alistair23-linux/arch/s390/kernel/compat_signal.c
Heiko Carstens a53c8fab3f s390/comments: unify copyright messages and remove file names
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-07-20 11:15:04 +02:00

585 lines
17 KiB
C

/*
* Copyright IBM Corp. 2000, 2006
* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
* Gerhard Tonn (ton@de.ibm.com)
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
*/
#include <linux/compat.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/tty.h>
#include <linux/personality.h>
#include <linux/binfmts.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/lowcore.h>
#include <asm/switch_to.h>
#include "compat_linux.h"
#include "compat_ptrace.h"
#include "entry.h"
typedef struct
{
__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
struct sigcontext32 sc;
_sigregs32 sregs;
int signo;
__u32 gprs_high[NUM_GPRS];
__u8 retcode[S390_SYSCALL_SIZE];
} sigframe32;
typedef struct
{
__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
__u8 retcode[S390_SYSCALL_SIZE];
compat_siginfo_t info;
struct ucontext32 uc;
__u32 gprs_high[NUM_GPRS];
} rt_sigframe32;
int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
{
int err;
if (!access_ok (VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
return -EFAULT;
/* If you change siginfo_t structure, please be sure
this code is fixed accordingly.
It should never copy any pad contained in the structure
to avoid security leaks, but must copy the generic
3 ints plus the relevant union member.
This routine must convert siginfo from 64bit to 32bit as well
at the same time. */
err = __put_user(from->si_signo, &to->si_signo);
err |= __put_user(from->si_errno, &to->si_errno);
err |= __put_user((short)from->si_code, &to->si_code);
if (from->si_code < 0)
err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
else {
switch (from->si_code >> 16) {
case __SI_RT >> 16: /* This is not generated by the kernel as of now. */
case __SI_MESGQ >> 16:
err |= __put_user(from->si_int, &to->si_int);
/* fallthrough */
case __SI_KILL >> 16:
err |= __put_user(from->si_pid, &to->si_pid);
err |= __put_user(from->si_uid, &to->si_uid);
break;
case __SI_CHLD >> 16:
err |= __put_user(from->si_pid, &to->si_pid);
err |= __put_user(from->si_uid, &to->si_uid);
err |= __put_user(from->si_utime, &to->si_utime);
err |= __put_user(from->si_stime, &to->si_stime);
err |= __put_user(from->si_status, &to->si_status);
break;
case __SI_FAULT >> 16:
err |= __put_user((unsigned long) from->si_addr,
&to->si_addr);
break;
case __SI_POLL >> 16:
err |= __put_user(from->si_band, &to->si_band);
err |= __put_user(from->si_fd, &to->si_fd);
break;
case __SI_TIMER >> 16:
err |= __put_user(from->si_tid, &to->si_tid);
err |= __put_user(from->si_overrun, &to->si_overrun);
err |= __put_user(from->si_int, &to->si_int);
break;
default:
break;
}
}
return err;
}
int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
{
int err;
u32 tmp;
if (!access_ok (VERIFY_READ, from, sizeof(compat_siginfo_t)))
return -EFAULT;
err = __get_user(to->si_signo, &from->si_signo);
err |= __get_user(to->si_errno, &from->si_errno);
err |= __get_user(to->si_code, &from->si_code);
if (to->si_code < 0)
err |= __copy_from_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
else {
switch (to->si_code >> 16) {
case __SI_RT >> 16: /* This is not generated by the kernel as of now. */
case __SI_MESGQ >> 16:
err |= __get_user(to->si_int, &from->si_int);
/* fallthrough */
case __SI_KILL >> 16:
err |= __get_user(to->si_pid, &from->si_pid);
err |= __get_user(to->si_uid, &from->si_uid);
break;
case __SI_CHLD >> 16:
err |= __get_user(to->si_pid, &from->si_pid);
err |= __get_user(to->si_uid, &from->si_uid);
