mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-05 19:21:05 +00:00
f0458cf4f9
Linux from 3.9 through 4.2 does not abort HTM transaction on syscalls, instead it suspend and resume it when leaving the kernel. The side-effects of the syscall will always remain visible, even if the transaction is aborted. This is an issue when transaction is used along with futex syscall, on pthread_cond_wait for instance, where the futex call might succeed but the transaction is rolled back leading the pthread_cond object in an inconsistent state. Glibc used to prevent it by always aborting a transaction before issuing a syscall. Linux 4.2 also decided to abort active transaction in syscalls which makes the glibc workaround superfluous. Worse, glibc transaction abortion leads to a performance issue on recent kernels where the HTM state is saved/restore lazily (v4.9). By aborting a transaction on every syscalls, regardless whether a transaction has being initiated before, GLIBS makes the kernel always save/restore HTM state (it can not even lazily disable it after a certain number of syscall iterations). Because of this shortcoming, Transactional Lock Elision is just enabled when it has been explicitly set (either by tunables of by a configure switch) and if kernel aborts HTM transactions on syscalls (PPC_FEATURE2_HTM_NOSC). It is reported that using simple benchmark [1], the context-switch is about 5% faster by not issuing a tabort in every syscall in newer kernels. Checked on powerpc64le-linux-gnu with 4.4.0 kernel (Ubuntu 16.04). * NEWS: Add note about new TLE support on powerpc64le. * sysdeps/powerpc/nptl/tcb-offsets.sym (TM_CAPABLE): Remove. * sysdeps/powerpc/nptl/tls.h (tcbhead_t): Rename tm_capable to __ununsed1. (TLS_INIT_TP, TLS_DEFINE_INIT_TP): Remove tm_capable setup. (THREAD_GET_TM_CAPABLE, THREAD_SET_TM_CAPABLE): Remove macros. * sysdeps/powerpc/powerpc32/sysdep.h, sysdeps/powerpc/powerpc64/sysdep.h (ABORT_TRANSACTION_IMPL, ABORT_TRANSACTION): Remove macros. * sysdeps/powerpc/sysdep.h (ABORT_TRANSACTION): Likewise. * sysdeps/unix/sysv/linux/powerpc/elision-conf.c (elision_init): Set __pthread_force_elision iff PPC_FEATURE2_HTM_NOSC is set. * sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h, sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h sysdeps/unix/sysv/linux/powerpc/syscall.S (ABORT_TRANSACTION): Remove usage. * sysdeps/unix/sysv/linux/powerpc/not-errno.h: Remove file. Reported-by: Breno Leitão <leitao@debian.org>
234 lines
9.0 KiB
C
234 lines
9.0 KiB
C
/* Copyright (C) 1992-2018 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/>. */
|
|
|
|
#ifndef _LINUX_POWERPC_SYSDEP_H
|
|
#define _LINUX_POWERPC_SYSDEP_H 1
|
|
|
|
#include <sysdeps/unix/sysv/linux/sysdep.h>
|
|
#include <sysdeps/unix/powerpc/sysdep.h>
|
|
#include <tls.h>
|
|
|
|
/* For Linux we can use the system call table in the header file
|
|
/usr/include/asm/unistd.h
|
|
of the kernel. But these symbols do not follow the SYS_* syntax
|
|
so we have to redefine the `SYS_ify' macro here. */
|
|
#undef SYS_ify
|
|
#define SYS_ify(syscall_name) __NR_##syscall_name
|
|
|
|
#ifndef __ASSEMBLER__
|
|
|
|
# include <errno.h>
|
|
|
|
/* Define a macro which expands inline into the wrapper code for a VDSO
|
|
call. This use is for internal calls that do not need to handle errors
|
|
normally. It will never touch errno.
