mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-22 04:50:07 +00:00
hurd: Implement sigreturn for x86_64
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> Message-Id: <20230429201822.2605207-2-bugaevc@gmail.com>
This commit is contained in:
parent
6b25b6ca4e
commit
b574ae0a28
162
sysdeps/mach/hurd/x86_64/sigreturn.c
Normal file
162
sysdeps/mach/hurd/x86_64/sigreturn.c
Normal file
@ -0,0 +1,162 @@
|
||||
/* Copyright (C) 1991-2023 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 <hurd.h>
|
||||
#include <hurd/signal.h>
|
||||
#include <hurd/msg.h>
|
||||
#include <stdlib.h>
|
||||
|
||||
/* This is run on the thread stack after restoring it, to be able to
|
||||
unlock SS off sigstack. */
|
||||
void
|
||||
__sigreturn2 (struct hurd_sigstate *ss, uintptr_t *usp,
|
||||
struct sigcontext *scp)
|
||||
{
|
||||
mach_port_t reply_port;
|
||||
_hurd_sigstate_unlock (ss);
|
||||
|
||||
/* Destroy the MiG reply port used by the signal handler, and restore the
|
||||
reply port in use by the thread when interrupted.
|
||||
|
||||
We cannot use the original reply port for our RPCs that we do here, since
|
||||
we could unexpectedly receive/consume a reply message meant for the user
|
||||
(in particular, msg_sig_post_reply), and also since we would deallocate
|
||||
the port if *our* RPC fails, which we don't want to do since the user
|
||||
still has the old name. And so, temporarily set MACH_PORT_DEAD as our
|
||||
reply name, and make sure destroying the port is the very last RPC we
|
||||
do. */
|
||||
reply_port = THREAD_GETMEM (THREAD_SELF, reply_port);
|
||||
THREAD_SETMEM (THREAD_SELF, reply_port, MACH_PORT_DEAD);
|
||||
if (__glibc_likely (MACH_PORT_VALID (reply_port)))
|
||||
(void) __mach_port_mod_refs (__mach_task_self (), reply_port,
|
||||
MACH_PORT_RIGHT_RECEIVE, -1);
|
||||
THREAD_SETMEM (THREAD_SELF, reply_port, scp->sc_reply_port);
|
||||
|
||||
asm volatile (
|
||||
/* Point the stack to the register dump. */
|
||||
"movq %0, %%rsp\n"
|
||||
/* Pop off the registers. */
|
||||
"popq %%r8\n"
|
||||
"popq %%r9\n"
|
||||
"popq %%r10\n"
|
||||
"popq %%r11\n"
|
||||
"popq %%r12\n"
|
||||
"popq %%r13\n"
|
||||
"popq %%r14\n"
|
||||
"popq %%r15\n"
|
||||
"popq %%rdi\n"
|
||||
"popq %%rsi\n"
|
||||
"popq %%rbp\n"
|
||||
"popq %%rbx\n"
|
||||
"popq %%rdx\n"
|
||||
"popq %%rcx\n"
|
||||
"popq %%rax\n"
|
||||
"popfq\n"
|
||||
/* Restore %rip and %rsp with a single instruction. */
|
||||
"retq $128" :
|
||||
: "rm" (usp));
|
||||
__builtin_unreachable ();
|
||||
}
|
||||
|
||||
int
|
||||
__sigreturn (struct sigcontext *scp)
|
||||
{
|
||||
struct hurd_sigstate *ss;
|
||||
struct hurd_userlink *link = (void *) &scp[1];
|
||||
|
||||
if (__glibc_unlikely (scp == NULL || (scp->sc_mask & _SIG_CANT_MASK)))
|
||||
{
|
||||
errno = EINVAL;
|
||||
return -1;
|
||||
}
|
||||
|
||||
ss = _hurd_self_sigstate ();
|
||||
_hurd_sigstate_lock (ss);
|
||||
|
||||
/* Remove the link on the `active resources' chain added by
|
||||
_hurd_setup_sighandler. Its purpose was to make sure
|
||||
that we got called; now we have, it is done. */
|
||||
_hurd_userlink_unlink (link);
|
||||
|
||||
/* Restore the set of blocked signals, and the intr_port slot. */
|
||||
ss->blocked = scp->sc_mask;
|
||||
ss->intr_port = scp->sc_intr_port;
|
||||
|
||||
/* Check for pending signals that were blocked by the old set. */
|
||||
if (_hurd_sigstate_pending (ss) & ~ss->blocked)
|
||||
{
|
||||
/* There are pending signals that just became unblocked. Wake up the
|
||||
signal thread to deliver them. But first, squirrel away SCP where
|
||||
the signal thread will notice it if it runs another handler, and
|
||||
arrange to have us called over again in the new reality. */
|
||||
ss->context = scp;
|
||||
_hurd_sigstate_unlock (ss);
|
||||
__msg_sig_post (_hurd_msgport, 0, 0, __mach_task_self ());
|
||||
/* If a pending signal was handled, sig_post never returned.
|
||||
If it did return, the pending signal didn't run a handler;
|
||||
proceed as usual. */
|
||||
_hurd_sigstate_lock (ss);
|
||||
ss->context = NULL;
|
||||
}
|
||||
|
||||
if (scp->sc_onstack)
|
||||
ss->sigaltstack.ss_flags &= ~SS_ONSTACK;
|
||||
|
||||
if (scp->sc_fpused)
|
||||
/* Restore the FPU state. Mach conveniently stores the state
|
||||
in the format the i387 `frstor' instruction uses to restore it. */
|
||||
asm volatile ("frstor %0" : : "m" (scp->sc_fpsave));
|
||||
|
||||
{
|
||||
/* There are convenient instructions to pop state off the stack, so we
|
||||
copy the registers onto the user's stack, switch there, pop and
|
||||
return. */
|
||||
|
||||
uintptr_t *usp = (uintptr_t *) scp->sc_ursp - 128;
|
||||
|
||||
*--usp = scp->sc_rip;
|
||||
*--usp = scp->sc_rfl;
|
||||
*--usp = scp->sc_rax;
|
||||
*--usp = scp->sc_rcx;
|
||||
*--usp = scp->sc_rdx;
|
||||
*--usp = scp->sc_rbx;
|
||||
*--usp = scp->sc_rbp;
|
||||
*--usp = scp->sc_rsi;
|
||||
*--usp = scp->sc_rdi;
|
||||
*--usp = scp->sc_r15;
|
||||
*--usp = scp->sc_r14;
|
||||
*--usp = scp->sc_r13;
|
||||
*--usp = scp->sc_r12;
|
||||
*--usp = scp->sc_r11;
|
||||
*--usp = scp->sc_r10;
|
||||
*--usp = scp->sc_r9;
|
||||
*--usp = scp->sc_r8;
|
||||
|
||||
/* Switch to the user's stack that we have just prepared, and call
|
||||
__sigreturn2. Clobber "memory" to make sure GCC flushes the stack
|
||||
setup to actual memory. We align the stack as per the ABI, but pass
|
||||
the original usp to __sigreturn2 as an argument. */
|
||||
asm volatile ("movq %1, %%rsp\n"
|
||||
"andq $-16, %%rsp\n"
|
||||
"call __sigreturn2" :
|
||||
: "D" (ss), "S" (usp), "d" (scp)
|
||||
: "memory");
|
||||
__builtin_unreachable ();
|
||||
}
|
||||
}
|
||||
|
||||
weak_alias (__sigreturn, sigreturn)
|
Loading…
Reference in New Issue
Block a user