With all Linux ABIs using the expected Linux kABI to indicate
syscalls errors, there is no need to replicate the INLINE_SYSCALL.
The generic Linux sysdep.h includes errno.h even for !__ASSEMBLER__,
which is ok now and it allows cleanup some archaic code that assume
otherwise.
Checked with a build against all affected ABIs.
It changes the mips INTERNAL_SYSCALL* and internal_syscall* macros
to return a negative value instead of the 'a3' register value on then
'err' macro argument.
The macro INTERNAL_SYSCALL_DECL is no longer required, and the
INTERNAL_SYSCALL_ERROR_P macro follows the other Linux kABIs.
The redefinition of INTERNAL_VSYSCALL_CALL is also no longer
required.
Checked on mips64-linux-gnu, mips64n32-linux-gnu, and mips-linux-gnu.
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 381a0c26d7).
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
GCC 10 (PR 91233) won't silently allow registers that are not architecturally
available to be present in the clobber list anymore, resulting in build failure
for mips*r6 targets in form of:
...
.../sysdep.h:146:2: error: the register ‘lo’ cannot be clobbered in ‘asm’ for the current target
146 | __asm__ volatile ( \
| ^~~~~~~
This is because base R6 ISA doesn't define hi and lo registers w/o DSP extension.
This patch provides the alternative definitions of __SYSCALL_CLOBBERS for r6
targets that won't include those registers.
* sysdeps/unix/sysv/linux/mips/mips32/sysdep.h (__SYSCALL_CLOBBERS): Exclude
hi and lo from the clobber list for __mips_isa_rev >= 6.
* sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h (__SYSCALL_CLOBBERS): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h (__SYSCALL_CLOBBERS): Likewise.
This patch consolidates the mips, mips64, and mips64-n32
INTERNAL_VSYSCALL_CALL on a single implementation.
No semantic changes. I checked against a build for mips-linux-gnu,
mips64-linux-gnu, and mips64-n32-linux-gnu.
* sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
(INTERNAL_VSYSCALL_CALL): Remove.
* sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h
(INTERNAL_VSYSCALL_CALL): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h
(INTERNAL_VSYSCALL_CALL): Likewise.
* sysdeps/unix/sysv/linux/mips/sysdep.h (INTERNAL_VSYSCALL_CALL):
New macro.
This patch assumes static vDSO is supported as default, it is now supported
on all current architectures that support vDSO. It allows removing both
ALWAYS_USE_VSYSCALL define, which an architecture requires to explicit define
and USE_VSYSCALL (which defines vDSO only for shared or if architecture defines
ALWAYS_USE_VSYSCALL).
Checked with a build against all affected ABIs.
[BZ #19767]
* sysdeps/unix/sysv/linux/aarch64/sysdep.h (ALWAYS_USE_VSYSCALL):
Remove definition.
* sysdeps/unix/sysv/linux/arm/sysdep.h (ALWAYS_USE_VSYSCALL):
Likewise.
* sysdeps/unix/sysv/linux/i386/sysdep.h (ALWAYS_USE_VSYSCALL):
Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/sysdep.h (ALWAYS_USE_VSYSCALL):
Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h
(ALWAYS_USE_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h
(ALWAYS_USE_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h
(ALWAYS_USE_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h
(ALWAYS_USE_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/riscv/sysdep.h (ALWAYS_USE_VSYSCALL):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h
(ALWAYS_USE_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h
(ALWAYS_USE_VSYSCALL): Likewise.
* sysdeps/unix/sysv/linux/sparc/sysdep.h (ALWAYS_USE_VSYSCALL):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/sysdep.h (ALWAYS_USE_VSYSCALL):
Likewise.
* sysdeps/unix/sysv/linux/x86/libc-vdso.h: Remove #if USE_VSYSCALL.
* sysdeps/unix/sysv/linux/sysdep-vdso.h: Likewise.
* sysdeps/unix/sysv/linux/sysdep.h (ALWAYS_USE_VSYSCALL,
USE_VSYSCALL): Remove defitions.
I have tested that this builds and the resulting program still work.
This was tested on gcc23.fsffrance.org, and for some reason the vdso
there seems unused even when using shared libraries.
[BZ #19767]
* sysdeps/unix/sysv/linux/mips/init-first.c: Remove #ifdef SHARED.
