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/*
* 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"
struct target_sigcontext {
abi_ulong sc_pc;
abi_ulong sc_ps;
abi_ulong sc_lbeg;
abi_ulong sc_lend;
abi_ulong sc_lcount;
abi_ulong sc_sar;
abi_ulong sc_acclo;
abi_ulong sc_acchi;
abi_ulong sc_a[16];
abi_ulong sc_xtregs;
};
struct target_ucontext {
abi_ulong tuc_flags;
abi_ulong tuc_link;
target_stack_t tuc_stack;
struct target_sigcontext tuc_mcontext;
target_sigset_t tuc_sigmask;
};
struct target_rt_sigframe {
target_siginfo_t info;
struct target_ucontext uc;
/* TODO: xtregs */
uint8_t retcode[6];
abi_ulong window[4];
};
static abi_ulong get_sigframe(struct target_sigaction *sa,
CPUXtensaState *env,
unsigned long framesize)
{
abi_ulong sp = env->regs[1];
/* This is the X/Open sanctioned signal stack switching. */
if ((sa->sa_flags & TARGET_SA_ONSTACK) != 0 && !sas_ss_flags(sp)) {
sp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
}
return (sp - framesize) & -16;
}
static int flush_window_regs(CPUXtensaState *env)
{
uint32_t wb = env->sregs[WINDOW_BASE];
uint32_t ws = xtensa_replicate_windowstart(env) >> (wb + 1);
unsigned d = ctz32(ws) + 1;
unsigned i;
int ret = 0;
for (i = d; i < env->config->nareg / 4; i += d) {
uint32_t ssp, osp;
unsigned j;
ws >>= d;
xtensa_rotate_window(env, d);
if (ws & 0x1) {
ssp = env->regs[5];
d = 1;
} else if (ws & 0x2) {
ssp = env->regs[9];
ret |= get_user_ual(osp, env->regs[1] - 12);
osp -= 32;
d = 2;
} else if (ws & 0x4) {
ssp = env->regs[13];
ret |= get_user_ual(osp, env->regs[1] - 12);
osp -= 48;
d = 3;
} else {
g_assert_not_reached();
}
for (j = 0; j < 4; ++j) {
ret |= put_user_ual(env->regs[j], ssp - 16 + j * 4);
}
for (j = 4; j < d * 4; ++j) {
ret |= put_user_ual(env->regs[j], osp - 16 + j * 4);
}
}
xtensa_rotate_window(env, d);
g_assert(env->sregs[WINDOW_BASE] == wb);
return ret == 0;
}
static int setup_sigcontext(struct target_rt_sigframe *frame,
CPUXtensaState *env)
{
struct target_sigcontext *sc = &frame->uc.tuc_mcontext;
int i;
__put_user(env->pc, &sc->sc_pc);
__put_user(env->sregs[PS], &sc->sc_ps);
__put_user(env->sregs[LBEG], &sc->sc_lbeg);
__put_user(env->sregs[LEND], &sc->sc_lend);
__put_user(env->sregs[LCOUNT], &sc->sc_lcount);
if (!flush_window_regs(env)) {
return 0;
}
for (i = 0; i < 16; ++i) {
__put_user(env->regs[i], sc->sc_a + i);
}
__put_user(0, &sc->sc_xtregs);
/* TODO: xtregs */
return 1;
}
void setup_rt_frame(int sig, struct target_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPUXtensaState *env)
{
abi_ulong frame_addr;
struct target_rt_sigframe *frame;
uint32_t ra;
int i;
frame_addr = get_sigframe(ka, env, sizeof(*frame));
trace_user_setup_rt_frame(env, frame_addr);
if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
goto give_sigsegv;
}
if (ka->sa_flags & SA_SIGINFO) {
tswap_siginfo(&frame->info, info);
}
__put_user(0, &frame->uc.tuc_flags);
__put_user(0, &frame->uc.tuc_link);
__put_user(target_sigaltstack_used.ss_sp,
&frame->uc.tuc_stack.ss_sp);
__put_user(sas_ss_flags(env->regs[1]),
&frame->uc.tuc_stack.ss_flags);
