
> The patch below, based on Adhemerval's version should do it. The changes
> I have done:
> - return err through v1 instead of using a negative value
> - fix build of mips16-syscallX.c
> - route mips16 syscalls with 5 to 7th arguments through __libc_do_syscall
Thanks for complementing it, I was about to send patched version with same
modification (I figured out 64 bits return ints can be used here reading
mips16 syscall code). Patch LGTM, I would just add some comments to give why
__libc_do_syscall is required (as for other ports). Comment below.
>
> I see no regression on mipsel o32. I have only lightly tested mips o32
> (the testsuite is still running). I haven't been able to fully compile
> mips16 due to the following error compiling dl-tunables.c:
>
> /tmp/ccI2NMgJ.s: Assembler messages:
> /tmp/ccI2NMgJ.s:1376: Error: branch to a symbol in another ISA mode
>
> It doesn't seem to be related to my changes.
I haven't tests with --enable-tunables, but I could build a mips16 with
default options. The only issue, although, is the new tst-gmon.c test:
tst-gmon.c: In function ‘f1’:
tst-gmon.c:25:1: sorry, unimplemented: mips16 function profiling
}
^
Which is unrelated to this patch.
>
> Aurelien
>
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/Makefile b/sysdeps/unix/sysv/linux/mips/mips32/Makefile
> index 33b461500c..cbdf032c3a 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/Makefile
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/Makefile
> @@ -1,8 +1,26 @@
> +ifeq ($(subdir),elf)
> +sysdep-dl-routines += libc-do-syscall
> +endif
> +
> ifeq ($(subdir),conform)
> # For bugs 17786 and 21278.
> conformtest-xfail-conds += mips-o32-linux
> endif
>
> +ifeq ($(subdir),io)
> +sysdep_routines += libc-do-syscall
> +endif
> +
> +ifeq ($(subdir),nptl)
> +libpthread-sysdep_routines += libc-do-syscall
> +libpthread-shared-only-routines += libc-do-syscall
> +endif
> +
> +ifeq ($(subdir),rt)
> +librt-sysdep_routines += libc-do-syscall
> +librt-shared-only-routines += libc-do-syscall
> +endif
> +
> ifeq ($(subdir),stdlib)
> tests += bug-getcontext-mips-gp
> endif
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/libc-do-syscall.S b/sysdeps/unix/sysv/linux/mips/mips32/libc-do-syscall.S
> new file mode 100644
> index 0000000000..c02f507008
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/libc-do-syscall.S
> @@ -0,0 +1,52 @@
> +/* Copyright (C) 2017 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library. If not, see
> + <http://www.gnu.org/licenses/>. */
> +
> +#include <sys/asm.h>
> +#include <sysdep.h>
> +#include <asm/unistd.h>
> +#include <sgidefs.h>
> +
> +
> +/* long int __libc_do_syscall (long int, ...) */
I added some comments in my version:
/* Out-of-line syscall stub used for 5, 6, and 7 argument syscall which
requires arguments in stack. It follows the MIPS ABI similar to the C
prototype:
long int __libc_do_syscall (long int, ...)