err |= __get_user(to->si_utime, &from->si_utime);
err |= __get_user(to->si_stime, &from->si_stime);
err |= __get_user(to->si_status, &from->si_status);
break;
case __SI_FAULT >> 16:
err |= __get_user(tmp, &from->si_addr);
to->si_addr = (void __force __user *)
(u64) (tmp & PSW32_ADDR_INSN);
break;
case __SI_POLL >> 16:
err |= __get_user(to->si_band, &from->si_band);
err |= __get_user(to->si_fd, &from->si_fd);
break;
case __SI_TIMER >> 16:
err |= __get_user(to->si_tid, &from->si_tid);
err |= __get_user(to->si_overrun, &from->si_overrun);
err |= __get_user(to->si_int, &from->si_int);
break;
default:
break;
}
}
return err;
}
asmlinkage long
sys32_sigaction(int sig, const struct old_sigaction32 __user *act,
struct old_sigaction32 __user *oact)
{
struct k_sigaction new_ka, old_ka;
unsigned long sa_handler, sa_restorer;
int ret;
if (act) {
compat_old_sigset_t mask;
if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
__get_user(sa_handler, &act->sa_handler) ||
__get_user(sa_restorer, &act->sa_restorer) ||
__get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
__get_user(mask, &act->sa_mask))
return -EFAULT;
new_ka.sa.sa_handler = (__sighandler_t) sa_handler;
new_ka.sa.sa_restorer = (void (*)(void)) sa_restorer;
siginitset(&new_ka.sa.sa_mask, mask);
}
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
if (!ret && oact) {
sa_handler = (unsigned long) old_ka.sa.sa_handler;
sa_restorer = (unsigned long) old_ka.sa.sa_restorer;
if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
__put_user(sa_handler, &oact->sa_handler) ||
__put_user(sa_restorer, &oact->sa_restorer) ||
__put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
return -EFAULT;
}
return ret;
}
asmlinkage long
sys32_rt_sigaction(int sig, const struct sigaction32 __user *act,
struct sigaction32 __user *oact, size_t sigsetsize)
{
struct k_sigaction new_ka, old_ka;
unsigned long sa_handler;
int ret;
compat_sigset_t set32;
/* XXX: Don't preclude handling different sized sigset_t's. */
if (sigsetsize != sizeof(compat_sigset_t))
return -EINVAL;
if (act) {
ret = get_user(sa_handler, &act->sa_handler);
ret |= __copy_from_user(&set32, &act->sa_mask,
sizeof(compat_sigset_t));
new_ka.sa.sa_mask.sig[0] =
set32.sig[0] | (((long)set32.sig[1]) << 32);
ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
if (ret)
return -EFAULT;
new_ka.sa.sa_handler = (__sighandler_t) sa_handler;
}
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
if (!ret && oact) {
set32.sig[1] = (old_ka.sa.sa_mask.sig[0] >> 32);
set32.sig[0] = old_ka.sa.sa_mask.sig[0];
ret = put_user((unsigned long)old_ka.sa.sa_handler, &oact->sa_handler);
ret |= __copy_to_user(&oact->sa_mask, &set32,
sizeof(compat_sigset_t));
ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
}
return ret;
}
asmlinkage long
sys32_sigaltstack(const stack_t32 __user *uss, stack_t32 __user *uoss)
{
struct pt_regs *regs = task_pt_regs(current);
stack_t kss, koss;
unsigned long ss_sp;
int ret, err = 0;
mm_segment_t old_fs = get_fs();
if (uss) {
if (!access_ok(VERIFY_READ, uss, sizeof(*uss)))
return -EFAULT;
err |= __get_user(ss_sp, &uss->ss_sp);
err |= __get_user(kss.ss_size, &uss->ss_size);
err |= __get_user(kss.ss_flags, &uss->ss_flags);
if (err)
return -EFAULT;
kss.ss_sp = (void __user *) ss_sp;
}
set_fs (KERNEL_DS);
ret = do_sigaltstack((stack_t __force __user *) (uss ? &kss : NULL),
(stack_t __force __user *) (uoss ? &koss : NULL),
regs->gprs[15]);
set_fs (old_fs);
if (!ret && uoss) {
if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss)))
return -EFAULT;
ss_sp = (unsigned long) koss.ss_sp;
err |= __put_user(ss_sp, &uoss->ss_sp);
err |= __put_user(koss.ss_size, &uoss->ss_size);
err |= __put_user(koss.ss_flags, &uoss->ss_flags);
