diff options
Diffstat (limited to 'sysdeps/mach/hurd/x86_64/setcontext.S')
| -rw-r--r-- | sysdeps/mach/hurd/x86_64/setcontext.S | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/x86_64/setcontext.S b/sysdeps/mach/hurd/x86_64/setcontext.S new file mode 100644 index 0000000000..99919ee2a8 --- /dev/null +++ b/sysdeps/mach/hurd/x86_64/setcontext.S @@ -0,0 +1,96 @@ +/* Install given context. + Copyright (C) 2024 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 + <https://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +#include "ucontext_i.h" + + +ENTRY(__setcontext) + /* Save argument since call will destroy it. */ + pushq %rdi + cfi_adjust_cfa_offset(8) + + /* Set the signal mask with + __sigprocmask (SIG_SETMASK, mask, NULL). */ + xorl %edx, %edx + leaq oSIGMASK(%rdi), %rsi + movl $SIG_SETMASK, %edi + call HIDDEN_JUMPTARGET (__sigprocmask) + /* Pop the pointer into RDX. The choice is arbitrary, but + leaving RDI and RSI available for use later can avoid + shuffling values. */ + popq %rdx + + test %rax, %rax + jne L(pseudo_end) + + /* 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 + + /* 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 +L(pseudo_end): + /* The following 'ret' will pop the address of the code and jump + to it. */ + ret +PSEUDO_END(__setcontext) +libc_hidden_def (__setcontext) + +weak_alias (__setcontext, setcontext) |