Need to provide i386 __libc_do_syscall when PROF is defined.
Define OPTIMIZE_FOR_GCC_5 for .S files so that it can be used
in libc-do-syscall.S.
* sysdeps/unix/sysv/linux/i386/libc-do-syscall.S: Replace
__GNUC_PREREQ (5,0) with OPTIMIZE_FOR_GCC_5.
* sysdeps/unix/sysv/linux/i386/sysdep.h (OPTIMIZE_FOR_GCC_5):
Moved before "#ifdef __ASSEMBLER__".
This patch follows the approach outlined in
<https://sourceware.org/ml/libc-alpha/2015-03/msg00656.html> to
support six-argument syscalls from INTERNAL_SYSCALL for 32-bit x86,
making them call a function __libc_do_syscall that takes the syscall
number and three syscall arguments in the registers in which the
kernel expects them, along with a pointer to a structure containing
the other three arguments.
In turn, this allows the generic lowlevellock-futex.h to be used on
32-bit x86, so supporting lll_futex_timed_wait_bitset (and so allowing
FUTEX_CLOCK_REALTIME to be used in various cases, so fixing bug 18138
for 32-bit x86 and leaving hppa as the only architecture missing
lll_futex_timed_wait_bitset). The change to lowlevellock.h's
definition of SYS_futex is because the generic lowlevelloc-futex.h
ends up bringing in bits/syscall.h which defines SYS_futex to
__NR_futex, so resulting in redefinition errors. The revised
definition in lowlevellock.h is in line with what the x86_64 version
does.
__libc_do_syscall is only needed in libpthread at present (meaning
nothing special needs to be done to make it shared-only in most
libraries containing it, static in libc only, as on ARM).
Tested for 32-bit x86, with the glibc testsuite and with the test in
bug 18138. The failures seen
FAIL: nptl/tst-cleanupx4
FAIL: rt/tst-cpuclock2
are pre-existing.
[BZ #18138]
* sysdeps/unix/sysv/linux/i386/sysdep.h (struct
libc_do_syscall_args): New structure.
(INTERNAL_SYSCALL_MAIN_0): New macro.
(INTERNAL_SYSCALL_MAIN_1): Likewise.
(INTERNAL_SYSCALL_MAIN_2): Likewise.
(INTERNAL_SYSCALL_MAIN_3): Likewise.
(INTERNAL_SYSCALL_MAIN_4): Likewise.
(INTERNAL_SYSCALL_MAIN_5): Likewise.
(INTERNAL_SYSCALL_MAIN_6): Likewise. Call __libc_do_syscall.
(INTERNAL_SYSCALL): Define to use INTERNAL_SYSCALL_MAIN_##nr.
Replace conditional definitions by conditional definitions of ....
(INTERNAL_SYSCALL_MAIN_INLINE): ... this. New macro.
* sysdeps/unix/sysv/linux/i386/libc-do-syscall.S: New file.
* sysdeps/unix/sysv/linux/i386/Makefile [$(subdir) = nptl]
(libpthread-sysdep_routines): Add libc-do-syscall.
* sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h: Remove file.
* sysdeps/unix/sysv/linux/i386/lowlevellock.h (SYS_futex): Define
to __NR_futex not 240.