if (err)
return -EFAULT;
}
return ret;
}
static int save_sigregs32(struct pt_regs *regs, _sigregs32 __user *sregs)
{
_s390_regs_common32 regs32;
int err, i;
regs32.psw.mask = psw32_user_bits |
((__u32)(regs->psw.mask >> 32) & PSW32_MASK_USER);
regs32.psw.addr = (__u32) regs->psw.addr |
(__u32)(regs->psw.mask & PSW_MASK_BA);
for (i = 0; i < NUM_GPRS; i++)
regs32.gprs[i] = (__u32) regs->gprs[i];
save_access_regs(current->thread.acrs);
memcpy(regs32.acrs, current->thread.acrs, sizeof(regs32.acrs));
err = __copy_to_user(&sregs->regs, &regs32, sizeof(regs32));
if (err)
return err;
save_fp_regs(&current->thread.fp_regs);
/* s390_fp_regs and _s390_fp_regs32 are the same ! */
return __copy_to_user(&sregs->fpregs, &current->thread.fp_regs,
sizeof(_s390_fp_regs32));
}
static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
{
_s390_regs_common32 regs32;
int err, i;
/* Alwys make any pending restarted system call return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
err = __copy_from_user(&regs32, &sregs->regs, sizeof(regs32));
if (err)
return err;
regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
(__u64)(regs32.psw.mask & PSW32_MASK_USER) << 32 |
(__u64)(regs32.psw.addr & PSW32_ADDR_AMODE);
regs->psw.addr = (__u64)(regs32.psw.addr & PSW32_ADDR_INSN);
for (i = 0; i < NUM_GPRS; i++)
regs->gprs[i] = (__u64) regs32.gprs[i];
memcpy(current->thread.acrs, regs32.acrs, sizeof(current->thread.acrs));
restore_access_regs(current->thread.acrs);
err = __copy_from_user(&current->thread.fp_regs, &sregs->fpregs,
sizeof(_s390_fp_regs32));
current->thread.fp_regs.fpc &= FPC_VALID_MASK;
if (err)
return err;
restore_fp_regs(&current->thread.fp_regs);
clear_thread_flag(TIF_SYSCALL); /* No longer in a system call */
return 0;
}
static int save_sigregs_gprs_high(struct pt_regs *regs, __u32 __user *uregs)
{
__u32 gprs_high[NUM_GPRS];
int i;
for (i = 0; i < NUM_GPRS; i++)
gprs_high[i] = regs->gprs[i] >> 32;
return __copy_to_user(uregs, &gprs_high, sizeof(gprs_high));
}
static int restore_sigregs_gprs_high(struct pt_regs *regs, __u32 __user *uregs)
{
__u32 gprs_high[NUM_GPRS];
int err, i;
err = __copy_from_user(&gprs_high, uregs, sizeof(gprs_high));
if (err)
return err;
for (i = 0; i < NUM_GPRS; i++)
*(__u32 *)&regs->gprs[i] = gprs_high[i];
return 0;
}
asmlinkage long sys32_sigreturn(void)
{
struct pt_regs *regs = task_pt_regs(current);
sigframe32 __user *frame = (sigframe32 __user *)regs->gprs[15];
sigset_t set;
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE32))
goto badframe;
set_current_blocked(&set);
if (restore_sigregs32(regs, &frame->sregs))
goto badframe;
if (restore_sigregs_gprs_high(regs, frame->gprs_high))
goto badframe;
return regs->gprs[2];
badframe:
force_sig(SIGSEGV, current);
return 0;
}
asmlinkage long sys32_rt_sigreturn(void)
{
struct pt_regs *regs = task_pt_regs(current);
rt_sigframe32 __user *frame = (rt_sigframe32 __user *)regs->gprs[15];
sigset_t set;
stack_t st;
__u32 ss_sp;
int err;
mm_segment_t old_fs = get_fs();
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
set_current_blocked(&set);
if (restore_sigregs32(regs, &frame->uc.uc_mcontext))
goto badframe;
if (restore_sigregs_gprs_high(regs, frame->gprs_high))
goto badframe;
err = __get_user(ss_sp, &frame->uc.uc_stack.ss_sp);
st.ss_sp = compat_ptr(ss_sp);
err |= __get_user(st.ss_size, &frame->uc.uc_stack.ss_size);
err |= __get_user(st.ss_flags, &frame->uc.uc_stack.ss_flags);
if (err)
goto badframe;
set_fs (KERNEL_DS);
do_sigaltstack((stack_t __force __user *)&st, NULL, regs->gprs[15]);
set_fs (old_fs);
return regs->gprs[2];
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* Set up a signal frame.
*/
/*
* Determine which stack to use..
