mirror of
https://sourceware.org/git/glibc.git
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09c76a7409
Current GLIBC has two ways to implement the single thread optimization
on syscalls to avoid calling the cancellation path: either by using
global variables (__{libc,pthread}_multiple_thread) or by accessing
the TCB field (defined by TLS_MULTIPLE_THREADS_IN_TCB). Both the
variables and the macros to acces its value are defined in the
architecture sysdep-cancel.h header.
This patch consolidates its definition on only one header,
sysdeps/unix/sysv/linux/sysdep-cancel.h, and adds a new define
(SINGLE_THREAD_BY_GLOBAL) which the architecture defines if it prefer
to use the global variables instead of the TCB field. This is an
optimization, so if the architecture does not define it, the TCB
method will be used as default.
Checked on x86_64-linux-gnu and on a build with major touched
ABIs (aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabihf,
hppa-linux-gnu, i686-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu,
mips-linux-gnu, mips64-linux-gnu, powerpc-linux-gnu,
powerpc64le-linux-gnu, s390-linux-gnu, s390x-linux-gnu, sh4-linux-gnu,
sparcv9-linux-gnu, sparc64-linux-gnu, tilegx-linux-gnu).
* sysdeps/unix/sysv/linux/aarch64/sysdep-cancel.h: Remove file.
* sysdeps/unix/sysv/linux/alpha/sysdep-cancel.h: Likewise.
* sysdeps/unix/sysv/linux/arm/sysdep-cancel.h: Likewise.
* sysdeps/unix/sysv/linux/hppa/sysdep-cancel.h: Likewise.
* sysdeps/unix/sysv/linux/mips/sysdep-cancel.h: Likewise.
* sysdeps/unix/sysv/linux/nios2/sysdep-cancel.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/sysdep-cancel.h: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/sysdep-cancel.h: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/sysdep-cancel.h: Likewise.
* sysdeps/unix/sysv/linux/sh/sysdep-cancel.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/sysdep-cancel.h: Likewise.
* sysdeps/unix/sysv/linux/tile/sysdep-cancel.h: Likewise.
* sysdeps/unix/sysv/linux/x86_64/sysdep-cancel.h: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h
(SINGLE_THREAD_BY_GLOBAL): Define.
* sysdeps/unix/sysv/linux/aarch64/sysdep.h (SINGLE_THREAD_BY_GLOBAL):
Likewise.
* sysdeps/unix/sysv/linux/alpha/sysdep.h (SINGLE_THREAD_BY_GLOBAL):
Likewise.
* sysdeps/unix/sysv/linux/arm/sysdep.h (SINGLE_THREAD_BY_GLOBAL):
Likewise.
* sysdeps/unix/sysv/linux/hppa/sysdep.h (SINGLE_THREAD_BY_GLOBAL):
Likewise.
* sysdeps/unix/sysv/linux/microblaze/sysdep.h
(SINGLE_THREAD_BY_GLOBAL): Likewise.
* sysdeps/unix/sysv/linux/x86_64/sysdep.h (SINGLE_THREAD_BY_GLOBAL):
Likewise.
428 lines
14 KiB
C
428 lines
14 KiB
C
/* Copyright (C) 2001-2017 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _LINUX_X86_64_SYSDEP_H
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#define _LINUX_X86_64_SYSDEP_H 1
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/* There is some commonality. */
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#include <sysdeps/unix/sysv/linux/sysdep.h>
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#include <sysdeps/unix/x86_64/sysdep.h>
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#include <tls.h>
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#if IS_IN (rtld)
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# include <dl-sysdep.h> /* Defines RTLD_PRIVATE_ERRNO. */
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#endif
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/* For Linux we can use the system call table in the header file
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/usr/include/asm/unistd.h
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of the kernel. But these symbols do not follow the SYS_* syntax
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so we have to redefine the `SYS_ify' macro here. */
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#undef SYS_ify
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#define SYS_ify(syscall_name) __NR_##syscall_name
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/* This is a kludge to make syscalls.list find these under the names
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pread and pwrite, since some kernel headers define those names
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and some define the *64 names for the same system calls. */
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#if !defined __NR_pread && defined __NR_pread64
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# define __NR_pread __NR_pread64
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#endif
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#if !defined __NR_pwrite && defined __NR_pwrite64
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# define __NR_pwrite __NR_pwrite64
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#endif
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/* This is to help the old kernel headers where __NR_semtimedop is not
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available. */
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#ifndef __NR_semtimedop
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# define __NR_semtimedop 220
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#endif
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#ifdef __ASSEMBLER__
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/* Linux uses a negative return value to indicate syscall errors,
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unlike most Unices, which use the condition codes' carry flag.