With syscall number in a0, first argument in a1, second in a2, third
in a3 and the 4th-7th on stack. */
> +
> +#define FRAMESZ 32
> +
> + .text
> + .set nomips16
> + .hidden __libc_do_syscall
> +ENTRY(__libc_do_syscall)
> + move v0, a0
> + move a0, a1
> + move a1, a2
> + move a2, a3
> + lw a3, 16(sp)
> + lw t0, 20(sp)
> + lw t1, 24(sp)
> + lw t2, 28(sp)
> + .set noreorder
> + PTR_SUBU sp, FRAMESZ
> + cfi_adjust_cfa_offset (FRAMESZ)
> + sw t0, 16(sp)
> + sw t1, 20(sp)
> + sw t2, 24(sp)
> + syscall
> + PTR_ADDU sp, FRAMESZ
> + cfi_adjust_cfa_offset (-FRAMESZ)
> + .set reorder
> + move v1, a3
> +1: ret
> +END (__libc_do_syscall)
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/mips16/Makefile b/sysdeps/unix/sysv/linux/mips/mips32/mips16/Makefile
> index fa9fcb7e6f..6869bf4f7c 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/mips16/Makefile
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/mips16/Makefile
> @@ -1,13 +1,9 @@
> ifeq ($(subdir),misc)
> sysdep_routines += mips16-syscall0 mips16-syscall1 mips16-syscall2
> -sysdep_routines += mips16-syscall3 mips16-syscall4 mips16-syscall5
> -sysdep_routines += mips16-syscall6 mips16-syscall7
> +sysdep_routines += mips16-syscall3 mips16-syscall4
> CFLAGS-mips16-syscall0.c += -fexceptions
> CFLAGS-mips16-syscall1.c += -fexceptions
> CFLAGS-mips16-syscall2.c += -fexceptions
> CFLAGS-mips16-syscall3.c += -fexceptions
> CFLAGS-mips16-syscall4.c += -fexceptions
> -CFLAGS-mips16-syscall5.c += -fexceptions
> -CFLAGS-mips16-syscall6.c += -fexceptions
> -CFLAGS-mips16-syscall7.c += -fexceptions
> endif
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/mips16/Versions b/sysdeps/unix/sysv/linux/mips/mips32/mips16/Versions
> index 73bcfb566c..bb21747f44 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/mips16/Versions
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/mips16/Versions
> @@ -1,6 +1,6 @@
> libc {
> GLIBC_PRIVATE {
> __mips16_syscall0; __mips16_syscall1; __mips16_syscall2; __mips16_syscall3;
> - __mips16_syscall4; __mips16_syscall5; __mips16_syscall6; __mips16_syscall7;
> + __mips16_syscall4;
> }
> }
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall.h b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall.h
> index 880e9908e8..60f856d248 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall.h
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall.h
> @@ -21,17 +21,6 @@
>
> #define __nomips16 __attribute__ ((nomips16))
>
> -union __mips16_syscall_return
> - {
> - long long val;
> - struct
> - {
> - long v0;
> - long v1;
> - }
> - reg;
> - };
> -
> long long __nomips16 __mips16_syscall0 (long number);
> #define __mips16_syscall0(dummy, number) \
> __mips16_syscall0 ((long) (number))
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall0.c b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall0.c
> index 490245b34e..b9f78e875f 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall0.c
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall0.c
> @@ -24,7 +24,7 @@
> long long __nomips16
> __mips16_syscall0 (long number)
> {
> - union __mips16_syscall_return ret;
> + union __libc_do_syscall_return ret;
> ret.reg.v0 = INTERNAL_SYSCALL_MIPS16 (number, ret.reg.v1, 0);
> return ret.val;
> }
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall1.c b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall1.c
> index 3061e8accb..284ce712cc 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall1.c
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall1.c
> @@ -25,7 +25,7 @@ long long __nomips16
> __mips16_syscall1 (long a0,
> long number)
> {
> - union __mips16_syscall_return ret;
> + union __libc_do_syscall_return ret;
> ret.reg.v0 = INTERNAL_SYSCALL_MIPS16 (number, ret.reg.v1, 1,
> a0);
> return ret.val;
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall2.c b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall2.c
> index 440a4ed285..4e76329239 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall2.c
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall2.c
> @@ -25,7 +25,7 @@ long long __nomips16
> __mips16_syscall2 (long a0, long a1,
> long number)
> {
> - union __mips16_syscall_return ret;
> + union __libc_do_syscall_return ret;
> ret.reg.v0 = INTERNAL_SYSCALL_MIPS16 (number, ret.reg.v1, 2,
> a0, a1);
> return ret.val;
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall3.c b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall3.c
> index c3f83fc1f6..dbb31d2f20 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall3.c
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall3.c
> @@ -25,7 +25,7 @@ long long __nomips16
> __mips16_syscall3 (long a0, long a1, long a2,
> long number)
> {
> - union __mips16_syscall_return ret;
> + union __libc_do_syscall_return ret;
> ret.reg.v0 = INTERNAL_SYSCALL_MIPS16 (number, ret.reg.v1, 3,
> a0, a1, a2);
> return ret.val;
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall4.c b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall4.c
> index 496297d296..a5dade3b3f 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall4.c
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall4.c
> @@ -25,7 +25,7 @@ long long __nomips16
> __mips16_syscall4 (long a0, long a1, long a2, long a3,
> long number)
> {
> - union __mips16_syscall_return ret;
> + union __libc_do_syscall_return ret;
> ret.reg.v0 = INTERNAL_SYSCALL_MIPS16 (number, ret.reg.v1, 4,
> a0, a1, a2, a3);
> return ret.val;
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall5.c b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall5.c
> deleted file mode 100644
> index ad265d88e2..0000000000
> --- a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall5.c
> +++ /dev/null
> @@ -1,33 +0,0 @@
> -/* MIPS16 syscall wrappers.
