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linux-next/arch/s390/kernel/compat_signal.c
Martin Schwidefsky 3c52e49d7c [S390] sparse: fix sparse warnings with __user pointers 
Use __force to quiet sparse warnings about user address space.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30 15:16:46 +01:00

597 lines
17 KiB
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/*
* arch/s390/kernel/compat_signal.c
*
* Copyright (C) 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 "compat_linux.h"
#include "compat_ptrace.h"
#include "entry.h"
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
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;
sigdelsetmask(&set, ~_BLOCKABLE);
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;
sigdelsetmask(&set, ~_BLOCKABLE);
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;
}
/* This is the legacy signal stack switching. */
else if (!user_mode(regs) &&
!(ka->sa.sa_flags & SA_RESTORER) &&
ka->sa.sa_restorer) {
sp = (unsigned long) ka->sa.sa_restorer;
}
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. */
regs->gprs[4] = current->thread.trap_no;
regs->gprs[5] = current->thread.prot_addr;
/* 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;
} else {
regs->gprs[14] = (__u64) frame->retcode;
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
*/
int handle_signal32(unsigned long sig, struct k_sigaction *ka,
siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
{
sigset_t blocked;
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 ret;
sigorsets(&blocked, &current->blocked, &ka->sa.sa_mask);
if (!(ka->sa.sa_flags & SA_NODEFER))
sigaddset(&blocked, sig);
set_current_blocked(&blocked);
return 0;
}
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