/*
* Emulation of Linux signals
*
* Copyright (c) 2003 Fabrice Bellard
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu.h"
#include "target_signal.h"
#include "signal-common.h"
#include "linux-user/trace.h"
/*
* code and data structures from linux kernel:
* include/asm-sh/sigcontext.h
* arch/sh/kernel/signal.c
*/
struct target_sigcontext {
target_ulong oldmask;
/* CPU registers */
target_ulong sc_gregs[16];
target_ulong sc_pc;
target_ulong sc_pr;
target_ulong sc_sr;
target_ulong sc_gbr;
target_ulong sc_mach;
target_ulong sc_macl;
/* FPU registers */
target_ulong sc_fpregs[16];
target_ulong sc_xfpregs[16];
unsigned int sc_fpscr;
unsigned int sc_fpul;
unsigned int sc_ownedfp;
};
struct target_sigframe
{
struct target_sigcontext sc;
target_ulong extramask[TARGET_NSIG_WORDS-1];
uint16_t retcode[3];
};
struct target_ucontext {
target_ulong tuc_flags;
struct target_ucontext *tuc_link;
target_stack_t tuc_stack;
struct target_sigcontext tuc_mcontext;
target_sigset_t tuc_sigmask; /* mask last for extensibility */
};
struct target_rt_sigframe
{
struct target_siginfo info;
struct target_ucontext uc;
uint16_t retcode[3];
};
#define MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */
#define TRAP_NOARG 0xc310 /* Syscall w/no args (NR in R3) SH3/4 */
static abi_ulong get_sigframe(struct target_sigaction *ka,
unsigned long sp, size_t frame_size)
{
if ((ka->sa_flags & TARGET_SA_ONSTACK) && (sas_ss_flags(sp) == 0)) {
sp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
}
return (sp - frame_size) & -8ul;
}
/* Notice when we're in the middle of a gUSA region and reset.
Note that this will only occur for !parallel_cpus, as we will
translate such sequences differently in a parallel context. */
static void unwind_gusa(CPUSH4State *regs)
{
/* If the stack pointer is sufficiently negative, and we haven't
completed the sequence, then reset to the entry to the region. */
/* ??? The SH4 kernel checks for and address above 0xC0000000.
However, the page mappings in qemu linux-user aren't as restricted
and we wind up with the normal stack mapped above 0xF0000000.
That said, there is no reason why the kernel should be allowing
a gUSA region that spans 1GB. Use a tighter check here, for what
can actually be enabled by the immediate move. */
if (regs->gregs[15] >= -128u && regs->pc < regs->gregs[0]) {
/* Reset the PC to before the gUSA region, as computed from
R0 = region end, SP = -(region size), plus one more for the
insn that actually initializes SP to the region size. */
regs->pc = regs->gregs[0] + regs->gregs[15] - 2;
/* Reset the SP to the saved version in R1. */
regs->gregs[15] = regs->gregs[1];
}
}
static void setup_sigcontext(struct target_sigcontext *sc,
CPUSH4State *regs, unsigned long mask)
{
int i;
#define COPY(x) __put_user(regs->x, &sc->sc_##x)
COPY(gregs[0]); COPY(gregs[1]);
COPY(gregs[2]); COPY(gregs[3]);
COPY(gregs[4]); COPY(gregs[5]);
COPY(gregs[6]); COPY(gregs[7]);
COPY(gregs[8]); COPY(gregs[9]);
COPY(gregs[10]); COPY(gregs[11]);
COPY(gregs[12]); COPY(gregs[13]);
COPY(gregs[14]); COPY(gregs[15]);
COPY(gbr); COPY(mach);
COPY(macl); COPY(pr);
COPY(sr); COPY(pc);
#undef COPY
for (i=0; i<16; i++) {
__put_user(regs->fregs[i], &sc->sc_fpregs[i]);
}
__put_user(regs->fpscr, &sc->sc_fpscr);
__put_user(regs->fpul, &sc->sc_fpul);
/* non-iBCS2 extensions.. */
__put_user(mask, &sc->oldmask);
}
static void restore_sigcontext(CPUSH4State *regs, struct target_sigcontext *sc)
{
int i;
#define COPY(x) __get_user(regs->x, &sc->sc_##x)
COPY(gregs[0]); COPY(gregs[1]);
COPY(gregs[2]); COPY(gregs[3]);
COPY(gregs[4]); COPY(gregs[5]);
COPY(gregs[6]); COPY(gregs[7]);
COPY(gregs[8]); COPY(gregs[9]);
COPY(gregs[10]); COPY(gregs[11]);
COPY(gregs[12]); COPY(gregs[13]);
COPY(gregs[14]); COPY(gregs[15]);
COPY(gbr); COPY(mach);
COPY(macl); COPY(pr);
COPY(sr); COPY(pc);
#undef COPY
for (i=0; i<16; i++) {
__get_user(regs->fregs[i], &sc->sc_fpregs[i]);
}
__get_user(regs->fpscr, &sc->sc_fpscr);
__get_user(regs->fpul, &sc->sc_fpul);
regs->tra = -1; /* disable syscall checks */
regs->flags &= ~(DELAY_SLOT_MASK | GUSA_MASK);
}
void setup_frame(int sig, struct target_sigaction *ka,
target_sigset_t *set, CPUSH4State *regs)
{
struct target_sigframe *frame;
abi_ulong frame_addr;
int i;
unwind_gusa(regs);
frame_addr = get_sigframe(ka, regs->gregs[15], sizeof(*frame));
trace_user_setup_frame(regs, frame_addr);
if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
