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linux-stable-rt/arch/ppc64/kernel/signal32.c

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/*
* signal32.c: Support 32bit signal syscalls.
*
* Copyright (C) 2001 IBM
* Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
* Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
*
* These routines maintain argument size conversion between 32bit and 64bit
* environment.
*
* 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.
*/
#include <linux/config.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/syscalls.h>
#include <linux/errno.h>
#include <linux/elf.h>
#include <linux/compat.h>
#include <linux/ptrace.h>
#include <asm/ppc32.h>
#include <asm/uaccess.h>
#include <asm/ppcdebug.h>
#include <asm/unistd.h>
#include <asm/cacheflush.h>
#include <asm/vdso.h>
#define DEBUG_SIG 0
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
#define GP_REGS_SIZE32 min(sizeof(elf_gregset_t32), sizeof(struct pt_regs32))
/*
* When we have signals to deliver, we set up on the
* user stack, going down from the original stack pointer:
* a sigregs32 struct
* a sigcontext32 struct
* a gap of __SIGNAL_FRAMESIZE32 bytes
*
* Each of these things must be a multiple of 16 bytes in size.
*
*/
struct sigregs32 {
struct mcontext32 mctx; /* all the register values */
/*
* Programs using the rs6000/xcoff abi can save up to 19 gp
* regs and 18 fp regs below sp before decrementing it.
*/
int abigap[56];
};
/* We use the mc_pad field for the signal return trampoline. */
#define tramp mc_pad
/*
* When we have rt signals to deliver, we set up on the
* user stack, going down from the original stack pointer:
* one rt_sigframe32 struct (siginfo + ucontext + ABI gap)
* a gap of __SIGNAL_FRAMESIZE32+16 bytes
* (the +16 is to get the siginfo and ucontext32 in the same
* positions as in older kernels).
*
* Each of these things must be a multiple of 16 bytes in size.
*
*/
struct rt_sigframe32 {
compat_siginfo_t info;
struct ucontext32 uc;
/*
* Programs using the rs6000/xcoff abi can save up to 19 gp
* regs and 18 fp regs below sp before decrementing it.
*/
int abigap[56];
};
/*
* Common utility functions used by signal and context support
*
*/
/*
* Restore the user process's signal mask
* (implemented in signal.c)
*/
extern void restore_sigmask(sigset_t *set);
/*
* Functions for flipping sigsets (thanks to brain dead generic
* implementation that makes things simple for little endian only
*/
static inline void compat_from_sigset(compat_sigset_t *compat, sigset_t *set)
{
switch (_NSIG_WORDS) {
case 4: compat->sig[5] = set->sig[3] & 0xffffffffull ;
compat->sig[7] = set->sig[3] >> 32;
case 3: compat->sig[4] = set->sig[2] & 0xffffffffull ;
compat->sig[5] = set->sig[2] >> 32;
case 2: compat->sig[2] = set->sig[1] & 0xffffffffull ;
compat->sig[3] = set->sig[1] >> 32;
case 1: compat->sig[0] = set->sig[0] & 0xffffffffull ;
compat->sig[1] = set->sig[0] >> 32;
}
}
static inline void sigset_from_compat(sigset_t *set, compat_sigset_t *compat)
{
switch (_NSIG_WORDS) {
case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32);
case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32);
case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32);
case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32);
}
}
/*
* Save the current user registers on the user stack.
* We only save the altivec registers if the process has used
* altivec instructions at some point.
*/
static int save_user_regs(struct pt_regs *regs, struct mcontext32 __user *frame, int sigret)
{
elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
int i, err = 0;
/* Make sure floating point registers are stored in regs */
flush_fp_to_thread(current);
/* save general and floating-point registers */
for (i = 0; i <= PT_RESULT; i ++)
err |= __put_user((unsigned int)gregs[i], &frame->mc_gregs[i]);
err |= __copy_to_user(&frame->mc_fregs, current->thread.fpr,
ELF_NFPREG * sizeof(double));
if (err)
return 1;
current->thread.fpscr = 0; /* turn off all fp exceptions */
#ifdef CONFIG_ALTIVEC
/* save altivec registers */
if (current->thread.used_vr) {
flush_altivec_to_thread(current);
if (__copy_to_user(&frame->mc_vregs, current->thread.vr,
ELF_NVRREG32 * sizeof(vector128)))
return 1;
/* set MSR_VEC in the saved MSR value to indicate that
frame->mc_vregs contains valid data */
if (__put_user(regs->msr | MSR_VEC, &frame->mc_gregs[PT_MSR]))
return 1;
}
/* else assert((regs->msr & MSR_VEC) == 0) */
/* We always copy to/from vrsave, it's 0 if we don't have or don't
* use altivec. Since VSCR only contains 32 bits saved in the least
* significant bits of a vector, we "cheat" and stuff VRSAVE in the
* most significant bits of that same vector. --BenH
*/
if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32]))
return 1;
#endif /* CONFIG_ALTIVEC */
if (sigret) {
/* Set up the sigreturn trampoline: li r0,sigret; sc */
if (__put_user(0x38000000UL + sigret, &frame->tramp[0])
|| __put_user(0x44000002UL, &frame->tramp[1]))
return 1;
flush_icache_range((unsigned long) &frame->tramp[0],
(unsigned long) &frame->tramp[2]);
}
return 0;
}
/*
* Restore the current user register values from the user stack,
* (except for MSR).