|
|
On powerpc a system call basically clobbers the same registers like a
|
|
function call, with the exception of LR (which is needed for the
|
|
"sc; bnslr+" sequence) and CR (where only CR0.SO is clobbered to signal
|
|
an error return status). */
|
|
# define INTERNAL_VSYSCALL_CALL_TYPE(funcptr, err, nr, type, args...) \
|
|
({ \
|
|
register void *r0 __asm__ ("r0"); \
|
|
register long int r3 __asm__ ("r3"); \
|
|
register long int r4 __asm__ ("r4"); \
|
|
register long int r5 __asm__ ("r5"); \
|
|
register long int r6 __asm__ ("r6"); \
|
|
register long int r7 __asm__ ("r7"); \
|
|
register long int r8 __asm__ ("r8"); \
|
|
register long int r9 __asm__ ("r9"); \
|
|
register long int r10 __asm__ ("r10"); \
|
|
register long int r11 __asm__ ("r11"); \
|
|
register long int r12 __asm__ ("r12"); \
|
|
register type rval __asm__ ("r3"); \
|
|
LOADARGS_##nr (funcptr, args); \
|
|
__asm__ __volatile__ \
|
|
("mtctr %0\n\t" \
|
|
"bctrl\n\t" \
|
|
"mfcr %0" \
|
|
: "+r" (r0), "+r" (r3), "+r" (r4), "+r" (r5), "+r" (r6), "+r" (r7), \
|
|
"+r" (r8), "+r" (r9), "+r" (r10), "+r" (r11), "+r" (r12) \
|
|
: : "cr0", "ctr", "lr", "memory"); \
|
|
err = (long int) r0; \
|
|
__asm__ __volatile__ ("" : "=r" (rval) : "r" (r3), "r" (r4)); \
|
|
rval; \
|
|
})
|
|
|
|
#define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...) \
|
|
INTERNAL_VSYSCALL_CALL_TYPE(funcptr, err, nr, long int, args)
|
|
|
|
# undef INLINE_SYSCALL
|
|
# define INLINE_SYSCALL(name, nr, args...) \
|
|
({ \
|
|
INTERNAL_SYSCALL_DECL (sc_err); \
|
|
long int sc_ret = INTERNAL_SYSCALL (name, sc_err, nr, args); \
|
|
if (INTERNAL_SYSCALL_ERROR_P (sc_ret, sc_err)) \
|
|
{ \
|
|
__set_errno (INTERNAL_SYSCALL_ERRNO (sc_ret, sc_err)); \
|
|
sc_ret = -1L; \
|
|
} \
|
|
sc_ret; \
|
|
})
|
|
|
|
/* Define a macro which expands inline into the wrapper code for a system
|
|
call. This use is for internal calls that do not need to handle errors
|
|
normally. It will never touch errno.
|
|
On powerpc a system call basically clobbers the same registers like a
|
|
function call, with the exception of LR (which is needed for the
|
|
"sc; bnslr+" sequence) and CR (where only CR0.SO is clobbered to signal
|
|
an error return status). */
|
|
|
|
# undef INTERNAL_SYSCALL_DECL
|
|
# define INTERNAL_SYSCALL_DECL(err) long int err __attribute__ ((unused))
|
|
|
|
# undef INTERNAL_SYSCALL
|
|
# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \
|
|
({ \
|
|
register long int r0 __asm__ ("r0"); \
|
|
register long int r3 __asm__ ("r3"); \
|
|
register long int r4 __asm__ ("r4"); \
|
|
register long int r5 __asm__ ("r5"); \
|
|
register long int r6 __asm__ ("r6"); \
|
|
register long int r7 __asm__ ("r7"); \
|
|
register long int r8 __asm__ ("r8"); \
|
|
register long int r9 __asm__ ("r9"); \
|
|
register long int r10 __asm__ ("r10"); \
|
|
register long int r11 __asm__ ("r11"); \
|
|
register long int r12 __asm__ ("r12"); \
|
|
LOADARGS_##nr(name, args); \
|
|
__asm__ __volatile__ \
|
|
("sc \n\t" \
|
|
"mfcr %0" \
|
|
: "=&r" (r0), \
|
|
"=&r" (r3), "=&r" (r4), "=&r" (r5), "=&r" (r6), "=&r" (r7), \
|
|
"=&r" (r8), "=&r" (r9), "=&r" (r10), "=&r" (r11), "=&r" (r12) \
|
|
: ASM_INPUT_##nr \
|
|
: "cr0", "ctr", "memory"); \
|
|
err = r0; \
|
|
(int) r3; \
|
|
})
|
|
# define INTERNAL_SYSCALL(name, err, nr, args...) \
|
|
INTERNAL_SYSCALL_NCS (__NR_##name, err, nr, ##args)
|
|
|
|
# undef INTERNAL_SYSCALL_ERROR_P
|
|
# define INTERNAL_SYSCALL_ERROR_P(val, err) \
|
|
((void) (val), __builtin_expect ((err) & (1 << 28), 0))
|
|
|
|
# undef INTERNAL_SYSCALL_ERRNO
|
|
# define INTERNAL_SYSCALL_ERRNO(val, err) (val)
|
|
|
|
# define INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK(name, err, type, nr, args...) \
|
|
({ \
|
|
type sc_ret = ENOSYS; \
|
|
\
|
|