*/
static inline void __user *
get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
{
unsigned long sp;
/* Default to using normal stack */
sp = (unsigned long) A(regs->gprs[15]);
/* Overflow on alternate signal stack gives SIGSEGV. */
if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
return (void __user *) -1UL;
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa.sa_flags & SA_ONSTACK) {
if (! sas_ss_flags(sp))
sp = current->sas_ss_sp + current->sas_ss_size;
}
return (void __user *)((sp - frame_size) & -8ul);
}
static inline int map_signal(int sig)
{
if (current_thread_info()->exec_domain
&& current_thread_info()->exec_domain->signal_invmap
&& sig < 32)
return current_thread_info()->exec_domain->signal_invmap[sig];
else
return sig;
}
static int setup_frame32(int sig, struct k_sigaction *ka,
sigset_t *set, struct pt_regs * regs)
{
sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(sigframe32));
if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe32)))
goto give_sigsegv;
if (frame == (void __user *) -1UL)
goto give_sigsegv;
if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE32))
goto give_sigsegv;
if (save_sigregs32(regs, &frame->sregs))
goto give_sigsegv;
if (save_sigregs_gprs_high(regs, frame->gprs_high))
goto give_sigsegv;
if (__put_user((unsigned long) &frame->sregs, &frame->sc.sregs))
goto give_sigsegv;
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa.sa_flags & SA_RESTORER) {
regs->gprs[14] = (__u64) ka->sa.sa_restorer | PSW32_ADDR_AMODE;
} else {
regs->gprs[14] = (__u64) frame->retcode | PSW32_ADDR_AMODE;
if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
(u16 __force __user *)(frame->retcode)))
goto give_sigsegv;
}
/* Set up backchain. */
if (__put_user(regs->gprs[15], (unsigned int __user *) frame))
goto give_sigsegv;
/* Set up registers for signal handler */
regs->gprs[15] = (__force __u64) frame;
regs->psw.mask |= PSW_MASK_BA; /* force amode 31 */
regs->psw.addr = (__force __u64) ka->sa.sa_handler;
regs->gprs[2] = map_signal(sig);
regs->gprs[3] = (__force __u64) &frame->sc;
/* We forgot to include these in the sigcontext.
To avoid breaking binary compatibility, they are passed as args. */
if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
sig == SIGTRAP || sig == SIGFPE) {
/* set extra registers only for synchronous signals */
regs->gprs[4] = regs->int_code & 127;
regs->gprs[5] = regs->int_parm_long;
}
/* Place signal number on stack to allow backtrace from handler. */
if (__put_user(regs->gprs[2], (int __force __user *) &frame->signo))
goto give_sigsegv;
return 0;
give_sigsegv:
force_sigsegv(sig, current);
return -EFAULT;
}
static int setup_rt_frame32(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs * regs)
{
int err = 0;
rt_sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(rt_sigframe32));
if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe32)))
goto give_sigsegv;
if (frame == (void __user *) -1UL)
goto give_sigsegv;
if (copy_siginfo_to_user32(&frame->info, info))
goto give_sigsegv;
/* Create the ucontext. */
err |= __put_user(UC_EXTENDED, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
err |= __put_user(sas_ss_flags(regs->gprs[15]),
&frame->uc.uc_stack.ss_flags);
err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
err |= save_sigregs32(regs, &frame->uc.uc_mcontext);
err |= save_sigregs_gprs_high(regs, frame->gprs_high);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
goto give_sigsegv;
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa.sa_flags & SA_RESTORER) {
regs->gprs[14] = (__u64) ka->sa.sa_restorer | PSW32_ADDR_AMODE;
} else {
regs->gprs[14] = (__u64) frame->retcode | PSW32_ADDR_AMODE;
err |= __put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
(u16 __force __user *)(frame->retcode));
}
/* Set up backchain. */
if (__put_user(regs->gprs[15], (unsigned int __force __user *) frame))
goto give_sigsegv;
/* Set up registers for signal handler */
regs->gprs[15] = (__force __u64) frame;
regs->psw.mask |= PSW_MASK_BA; /* force amode 31 */
regs->psw.addr = (__u64) ka->sa.sa_handler;
regs->gprs[2] = map_signal(sig);
regs->gprs[3] = (__force __u64) &frame->info;
regs->gprs[4] = (__force __u64) &frame->uc;
return 0;
give_sigsegv:
force_sigsegv(sig, current);
return -EFAULT;
}
/*
* OK, we're invoking a handler
*/
void handle_signal32(unsigned long sig, struct k_sigaction *ka,
siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
{
int ret;
/* Set up the stack frame */
if (ka->sa.sa_flags & SA_SIGINFO)
ret = setup_rt_frame32(sig, ka, info, oldset, regs);
else
ret = setup_frame32(sig, ka, oldset, regs);
if (ret)
return;
signal_delivered(sig, info, ka, regs,
test_thread_flag(TIF_SINGLE_STEP));
}