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Since version 2.1 the return value of a system call might be
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negative even if the call succeeded. E.g., the `lseek' system call
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might return a large offset. Therefore we must not anymore test
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for < 0, but test for a real error by making sure the value in %eax
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is a real error number. Linus said he will make sure the no syscall
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returns a value in -1 .. -4095 as a valid result so we can savely
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test with -4095. */
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/* We don't want the label for the error handle to be global when we define
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it here. */
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# ifdef PIC
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# define SYSCALL_ERROR_LABEL 0f
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# else
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# define SYSCALL_ERROR_LABEL syscall_error
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# endif
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# undef PSEUDO
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# define PSEUDO(name, syscall_name, args) \
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.text; \
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ENTRY (name) \
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DO_CALL (syscall_name, args); \
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cmpq $-4095, %rax; \
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jae SYSCALL_ERROR_LABEL
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# undef PSEUDO_END
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# define PSEUDO_END(name) \
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SYSCALL_ERROR_HANDLER \
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END (name)
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# undef PSEUDO_NOERRNO
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# define PSEUDO_NOERRNO(name, syscall_name, args) \
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.text; \
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ENTRY (name) \
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DO_CALL (syscall_name, args)
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# undef PSEUDO_END_NOERRNO
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# define PSEUDO_END_NOERRNO(name) \
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END (name)
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# define ret_NOERRNO ret
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# undef PSEUDO_ERRVAL
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# define PSEUDO_ERRVAL(name, syscall_name, args) \
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.text; \
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ENTRY (name) \
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DO_CALL (syscall_name, args); \
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negq %rax
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# undef PSEUDO_END_ERRVAL
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# define PSEUDO_END_ERRVAL(name) \
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END (name)
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# define ret_ERRVAL ret
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# if defined PIC && defined RTLD_PRIVATE_ERRNO
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# define SYSCALL_SET_ERRNO \
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lea rtld_errno(%rip), %RCX_LP; \
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neg %eax; \
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movl %eax, (%rcx)
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# else
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# if IS_IN (libc)
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# define SYSCALL_ERROR_ERRNO __libc_errno
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# else
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# define SYSCALL_ERROR_ERRNO errno
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# endif
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# define SYSCALL_SET_ERRNO \
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movq SYSCALL_ERROR_ERRNO@GOTTPOFF(%rip), %rcx;\
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neg %eax; \
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movl %eax, %fs:(%rcx);
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# endif
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# ifndef PIC
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# define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */
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# else
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# define SYSCALL_ERROR_HANDLER \
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0: \
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SYSCALL_SET_ERRNO; \
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or $-1, %RAX_LP; \
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ret;
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# endif /* PIC */
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/* The Linux/x86-64 kernel expects the system call parameters in
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registers according to the following table:
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syscall number rax
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arg 1 rdi
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arg 2 rsi
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arg 3 rdx
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arg 4 r10
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arg 5 r8
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arg 6 r9
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The Linux kernel uses and destroys internally these registers:
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return address from
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syscall rcx
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eflags from syscall r11
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Normal function call, including calls to the system call stub
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functions in the libc, get the first six parameters passed in
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registers and the seventh parameter and later on the stack. The
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register use is as follows:
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system call number in the DO_CALL macro
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arg 1 rdi
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arg 2 rsi
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arg 3 rdx
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arg 4 rcx
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arg 5 r8
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arg 6 r9
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We have to take care that the stack is aligned to 16 bytes. When
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called the stack is not aligned since the return address has just
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been pushed.