*/
static long restore_user_regs(struct pt_regs *regs,
struct mcontext32 __user *sr, int sig)
{
elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
int i;
long err = 0;
unsigned int save_r2 = 0;
#ifdef CONFIG_ALTIVEC
unsigned long msr;
#endif
/*
* restore general registers but not including MSR or SOFTE. Also
* take care of keeping r2 (TLS) intact if not a signal
*/
if (!sig)
save_r2 = (unsigned int)regs->gpr[2];
for (i = 0; i <= PT_RESULT; i++) {
if ((i == PT_MSR) || (i == PT_SOFTE))
continue;
err |= __get_user(gregs[i], &sr->mc_gregs[i]);
}
if (!sig)
regs->gpr[2] = (unsigned long) save_r2;
if (err)
return 1;
/* force the process to reload the FP registers from
current->thread when it next does FP instructions */
regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1);
if (__copy_from_user(current->thread.fpr, &sr->mc_fregs,
sizeof(sr->mc_fregs)))
return 1;
#ifdef CONFIG_ALTIVEC
/* force the process to reload the altivec registers from
current->thread when it next does altivec instructions */
regs->msr &= ~MSR_VEC;
if (!__get_user(msr, &sr->mc_gregs[PT_MSR]) && (msr & MSR_VEC) != 0) {
/* restore altivec registers from the stack */
if (__copy_from_user(current->thread.vr, &sr->mc_vregs,
sizeof(sr->mc_vregs)))
return 1;
} else if (current->thread.used_vr)
memset(current->thread.vr, 0, ELF_NVRREG32 * sizeof(vector128));
/* Always get VRSAVE back */
if (__get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32]))
return 1;
#endif /* CONFIG_ALTIVEC */
#ifndef CONFIG_SMP
preempt_disable();
if (last_task_used_math == current)
last_task_used_math = NULL;
if (last_task_used_altivec == current)
last_task_used_altivec = NULL;
preempt_enable();
#endif
return 0;
}
/*
* Start of nonRT signal support
*
* sigset_t is 32 bits for non-rt signals
*
* System Calls
* sigaction sys32_sigaction
* sigreturn sys32_sigreturn
*
* Note sigsuspend has no special 32 bit routine - uses the 64 bit routine
*
* Other routines
* setup_frame32
*/
/*
* Atomically swap in the new signal mask, and wait for a signal.
*/
long sys32_sigsuspend(old_sigset_t mask, int p2, int p3, int p4, int p6, int p7,
struct pt_regs *regs)
{
sigset_t saveset;
mask &= _BLOCKABLE;
spin_lock_irq(&current->sighand->siglock);
saveset = current->blocked;
siginitset(&current->blocked, mask);
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
regs->result = -EINTR;
regs->gpr[3] = EINTR;
regs->ccr |= 0x10000000;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal32(&saveset, regs))
/*
* Returning 0 means we return to userspace via
* ret_from_except and thus restore all user
* registers from *regs. This is what we need
* to do when a signal has been delivered.
*/
return 0;
}
}
long sys32_sigaction(int sig, struct old_sigaction32 __user *act,
struct old_sigaction32 __user *oact)
{
struct k_sigaction new_ka, old_ka;
int ret;
if (sig < 0)
sig = -sig;
if (act) {
compat_old_sigset_t mask;
compat_uptr_t handler, restorer;
if (get_user(handler, &act->sa_handler) ||
__get_user(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 = compat_ptr(handler);
new_ka.sa.sa_restorer = compat_ptr(restorer);
siginitset(&new_ka.sa.sa_mask, mask);
}
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
if (!ret && oact) {
if (put_user((long)old_ka.sa.sa_handler, &oact->sa_handler) ||
__put_user((long)old_ka.sa.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;
}
/*
* Start of RT signal support
*
* sigset_t is 64 bits for rt signals
*
* System Calls
* sigaction sys32_rt_sigaction
* sigpending sys32_rt_sigpending
* sigprocmask sys32_rt_sigprocmask
* sigreturn sys32_rt_sigreturn
* sigqueueinfo sys32_rt_sigqueueinfo
* sigsuspend sys32_rt_sigsuspend
*
* Other routines
* setup_rt_frame32
* copy_siginfo_to_user32
* siginfo32to64
*/
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;
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) {
compat_uptr_t handler;
ret = get_user(handler, &act->sa_handler);
new_ka.sa.sa_handler = compat_ptr(handler);
ret |= __copy_from_user(&set32, &act->sa_mask,
sizeof(compat_sigset_t));
sigset_from_compat(&new_ka.sa.sa_mask, &set32);
ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
if (ret)
return -EFAULT;
}
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
if (!ret && oact) {
compat_from_sigset(&set32, &old_ka.sa.sa_mask);
ret = put_user((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;
}
/*
* Note: it is necessary to treat how as an unsigned int, with the
* corresponding cast to a signed int to insure that the proper
* conversion (sign extension) between the register representation
* of a signed int (msr in 32-bit mode) and the register representation
* of a signed int (msr in 64-bit mode) is performed.
