similarity index 71%
rename from sysdeps/mach/hurd/i386/trampoline.c
rename to sysdeps/mach/hurd/x86/trampoline.c
@@ -1,4 +1,4 @@
-/* Set thread_state for sighandler, and sigcontext to recover. i386 version.
+/* Set thread_state for sighandler, and sigcontext to recover. x86 version.
Copyright (C) 1994-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
@@ -46,7 +46,13 @@ static void fill_siginfo (siginfo_t *si, int signo,
if (detail->exc == EXC_BAD_ACCESS)
si->si_addr = (void *) detail->exc_subcode;
else
- si->si_addr = (void *) state->basic.eip;
+ {
+#ifdef __x86_64__
+ si->si_addr = (void *) state->basic.rip;
+#else
+ si->si_addr = (void *) state->basic.eip;
+#endif
+ }
/* XXX On SIGCHLD, this should be the exit status of the child
* process. We would need a protocol change for the proc server
@@ -63,17 +69,26 @@ static void fill_ucontext (ucontext_t *uc, const struct sigcontext *sc)
uc->uc_flags = 0;
uc->uc_link = NULL;
uc->uc_sigmask = sc->sc_mask;
+#ifdef __x86_64__
+ uc->uc_stack.ss_sp = (__ptr_t) sc->sc_ursp;
+#else
uc->uc_stack.ss_sp = (__ptr_t) sc->sc_uesp;
+#endif
uc->uc_stack.ss_size = 0;
uc->uc_stack.ss_flags = 0;
/* Registers. */
+#ifdef __x86_64__
+ memcpy (&uc->uc_mcontext.gregs[REG_GSFS], &sc->sc_gs,
+ (REG_ERR - REG_GSFS) * sizeof (long));
+#else
memcpy (&uc->uc_mcontext.gregs[REG_GS], &sc->sc_gs,
- (REG_TRAPNO - REG_GS) * sizeof (int));
- uc->uc_mcontext.gregs[REG_TRAPNO] = 0;
- uc->uc_mcontext.gregs[REG_ERR] = 0;
+ (REG_TRAPNO - REG_GS) * sizeof (int));
memcpy (&uc->uc_mcontext.gregs[REG_EIP], &sc->sc_eip,
(NGREG - REG_EIP) * sizeof (int));
+#endif
+ uc->uc_mcontext.gregs[REG_TRAPNO] = 0;
+ uc->uc_mcontext.gregs[REG_ERR] = 0;
/* XXX FPU state. */
memset (&uc->uc_mcontext.fpregs, 0, sizeof (fpregset_t));
@@ -93,7 +108,14 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action
struct sigcontext *scp;
struct
{
- int signo;
+ union
+ {
+ int signo;
+ /* Make sure signo takes up a pointer-sized slot on the stack.
+ (This should already be the case considering the siginfop
+ pointer below, but better be explicit.) */
+ void *_pointer_sized;
+ };
union
{
/* Extra arguments for traditional signal handlers */
@@ -142,7 +164,11 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action
/* Save the original SP in the gratuitous `esp' slot.
We may need to reset the SP (the `uesp' slot) to avoid clobbering an
interrupted RPC frame. */
+#ifdef __x86_64__
+ state->basic.rsp = state->basic.ursp;
+#else
state->basic.esp = state->basic.uesp;
+#endif
if ((action->sa_flags & SA_ONSTACK)
&& !(ss->sigaltstack.ss_flags & (SS_DISABLE|SS_ONSTACK)))
@@ -151,7 +177,15 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action
ss->sigaltstack.ss_flags |= SS_ONSTACK;
}
else
- sigsp = (char *) state->basic.uesp;
+ {
+#ifdef __x86_64__
+ /* Per the ABI, we're not supposed to clobber 128 bytes below
+ SP -- the red zone. */
+ sigsp = (char *) state->basic.ursp - 128;
+#else
+ sigsp = (char *) state->basic.uesp;
+#endif
+ }
/* Push the arguments to call `trampoline' on the stack. */
sigsp -= sizeof (*stackframe);
@@ -238,6 +272,52 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action
}
/* Modify the thread state to call the trampoline code on the new stack. */
+#ifdef __x86_64__
+ if (rpc_wait)
+ {
+ /* The signalee thread was blocked in a mach_msg_trap system call,
+ still waiting for a reply. We will have it run the special
+ trampoline code which retries the message receive before running
+ the signal handler.
