diff options
Diffstat (limited to 'sysdeps/mach/hurd/mips')
| -rw-r--r-- | sysdeps/mach/hurd/mips/exc2signal.c | 98 | ||||
| -rw-r--r-- | sysdeps/mach/hurd/mips/init-fault.c | 41 | ||||
| -rw-r--r-- | sysdeps/mach/hurd/mips/longjmp-ctx.c | 41 | ||||
| -rw-r--r-- | sysdeps/mach/hurd/mips/longjmp-ts.c | 45 | ||||
| -rw-r--r-- | sysdeps/mach/hurd/mips/sigcontext.h | 71 | ||||
| -rw-r--r-- | sysdeps/mach/hurd/mips/sigreturn.c | 169 | ||||
| -rw-r--r-- | sysdeps/mach/hurd/mips/trampoline.c | 260 |
7 files changed, 725 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/mips/exc2signal.c b/sysdeps/mach/hurd/mips/exc2signal.c new file mode 100644 index 0000000000..f907c89cf0 --- /dev/null +++ b/sysdeps/mach/hurd/mips/exc2signal.c @@ -0,0 +1,98 @@ +/* Translate Mach exception codes into signal numbers. MIPS version. +Copyright (C) 1991, 1992, 1994, 1995 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 Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <hurd.h> +#include <hurd/signal.h> +#include <mach/exception.h> + +/* Translate the Mach exception codes, as received in an `exception_raise' RPC, + into a signal number and signal subcode. */ + +void +_hurd_exception2signal (int exception, int code, int subcode, + int *signo, long int *sigcode, int *error) +{ + *error = 0; + + switch (exception) + { + default: + *signo = SIGIOT; + *sigcode = exception; + break; + + case EXC_BAD_ACCESS: + if (code == KERN_PROTECTION_FAILURE) + *signo = SIGSEGV; + else + *signo = SIGBUS; + *sigcode = subcode; + *error = code; + break; + + case EXC_BAD_INSTRUCTION: + *signo = SIGILL; + if (code == EXC_MIPS_II) + *sigcode = code; + else + *sigcode = 0; + break; + + case EXC_ARITHMETIC: + switch (code) + { + case EXC_MIPS_OV: /* integer overflow */ + *signo = SIGFPE; + *sigcode = EXC_MIPS_FLT_OVERFLOW; + break; + + default: + *signo = SIGFPE; + *sigcode = 0; + break; + + case EXC_MIPS_INT: + /* Subcode is the fp_status word saved by the hardware. + Give an error code corresponding to the first bit set. */ + if (subcode == EXC_MIPS_FLT_UNIMP) + *signo = SIGILL; + else + *signo = SIGFPE; + *sigcode = subcode; + break; + } + break; + + case EXC_EMULATION: + /* 3.0 doesn't give this one, why, I don't know. */ + *signo = SIGEMT; + *sigcode = 0; + break; + + case EXC_SOFTWARE: + *signo = SIGEMT; + *sigcode = 0; + break; + + case EXC_BREAKPOINT: + *signo = SIGTRAP; + *sigcode = code; + break; + } +} diff --git a/sysdeps/mach/hurd/mips/init-fault.c b/sysdeps/mach/hurd/mips/init-fault.c new file mode 100644 index 0000000000..e6f8acf64d --- /dev/null +++ b/sysdeps/mach/hurd/mips/init-fault.c @@ -0,0 +1,41 @@ +/* Set up a thread_state for proc_handle_exceptions. MIPS version. +Copyright (C) 1994 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 Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <hurd/signal.h> +#include <mach/thread_status.h> +#include <string.h> +#include <setjmp.h> + +extern jmp_buf _hurd_sigthread_fault_env; + +static char fault_stack[32]; +static volatile void +faulted (void) +{ + __longjmp (_hurd_sigthread_fault_env, 1); +} + +void +_hurd_initialize_fault_recovery_state (void *state) +{ + struct mips_thread_state *ts = state; + memset (ts, 0, sizeof (*ts)); + ts->r29 = (int) &fault_stack[sizeof (fault_stack)]; + ts->pc = (int) &faulted; +} diff --git a/sysdeps/mach/hurd/mips/longjmp-ctx.c