*/
long sys32_rt_sigprocmask(u32 how, compat_sigset_t __user *set,
compat_sigset_t __user *oset, size_t sigsetsize)
{
sigset_t s;
sigset_t __user *up;
compat_sigset_t s32;
int ret;
mm_segment_t old_fs = get_fs();
if (set) {
if (copy_from_user (&s32, set, sizeof(compat_sigset_t)))
return -EFAULT;
sigset_from_compat(&s, &s32);
}
set_fs(KERNEL_DS);
/* This is valid because of the set_fs() */
up = (sigset_t __user *) &s;
ret = sys_rt_sigprocmask((int)how, set ? up : NULL, oset ? up : NULL,
sigsetsize);
set_fs(old_fs);
if (ret)
return ret;
if (oset) {
compat_from_sigset(&s32, &s);
if (copy_to_user (oset, &s32, sizeof(compat_sigset_t)))
return -EFAULT;
}
return 0;
}
long sys32_rt_sigpending(compat_sigset_t __user *set, compat_size_t sigsetsize)
{
sigset_t s;
compat_sigset_t s32;
int ret;
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
/* The __user pointer cast is valid because of the set_fs() */
ret = sys_rt_sigpending((sigset_t __user *) &s, sigsetsize);
set_fs(old_fs);
if (!ret) {
compat_from_sigset(&s32, &s);
if (copy_to_user (set, &s32, sizeof(compat_sigset_t)))
return -EFAULT;
}
return ret;
}
int copy_siginfo_to_user32(struct compat_siginfo __user *d, siginfo_t *s)
{
int err;
if (!access_ok (VERIFY_WRITE, d, sizeof(*d)))
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(s->si_signo, &d->si_signo);
err |= __put_user(s->si_errno, &d->si_errno);
err |= __put_user((short)s->si_code, &d->si_code);
if (s->si_code < 0)
err |= __copy_to_user(&d->_sifields._pad, &s->_sifields._pad,
SI_PAD_SIZE32);
else switch(s->si_code >> 16) {
case __SI_CHLD >> 16:
err |= __put_user(s->si_pid, &d->si_pid);
err |= __put_user(s->si_uid, &d->si_uid);
err |= __put_user(s->si_utime, &d->si_utime);
err |= __put_user(s->si_stime, &d->si_stime);
err |= __put_user(s->si_status, &d->si_status);
break;
case __SI_FAULT >> 16:
err |= __put_user((unsigned int)(unsigned long)s->si_addr,
&d->si_addr);
break;
case __SI_POLL >> 16:
err |= __put_user(s->si_band, &d->si_band);
err |= __put_user(s->si_fd, &d->si_fd);
break;
case __SI_TIMER >> 16:
err |= __put_user(s->si_tid, &d->si_tid);
err |= __put_user(s->si_overrun, &d->si_overrun);
err |= __put_user(s->si_int, &d->si_int);
break;
case __SI_RT >> 16: /* This is not generated by the kernel as of now. */
case __SI_MESGQ >> 16:
err |= __put_user(s->si_int, &d->si_int);
/* fallthrough */
case __SI_KILL >> 16:
default:
err |= __put_user(s->si_pid, &d->si_pid);
err |= __put_user(s->si_uid, &d->si_uid);
break;
}
return err;
}
/*
* Note: it is necessary to treat pid and sig as unsigned ints, with the
* corresponding cast to a signed int to insure that the proper conversion
* (sign extension) between the register representation of a signed int
* (msr in 32-bit mode) and the register representation of a signed int
* (msr in 64-bit mode) is performed.