goto give_sigsegv;
}
setup_sigcontext(&frame->sc, regs, set->sig[0]);
for (i = 0; i < TARGET_NSIG_WORDS - 1; i++) {
__put_user(set->sig[i + 1], &frame->extramask[i]);
}
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa_flags & TARGET_SA_RESTORER) {
regs->pr = (unsigned long) ka->sa_restorer;
} else {
/* Generate return code (system call to sigreturn) */
abi_ulong retcode_addr = frame_addr +
offsetof(struct target_sigframe, retcode);
__put_user(MOVW(2), &frame->retcode[0]);
__put_user(TRAP_NOARG, &frame->retcode[1]);
__put_user((TARGET_NR_sigreturn), &frame->retcode[2]);
regs->pr = (unsigned long) retcode_addr;
}
/* Set up registers for signal handler */
regs->gregs[15] = frame_addr;
regs->gregs[4] = sig; /* Arg for signal handler */
regs->gregs[5] = 0;
regs->gregs[6] = frame_addr += offsetof(typeof(*frame), sc);
regs->pc = (unsigned long) ka->_sa_handler;
regs->flags &= ~(DELAY_SLOT_MASK | GUSA_MASK);
unlock_user_struct(frame, frame_addr, 1);
return;
give_sigsegv:
unlock_user_struct(frame, frame_addr, 1);
force_sigsegv(sig);
}
void setup_rt_frame(int sig, struct target_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPUSH4State *regs)
{
struct target_rt_sigframe *frame;
abi_ulong frame_addr;
int i;
unwind_gusa(regs);
frame_addr = get_sigframe(ka, regs->gregs[15], sizeof(*frame));
trace_user_setup_rt_frame(regs, frame_addr);
if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
goto give_sigsegv;
}
tswap_siginfo(&frame->info, info);
/* Create the ucontext. */
__put_user(0, &frame->uc.tuc_flags);
__put_user(0, (unsigned long *)&frame->uc.tuc_link);
__put_user((unsigned long)target_sigaltstack_used.ss_sp,
&frame->uc.tuc_stack.ss_sp);
__put_user(sas_ss_flags(regs->gregs[15]),
&frame->uc.tuc_stack.ss_flags);
__put_user(target_sigaltstack_used.ss_size,
&frame->uc.tuc_stack.ss_size);
setup_sigcontext(&frame->uc.tuc_mcontext,
regs, set->sig[0]);
for(i = 0; i < TARGET_NSIG_WORDS; i++) {
__put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
}
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa_flags & TARGET_SA_RESTORER) {
regs->pr = (unsigned long) ka->sa_restorer;
} else {
/* Generate return code (system call to sigreturn) */
abi_ulong retcode_addr = frame_addr +
offsetof(struct target_rt_sigframe, retcode);
__put_user(MOVW(2), &frame->retcode[0]);
__put_user(TRAP_NOARG, &frame->retcode[1]);
__put_user((TARGET_NR_rt_sigreturn), &frame->retcode[2]);
regs->pr = (unsigned long) retcode_addr;
}
/* Set up registers for signal handler */
regs->gregs[15] = frame_addr;
regs->gregs[4] = sig; /* Arg for signal handler */
regs->gregs[5] = frame_addr + offsetof(typeof(*frame), info);
regs->gregs[6] = frame_addr + offsetof(typeof(*frame), uc);
regs->pc = (unsigned long) ka->_sa_handler;
regs->flags &= ~(DELAY_SLOT_MASK | GUSA_MASK);
unlock_user_struct(frame, frame_addr, 1);
return;
give_sigsegv:
unlock_user_struct(frame, frame_addr, 1);
force_sigsegv(sig);
}
long do_sigreturn(CPUSH4State *regs)
{
struct target_sigframe *frame;
abi_ulong frame_addr;
sigset_t blocked;
target_sigset_t target_set;
int i;
int err = 0;
frame_addr = regs->gregs[15];
trace_user_do_sigreturn(regs, frame_addr);
if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
goto badframe;
}
__get_user(target_set.sig[0], &frame->sc.oldmask);
for(i = 1; i < TARGET_NSIG_WORDS; i++) {
__get_user(target_set.sig[i], &frame->extramask[i - 1]);
}
if (err)
goto badframe;
target_to_host_sigset_internal(&blocked, &target_set);
set_sigmask(&blocked);
restore_sigcontext(regs, &frame->sc);
unlock_user_struct(frame, frame_addr, 0);
return -TARGET_QEMU_ESIGRETURN;
badframe:
unlock_user_struct(frame, frame_addr, 0);
force_sig(TARGET_SIGSEGV);
return -TARGET_QEMU_ESIGRETURN;
}
long do_rt_sigreturn(CPUSH4State *regs)
{
struct target_rt_sigframe *frame;
abi_ulong frame_addr;
sigset_t blocked;
frame_addr = regs->gregs[15];
trace_user_do_rt_sigreturn(regs, frame_addr);
if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
goto badframe;
}
target_to_host_sigset(&blocked, &frame->uc.tuc_sigmask);
set_sigmask(&blocked);
restore_sigcontext(regs, &frame->uc.tuc_mcontext);
if (do_sigaltstack(frame_addr +
offsetof(struct target_rt_sigframe, uc.tuc_stack),
0, get_sp_from_cpustate(regs)) == -EFAULT) {
goto badframe;
}
unlock_user_struct(frame, frame_addr, 0);
return -TARGET_QEMU_ESIGRETURN;
badframe:
unlock_user_struct(frame, frame_addr, 0);
force_sig(TARGET_SIGSEGV);
return -TARGET_QEMU_ESIGRETURN;
}
