qemu/linux-user/mips/signal.c

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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 "user-internals.h"
#include "signal-common.h"
#include "linux-user/trace.h"
# if defined(TARGET_ABI_MIPSO32)
struct target_sigcontext {
uint32_t sc_regmask; /* Unused */
uint32_t sc_status;
uint64_t sc_pc;
uint64_t sc_regs[32];
uint64_t sc_fpregs[32];
uint32_t sc_ownedfp; /* Unused */
uint32_t sc_fpc_csr;
uint32_t sc_fpc_eir; /* Unused */
uint32_t sc_used_math;
uint32_t sc_dsp; /* dsp status, was sc_ssflags */
uint32_t pad0;
uint64_t sc_mdhi;
uint64_t sc_mdlo;
target_ulong sc_hi1; /* Was sc_cause */
target_ulong sc_lo1; /* Was sc_badvaddr */
target_ulong sc_hi2; /* Was sc_sigset[4] */
target_ulong sc_lo2;
target_ulong sc_hi3;
target_ulong sc_lo3;
};
# else /* N32 || N64 */
struct target_sigcontext {
uint64_t sc_regs[32];
uint64_t sc_fpregs[32];
uint64_t sc_mdhi;
uint64_t sc_hi1;
uint64_t sc_hi2;
uint64_t sc_hi3;
uint64_t sc_mdlo;
uint64_t sc_lo1;
uint64_t sc_lo2;
uint64_t sc_lo3;
uint64_t sc_pc;
uint32_t sc_fpc_csr;
uint32_t sc_used_math;
uint32_t sc_dsp;
uint32_t sc_reserved;
};
# endif /* O32 */
struct sigframe {
uint32_t sf_ass[4]; /* argument save space for o32 */
uint32_t sf_code[2]; /* signal trampoline */
struct target_sigcontext sf_sc;
target_sigset_t sf_mask;
};
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 {
uint32_t rs_ass[4]; /* argument save space for o32 */
uint32_t rs_code[2]; /* signal trampoline */
struct target_siginfo rs_info;
struct target_ucontext rs_uc;
};
/* Install trampoline to jump back from signal handler */
static void install_sigtramp(uint32_t *tramp, unsigned int syscall)
{
/*
* Set up the return code ...
*
* li v0, __NR__foo_sigreturn
* syscall
*/
__put_user(0x24020000 + syscall, tramp + 0);
__put_user(0x0000000c , tramp + 1);
}
static inline void setup_sigcontext(CPUMIPSState *regs,
struct target_sigcontext *sc)
{
int i;
__put_user(exception_resume_pc(regs), &sc->sc_pc);
regs->hflags &= ~MIPS_HFLAG_BMASK;
__put_user(0, &sc->sc_regs[0]);
for (i = 1; i < 32; ++i) {
__put_user(regs->active_tc.gpr[i], &sc->sc_regs[i]);
}
__put_user(regs->active_tc.HI[0], &sc->sc_mdhi);
__put_user(regs->active_tc.LO[0], &sc->sc_mdlo);
/* Rather than checking for dsp existence, always copy. The storage
would just be garbage otherwise. */
__put_user(regs->active_tc.HI[1], &sc->sc_hi1);
__put_user(regs->active_tc.HI[2], &sc->sc_hi2);
__put_user(regs->active_tc.HI[3], &sc->sc_hi3);
__put_user(regs->active_tc.LO[1], &sc->sc_lo1);
__put_user(regs->active_tc.LO[2], &sc->sc_lo2);
__put_user(regs->active_tc.LO[3], &sc->sc_lo3);
{
uint32_t dsp = cpu_rddsp(0x3ff, regs);
__put_user(dsp, &sc->sc_dsp);
}
__put_user(1, &sc->sc_used_math);
for (i = 0; i < 32; ++i) {
__put_user(regs->active_fpu.fpr[i].d, &sc->sc_fpregs[i]);
}
}
static inline void
restore_sigcontext(CPUMIPSState *regs, struct target_sigcontext *sc)
{
int i;
__get_user(regs->CP0_EPC, &sc->sc_pc);
__get_user(regs->active_tc.HI[0], &sc->sc_mdhi);
__get_user(regs->active_tc.LO[0], &sc->sc_mdlo);
for (i = 1; i < 32; ++i) {
__get_user(regs->active_tc.gpr[i], &sc->sc_regs[i]);
}
__get_user(regs->active_tc.HI[1], &sc->sc_hi1);
__get_user(regs->active_tc.HI[2], &sc->sc_hi2);
__get_user(regs->active_tc.HI[3], &sc->sc_hi3);
__get_user(regs->active_tc.LO[1], &sc->sc_lo1);
__get_user(regs->active_tc.LO[2], &sc->sc_lo2);
__get_user(regs->active_tc.LO[3], &sc->sc_lo3);
{
uint32_t dsp;
__get_user(dsp, &sc->sc_dsp);
cpu_wrdsp(dsp, 0x3ff, regs);
}
for (i = 0; i < 32; ++i) {
__get_user(regs->active_fpu.fpr[i].d, &sc->sc_fpregs[i]);
}
}
/*
* Determine which stack to use..