> - Copyright (C) 2013-2017 Free Software Foundation, Inc.
> - This file is part of the GNU C Library.
> -
> - The GNU C Library is free software; you can redistribute it and/or
> - modify it under the terms of the GNU Lesser General Public
> - License as published by the Free Software Foundation; either
> - version 2.1 of the License, or (at your option) any later version.
> -
> - The GNU C Library is distributed in the hope that it will be useful,
> - but WITHOUT ANY WARRANTY; without even the implied warranty of
> - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> - Lesser General Public License for more details.
> -
> - You should have received a copy of the GNU Lesser General Public
> - License along with the GNU C Library; if not, see
> - <http://www.gnu.org/licenses/>. */
> -
> -#include <sysdep.h>
> -#include <mips16-syscall.h>
> -
> -#undef __mips16_syscall5
> -
> -long long __nomips16
> -__mips16_syscall5 (long a0, long a1, long a2, long a3,
> - long a4,
> - long number)
> -{
> - union __mips16_syscall_return ret;
> - ret.reg.v0 = INTERNAL_SYSCALL_MIPS16 (number, ret.reg.v1, 5,
> - a0, a1, a2, a3, a4);
> - return ret.val;
> -}
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall6.c b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall6.c
> deleted file mode 100644
> index bfbd395ed3..0000000000
> --- a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall6.c
> +++ /dev/null
> @@ -1,33 +0,0 @@
> -/* MIPS16 syscall wrappers.
> - Copyright (C) 2013-2017 Free Software Foundation, Inc.
> - This file is part of the GNU C Library.
> -
> - The GNU C Library is free software; you can redistribute it and/or
> - modify it under the terms of the GNU Lesser General Public
> - License as published by the Free Software Foundation; either
> - version 2.1 of the License, or (at your option) any later version.
> -
> - The GNU C Library is distributed in the hope that it will be useful,
> - but WITHOUT ANY WARRANTY; without even the implied warranty of
> - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> - Lesser General Public License for more details.
> -
> - You should have received a copy of the GNU Lesser General Public
> - License along with the GNU C Library; if not, see
> - <http://www.gnu.org/licenses/>. */
> -
> -#include <sysdep.h>
> -#include <mips16-syscall.h>
> -
> -#undef __mips16_syscall6
> -
> -long long __nomips16
> -__mips16_syscall6 (long a0, long a1, long a2, long a3,
> - long a4, long a5,
> - long number)
> -{
> - union __mips16_syscall_return ret;
> - ret.reg.v0 = INTERNAL_SYSCALL_MIPS16 (number, ret.reg.v1, 6,
> - a0, a1, a2, a3, a4, a5);
> - return ret.val;
> -}
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall7.c b/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall7.c
> deleted file mode 100644
> index e1267616dc..0000000000
> --- a/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall7.c
> +++ /dev/null
> @@ -1,33 +0,0 @@
> -/* MIPS16 syscall wrappers.
> - Copyright (C) 2013-2017 Free Software Foundation, Inc.
> - This file is part of the GNU C Library.
> -
> - The GNU C Library is free software; you can redistribute it and/or
> - modify it under the terms of the GNU Lesser General Public
> - License as published by the Free Software Foundation; either
> - version 2.1 of the License, or (at your option) any later version.
> -
> - The GNU C Library is distributed in the hope that it will be useful,
> - but WITHOUT ANY WARRANTY; without even the implied warranty of
> - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> - Lesser General Public License for more details.