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Syscalls of more than 6 arguments are not supported. */
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# undef DO_CALL
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# define DO_CALL(syscall_name, args) \
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DOARGS_##args \
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movl $SYS_ify (syscall_name), %eax; \
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syscall;
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# define DOARGS_0 /* nothing */
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# define DOARGS_1 /* nothing */
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# define DOARGS_2 /* nothing */
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# define DOARGS_3 /* nothing */
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# define DOARGS_4 movq %rcx, %r10;
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# define DOARGS_5 DOARGS_4
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# define DOARGS_6 DOARGS_5
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#else /* !__ASSEMBLER__ */
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/* Define a macro which expands inline into the wrapper code for a system
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call. */
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# undef INLINE_SYSCALL
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# define INLINE_SYSCALL(name, nr, args...) \
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({ \
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unsigned long int resultvar = INTERNAL_SYSCALL (name, , nr, args); \
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if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (resultvar, ))) \
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{ \
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__set_errno (INTERNAL_SYSCALL_ERRNO (resultvar, )); \
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resultvar = (unsigned long int) -1; \
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} \
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(long int) resultvar; })
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/* Define a macro with explicit types for arguments, which expands inline
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into the wrapper code for a system call. It should be used when size
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of any argument > size of long int. */
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# undef INLINE_SYSCALL_TYPES
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# define INLINE_SYSCALL_TYPES(name, nr, args...) \
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({ \
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unsigned long int resultvar = INTERNAL_SYSCALL_TYPES (name, , nr, args); \
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if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (resultvar, ))) \
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{ \
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__set_errno (INTERNAL_SYSCALL_ERRNO (resultvar, )); \
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resultvar = (unsigned long int) -1; \
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} \
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(long int) resultvar; })
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# undef INTERNAL_SYSCALL_DECL
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# define INTERNAL_SYSCALL_DECL(err) do { } while (0)
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/* Registers clobbered by syscall. */
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# define REGISTERS_CLOBBERED_BY_SYSCALL "cc", "r11", "cx"
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/* Create a variable 'name' based on type 'X' to avoid explicit types.
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This is mainly used set use 64-bits arguments in x32. */
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#define TYPEFY(X, name) __typeof__ ((X) - (X)) name
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/* Explicit cast the argument to avoid integer from pointer warning on
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x32. */
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#define ARGIFY(X) ((__typeof__ ((X) - (X))) (X))
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#undef INTERNAL_SYSCALL
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#define INTERNAL_SYSCALL(name, err, nr, args...) \
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internal_syscall##nr (SYS_ify (name), err, args)
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#undef INTERNAL_SYSCALL_NCS
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#define INTERNAL_SYSCALL_NCS(number, err, nr, args...) \
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internal_syscall##nr (number, err, args)
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#undef internal_syscall0
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#define internal_syscall0(number, err, dummy...) \
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({ \
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unsigned long int resultvar; \
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asm volatile ( \
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"syscall\n\t" \
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: "=a" (resultvar) \
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: "0" (number) \
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: "memory", REGISTERS_CLOBBERED_BY_SYSCALL); \
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(long int) resultvar; \
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})
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#undef internal_syscall1
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#define internal_syscall1(number, err, arg1) \
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({ \
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unsigned long int resultvar; \