__put_user(target_sigaltstack_used.ss_size,
&frame->uc.tuc_stack.ss_size);
if (!setup_sigcontext(frame, env)) {
unlock_user_struct(frame, frame_addr, 0);
goto give_sigsegv;
}
for (i = 0; i < TARGET_NSIG_WORDS; ++i) {
__put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
}
if (ka->sa_flags & TARGET_SA_RESTORER) {
ra = ka->sa_restorer;
} else {
ra = frame_addr + offsetof(struct target_rt_sigframe, retcode);
#ifdef TARGET_WORDS_BIGENDIAN
/* Generate instruction: MOVI a2, __NR_rt_sigreturn */
__put_user(0x22, &frame->retcode[0]);
__put_user(0x0a, &frame->retcode[1]);
__put_user(TARGET_NR_rt_sigreturn, &frame->retcode[2]);
/* Generate instruction: SYSCALL */
__put_user(0x00, &frame->retcode[3]);
__put_user(0x05, &frame->retcode[4]);
__put_user(0x00, &frame->retcode[5]);
#else
/* Generate instruction: MOVI a2, __NR_rt_sigreturn */
__put_user(0x22, &frame->retcode[0]);
__put_user(0xa0, &frame->retcode[1]);
__put_user(TARGET_NR_rt_sigreturn, &frame->retcode[2]);
/* Generate instruction: SYSCALL */
__put_user(0x00, &frame->retcode[3]);
__put_user(0x50, &frame->retcode[4]);
__put_user(0x00, &frame->retcode[5]);
#endif
}
env->sregs[PS] = PS_UM | (3 << PS_RING_SHIFT);
if (xtensa_option_enabled(env->config, XTENSA_OPTION_WINDOWED_REGISTER)) {
env->sregs[PS] |= PS_WOE | (1 << PS_CALLINC_SHIFT);
}
memset(env->regs, 0, sizeof(env->regs));
env->pc = ka->_sa_handler;
env->regs[1] = frame_addr;
env->sregs[WINDOW_BASE] = 0;
env->sregs[WINDOW_START] = 1;
env->regs[4] = (ra & 0x3fffffff) | 0x40000000;
env->regs[6] = sig;
env->regs[7] = frame_addr + offsetof(struct target_rt_sigframe, info);
env->regs[8] = frame_addr + offsetof(struct target_rt_sigframe, uc);
unlock_user_struct(frame, frame_addr, 1);
return;
give_sigsegv:
force_sigsegv(sig);
return;
}
static void restore_sigcontext(CPUXtensaState *env,
struct target_rt_sigframe *frame)
{
struct target_sigcontext *sc = &frame->uc.tuc_mcontext;
uint32_t ps;
int i;
__get_user(env->pc, &sc->sc_pc);
__get_user(ps, &sc->sc_ps);
__get_user(env->sregs[LBEG], &sc->sc_lbeg);
__get_user(env->sregs[LEND], &sc->sc_lend);
__get_user(env->sregs[LCOUNT], &sc->sc_lcount);
env->sregs[WINDOW_BASE] = 0;
env->sregs[WINDOW_START] = 1;
env->sregs[PS] = deposit32(env->sregs[PS],
PS_CALLINC_SHIFT,
PS_CALLINC_LEN,
extract32(ps, PS_CALLINC_SHIFT,
PS_CALLINC_LEN));
for (i = 0; i < 16; ++i) {
__get_user(env->regs[i], sc->sc_a + i);
}
/* TODO: xtregs */
}
long do_rt_sigreturn(CPUXtensaState *env)
{
abi_ulong frame_addr = env->regs[1];
struct target_rt_sigframe *frame;
sigset_t set;
trace_user_do_rt_sigreturn(env, frame_addr);
if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
goto badframe;
}
target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
set_sigmask(&set);
restore_sigcontext(env, frame);
if (do_sigaltstack(frame_addr +
offsetof(struct target_rt_sigframe, uc.tuc_stack),
0, get_sp_from_cpustate(env)) == -TARGET_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;
}
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