b/sysdeps/mach/hurd/mips/longjmp-ctx.c new file mode 100644 index 0000000000..0c78f6b4d6 --- /dev/null +++ b/sysdeps/mach/hurd/mips/longjmp-ctx.c @@ -0,0 +1,41 @@ +/* Perform a `longjmp' on a `struct sigcontext'. MIPS version. +Copyright (C) 1994 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 Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <setjmp.h> +#include <hurd/signal.h> +#include <string.h> + +void +_hurd_longjmp_sigcontext (struct sigcontext *scp, jmp_buf env, int retval) +{ + scp->sc_gpr[16] = env[0].__regs[0]; + scp->sc_gpr[17] = env[0].__regs[1]; + scp->sc_gpr[18] = env[0].__regs[2]; + scp->sc_gpr[19] = env[0].__regs[3]; + scp->sc_gpr[20] = env[0].__regs[4]; + scp->sc_gpr[21] = env[0].__regs[5]; + scp->sc_gpr[22] = env[0].__regs[6]; + scp->sc_gpr[23] = env[0].__regs[7]; + + scp->sc_gpr[28] = (int) env[0].__gp; + scp->sc_fp = (int) env[0].__fp; + scp->sc_sp = (int) env[0].__sp; + scp->sc_pc = (int) env[0].__pc; + scp->sc_gpr[2] = retval ?: 1; +} diff --git a/sysdeps/mach/hurd/mips/longjmp-ts.c b/sysdeps/mach/hurd/mips/longjmp-ts.c new file mode 100644 index 0000000000..980a2ceb94 --- /dev/null +++ b/sysdeps/mach/hurd/mips/longjmp-ts.c @@ -0,0 +1,45 @@ +/* Perform a `longjmp' on a Mach thread_state. MIPS version. +Copyright (C) 1991, 1994 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 Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <hurd/signal.h> +#include <setjmp.h> +#include <mach/thread_status.h> + + +/* Set up STATE to do the equivalent of `longjmp (ENV, VAL);'. */ + +void +_hurd_longjmp_thread_state (void *state, jmp_buf env, int val) +{ + struct mips_thread_state *ts = state; + + ts->r16 = env[0].__jmpbuf[0].__regs[0]; + ts->r17 = env[0].__jmpbuf[0].__regs[1]; + ts->r18 = env[0].__jmpbuf[0].__regs[2]; + ts->r19 = env[0].__jmpbuf[0].__regs[3]; + ts->r20 = env[0].__jmpbuf[0].__regs[4]; + ts->r21 = env[0].__jmpbuf[0].__regs[5]; + ts->r22 = env[0].__jmpbuf[0].__regs[6]; + ts->r23 = env[0].__jmpbuf[0].__regs[7]; + ts->r28 = (int) env[0].__jmpbuf[0].__gp; + ts->r29 = (int) env[0].__jmpbuf[0].__sp; + ts->r30 = (int) env[0].__jmpbuf[0].__fp; + ts->pc = (int) env[0].__jmpbuf[0].__pc; + ts->r2 = val ?: 1; +} diff --git a/sysdeps/mach/hurd/mips/sigcontext.h b/sysdeps/mach/hurd/mips/sigcontext.h new file mode 100644 index 0000000000..81d1f25f25 --- /dev/null +++ b/sysdeps/mach/hurd/mips/sigcontext.h @@ -0,0 +1,71 @@ +/* Copyright (C) 1994 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 Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +/* Signal handlers are actually called: + void handler (int sig, int code, struct sigcontext *scp); */ + +/* State of this thread when the signal was taken. */ +struct sigcontext + { + /* These first members are machine-independent. */ + + int sc_onstack; /* Nonzero if running on sigstack. */ + __sigset_t sc_mask; /* Blocked signals to restore. */ + + /* MiG reply port this thread is using. */ + unsigned int sc_reply_port; + + /* Port this thread is doing an interruptible RPC on. */ + unsigned int sc_intr_port; + + /* Error code associated with this signal (interpreted as `error_t'). */ + int sc_error; + + /* All following members are machine-dependent. The rest of this + structure is written to be laid out identically to: + { + struct mips_thread_state ts; + struct mips_exc_state es; + struct mips_float_state