*/
static inline abi_ulong
get_sigframe(struct target_sigaction *ka, CPUMIPSState *regs, size_t frame_size)
{
unsigned long sp;
/*
* FPU emulator may have its own trampoline active just
* above the user stack, 16-bytes before the next lowest
* 16 byte boundary. Try to avoid trashing it.
*/
sp = target_sigsp(get_sp_from_cpustate(regs) - 32, ka);
return (sp - frame_size) & ~7;
}
static void mips_set_hflags_isa_mode_from_pc(CPUMIPSState *env)
{
if (env->insn_flags & (ASE_MIPS16 | ASE_MICROMIPS)) {
env->hflags &= ~MIPS_HFLAG_M16;
env->hflags |= (env->active_tc.PC & 1) << MIPS_HFLAG_M16_SHIFT;
env->active_tc.PC &= ~(target_ulong) 1;
}
}
# if defined(TARGET_ABI_MIPSO32)
/* compare linux/arch/mips/kernel/signal.c:setup_frame() */
void setup_frame(int sig, struct target_sigaction * ka,
target_sigset_t *set, CPUMIPSState *regs)
{
struct sigframe *frame;
abi_ulong frame_addr;
int i;
frame_addr = get_sigframe(ka, regs, sizeof(*frame));
trace_user_setup_frame(regs, frame_addr);
if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
goto give_sigsegv;
}
setup_sigcontext(regs, &frame->sf_sc);
for(i = 0; i < TARGET_NSIG_WORDS; i++) {
__put_user(set->sig[i], &frame->sf_mask.sig[i]);
}
/*
* Arguments to signal handler:
*
* a0 = signal number
* a1 = 0 (should be cause)
* a2 = pointer to struct sigcontext
*
* $25 and PC point to the signal handler, $29 points to the
* struct sigframe.
*/
regs->active_tc.gpr[ 4] = sig;
regs->active_tc.gpr[ 5] = 0;
regs->active_tc.gpr[ 6] = frame_addr + offsetof(struct sigframe, sf_sc);
regs->active_tc.gpr[29] = frame_addr;
regs->active_tc.gpr[31] = default_sigreturn;
/* The original kernel code sets CP0_EPC to the handler
* since it returns to userland using eret
* we cannot do this here, and we must set PC directly */
regs->active_tc.PC = regs->active_tc.gpr[25] = ka->_sa_handler;
mips_set_hflags_isa_mode_from_pc(regs);
unlock_user_struct(frame, frame_addr, 1);
return;
give_sigsegv:
force_sigsegv(sig);
}
long do_sigreturn(CPUMIPSState *regs)
{
struct sigframe *frame;
abi_ulong frame_addr;
sigset_t blocked;
target_sigset_t target_set;
int i;
frame_addr = regs->active_tc.gpr[29];
trace_user_do_sigreturn(regs, frame_addr);
if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
goto badframe;
for(i = 0; i < TARGET_NSIG_WORDS; i++) {
__get_user(target_set.sig[i], &frame->sf_mask.sig[i]);
}
target_to_host_sigset_internal(&blocked, &target_set);
set_sigmask(&blocked);
restore_sigcontext(regs, &frame->sf_sc);
#if 0
/*
* Don't let your children do this ...