__typeof (__vdso_##name) vdsop = __vdso_##name; \
|
|
PTR_DEMANGLE (vdsop); \
|
|
if (vdsop != NULL) \
|
|
sc_ret = \
|
|
INTERNAL_VSYSCALL_CALL_TYPE (vdsop, err, nr, type, ##args); \
|
|
else \
|
|
err = 1 << 28; \
|
|
sc_ret; \
|
|
})
|
|
|
|
/* List of system calls which are supported as vsyscalls. */
|
|
# define HAVE_CLOCK_GETRES_VSYSCALL 1
|
|
# define HAVE_CLOCK_GETTIME_VSYSCALL 1
|
|
# define HAVE_GETCPU_VSYSCALL 1
|
|
|
|
|
|
# define LOADARGS_0(name, dummy) \
|
|
r0 = name
|
|
# define LOADARGS_1(name, __arg1) \
|
|
long int arg1 = (long int) (__arg1); \
|
|
LOADARGS_0(name, 0); \
|
|
extern void __illegally_sized_syscall_arg1 (void); \
|
|
if (__builtin_classify_type (__arg1) != 5 && sizeof (__arg1) > 4) \
|
|
__illegally_sized_syscall_arg1 (); \
|
|
r3 = arg1
|
|
# define LOADARGS_2(name, __arg1, __arg2) \
|
|
long int arg2 = (long int) (__arg2); \
|
|
LOADARGS_1(name, __arg1); \
|
|
extern void __illegally_sized_syscall_arg2 (void); \
|
|
if (__builtin_classify_type (__arg2) != 5 && sizeof (__arg2) > 4) \
|
|
__illegally_sized_syscall_arg2 (); \
|
|
r4 = arg2
|
|
# define LOADARGS_3(name, __arg1, __arg2, __arg3) \
|
|
long int arg3 = (long int) (__arg3); \
|
|
LOADARGS_2(name, __arg1, __arg2); \
|
|
extern void __illegally_sized_syscall_arg3 (void); \
|
|
if (__builtin_classify_type (__arg3) != 5 && sizeof (__arg3) > 4) \
|
|
__illegally_sized_syscall_arg3 (); \
|
|
r5 = arg3
|
|
# define LOADARGS_4(name, __arg1, __arg2, __arg3, __arg4) \
|
|
long int arg4 = (long int) (__arg4); \
|
|
LOADARGS_3(name, __arg1, __arg2, __arg3); \
|
|
extern void __illegally_sized_syscall_arg4 (void); \
|
|
if (__builtin_classify_type (__arg4) != 5 && sizeof (__arg4) > 4) \
|
|
__illegally_sized_syscall_arg4 (); \
|
|
r6 = arg4
|
|
# define LOADARGS_5(name, __arg1, __arg2, __arg3, __arg4, __arg5) \
|
|
long int arg5 = (long int) (__arg5); \
|
|
LOADARGS_4(name, __arg1, __arg2, __arg3, __arg4); \
|
|
extern void __illegally_sized_syscall_arg5 (void); \
|
|
if (__builtin_classify_type (__arg5) != 5 && sizeof (__arg5) > 4) \
|
|
__illegally_sized_syscall_arg5 (); \
|
|
r7 = arg5
|
|
# define LOADARGS_6(name, __arg1, __arg2, __arg3, __arg4, __arg5, __arg6) \
|
|
long int arg6 = (long int) (__arg6); \
|
|
LOADARGS_5(name, __arg1, __arg2, __arg3, __arg4, __arg5); \
|
|
extern void __illegally_sized_syscall_arg6 (void); \
|
|
if (__builtin_classify_type (__arg6) != 5 && sizeof (__arg6) > 4) \
|
|
__illegally_sized_syscall_arg6 (); \
|
|
r8 = arg6
|
|
|
|
# define ASM_INPUT_0 "0" (r0)
|
|
# define ASM_INPUT_1 ASM_INPUT_0, "1" (r3)
|
|
# define ASM_INPUT_2 ASM_INPUT_1, "2" (r4)
|
|
# define ASM_INPUT_3 ASM_INPUT_2, "3" (r5)
|
|
# define ASM_INPUT_4 ASM_INPUT_3, "4" (r6)
|
|
# define ASM_INPUT_5 ASM_INPUT_4, "5" (r7)
|
|
# define ASM_INPUT_6 ASM_INPUT_5, "6" (r8)
|
|
|
|
#endif /* __ASSEMBLER__ */
|
|
|
|
|
|
/* Pointer mangling support. */
|
|
#if IS_IN (rtld)
|
|
/* We cannot use the thread descriptor because in ld.so we use setjmp
|
|
earlier than the descriptor is initialized. */
|
|
#else
|
|
# ifdef __ASSEMBLER__
|
|
# define PTR_MANGLE(reg, tmpreg) \
|
|
lwz tmpreg,POINTER_GUARD(r2); \
|
|
xor reg,tmpreg,reg
|
|
# define PTR_MANGLE2(reg, tmpreg) \
|
|
xor reg,tmpreg,reg
|
|
# define PTR_MANGLE3(destreg, reg, tmpreg) \
|
|
lwz tmpreg,POINTER_GUARD(r2); \
|
|
xor destreg,tmpreg,reg
|
|
# define PTR_DEMANGLE(reg, tmpreg) PTR_MANGLE (reg, tmpreg)
|
|
# define PTR_DEMANGLE2(reg, tmpreg) PTR_MANGLE2 (reg, tmpreg)
|
|
# define PTR_DEMANGLE3(destreg, reg, tmpreg) PTR_MANGLE3 (destreg, reg, tmpreg)
|
|
# else
|
|
# define PTR_MANGLE(var) \
|
|
(var) = (__typeof (var)) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
|
|
# define PTR_DEMANGLE(var) PTR_MANGLE (var)
|
|
# endif
|
|
#endif
|
|
|
|
#endif /* linux/powerpc/powerpc32/sysdep.h */
|