> -
> - You should have received a copy of the GNU Lesser General Public
> - License along with the GNU C Library; if not, see
> - <http://www.gnu.org/licenses/>. */
> -
> -#include <sysdep.h>
> -#include <mips16-syscall.h>
> -
> -#undef __mips16_syscall7
> -
> -long long __nomips16
> -__mips16_syscall7 (long a0, long a1, long a2, long a3,
> - long a4, long a5, long a6,
> - long number)
> -{
> - union __mips16_syscall_return ret;
> - ret.reg.v0 = INTERNAL_SYSCALL_MIPS16 (number, ret.reg.v1, 7,
> - a0, a1, a2, a3, a4, a5, a6);
> - return ret.val;
> -}
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h b/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
> index e9e3ee7e82..8e55538a5c 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
> @@ -49,9 +49,9 @@
> /* Define a macro which expands into the inline wrapper code for a system
> call. */
> #undef INLINE_SYSCALL
> -#define INLINE_SYSCALL(name, nr, args...) \
> +#define INLINE_SYSCALL(name, nr, ...) \
> ({ INTERNAL_SYSCALL_DECL (_sc_err); \
> - long result_var = INTERNAL_SYSCALL (name, _sc_err, nr, args); \
> + long result_var = INTERNAL_SYSCALL (name, _sc_err, nr, ## __VA_ARGS__); \
> if ( INTERNAL_SYSCALL_ERROR_P (result_var, _sc_err) ) \
> { \
> __set_errno (INTERNAL_SYSCALL_ERRNO (result_var, _sc_err)); \
> @@ -98,6 +98,19 @@
> #undef INTERNAL_SYSCALL
> #undef INTERNAL_SYSCALL_NCS
>
> +long long __attribute__ ((nomips16)) __libc_do_syscall (long int, ...) attribute_hidden;
Same as before, I think it worth adding a comment:
/* MIPS kernel ABI requires for internal_syscall5/6/7 that the 5th and
following arguments to be on the stack. To avoid trying force a stack
allocation (which compiler may optimize) the macros use a auxiliary
function to actually issue the syscall. */
> +
> +union __libc_do_syscall_return
> + {
> + long long val;
> + struct
> + {
> + long v0;
> + long v1;
> + }
> + reg;
> + };
> +
> #ifdef __mips16
> /* There's no MIPS16 syscall instruction, so we go through out-of-line
> standard MIPS wrappers. These do use inline snippets below though,
> @@ -107,13 +120,16 @@
>
> # include <mips16-syscall.h>
>
> -# define INTERNAL_SYSCALL(name, err, nr, args...) \
> - INTERNAL_SYSCALL_NCS (SYS_ify (name), err, nr, args)
> +# define INTERNAL_SYSCALL(name, err, nr, ...) \
> + INTERNAL_SYSCALL_NCS (SYS_ify (name), err, nr, ## __VA_ARGS__)
>
> -# define INTERNAL_SYSCALL_NCS(number, err, nr, args...) \
> +# define INTERNAL_SYSCALL_NCS(number, err, nr, ...) \
> ({ \
> - union __mips16_syscall_return _sc_ret; \
> - _sc_ret.val = __mips16_syscall##nr (args, number); \
> + union __libc_do_syscall_return _sc_ret; \
> + if (nr <= 4) \
> + _sc_ret.val = __mips16_syscall##nr (__VA_ARGS__, number); \
> + else \
> + _sc_ret.val = __libc_do_syscall (number, ## __VA_ARGS__); \
> err = _sc_ret.reg.v1; \
> _sc_ret.reg.v0; \
> })
> @@ -121,13 +137,13 @@
> # define INTERNAL_SYSCALL_MIPS16(number, err, nr, args...) \
> internal_syscall##nr ("lw\t%0, %2\n\t", \
> "R" (number), \
> - 0, err, args)
> + number, err, args)
>
> #else /* !__mips16 */
> # define INTERNAL_SYSCALL(name, err, nr, args...) \
> internal_syscall##nr ("li\t%0, %2\t\t\t# " #name "\n\t", \
> "IK" (SYS_ify (name)), \
> - 0, err, args)
> + SYS_ify(name), err, args)
>
> # define INTERNAL_SYSCALL_NCS(number, err, nr, args...) \
> internal_syscall##nr (MOVE32 "\t%0, %2\n\t", \