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TYPEFY (arg1, __arg1) = ARGIFY (arg1); \
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register TYPEFY (arg1, _a1) asm ("rdi") = __arg1; \
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asm volatile ( \
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"syscall\n\t" \
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: "=a" (resultvar) \
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: "0" (number), "r" (_a1) \
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: "memory", REGISTERS_CLOBBERED_BY_SYSCALL); \
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(long int) resultvar; \
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})
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#undef internal_syscall2
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#define internal_syscall2(number, err, arg1, arg2) \
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({ \
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unsigned long int resultvar; \
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TYPEFY (arg2, __arg2) = ARGIFY (arg2); \
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TYPEFY (arg1, __arg1) = ARGIFY (arg1); \
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register TYPEFY (arg2, _a2) asm ("rsi") = __arg2; \
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register TYPEFY (arg1, _a1) asm ("rdi") = __arg1; \
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asm volatile ( \
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"syscall\n\t" \
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: "=a" (resultvar) \
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: "0" (number), "r" (_a1), "r" (_a2) \
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: "memory", REGISTERS_CLOBBERED_BY_SYSCALL); \
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(long int) resultvar; \
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})
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#undef internal_syscall3
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#define internal_syscall3(number, err, arg1, arg2, arg3) \
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({ \
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unsigned long int resultvar; \
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TYPEFY (arg3, __arg3) = ARGIFY (arg3); \
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TYPEFY (arg2, __arg2) = ARGIFY (arg2); \
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TYPEFY (arg1, __arg1) = ARGIFY (arg1); \
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register TYPEFY (arg3, _a3) asm ("rdx") = __arg3; \
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register TYPEFY (arg2, _a2) asm ("rsi") = __arg2; \
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register TYPEFY (arg1, _a1) asm ("rdi") = __arg1; \
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asm volatile ( \
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"syscall\n\t" \
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: "=a" (resultvar) \
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: "0" (number), "r" (_a1), "r" (_a2), "r" (_a3) \
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: "memory", REGISTERS_CLOBBERED_BY_SYSCALL); \
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(long int) resultvar; \
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})
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#undef internal_syscall4
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#define internal_syscall4(number, err, arg1, arg2, arg3, arg4) \
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({ \
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unsigned long int resultvar; \
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TYPEFY (arg4, __arg4) = ARGIFY (arg4); \
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TYPEFY (arg3, __arg3) = ARGIFY (arg3); \
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TYPEFY (arg2, __arg2) = ARGIFY (arg2); \
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TYPEFY (arg1, __arg1) = ARGIFY (arg1); \
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register TYPEFY (arg4, _a4) asm ("r10") = __arg4; \
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register TYPEFY (arg3, _a3) asm ("rdx") = __arg3; \
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register TYPEFY (arg2, _a2) asm ("rsi") = __arg2; \
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register TYPEFY (arg1, _a1) asm ("rdi") = __arg1; \
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asm volatile ( \
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"syscall\n\t" \
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: "=a" (resultvar) \
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: "0" (number), "r" (_a1), "r" (_a2), "r" (_a3), "r" (_a4) \
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: "memory", REGISTERS_CLOBBERED_BY_SYSCALL); \
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(long int) resultvar; \
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})
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#undef internal_syscall5
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#define internal_syscall5(number, err, arg1, arg2, arg3, arg4, arg5) \
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({ \
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unsigned long int resultvar; \
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TYPEFY (arg5, __arg5) = ARGIFY (arg5); \
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TYPEFY (arg4, __arg4) = ARGIFY (arg4); \
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TYPEFY (arg3, __arg3) = ARGIFY (arg3); \
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TYPEFY (arg2, __arg2) = ARGIFY (arg2); \
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TYPEFY (arg1, __arg1) = ARGIFY (arg1); \
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register TYPEFY (arg5, _a5) asm ("r8") = __arg5; \
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register TYPEFY (arg4, _a4) asm ("r10") = __arg4; \
