/*
* 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"
#define __NUM_GPRS 16
#define __NUM_FPRS 16
#define __NUM_ACRS 16
#define __SIGNAL_FRAMESIZE 160 /* FIXME: 31-bit mode -> 96 */
#define _SIGCONTEXT_NSIG 64
#define _SIGCONTEXT_NSIG_BPW 64 /* FIXME: 31-bit mode -> 32 */
#define _SIGCONTEXT_NSIG_WORDS (_SIGCONTEXT_NSIG / _SIGCONTEXT_NSIG_BPW)
#define _SIGMASK_COPY_SIZE (sizeof(unsigned long)*_SIGCONTEXT_NSIG_WORDS)
#define S390_SYSCALL_OPCODE ((uint16_t)0x0a00)
typedef struct {
target_psw_t psw;
abi_ulong gprs[__NUM_GPRS];
abi_uint acrs[__NUM_ACRS];
} target_s390_regs_common;
typedef struct {
uint32_t fpc;
uint32_t pad;
uint64_t fprs[__NUM_FPRS];
} target_s390_fp_regs;
typedef struct {
target_s390_regs_common regs;
target_s390_fp_regs fpregs;
} target_sigregs;
typedef struct {
uint64_t vxrs_low[16];
uint64_t vxrs_high[16][2];
uint8_t reserved[128];
} target_sigregs_ext;
typedef struct {
abi_ulong oldmask[_SIGCONTEXT_NSIG_WORDS];
abi_ulong sregs;
} target_sigcontext;
typedef struct {
uint8_t callee_used_stack[__SIGNAL_FRAMESIZE];
target_sigcontext sc;
target_sigregs sregs;
int signo;
target_sigregs_ext sregs_ext;
} sigframe;
#define TARGET_UC_VXRS 2
struct target_ucontext {
abi_ulong tuc_flags;
abi_ulong tuc_link;
target_stack_t tuc_stack;
target_sigregs tuc_mcontext;
target_sigset_t tuc_sigmask;
uint8_t reserved[128 - sizeof(target_sigset_t)];
target_sigregs_ext tuc_mcontext_ext;
};
typedef struct {
uint8_t callee_used_stack[__SIGNAL_FRAMESIZE];
/*
* This field is no longer initialized by the kernel, but it's still a part
* of the ABI.
*/
uint16_t svc_insn;
struct target_siginfo info;
struct target_ucontext uc;
} rt_sigframe;
static inline abi_ulong
get_sigframe(struct target_sigaction *ka, CPUS390XState *env, size_t frame_size)
{
abi_ulong sp;
/* Default to using normal stack */
sp = get_sp_from_cpustate(env);
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa_flags & TARGET_SA_ONSTACK) {
sp = target_sigsp(sp, ka);
}
/* This is the legacy signal stack switching. */
else if (/* FIXME !user_mode(regs) */ 0 &&
!(ka->sa_flags & TARGET_SA_RESTORER) &&
ka->sa_restorer) {
sp = (abi_ulong) ka->sa_restorer;
}
return (sp - frame_size) & -8ul;
}
#define PSW_USER_BITS (PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | \
PSW_MASK_MCHECK | PSW_MASK_PSTATE | PSW_ASC_PRIMARY)
#define PSW_MASK_USER (PSW_MASK_ASC | PSW_MASK_CC | PSW_MASK_PM | \
PSW_MASK_64 | PSW_MASK_32)
static void save_sigregs(CPUS390XState *env, target_sigregs *sregs)
{
uint64_t psw_mask = s390_cpu_get_psw_mask(env);
int i;
/*
* Copy a 'clean' PSW mask to the user to avoid leaking
* information about whether PER is currently on.
* TODO: qemu does not support PSW_MASK_RI; it will never be set.
*/
psw_mask = PSW_USER_BITS | (psw_mask & PSW_MASK_USER);
__put_user(psw_mask, &sregs->regs.psw.mask);
__put_user(env->psw.addr, &sregs->regs.psw.addr);
for (i = 0; i < 16; i++) {
__put_user(env->regs[i], &sregs->regs.gprs[i]);
}
for (i = 0; i < 16; i++) {
__put_user(env->aregs[i], &sregs->regs.acrs[i]);
}
/*
* We have to store the fp registers to current->thread.fp_regs
* to merge them with the emulated registers.
*/
__put_user(env->fpc, &sregs->fpregs.fpc);
for (i = 0; i < 16; i++) {
__put_user(*get_freg(env, i), &sregs->fpregs.fprs[i]);
}
}
static void save_sigregs_ext(CPUS390XState *env, target_sigregs_ext *ext)
{
int i;
/*
* if (MACHINE_HAS_VX) ...
