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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 {
struct target_pt_regs regs;
abi_ulong oldmask;
abi_ulong usp;
};
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; /* mask last for extensibility */
};
struct target_rt_sigframe {
abi_ulong pinfo;
uint64_t puc;
struct target_siginfo info;
struct target_sigcontext sc;
struct target_ucontext uc;
unsigned char retcode[16]; /* trampoline code */
};
/* This is the asm-generic/ucontext.h version */
#if 0
static int restore_sigcontext(CPUOpenRISCState *regs,
struct target_sigcontext *sc)
{
unsigned int err = 0;
unsigned long old_usp;
/* Alwys make any pending restarted system call return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
/* restore the regs from &sc->regs (same as sc, since regs is first)
* (sc is already checked for VERIFY_READ since the sigframe was
* checked in sys_sigreturn previously)
*/
if (copy_from_user(regs, &sc, sizeof(struct target_pt_regs))) {
goto badframe;
}
/* make sure the U-flag is set so user-mode cannot fool us */
regs->sr &= ~SR_SM;
/* restore the old USP as it was before we stacked the sc etc.
* (we cannot just pop the sigcontext since we aligned the sp and
* stuff after pushing it)
*/
__get_user(old_usp, &sc->usp);
phx_signal("old_usp 0x%lx", old_usp);
__PHX__ REALLY /* ??? */
wrusp(old_usp);
regs->gpr[1] = old_usp;
/* TODO: the other ports use regs->orig_XX to disable syscall checks
* after this completes, but we don't use that mechanism. maybe we can
* use it now ?
*/
return err;
badframe:
return 1;
}
#endif
/* Set up a signal frame. */
static void setup_sigcontext(struct target_sigcontext *sc,
CPUOpenRISCState *regs,
unsigned long mask)
{
unsigned long usp = cpu_get_gpr(regs, 1);
/* copy the regs. they are first in sc so we can use sc directly */
/*copy_to_user(&sc, regs, sizeof(struct target_pt_regs));*/
/* Set the frametype to CRIS_FRAME_NORMAL for the execution of
the signal handler. The frametype will be restored to its previous
value in restore_sigcontext. */
/*regs->frametype = CRIS_FRAME_NORMAL;*/
/* then some other stuff */
__put_user(mask, &sc->oldmask);
__put_user(usp, &sc->usp);
}
static inline unsigned long align_sigframe(unsigned long sp)
{
return sp & ~3UL;
}
static inline abi_ulong get_sigframe(struct target_sigaction *ka,
CPUOpenRISCState *regs,
size_t frame_size)
{
unsigned long sp = cpu_get_gpr(regs, 1);
int onsigstack = on_sig_stack(sp);
/* redzone */
/* This is the X/Open sanctioned signal stack switching. */
if ((ka->sa_flags & TARGET_SA_ONSTACK) != 0 && !onsigstack) {
sp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
}
sp = align_sigframe(sp - frame_size);
/*
* If we are on the alternate signal stack and would overflow it, don't.
* Return an always-bogus address instead so we will die with SIGSEGV.
*/
if (onsigstack && !likely(on_sig_stack(sp))) {
return -1L;
}
return sp;
}
void setup_rt_frame(int sig, struct target_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPUOpenRISCState *env)
{
int err = 0;
abi_ulong frame_addr;
unsigned long return_ip;
struct target_rt_sigframe *frame;
abi_ulong info_addr, uc_addr;
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;
}
info_addr = frame_addr + offsetof(struct target_rt_sigframe, info);
__put_user(info_addr, &frame->pinfo);
uc_addr = frame_addr + offsetof(struct target_rt_sigframe, uc);
__put_user(uc_addr, &frame->puc);
if (ka->sa_flags & SA_SIGINFO) {
tswap_siginfo(&frame->info, info);
}
/*err |= __clear_user(&frame->uc, offsetof(ucontext_t, uc_mcontext));*/
__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(cpu_get_gpr(env, 1)),
&frame->uc.tuc_stack.ss_flags);
__put_user(target_sigaltstack_used.ss_size,
&frame->uc.tuc_stack.ss_size);
setup_sigcontext(&frame->sc, env, set->sig[0]);
/*err |= copy_to_user(frame->uc.tuc_sigmask, set, sizeof(*set));*/
/* trampoline - the desired return ip is the retcode itself */
return_ip = (unsigned long)&frame->retcode;
/* This is l.ori r11,r0,__NR_sigreturn, l.sys 1 */
__put_user(0xa960, (short *)(frame->retcode + 0));
__put_user(TARGET_NR_rt_sigreturn, (short *)(frame->retcode + 2));
__put_user(0x20000001, (unsigned long *)(frame->retcode + 4));
__put_user(0x15000000, (unsigned long *)(frame->retcode + 8));
if (err) {
goto give_sigsegv;
}
/* TODO what is the current->exec_domain stuff and invmap ? */
/* Set up registers for signal handler */
env->pc = (unsigned long)ka->_sa_handler; /* what we enter NOW */
cpu_set_gpr(env, 9, (unsigned long)return_ip); /* what we enter LATER */
cpu_set_gpr(env, 3, (unsigned long)sig); /* arg 1: signo */
cpu_set_gpr(env, 4, (unsigned long)&frame->info); /* arg 2: (siginfo_t*) */
cpu_set_gpr(env, 5, (unsigned long)&frame->uc); /* arg 3: ucontext */
/* actually move the usp to reflect the stacked frame */
cpu_set_gpr(env, 1, (unsigned long)frame);
return;
give_sigsegv:
unlock_user_struct(frame, frame_addr, 1);
force_sigsegv(sig);
}
long do_sigreturn(CPUOpenRISCState *env)
{
trace_user_do_sigreturn(env, 0);
fprintf(stderr, "do_sigreturn: not implemented\n");
return -TARGET_ENOSYS;
}
long do_rt_sigreturn(CPUOpenRISCState *env)
{
trace_user_do_rt_sigreturn(env, 0);
fprintf(stderr, "do_rt_sigreturn: not implemented\n");
return -TARGET_ENOSYS;
}
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