* sysdeps/unix/sysv/linux/mips/libc-vdso.h: Remove #ifdef SHARED.
* sysdeps/unix/sysv/linux/mips/mips32/sysdep.h: Define
ALWAYS_USE_VSYSCALL.
* sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h: Define
ALWAYS_USE_VSYSCALL.
* sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h: Define
ALWAYS_USE_VSYSCALL.
Fix a commit cc25c8b4c1 ("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'.
This patch adds support for using the implementations of gettimeofday()
and clock_gettime() provided by the kernel in the VDSO. The VDSO will
always provide clock_gettime() as CLOCK_{REALTIME,MONOTONIC}_COARSE can
be implemented regardless of platform. CLOCK_{REALTIME,MONOTONIC}, along
with gettimeofday(), are only implemented on platforms which make use of
either the CP0 count or GIC as their clocksource. On other platforms,
the VDSO does not provide the __vdso_gettimeofday symbol, as it is
never useful.
The VDSO functions return ENOSYS when they encounter an unsupported
request, in which case glibc should fall back to the standard syscall.
Tested with upstream kernel 4.5 and QEMU emulating Malta.
./vdsotest gettimeofday bench
gettimeofday: syscall: 1021 nsec/call
gettimeofday: libc: 262 nsec/call
gettimeofday: vdso: 174 nsec/call
* sysdeps/unix/sysv/linux/mips/Makefile (sysdep_routines):
Include dl-vdso.
* sysdeps/unix/sysv/linux/mips/Versions: Add
__vdso_clock_gettime.
* sysdeps/unix/sysv/linux/mips/init-first.c: New file.
* sysdeps/unix/sysv/linux/mips/libc-vdso.h: New file.
* sysdeps/unix/sysv/linux/mips/mips32/sysdep.h:
(INTERNAL_VSYSCALL_CALL): Define to be compatible with MIPS
definitions of INTERNAL_SYSCALL_{ERROR_P,ERRNO}.
(HAVE_CLOCK_GETTIME_VSYSCALL): Define.
(HAVE_GETTIMEOFDAY_VSYSCALL): Define.
* sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h: Likewise.
Carlos noted in
<https://sourceware.org/ml/libc-alpha/2015-05/msg00680.html> that
various ports use potentially problematic short variables names in
their syscall macros, which could shadow variables with the same name
from containing scopes.
This patch fixes variables called err and ret in MIPS macros. (I left
result_var and _sys_result - separate variables in different macros,
which need separate names - alone.)
Tested for mips64 (all three ABIs) that installed stripped shared
libraries are unchanged by this patch.
* sysdeps/unix/sysv/linux/mips/mips32/sysdep.h (INLINE_SYSCALL):
Use variable name _sc_err instead of err.
[__mips16] (INTERNAL_SYSCALL_NCS): Use variable name _sc_ret
instead of ret.
* sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h
(INLINE_SYSCALL): Use variable name _sc_err instead of err.
* sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h
(INLINE_SYSCALL): Likewise.
I've moved the MIPS port from ports to the main sysdeps hierarchy.
Beyond the README update, the move of the files was simply
git mv ports/sysdeps/mips sysdeps/mips
git mv ports/sysdeps/unix/mips sysdeps/unix/mips
git mv ports/sysdeps/unix/sysv/linux/mips sysdeps/unix/sysv/linux/mips
and in addition to the ChangeLog entries here, I put a note at the top
of ports/ChangeLog.mips similar to those in other files.
Tested that disassembly of installed shared libraries for mips is the
same before and after this patch (except for ld.so where paths in
assertions are involved, as for arm).
* sysdeps/mips: Move directory from ports/sysdeps/mips.
* sysdeps/unix/mips: Move directory from ports/sysdeps/unix/mips.
* sysdeps/unix/sysv/linux/mips: Move directory from
ports/sysdeps/unix/sysv/linux/mips.
* README: Update listing for mips-*-linux-gnu and
mips64-*-linux-gnu.
* sysdeps/mips: Move directory to ../sysdeps/mips.
* sysdeps/unix/mips: Move directory to ../sysdeps/unix/mips.
* sysdeps/unix/sysv/linux/mips: Move directory to
../sysdeps/unix/sysv/linux/mips.