* That said, we always allocate the stack storage and the
* space is always available in env.
*/
for (i = 0; i < 16; ++i) {
__put_user(env->vregs[i][1], &ext->vxrs_low[i]);
}
for (i = 0; i < 16; ++i) {
__put_user(env->vregs[i + 16][0], &ext->vxrs_high[i][0]);
__put_user(env->vregs[i + 16][1], &ext->vxrs_high[i][1]);
}
}
void setup_frame(int sig, struct target_sigaction *ka,
target_sigset_t *set, CPUS390XState *env)
{
sigframe *frame;
abi_ulong frame_addr;
abi_ulong restorer;
frame_addr = get_sigframe(ka, env, sizeof(*frame));
trace_user_setup_frame(env, frame_addr);
if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
force_sigsegv(sig);
return;
}
/* Set up backchain. */
__put_user(env->regs[15], (abi_ulong *) frame);
/* Create struct sigcontext on the signal stack. */
/* Make sure that we're initializing all of oldmask. */
QEMU_BUILD_BUG_ON(ARRAY_SIZE(frame->sc.oldmask) != 1);
__put_user(set->sig[0], &frame->sc.oldmask[0]);
__put_user(frame_addr + offsetof(sigframe, sregs), &frame->sc.sregs);
/* Create _sigregs on the signal stack */
save_sigregs(env, &frame->sregs);
/*
* ??? The kernel uses regs->gprs[2] here, which is not yet the signo.
* Moreover the comment talks about allowing backtrace, which is really
* done by the r15 copy above.
*/
__put_user(sig, &frame->signo);
/* Create sigregs_ext on the signal stack. */
save_sigregs_ext(env, &frame->sregs_ext);
/*
* Set up to return from userspace.
* If provided, use a stub already in userspace.
*/
if (ka->sa_flags & TARGET_SA_RESTORER) {
restorer = ka->sa_restorer;
} else {
restorer = default_sigreturn;
}
/* Set up registers for signal handler */
env->regs[14] = restorer;
env->regs[15] = frame_addr;
/* Force default amode and default user address space control. */
env->psw.mask = PSW_MASK_64 | PSW_MASK_32 | PSW_ASC_PRIMARY
| (env->psw.mask & ~PSW_MASK_ASC);
env->psw.addr = ka->_sa_handler;
env->regs[2] = sig;
env->regs[3] = frame_addr + offsetof(typeof(*frame), sc);
/*
* We forgot to include these in the sigcontext.
* To avoid breaking binary compatibility, they are passed as args.
*/
env->regs[4] = 0; /* FIXME: regs->int_code & 127 */
env->regs[5] = 0; /* FIXME: regs->int_parm_long */
env->regs[6] = 0; /* FIXME: current->thread.last_break */
unlock_user_struct(frame, frame_addr, 1);
}
void setup_rt_frame(int sig, struct target_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPUS390XState *env)
{
rt_sigframe *frame;
abi_ulong frame_addr;
abi_ulong restorer;
abi_ulong uc_flags;
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)) {
force_sigsegv(sig);
return;
}
/* Set up backchain. */
__put_user(env->regs[15], (abi_ulong *) frame);
/*
* Set up to return from userspace.
* If provided, use a stub already in userspace.
*/
if (ka->sa_flags & TARGET_SA_RESTORER) {
restorer = ka->sa_restorer;
} else {
restorer = default_rt_sigreturn;
}
/* Create siginfo on the signal stack. */
tswap_siginfo(&frame->info, info);
/* Create ucontext on the signal stack. */
uc_flags = 0;
if (s390_has_feat(S390_FEAT_VECTOR)) {
uc_flags |= TARGET_UC_VXRS;
}
__put_user(uc_flags, &frame->uc.tuc_flags);
__put_user(0, &frame->uc.tuc_link);
target_save_altstack(&frame->uc.tuc_stack, env);
save_sigregs(env, &frame->uc.tuc_mcontext);
save_sigregs_ext(env, &frame->uc.tuc_mcontext_ext);
tswap_sigset(&frame->uc.tuc_sigmask, set);
/* Set up registers for signal handler */
env->regs[14] = restorer;
env->regs[15] = frame_addr;
/* Force default amode and default user address space control. */
env->psw.mask = PSW_MASK_64 | PSW_MASK_32 | PSW_ASC_PRIMARY
| (env->psw.mask & ~PSW_MASK_ASC);
env->psw.addr = ka->_sa_handler;
env->regs[2] = sig;
env->regs[3] = frame_addr + offsetof(typeof(*frame), info);
env->regs[4] = frame_addr + offsetof(typeof(*frame), uc);
env->regs[5] = 0; /* FIXME: current->thread.last_break */
}
static void restore_sigregs(CPUS390XState *env, target_sigregs *sc)
{
uint64_t prev_addr, prev_mask, mask, addr;
int i;
for (i = 0; i < 16; i++) {
__get_user(env->regs[i], &sc->regs.gprs[i]);
}
prev_addr = env->psw.addr;
__get_user(mask, &sc->regs.psw.mask);
__get_user(addr, &sc->regs.psw.addr);
trace_user_s390x_restore_sigregs(env, addr, prev_addr);
/*
* Use current psw.mask to preserve PER bit.