fs; + } + trampoline.c knows this, so it must be changed if this changes. */ +#define sc_mips_thread_state sc_gpr /* Beginning of correspondence. */ + int sc_gpr[31]; /* "General" registers; [0] is r1. */ + int sc_mdlo, sc_mdhi; /* Low and high multiplication results. */ + int sc_pc; /* Instruction pointer. */ + + /* struct mips_exc_state */ +#define sc_mips_exc_state sc_cause + unsigned int sc_cause; /* Machine-level trap code. */ +#define SC_CAUSE_SST 0x00000044 + unsigned int sc_badvaddr; + unsigned int sc_coproc_used; /* Which coprocessors the thread has used. */ +#define SC_COPROC_USE_COP0 1 /* (by definition) */ +#define SC_COPROC_USE_COP1 2 /* FPA */ +#define SC_COPROC_USE_FPU SC_COPROC_USE_COP1 +#define SC_COPROC_USE_COP2 4 +#define SC_COPROC_USE_COP3 8 + + /* struct mips_float_state + This is only filled in if the SC_COPROC_USE_FPU bit + is set in sc_coproc_used. */ +#define sc_mips_float_state sc_fpr + int sc_fpr[32]; /* FP registers. */ + int sc_fpcsr; /* FPU status register. */ + int sc_fpeir; /* FP exception instruction register. */ + }; diff --git a/sysdeps/mach/hurd/mips/sigreturn.c b/sysdeps/mach/hurd/mips/sigreturn.c new file mode 100644 index 0000000000..7396a8bb22 --- /dev/null +++ b/sysdeps/mach/hurd/mips/sigreturn.c @@ -0,0 +1,169 @@ +/* Copyright (C) 1991, 1992, 1994, 1995 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 Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <hurd.h> +#include <hurd/signal.h> +#include <hurd/threadvar.h> +#include <stdlib.h> + +int +__sigreturn (struct sigcontext *scp) +{ + struct hurd_sigstate *ss; + mach_port_t *reply_port; + + if (scp == NULL || (scp->sc_mask & _SIG_CANT_MASK)) + { + errno = EINVAL; + return -1; + } + + ss = _hurd_self_sigstate (); + __spin_lock (&ss->lock); + + /* 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 (ss->pending & ~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; + /* Clear the intr_port slot, since we are not in fact doing + an interruptible RPC right now. If SS->intr_port is not null, + the SCP context is doing an interruptible RPC, but the signal + thread will examine us while we are blocked in the sig_post RPC. */ + ss->intr_port = MACH_PORT_NULL; + __spin_unlock (&ss->lock); + __msg_sig_post (_hurd_msgport, 0, __mach_task_self ()); + /* If a pending signal was handled, sig_post never returned. */ + __spin_lock (&ss->lock); + } + + if (scp->sc_onstack) + { + ss->sigaltstack.ss_flags &= ~SA_ONSTACK; /* XXX threadvars */ + /* XXX cannot unlock until off sigstack */ + abort (); + } + else + __spin_unlock (&ss->lock); + + /* Destroy the MiG reply port used by the signal handler, and restore the + reply port in use by the thread when interrupted. */ + reply_port = + (mach_port_t *) __hurd_threadvar_location (_HURD_THREADVAR_MIG_REPLY); + if (*reply_port) + __mach_port_destroy (__mach_task_self (), *reply_port); + *reply_port = scp->sc_reply_port; + + if (scp->sc_coproc_used & SC_COPROC_USE_FPU) + { + /* Restore FPU state. */ +#define restore_fpr(n) \ + asm volatile ("l.d $f" #n ",%0" : : "m" (scp->sc_fpr[n])) + + /* Restore floating-point registers. */ + restore_fpr (0); + restore_fpr (2); + restore_fpr (4); + restore_fpr (6); + restore_fpr (8); + restore_fpr (10); + restore_fpr (12); + restore_fpr (14); + restore_fpr (16); + restore_fpr (18); + restore_fpr (20); + restore_fpr (22); + restore_fpr (24); + restore_fpr (26); + restore_fpr (28); + restore_fpr (30); + + /* Restore the floating-point control/status register ($f31). */ + asm volatile ("ctc1 %0,$f31" : : "r" (scp->sc_fpcsr)); + } + + /* Load all the registers from the sigcontext. */ +#define restore_gpr(n) \ + asm volatile ("lw $" #n ",%0" : : "m" (scpreg->sc_gpr[n - 1])) + + { + register const struct sigcontext *const scpreg asm ("$1") = scp; + register int *at asm ("$1"); + + /* First restore the multiplication result registers. The compiler + will use some temporary registers, so we do this before restoring + the general registers. */ + asm volatile ("mtlo %0" : : "r" (scpreg->sc_mdlo)); + asm volatile ("mthi %0" : : "r" (scpreg->sc_mdhi)); + + /* In the word after the saved PC, store the saved $1 value. */ + (&scpreg->sc_pc)[1] = scpreg->sc_gpr[0]; + + asm volatile (".set noreorder; .set noat;"); + + /* Restore the normal registers. */ + restore_gpr (2); + restore_gpr (3); + restore_gpr (4); + restore_gpr (5); + restore_gpr (6); + restore_gpr (7); + restore_gpr (8); + restore_gpr (9); + restore_gpr (10); + restore_gpr (11); + restore_gpr (12); + restore_gpr (13); + restore_gpr (14); + restore_gpr (15); + restore_gpr (16); + restore_gpr (17); + restore_gpr (18); + restore_gpr (19); + restore_gpr (20); + restore_gpr (21); + restore_gpr (22); + restore_gpr (23); + restore_gpr (24); + restore_gpr (25); + /* Registers 26-27 are kernel-only. */ + restore_gpr (28); + restore_gpr (29); /* Stack pointer. */ + restore_gpr (30); /* Frame pointer. */ + restore_gpr (31); /* Return address. */ + + at = &scpreg->sc_pc; + /* This is an emulated instruction that will find at the address in $1 + two words: the PC value to restore, and the $1 value to restore. */ + asm volatile (".word op_sigreturn"); + + asm volatile (".set reorder; .set at;"); + } + + /* NOTREACHED */ + return -1; +} + +weak_alias (__sigreturn, sigreturn) diff --git a/sysdeps/mach/hurd/mips/trampoline.c b/sysdeps/mach/hurd/mips/trampoline.c new file mode 100644 index 0000000000..f03ad5852f --- /dev/null +++ b/sysdeps/mach/hurd/mips/trampoline.c @@ -0,0 +1,260 @@ +/* Set thread_state for sighandler, and sigcontext to recover. MIPS version. +Copyright (C) 1994, 1995 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 Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <hurd/signal.h> +#include "thread_state.h" + + +struct mach_msg_trap_args + { + /* This is the order of arguments to mach_msg_trap. */ + mach_msg_header_t *msg; + mach_msg_option_t option; + mach_msg_size_t send_size; + mach_msg_size_t rcv_size; + mach_port_t rcv_name; + mach_msg_timeout_t timeout; + mach_port_t notify; + }; + + +struct sigcontext * +_hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler, + int signo, long int sigcode, + int rpc_wait, + struct machine_thread_all_state *state) +{ + + __label__ trampoline, rpc_wait_trampoline; + void *sigsp; + struct sigcontext *scp; + + if (ss->context) + { + /* We have a previous sigcontext that sigreturn was about + to restore when another signal arrived. We will just base + our setup on that. */ + if (! setjmp (_hurd_sigthread_fault_env)) + { + memcpy (&state->basic, &ss->context->sc_mips_thread_state, + sizeof (state->basic)); + memcpy (&state->exc, &ss->context->sc_mips_exc_state, + sizeof (state->exc)); + state->set = (1 << MIPS_THREAD_STATE) | (1 << MIPS_EXC_STATE); + if (state->exc.coproc_state & SC_COPROC_USE_FPU) + { + memcpy (&state->fpu, &ss->context->sc_mips_float_state, + sizeof (state->fpu)); + state->set |= (1 << MIPS_FLOAT_STATE); + } + assert (! rpc_wait); + /* The intr_port slot was cleared before sigreturn sent us the + sig_post that made us notice this pending signal, so + _hurd_internal_post_signal wouldn't do interrupt_operation. + After we return, our caller will set SCP->sc_intr_port (in the + new context) from SS->intr_port and clear SS->intr_port. Now + that we are restoring this old context recorded by sigreturn, + we want to restore its intr_port too; so store it in + SS->intr_port now, so it will end up in SCP->sc_intr_port + later. */ + ss->intr_port = ss->context->sc_intr_port; + } + /* If the sigreturn context was bogus, just ignore it. */ + ss->context = NULL; + } + else if (! machine_get_basic_state (ss->thread, state)) + return NULL; + + if ((ss->actions[signo].sa_flags & SA_ONSTACK) && + !(ss->sigaltstack.ss_flags & (SA_DISABLE|SA_ONSTACK))) + { + sigsp = ss->sigaltstack.ss_sp + ss->sigaltstack.ss_size; + ss->sigaltstack.ss_flags |= SA_ONSTACK; + /* XXX need to set up base of new stack for + per-thread variables, cthreads. */ + } + else + sigsp = (char *) state->basic.r29; + + /* Set up the sigcontext structure on the stack. This is all the stack + needs, since the args are passed in registers (below). */ + sigsp -= sizeof (*scp); + scp = sigsp; + + if (! setjmp (_hurd_sigthread_fault_env)) + { + /* Set up the sigcontext from the current state of the thread. */ + + scp->sc_onstack = ss->sigaltstack.ss_flags & SA_ONSTACK ? 1 : 0; + + /* struct sigcontext is laid out so that starting at sc_gpr + mimics a struct mips_thread_state. */ + memcpy (&scp->sc_mips_thread_state, + &state->basic, sizeof (state->basic)); + + /* struct sigcontext is laid out so that starting at sc_cause + mimics a struct mips_exc_state. */ + if (! machine_get_state (ss->thread, state, MIPS_EXC_STATE, + &state->exc, &scp->sc_cause, + sizeof (state->exc))) + return NULL; + if ((scp->sc_coproc_used & SC_COPROC_USE_FPU) && + /* struct sigcontext is laid out so that starting at sc_fpr + mimics a struct mips_float_state. This state + is only meaningful if the coprocessor was used. */ + ! machine_get_state (ss->thread, state, MIPS_FLOAT_STATE, + &state->fpu, + &scp->sc_mips_float_state, sizeof (state->fpu))) + return NULL; + } + else + /* We got a fault trying to write the stack frame. + We cannot set up the signal handler. + Returning NULL tells our caller, who will nuke us with a SIGILL. */ + return NULL; + + /* Modify the thread state to call the trampoline code on the new stack. */ + 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 its registers to + enable only message reception, since the request message has + already been sent. */ + + /* The system call arguments are stored in consecutive registers + starting with a0 ($4). */ + struct mach_msg_trap_args *args = (void *) &state->basic.r4; + + assert (args->option & MACH_RCV_MSG); + /* Disable the message-send, since it has already completed. The + calls we retry need only wait to receive the reply message. */ + args->option &= ~MACH_SEND_MSG; + + state->basic.pc = (int) &&rpc_wait_trampoline; + state->basic.r29 = (int) sigsp; /* $29 is the stack pointer register. */ + /* After doing the message receive, the trampoline code will need to + update the v0 ($2) 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 v1 ($3). */ + state->basic.r3 = (int) &scp->sc_gpr[1]; + /* We must preserve the mach_msg_trap args in a0..t2 ($4..