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register TYPEFY (arg3, _a3) asm ("rdx") = __arg3; \
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register TYPEFY (arg2, _a2) asm ("rsi") = __arg2; \
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register TYPEFY (arg1, _a1) asm ("rdi") = __arg1; \
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asm volatile ( \
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"syscall\n\t" \
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: "=a" (resultvar) \
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: "0" (number), "r" (_a1), "r" (_a2), "r" (_a3), "r" (_a4), \
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"r" (_a5) \
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: "memory", REGISTERS_CLOBBERED_BY_SYSCALL); \
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(long int) resultvar; \
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})
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#undef internal_syscall6
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#define internal_syscall6(number, err, arg1, arg2, arg3, arg4, arg5, arg6) \
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({ \
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unsigned long int resultvar; \
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TYPEFY (arg6, __arg6) = ARGIFY (arg6); \
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TYPEFY (arg5, __arg5) = ARGIFY (arg5); \
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TYPEFY (arg4, __arg4) = ARGIFY (arg4); \
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TYPEFY (arg3, __arg3) = ARGIFY (arg3); \
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TYPEFY (arg2, __arg2) = ARGIFY (arg2); \
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TYPEFY (arg1, __arg1) = ARGIFY (arg1); \
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register TYPEFY (arg6, _a6) asm ("r9") = __arg6; \
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register TYPEFY (arg5, _a5) asm ("r8") = __arg5; \
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register TYPEFY (arg4, _a4) asm ("r10") = __arg4; \
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register TYPEFY (arg3, _a3) asm ("rdx") = __arg3; \
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register TYPEFY (arg2, _a2) asm ("rsi") = __arg2; \
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register TYPEFY (arg1, _a1) asm ("rdi") = __arg1; \
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asm volatile ( \
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"syscall\n\t" \
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: "=a" (resultvar) \
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: "0" (number), "r" (_a1), "r" (_a2), "r" (_a3), "r" (_a4), \
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"r" (_a5), "r" (_a6) \
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: "memory", REGISTERS_CLOBBERED_BY_SYSCALL); \
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(long int) resultvar; \
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})
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# undef INTERNAL_SYSCALL_ERROR_P
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# define INTERNAL_SYSCALL_ERROR_P(val, err) \
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((unsigned long int) (long int) (val) >= -4095L)
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# undef INTERNAL_SYSCALL_ERRNO
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# define INTERNAL_SYSCALL_ERRNO(val, err) (-(val))
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/* List of system calls which are supported as vsyscalls. */
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# define HAVE_CLOCK_GETTIME_VSYSCALL 1
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# define HAVE_GETTIMEOFDAY_VSYSCALL 1
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# define HAVE_GETCPU_VSYSCALL 1
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# define SINGLE_THREAD_BY_GLOBAL 1
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#endif /* __ASSEMBLER__ */
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/* Pointer mangling support. */
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#if IS_IN (rtld)
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/* We cannot use the thread descriptor because in ld.so we use setjmp
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earlier than the descriptor is initialized. */
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# ifdef __ASSEMBLER__
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# define PTR_MANGLE(reg) xor __pointer_chk_guard_local(%rip), reg; \
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rol $2*LP_SIZE+1, reg
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# define PTR_DEMANGLE(reg) ror $2*LP_SIZE+1, reg; \
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xor __pointer_chk_guard_local(%rip), reg
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# else
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# define PTR_MANGLE(reg) asm ("xor __pointer_chk_guard_local(%%rip), %0\n" \
|
|
"rol $2*" LP_SIZE "+1, %0" \
|
|
: "=r" (reg) : "0" (reg))
|
|
# define PTR_DEMANGLE(reg) asm ("ror $2*" LP_SIZE "+1, %0\n" \
|
|
"xor __pointer_chk_guard_local(%%rip), %0" \
|
|
: "=r" (reg) : "0" (reg))
|
|
# endif
|
|
#else
|
|
# ifdef __ASSEMBLER__
|
|
# define PTR_MANGLE(reg) xor %fs:POINTER_GUARD, reg; \
|
|
rol $2*LP_SIZE+1, reg
|
|
# define PTR_DEMANGLE(reg) ror $2*LP_SIZE+1, reg; \
|
|
xor %fs:POINTER_GUARD, reg
|
|
# else
|
|
# define PTR_MANGLE(var) asm ("xor %%fs:%c2, %0\n" \
|
|
"rol $2*" LP_SIZE "+1, %0" \
|
|
: "=r" (var) \
|
|
: "0" (var), \
|
|
"i" (offsetof (tcbhead_t, \
|
|
pointer_guard)))
|
|
# define PTR_DEMANGLE(var) asm ("ror $2*" LP_SIZE "+1, %0\n" \
|
|
"xor %%fs:%c2, %0" \
|
|
: "=r" (var) \
|
|
: "0" (var), \
|
|
"i" (offsetof (tcbhead_t, \
|
|
pointer_guard)))
|
|
# endif
|
|
#endif
|
|
|
|
/* How to pass the off{64}_t argument on p{readv,writev}{64}. */
|
|
#undef LO_HI_LONG
|
|
#define LO_HI_LONG(val) (val), 0
|
|
|
|
#endif /* linux/x86_64/sysdep.h */
|