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kernel-fxtec-pro1x/arch/s390/kernel/compat_signal.c
Heiko Carstens d12a297038 s390/uaccess: remove pointless access_ok() checks 
access_ok() always returns 'true' on s390. Therefore all calls
are quite pointless and can be removed.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-02-28 09:37:09 +01:00

450 lines
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/*
* 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 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;
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;
}
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);
/* Check for invalid user address space control. */
if ((regs->psw.mask & PSW_MASK_ASC) >= (psw_kernel_bits & PSW_MASK_ASC))
regs->psw.mask = (psw_user_bits & PSW_MASK_ASC) |
(regs->psw.mask & ~PSW_MASK_ASC);
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 (__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;
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;
if (compat_restore_altstack(&frame->uc.uc_stack))
goto badframe;
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 (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;
/* Force 31 bit amode and default user address space control. */
regs->psw.mask = PSW_MASK_BA |
(psw_user_bits & PSW_MASK_ASC) |
(regs->psw.mask & ~PSW_MASK_ASC);
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 (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 |= __compat_save_altstack(&frame->uc.uc_stack, regs->gprs[15]);
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;
/* Force 31 bit amode and default user address space control. */
regs->psw.mask = PSW_MASK_BA |
(psw_user_bits & PSW_MASK_ASC) |
(regs->psw.mask & ~PSW_MASK_ASC);
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));
}
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