$10). + Pass the handler args to the trampoline code in s1..s3 ($17..$19). */ + state->basic.r17 = signo; + state->basic.r18 = sigcode; + state->basic.r19 = (int) scp; + } + else + { + state->basic.pc = (int) &&trampoline; + state->basic.r29 = (int) sigsp; + state->basic.r4 = signo; + state->basic.r5 = sigcode; + state->basic.r6 = (int) scp; + } + + /* We pass the handler function to the trampoline code in at ($1). */ + state->basic.r1 = (int) handler; + /* In the callee-saved register s0 ($16), we save the SCP value to pass + to __sigreturn after the handler returns. */ + state->basic.r16 = (int) scp; + + return scp; + + /* The trampoline code follows. This is not actually executed as part of + this function, it is just convenient to write it that way. */ + + rpc_wait_trampoline: + /* 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 in our registers. For our convenience, + $3 points to the sc_gpr[1] member of the sigcontext (saved v0 ($2)). */ + asm volatile + (".set noat; .set noreorder; .set nomacro\n" + /* Retry the interrupted mach_msg system call. */ + "li $2, -25\n" /* mach_msg_trap */ + "syscall\n" + /* When the sigcontext was saved, v0 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 v0. So + store the new v0 value into the sc_gpr[1] member of the sigcontext + (whose address is in v1 to make this code simpler). */ + "sw $2, ($3)\n" + /* Since the argument registers needed to have the mach_msg_trap + arguments, we've stored the arguments to the handler function + in registers s1..s3 ($17..$19). */ + "move $4, $17\n" + "move $5, $18\n" + "move $6, $19\n"); + + trampoline: + /* Entry point for running the handler normally. The arguments to the + handler function are already in the standard registers: + + a0 SIGNO + a1 SIGCODE + a2 SCP + */ + asm volatile + ("jal $1; nop\n" /* Call the handler function. */ + /* Call __sigreturn (SCP); this cannot return. */ + "j %0\n" + "move $4, $16" /* Set up arg from saved SCP in delay slot. */ + : : "i" (&__sigreturn)); + + /* NOTREACHED */ + asm volatile (".set reorder; .set at; .set macro"); + + return NULL; +} + +/* STATE describes a thread that had intr_port set (meaning it was inside + HURD_EINTR_RPC), after it has been thread_abort'd. It it looks to have + just completed a mach_msg_trap system call that returned + MACH_RCV_INTERRUPTED, return nonzero and set *PORT to the receive right + being waited on. */ +int +_hurdsig_rcv_interrupted_p (struct machine_thread_all_state *state, + mach_port_t *port) +{ + const unsigned int *const pc = (void *) state->basic.pc; + + if (_hurdsig_catch_fault (SIGSEGV)) + assert (_hurdsig_fault_sigcode == (long int) pc); + else + { + if (state->basic.r2 == MACH_RCV_INTERRUPTED && + pc[-1] == 0xc) /* syscall */ + { + /* We did just return from a mach_msg_trap system call + doing a message receive that was interrupted. + Examine the parameters to find the receive right. */ + struct mach_msg_trap_args *args = (void *) &state->basic.r4; + + *port = args->rcv_name; + return 1; + } + } + + return 0; +} |