mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-27 05:00:15 +00:00
2b778ceb40
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master
198 lines
5.1 KiB
ArmAsm
198 lines
5.1 KiB
ArmAsm
/* Install given context.
|
|
Copyright (C) 2002-2021 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 __setcontext (const ucontext_t *ucp)
|
|
|
|
Restores the machine context in UCP and thereby resumes execution
|
|
in that context.
|
|
|
|
This implementation is intended to be used for *synchronous* context
|
|
switches only. Therefore, it does not have to restore anything
|
|
other than the PRESERVED state. */
|
|
|
|
ENTRY(__setcontext)
|
|
/* Save argument since syscall will destroy it. */
|
|
pushq %rdi
|
|
cfi_adjust_cfa_offset(8)
|
|
|
|
/* Set the signal mask with
|
|
rt_sigprocmask (SIG_SETMASK, mask, NULL, _NSIG/8). */
|
|
leaq oSIGMASK(%rdi), %rsi
|
|
xorl %edx, %edx
|
|
movl $SIG_SETMASK, %edi
|
|
movl $_NSIG8,%r10d
|
|
movl $__NR_rt_sigprocmask, %eax
|
|
syscall
|
|
/* Pop the pointer into RDX. The choice is arbitrary, but
|
|
leaving RDI and RSI available for use later can avoid
|
|
shuffling values. */
|
|
popq %rdx
|
|
cfi_adjust_cfa_offset(-8)
|
|
cmpq $-4095, %rax /* Check %rax for error. */
|
|
jae SYSCALL_ERROR_LABEL /* Jump to error handler if error. */
|
|
|
|
/* Restore the floating-point context. Not the registers, only the
|
|
rest. */
|
|
movq oFPREGS(%rdx), %rcx
|
|
fldenv (%rcx)
|
|
ldmxcsr oMXCSR(%rdx)
|
|
|
|
|
|
/* Load the new stack pointer, the preserved registers and
|
|
registers used for passing args. */
|
|
cfi_def_cfa(%rdx, 0)
|
|
cfi_offset(%rbx,oRBX)
|
|
cfi_offset(%rbp,oRBP)
|
|
cfi_offset(%r12,oR12)
|
|
cfi_offset(%r13,oR13)
|
|
cfi_offset(%r14,oR14)
|
|
cfi_offset(%r15,oR15)
|
|
cfi_offset(%rsp,oRSP)
|
|
cfi_offset(%rip,oRIP)
|
|
|
|
movq oRSP(%rdx), %rsp
|
|
movq oRBX(%rdx), %rbx
|
|
movq oRBP(%rdx), %rbp
|
|
movq oR12(%rdx), %r12
|
|
movq oR13(%rdx), %r13
|
|
movq oR14(%rdx), %r14
|
|
movq oR15(%rdx), %r15
|
|
|
|
#if SHSTK_ENABLED
|
|
/* Check if shadow stack is enabled. */
|
|
testl $X86_FEATURE_1_SHSTK, %fs:FEATURE_1_OFFSET
|
|
jz L(no_shstk)
|
|
|
|
/* If the base of the target shadow stack is the same as the
|
|
base of the current shadow stack, we unwind the shadow
|
|
stack. Otherwise it is a stack switch and we look for a
|
|
restore token. */
|
|
movq oSSP(%rdx), %rsi
|
|
movq %rsi, %rdi
|
|
|
|
/* Get the base of the target shadow stack. */
|
|
movq (oSSP + 8)(%rdx), %rcx
|
|
cmpq %fs:SSP_BASE_OFFSET, %rcx
|
|
je L(unwind_shadow_stack)
|
|
|
|
L(find_restore_token_loop):
|
|
/* Look for a restore token. */
|
|
movq -8(%rsi), %rax
|
|
andq $-8, %rax
|
|
cmpq %rsi, %rax
|
|
je L(restore_shadow_stack)
|
|
|
|
/* Try the next slot. */
|
|
subq $8, %rsi
|
|
jmp L(find_restore_token_loop)
|
|
|
|
L(restore_shadow_stack):
|
|
/* Pop return address from the shadow stack since setcontext
|
|
will not return. */
|
|
movq $1, %rax
|
|
incsspq %rax
|
|
|
|
/* Use the restore stoken to restore the target shadow stack. */
|
|
rstorssp -8(%rsi)
|
|
|
|
/* Save the restore token on the old shadow stack. NB: This
|
|
restore token may be checked by setcontext or swapcontext
|
|
later. */
|
|
saveprevssp
|
|
|
|
/* Record the new shadow stack base that was switched to. */
|
|
movq (oSSP + 8)(%rdx), %rax
|
|
movq %rax, %fs:SSP_BASE_OFFSET
|
|
|
|
L(unwind_shadow_stack):
|
|
rdsspq %rcx
|
|
subq %rdi, %rcx
|
|
je L(skip_unwind_shadow_stack)
|
|
negq %rcx
|
|
shrq $3, %rcx
|
|
movl $255, %esi
|
|
L(loop):
|
|
cmpq %rsi, %rcx
|
|
cmovb %rcx, %rsi
|
|
incsspq %rsi
|
|
subq %rsi, %rcx
|
|
ja L(loop)
|
|
|
|
L(skip_unwind_shadow_stack):
|
|
movq oRSI(%rdx), %rsi
|
|
movq oRDI(%rdx), %rdi
|
|
movq oRCX(%rdx), %rcx
|
|
movq oR8(%rdx), %r8
|
|
movq oR9(%rdx), %r9
|
|
|
|
/* Get the return address set with getcontext. */
|
|
movq oRIP(%rdx), %r10
|
|
|
|
/* Setup finally %rdx. */
|
|
movq oRDX(%rdx), %rdx
|
|
|
|
/* Check if return address is valid for the case when setcontext
|
|
is invoked from __start_context with linked context. */
|
|
rdsspq %rax
|
|
cmpq (%rax), %r10
|
|
/* Clear RAX to indicate success. NB: Don't use xorl to keep
|
|
EFLAGS for jne. */
|
|
movl $0, %eax
|
|
jne L(jmp)
|
|
/* Return to the new context if return address valid. */
|
|
pushq %r10
|
|
ret
|
|
|
|
L(jmp):
|
|
/* Jump to the new context directly. */
|
|
jmp *%r10
|
|
|
|
L(no_shstk):
|
|
#endif
|
|
/* The following ret should return to the address set with
|
|
getcontext. Therefore push the address on the stack. */
|
|
movq oRIP(%rdx), %rcx
|
|
pushq %rcx
|
|
|
|
movq oRSI(%rdx), %rsi
|
|
movq oRDI(%rdx), %rdi
|
|
movq oRCX(%rdx), %rcx
|
|
movq oR8(%rdx), %r8
|
|
movq oR9(%rdx), %r9
|
|
|
|
/* Setup finally %rdx. */
|
|
movq oRDX(%rdx), %rdx
|
|
|
|
/* End FDE here, we fall into another context. */
|
|
cfi_endproc
|
|
cfi_startproc
|
|
|
|
/* Clear rax to indicate success. */
|
|
xorl %eax, %eax
|
|
ret
|
|
PSEUDO_END(__setcontext)
|
|
|
|
weak_alias (__setcontext, setcontext)
|