> @@ -136,6 +152,7 @@
>
> #endif /* !__mips16 */
>
> +
> #define internal_syscall0(v0_init, input, number, err, dummy...) \
> ({ \
> long _sys_result; \
> @@ -262,110 +279,34 @@
> _sys_result; \
> })
>
> -/* We need to use a frame pointer for the functions in which we
> - adjust $sp around the syscall, or debug information and unwind
> - information will be $sp relative and thus wrong during the syscall. As
> - of GCC 4.7, this is sufficient. */
> -#define FORCE_FRAME_POINTER \
> - void *volatile __fp_force __attribute__ ((unused)) = alloca (4)
> -
> #define internal_syscall5(v0_init, input, number, err, \
> arg1, arg2, arg3, arg4, arg5) \
> ({ \
> - long _sys_result; \
> - \
> - FORCE_FRAME_POINTER; \
> - { \
> - 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); \
> - __asm__ volatile ( \
> - ".set\tnoreorder\n\t" \
> - "subu\t$29, 32\n\t" \
> - "sw\t%6, 16($29)\n\t" \
> - v0_init \
> - "syscall\n\t" \
> - "addiu\t$29, 32\n\t" \
> - ".set\treorder" \
> - : "=r" (__v0), "+r" (__a3) \
> - : input, "r" (__a0), "r" (__a1), "r" (__a2), \
> - "r" ((long) (arg5)) \
> - : __SYSCALL_CLOBBERS); \
> - err = __a3; \
> - _sys_result = __v0; \
> - } \
> - _sys_result; \
> + union __libc_do_syscall_return _sys_result; \
> + _sys_result.val = __libc_do_syscall (number, arg1, arg2, arg3, \
> + arg4, arg5); \
> + err = _sys_result.reg.v1; \
> + _sys_result.reg.v0; \
> })
>
> #define internal_syscall6(v0_init, input, number, err, \
> arg1, arg2, arg3, arg4, arg5, arg6) \
> ({ \
> - long _sys_result; \
> - \
> - FORCE_FRAME_POINTER; \
> - { \
> - 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); \
> - __asm__ volatile ( \
> - ".set\tnoreorder\n\t" \
> - "subu\t$29, 32\n\t" \
> - "sw\t%6, 16($29)\n\t" \
> - "sw\t%7, 20($29)\n\t" \
> - v0_init \
> - "syscall\n\t" \
> - "addiu\t$29, 32\n\t" \
> - ".set\treorder" \
> - : "=r" (__v0), "+r" (__a3) \
> - : input, "r" (__a0), "r" (__a1), "r" (__a2), \
> - "r" ((long) (arg5)), "r" ((long) (arg6)) \
> - : __SYSCALL_CLOBBERS); \
> - err = __a3; \
> - _sys_result = __v0; \
> - } \
> - _sys_result; \
> + union __libc_do_syscall_return _sys_result; \
> + _sys_result.val = __libc_do_syscall (number, arg1, arg2, arg3, \
> + arg4, arg5, arg6); \
> + err = _sys_result.reg.v1; \
> + _sys_result.reg.v0; \
> })
>
> #define internal_syscall7(v0_init, input, number, err, \
> arg1, arg2, arg3, arg4, arg5, arg6, arg7) \
> ({ \
> - long _sys_result; \
> - \
> - FORCE_FRAME_POINTER; \
> - { \
> - 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); \
> - __asm__ volatile ( \
> - ".set\tnoreorder\n\t" \
> - "subu\t$29, 32\n\t" \
> - "sw\t%6, 16($29)\n\t" \
> - "sw\t%7, 20($29)\n\t" \
> - "sw\t%8, 24($29)\n\t" \
> - v0_init \
> - "syscall\n\t" \
> - "addiu\t$29, 32\n\t" \
> - ".set\treorder" \
> - : "=r" (__v0), "+r" (__a3) \
> - : input, "r" (__a0), "r" (__a1), "r" (__a2), \
> - "r" ((long) (arg5)), "r" ((long) (arg6)), "r" ((long) (arg7)) \
> - : __SYSCALL_CLOBBERS); \
> - err = __a3; \
> - _sys_result = __v0; \
> - } \
> - _sys_result; \
> + union __libc_do_syscall_return _sys_result; \
> + _sys_result.val = __libc_do_syscall (number, arg1, arg2, arg3, \
> + arg4, arg5, arg6, arg7); \
> + err = _sys_result.reg.v1; \
> + _sys_result.reg.v0; \
> })
>
> #define __SYSCALL_CLOBBERS "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", \
>
>