*/
__asm__ __volatile__(
"move\t$29, %0\n\t"
"j\tsyscall_exit"
:/* no outputs */
:"r" (&regs));
/* Unreached */
#endif
regs->active_tc.PC = regs->CP0_EPC;
mips_set_hflags_isa_mode_from_pc(regs);
/* I am not sure this is right, but it seems to work
* maybe a problem with nested signals ? */
regs->CP0_EPC = 0;
return -QEMU_ESIGRETURN;
badframe:
force_sig(TARGET_SIGSEGV);
return -QEMU_ESIGRETURN;
}
# endif /* O32 */
void setup_rt_frame(int sig, struct target_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPUMIPSState *env)
{
struct target_rt_sigframe *frame;
abi_ulong frame_addr;
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;
}
tswap_siginfo(&frame->rs_info, info);
__put_user(0, &frame->rs_uc.tuc_flags);
__put_user(0, &frame->rs_uc.tuc_link);
target_save_altstack(&frame->rs_uc.tuc_stack, env);
setup_sigcontext(env, &frame->rs_uc.tuc_mcontext);
for(i = 0; i < TARGET_NSIG_WORDS; i++) {
__put_user(set->sig[i], &frame->rs_uc.tuc_sigmask.sig[i]);
}
/*
* Arguments to signal handler:
*
* a0 = signal number
* a1 = pointer to siginfo_t
* a2 = pointer to ucontext_t
*
* $25 and PC point to the signal handler, $29 points to the
* struct sigframe.
*/
env->active_tc.gpr[ 4] = sig;
env->active_tc.gpr[ 5] = frame_addr
+ offsetof(struct target_rt_sigframe, rs_info);
env->active_tc.gpr[ 6] = frame_addr
+ offsetof(struct target_rt_sigframe, rs_uc);
env->active_tc.gpr[29] = frame_addr;
env->active_tc.gpr[31] = default_rt_sigreturn;
/*
* The original kernel code sets CP0_EPC to the handler
* since it returns to userland using eret
* we cannot do this here, and we must set PC directly
*/
env->active_tc.PC = env->active_tc.gpr[25] = ka->_sa_handler;
mips_set_hflags_isa_mode_from_pc(env);
unlock_user_struct(frame, frame_addr, 1);
return;
give_sigsegv:
unlock_user_struct(frame, frame_addr, 1);
force_sigsegv(sig);
}
long do_rt_sigreturn(CPUMIPSState *env)
{
struct target_rt_sigframe *frame;
abi_ulong frame_addr;
sigset_t blocked;
frame_addr = env->active_tc.gpr[29];
trace_user_do_rt_sigreturn(env, frame_addr);
if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
goto badframe;
}
target_to_host_sigset(&blocked, &frame->rs_uc.tuc_sigmask);
set_sigmask(&blocked);
restore_sigcontext(env, &frame->rs_uc.tuc_mcontext);
target_restore_altstack(&frame->rs_uc.tuc_stack, env);
env->active_tc.PC = env->CP0_EPC;
mips_set_hflags_isa_mode_from_pc(env);
/* I am not sure this is right, but it seems to work
* maybe a problem with nested signals ? */
env->CP0_EPC = 0;
return -QEMU_ESIGRETURN;
badframe:
force_sig(TARGET_SIGSEGV);
return -QEMU_ESIGRETURN;
}
void setup_sigtramp(abi_ulong sigtramp_page)
{
uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0);
assert(tramp != NULL);
#ifdef TARGET_ARCH_HAS_SETUP_FRAME
default_sigreturn = sigtramp_page;
install_sigtramp(tramp, TARGET_NR_sigreturn);
#endif
default_rt_sigreturn = sigtramp_page + 8;
install_sigtramp(tramp + 2, TARGET_NR_rt_sigreturn);
unlock_user(tramp, sigtramp_page, 2 * 8);
}