+
+ To do this we change the OPTION argument (in rsi) to enable only
+ message reception, since the request message has already been
+ sent. */
+
+ assert (state->basic.rsi & MACH_RCV_MSG);
+ /* Disable the message-send, since it has already completed. The
+ calls we retry need only wait to receive the reply message. */
+ state->basic.rsi &= ~MACH_SEND_MSG;
+
+ /* Limit the time to receive the reply message, in case the server
+ claimed that `interrupt_operation' succeeded but in fact the RPC
+ is hung. */
+ state->basic.rsi |= MACH_RCV_TIMEOUT;
+ state->basic.r9 = _hurd_interrupted_rpc_timeout;
+
+ state->basic.rip = (uintptr_t) rpc_wait_trampoline;
+ /* The reply-receiving trampoline code runs initially on the original
+ user stack. We pass it the signal stack pointer in %rbx. */
+ state->basic.rbx = (uintptr_t) sigsp;
+ /* After doing the message receive, the trampoline code will need to
+ update the %rax value to be restored by sigreturn. To simplify
+ the assembly code, we pass the address of its slot in SCP to the
+ trampoline code in %r12. */
+ state->basic.r12 = (uintptr_t) &scp->sc_rax;
+ }
+ else
+ {
+ state->basic.rip = (uintptr_t) trampoline;
+ state->basic.ursp = (uintptr_t) sigsp;
+ }
+ /* We pass the handler function to the trampoline code in %r13. */
+ state->basic.r13 = (uintptr_t) handler;
+
+ /* The x86 ABI says the DF bit is clear on entry to any function. */
+ state->basic.rfl &= ~EFL_DF;
+
+#else
+
if (rpc_wait)
{
/* The signalee thread was blocked in a mach_msg_trap system call,
@@ -290,6 +370,7 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action
/* The x86 ABI says the DF bit is clear on entry to any function. */
state->basic.efl &= ~EFL_DF;
+#endif
return scp;
}
@@ -301,6 +382,49 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action
- in gcc: libgcc/config/i386/gnu-unwind.h x86_gnu_fallback_frame_state,
- in gdb: gdb/i386-gnu-tdep.c gnu_sigtramp_code. */
+#ifdef __x86_64__
+asm ("rpc_wait_trampoline:\n"
+ /* This is the entry point when we have an RPC reply message to receive
+ before running the handler. The MACH_MSG_SEND bit has already been
+ cleared in the OPTION argument on our stack. The interrupted user
+ stack pointer has not been changed, so the system call can find its
+ arguments; the signal stack pointer is in %rbx. For our convenience,
+ %r12 points to the sc_rax member of the sigcontext. */
+ "movq $-25, %rax\n" /* mach_msg_trap */
+ "syscall\n"
+ /* When the sigcontext was saved, %rax was MACH_RCV_INTERRUPTED. But
+ now the message receive has completed and the original caller of
+ the RPC (i.e. the code running when the signal arrived) needs to
+ see the final return value of the message receive in %rax. So
+ store the new %rax value into the sc_rax member of the sigcontext
+ (whose address is in %r12 to make this code simpler). */
+ "movq %rax, (%r12)\n"
+ /* Switch to the signal stack. */
+ "movq %rbx, %rsp\n"
+
+ "trampoline:\n"
+ /* Entry point for running the handler normally. The arguments to the
+ handler function are on the top of the stack, same as in the i386
+ version:
+
+ 0(%rsp) SIGNO
+ 8(%rsp) SIGCODE
+ 16(%rsp) SCP
+
+ Pop them off to the registers, to pass as arguments to the handler.
+ */
+ "popq %rdi\n"
+ "popq %rsi\n"
+ "popq %rdx\n"
+ "call *%r13\n" /* Call the handler function. */
+ /* The word at the top of stack is &__sigreturn; following are a dummy
+ word to fill the slot for the address for __sigreturn to return to,
+ and a copy of SCP for __sigreturn's argument. Load the SCP as for a
+ call, and "return" to calling __sigreturn (SCP); this call never
+ returns. */
+ "movq 16(%rsp), %rdi\n"
+ "ret");
+#else
asm ("rpc_wait_trampoline:\n");
/* This is the entry point when we have an RPC reply message to receive
before running the handler. The MACH_MSG_SEND bit has already been
@@ -336,6 +460,7 @@ asm ("call *%edx\n" /* Call the handler function. */
and a copy of SCP for __sigreturn's argument. "Return" to calling
__sigreturn (SCP); this call never returns. */
"ret");
+#endif
asm ("firewall:\n"
"hlt");
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> --- Same as for intr-msg.h, can't know whether this works until we try it. sysdeps/mach/hurd/{i386 => x86}/trampoline.c | 139 ++++++++++++++++++- 1 file changed, 132 insertions(+), 7 deletions(-) rename sysdeps/mach/hurd/{i386 => x86}/trampoline.c (71%)