* TODO:
* if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW_MASK_RI))
* return -EINVAL;
* Simply do not allow it to be set in mask.
*/
prev_mask = s390_cpu_get_psw_mask(env);
mask = (prev_mask & ~PSW_MASK_USER) | (mask & PSW_MASK_USER);
/* Check for invalid user address space control. */
if ((mask & PSW_MASK_ASC) == PSW_ASC_HOME) {
mask = (mask & ~PSW_MASK_ASC) | PSW_ASC_PRIMARY;
}
/* Check for invalid amode. */
if (mask & PSW_MASK_64) {
mask |= PSW_MASK_32;
}
s390_cpu_set_psw(env, mask, addr);
for (i = 0; i < 16; i++) {
__get_user(env->aregs[i], &sc->regs.acrs[i]);
}
__get_user(env->fpc, &sc->fpregs.fpc);
for (i = 0; i < 16; i++) {
__get_user(*get_freg(env, i), &sc->fpregs.fprs[i]);
}
}
static void restore_sigregs_ext(CPUS390XState *env, target_sigregs_ext *ext)
{
int i;
/*
* if (MACHINE_HAS_VX) ...
* That said, we always allocate the stack storage and the
* space is always available in env.
*/
for (i = 0; i < 16; ++i) {
__get_user(env->vregs[i][1], &ext->vxrs_low[i]);
}
for (i = 0; i < 16; ++i) {
__get_user(env->vregs[i + 16][0], &ext->vxrs_high[i][0]);
__get_user(env->vregs[i + 16][1], &ext->vxrs_high[i][1]);
}
}
long do_sigreturn(CPUS390XState *env)
{
sigframe *frame;
abi_ulong frame_addr = env->regs[15];
target_sigset_t target_set;
sigset_t set;
trace_user_do_sigreturn(env, frame_addr);
if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
force_sig(TARGET_SIGSEGV);
return -QEMU_ESIGRETURN;
}
/* Make sure that we're initializing all of target_set. */
QEMU_BUILD_BUG_ON(ARRAY_SIZE(target_set.sig) != 1);
__get_user(target_set.sig[0], &frame->sc.oldmask[0]);
target_to_host_sigset_internal(&set, &target_set);
set_sigmask(&set); /* ~_BLOCKABLE? */
restore_sigregs(env, &frame->sregs);
restore_sigregs_ext(env, &frame->sregs_ext);
unlock_user_struct(frame, frame_addr, 0);
return -QEMU_ESIGRETURN;
}
long do_rt_sigreturn(CPUS390XState *env)
{
rt_sigframe *frame;
abi_ulong frame_addr = env->regs[15];
sigset_t set;
trace_user_do_rt_sigreturn(env, frame_addr);
if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
force_sig(TARGET_SIGSEGV);
return -QEMU_ESIGRETURN;
}
target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
set_sigmask(&set); /* ~_BLOCKABLE? */
restore_sigregs(env, &frame->uc.tuc_mcontext);
restore_sigregs_ext(env, &frame->uc.tuc_mcontext_ext);
target_restore_altstack(&frame->uc.tuc_stack, env);
unlock_user_struct(frame, frame_addr, 0);
return -QEMU_ESIGRETURN;
}
void setup_sigtramp(abi_ulong sigtramp_page)
{
uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 + 2, 0);
assert(tramp != NULL);
default_sigreturn = sigtramp_page;
__put_user(S390_SYSCALL_OPCODE | TARGET_NR_sigreturn, &tramp[0]);
default_rt_sigreturn = sigtramp_page + 2;
__put_user(S390_SYSCALL_OPCODE | TARGET_NR_rt_sigreturn, &tramp[1]);
unlock_user(tramp, sigtramp_page, 2 + 2);
}
