glibc/sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall4.c

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/* MIPS16 syscall wrappers.
Copyright (C) 2013-2020 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
Prefer https to http for gnu.org and fsf.org URLs Also, change sources.redhat.com to sourceware.org. This patch was automatically generated by running the following shell script, which uses GNU sed, and which avoids modifying files imported from upstream: sed -ri ' s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g ' \ $(find $(git ls-files) -prune -type f \ ! -name '*.po' \ ! -name 'ChangeLog*' \ ! -path COPYING ! -path COPYING.LIB \ ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \ ! -path manual/texinfo.tex ! -path scripts/config.guess \ ! -path scripts/config.sub ! -path scripts/install-sh \ ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \ ! -path INSTALL ! -path locale/programs/charmap-kw.h \ ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \ ! '(' -name configure \ -execdir test -f configure.ac -o -f configure.in ';' ')' \ ! '(' -name preconfigure \ -execdir test -f preconfigure.ac ';' ')' \ -print) and then by running 'make dist-prepare' to regenerate files built from the altered files, and then executing the following to cleanup: chmod a+x sysdeps/unix/sysv/linux/riscv/configure # Omit irrelevant whitespace and comment-only changes, # perhaps from a slightly-different Autoconf version. git checkout -f \ sysdeps/csky/configure \ sysdeps/hppa/configure \ sysdeps/riscv/configure \ sysdeps/unix/sysv/linux/csky/configure # Omit changes that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines git checkout -f \ sysdeps/powerpc/powerpc64/ppc-mcount.S \ sysdeps/unix/sysv/linux/s390/s390-64/syscall.S # Omit change that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 05:40:42 +00:00
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#undef __mips16_syscall4
long long __nomips16
__mips16_syscall4 (long a0, long a1, long a2, long a3,
long number)
{
MIPS/o32: Fix internal_syscall5/6/7 Fix a commit cc25c8b4c119 ("New pthread rwlock that is more scalable.") regression and prevent uncontrolled stack space usage from happening when a 5-, 6- or 7-argument syscall wrapper is placed in a loop. The cause of the problem is the use of `alloca' in regular MIPS/Linux wrappers to force the use of the frame pointer register in any function using one or more of these wrappers. Using the frame pointer register is required so as not to break frame unwinding as the the stack pointer is lowered within the inline asm used by these wrappers to make room for the stack arguments, which 5-, 6- and 7-argument syscalls use with the o32 ABI. The regular MIPS/Linux wrappers are macros however, expanded inline, and stack allocations made with `alloca' are not discarded until the return of the function they are made in. Consequently if called in a loop, then virtual memory is wasted, and if the loop goes through enough iterations, then ultimately available memory can get exhausted causing the program to crash. Address the issue by replacing the inline code with standalone assembly functions, which rely on the compiler arranging syscall arguments according to the o32 function calling convention, which MIPS/Linux syscalls also use, except for the syscall number passed and the error flag returned. This way there is no need to fiddle with the stack pointer anymore and all that has to be handled in the new standalone functions is the special handling of the syscall number and the error flag. Redirect 5-, 6- or 7-argument MIPS16/Linux syscall wrappers to these new functions as well, so as to avoid an unnecessary double call the existing wrappers would cause with the new arrangement. [BZ #21956] * sysdeps/unix/sysv/linux/mips/mips32/mips16/Makefile [subdir = misc] (sysdep_routines): Remove `mips16-syscall5', `mips16-syscall6' and `mips16-syscall7'. (CFLAGS-mips16-syscall5.c, CFLAGS-mips16-syscall6.c) (CFLAGS-mips16-syscall7.c): Remove. * sysdeps/unix/sysv/linux/mips/mips32/mips16/Versions (libc): Remove `__mips16_syscall5', `__mips16_syscall6' and `__mips16_syscall7'. * sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall0.c (__mips16_syscall0): Rename `__mips16_syscall_return' to `__mips_syscall_return'. * sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall1.c (__mips16_syscall1): Likewise. * sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall2.c (__mips16_syscall2): Likewise. * sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall3.c (__mips16_syscall3): Likewise. * sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall4.c (__mips16_syscall4): Likewise. * sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall5.c: Remove. * sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall6.c: Remove. * sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall7.c: Remove. * sysdeps/unix/sysv/linux/mips/mips32/mips16/mips16-syscall.h (__mips16_syscall5): Expand to `__mips_syscall5' rather than `__mips16_syscall5'. Remove prototype. (__mips16_syscall6): Expand to `__mips_syscall6' rather than `__mips16_syscall6'. Remove prototype. (__mips16_syscall7): Expand to `__mips_syscall7' rather than `__mips16_syscall7'. Remove prototype. (__nomips16, __mips16_syscall_return): Move to... * sysdeps/unix/sysv/linux/mips/mips32/sysdep.h (__nomips16, __mips_syscall_return): ... here. [__mips16] (INTERNAL_SYSCALL_NCS): Rename `__mips16_syscall_return' to `__mips_syscall_return'. [__mips16] (INTERNAL_SYSCALL_MIPS16): Pass `number' to `internal_syscall##nr'. [!__mips16] (INTERNAL_SYSCALL): Pass `SYS_ify (name)' to `internal_syscall##nr'. (FORCE_FRAME_POINTER): Remove. (__mips_syscall5): New prototype. (internal_syscall5): Rewrite to call `__mips_syscall5'. (__mips_syscall6): New prototype. (internal_syscall6): Rewrite to call `__mips_syscall6'. (__mips_syscall7): New prototype. (internal_syscall7): Rewrite to call `__mips_syscall7'. * sysdeps/unix/sysv/linux/mips/mips32/mips-syscall5.S: New file. * sysdeps/unix/sysv/linux/mips/mips32/mips-syscall6.S: New file. * sysdeps/unix/sysv/linux/mips/mips32/mips-syscall7.S: New file. * sysdeps/unix/sysv/linux/mips/mips32/Makefile [subdir = misc] (sysdep_routines): Add libc-do-syscall. * sysdeps/unix/sysv/linux/mips/mips32/Versions (libc): Add `__mips_syscall5', `__mips_syscall6' and `__mips_syscall7'.
2017-08-29 17:31:08 +00:00
union __mips_syscall_return ret;
ret.reg.v0 = INTERNAL_SYSCALL_MIPS16 (number, ret.reg.v1, 4,
a0, a1, a2, a3);
return ret.val;
}