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glibc/sysdeps/unix/sysv/linux/x86_64/getcontext.S
Paul Eggert 5a82c74822 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 02:43:31 -07:00

138 lines
3.7 KiB
ArmAsm

/* Save current context.
Copyright (C) 2002-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Andreas Jaeger <aj@suse.de>, 2002.
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
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <asm/prctl.h>
#include "ucontext_i.h"
/* int __getcontext (ucontext_t *ucp)
Saves the machine context in UCP such that when it is activated,
it appears as if __getcontext() returned again.
This implementation is intended to be used for *synchronous* context
switches only. Therefore, it does not have to save anything
other than the PRESERVED state. */
ENTRY(__getcontext)
/* Save the preserved registers, the registers used for passing
args, and the return address. */
movq %rbx, oRBX(%rdi)
movq %rbp, oRBP(%rdi)
movq %r12, oR12(%rdi)
movq %r13, oR13(%rdi)
movq %r14, oR14(%rdi)
movq %r15, oR15(%rdi)
movq %rdi, oRDI(%rdi)
movq %rsi, oRSI(%rdi)
movq %rdx, oRDX(%rdi)
movq %rcx, oRCX(%rdi)
movq %r8, oR8(%rdi)
movq %r9, oR9(%rdi)
movq (%rsp), %rcx
movq %rcx, oRIP(%rdi)
leaq 8(%rsp), %rcx /* Exclude the return address. */
movq %rcx, oRSP(%rdi)
#if SHSTK_ENABLED
/* Check if shadow stack is enabled. */
testl $X86_FEATURE_1_SHSTK, %fs:FEATURE_1_OFFSET
jz L(no_shstk)
/* Save RDI in RDX which won't be clobbered by syscall. */
movq %rdi, %rdx
xorl %eax, %eax
cmpq %fs:SSP_BASE_OFFSET, %rax
jnz L(shadow_stack_bound_recorded)
/* Get the base address and size of the default shadow stack
which must be the current shadow stack since nothing has
been recorded yet. */
sub $24, %RSP_LP
mov %RSP_LP, %RSI_LP
movl $ARCH_CET_STATUS, %edi
movl $__NR_arch_prctl, %eax
syscall
testq %rax, %rax
jz L(continue_no_err)
/* This should never happen. */
hlt
L(continue_no_err):
/* Record the base of the current shadow stack. */
movq 8(%rsp), %rax
movq %rax, %fs:SSP_BASE_OFFSET
add $24, %RSP_LP
/* Restore RDI. */
movq %rdx, %rdi
L(shadow_stack_bound_recorded):
/* Get the current shadow stack pointer. */
rdsspq %rax
/* NB: Save the caller's shadow stack so that we can jump back
to the caller directly. */
addq $8, %rax
movq %rax, oSSP(%rdx)
/* Save the current shadow stack base in ucontext. */
movq %fs:SSP_BASE_OFFSET, %rax
movq %rax, (oSSP + 8)(%rdi)
L(no_shstk):
#endif
/* We have separate floating-point register content memory on the
stack. We use the __fpregs_mem block in the context. Set the
links up correctly. */
leaq oFPREGSMEM(%rdi), %rcx
movq %rcx, oFPREGS(%rdi)
/* Save the floating-point environment. */
fnstenv (%rcx)
fldenv (%rcx)
stmxcsr oMXCSR(%rdi)
/* Save the current signal mask with
rt_sigprocmask (SIG_BLOCK, NULL, set,_NSIG/8). */
leaq oSIGMASK(%rdi), %rdx
xorl %esi,%esi
#if SIG_BLOCK == 0
xorl %edi, %edi
#else
movl $SIG_BLOCK, %edi
#endif
movl $_NSIG8,%r10d
movl $__NR_rt_sigprocmask, %eax
syscall
cmpq $-4095, %rax /* Check %rax for error. */
jae SYSCALL_ERROR_LABEL /* Jump to error handler if error. */
/* All done, return 0 for success. */
xorl %eax, %eax
ret
PSEUDO_END(__getcontext)
weak_alias (__getcontext, getcontext)