*/
long sys32_rt_sigqueueinfo(u32 pid, u32 sig, compat_siginfo_t __user *uinfo)
{
siginfo_t info;
int ret;
mm_segment_t old_fs = get_fs();
if (copy_from_user (&info, uinfo, 3*sizeof(int)) ||
copy_from_user (info._sifields._pad, uinfo->_sifields._pad, SI_PAD_SIZE32))
return -EFAULT;
set_fs (KERNEL_DS);
/* The __user pointer cast is valid becasuse of the set_fs() */
ret = sys_rt_sigqueueinfo((int)pid, (int)sig, (siginfo_t __user *) &info);
set_fs (old_fs);
return ret;
}
int sys32_rt_sigsuspend(compat_sigset_t __user * unewset, size_t sigsetsize, int p3,
int p4, int p6, int p7, struct pt_regs *regs)
{
sigset_t saveset, newset;
compat_sigset_t s32;
/* XXX: Don't preclude handling different sized sigset_t's. */
if (sigsetsize != sizeof(sigset_t))
return -EINVAL;
if (copy_from_user(&s32, unewset, sizeof(s32)))
return -EFAULT;
/*
* Swap the 2 words of the 64-bit sigset_t (they are stored
* in the "wrong" endian in 32-bit user storage).
*/
sigset_from_compat(&newset, &s32);
sigdelsetmask(&newset, ~_BLOCKABLE);
spin_lock_irq(&current->sighand->siglock);
saveset = current->blocked;
current->blocked = newset;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
regs->result = -EINTR;
regs->gpr[3] = EINTR;
regs->ccr |= 0x10000000;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal32(&saveset, regs))
/*
* Returning 0 means we return to userspace via
* ret_from_except and thus restore all user
* registers from *regs. This is what we need
* to do when a signal has been delivered.
*/
return 0;
}
}
/*
* Start Alternate signal stack support
*
* System Calls
* sigaltatck sys32_sigaltstack
*/
int sys32_sigaltstack(u32 __new, u32 __old, int r5,
int r6, int r7, int r8, struct pt_regs *regs)
{
stack_32_t __user * newstack = (stack_32_t __user *)(long) __new;
stack_32_t __user * oldstack = (stack_32_t __user *)(long) __old;
stack_t uss, uoss;
int ret;
mm_segment_t old_fs;
unsigned long sp;
compat_uptr_t ss_sp;
/*
* set sp to the user stack on entry to the system call
* the system call router sets R9 to the saved registers
*/
sp = regs->gpr[1];
/* Put new stack info in local 64 bit stack struct */
if (newstack) {
if (get_user(ss_sp, &newstack->ss_sp) ||
__get_user(uss.ss_flags, &newstack->ss_flags) ||
__get_user(uss.ss_size, &newstack->ss_size))
return -EFAULT;
uss.ss_sp = compat_ptr(ss_sp);
}
old_fs = get_fs();
set_fs(KERNEL_DS);
/* The __user pointer casts are valid because of the set_fs() */
ret = do_sigaltstack(
newstack ? (stack_t __user *) &uss : NULL,
oldstack ? (stack_t __user *) &uoss : NULL,
sp);
set_fs(old_fs);
/* Copy the stack information to the user output buffer */
if (!ret && oldstack &&
(put_user((long)uoss.ss_sp, &oldstack->ss_sp) ||
__put_user(uoss.ss_flags, &oldstack->ss_flags) ||
__put_user(uoss.ss_size, &oldstack->ss_size)))
return -EFAULT;
return ret;
}
/*
* Set up a signal frame for a "real-time" signal handler
* (one which gets siginfo).
*/
static int handle_rt_signal32(unsigned long sig, struct k_sigaction *ka,
siginfo_t *info, sigset_t *oldset,
struct pt_regs * regs, unsigned long newsp)
{
struct rt_sigframe32 __user *rt_sf;
struct mcontext32 __user *frame;
unsigned long origsp = newsp;
compat_sigset_t c_oldset;
/* Set up Signal Frame */
/* Put a Real Time Context onto stack */
newsp -= sizeof(*rt_sf);
rt_sf = (struct rt_sigframe32 __user *)newsp;
/* create a stack frame for the caller of the handler */
newsp -= __SIGNAL_FRAMESIZE32 + 16;
if (!access_ok(VERIFY_WRITE, (void __user *)newsp, origsp - newsp))
goto badframe;
compat_from_sigset(&c_oldset, oldset);
/* Put the siginfo & fill in most of the ucontext */
if (copy_siginfo_to_user32(&rt_sf->info, info)
|| __put_user(0, &rt_sf->uc.uc_flags)
|| __put_user(0, &rt_sf->uc.uc_link)
|| __put_user(current->sas_ss_sp, &rt_sf->uc.uc_stack.ss_sp)
|| __put_user(sas_ss_flags(regs->gpr[1]),
&rt_sf->uc.uc_stack.ss_flags)
|| __put_user(current->sas_ss_size, &rt_sf->uc.uc_stack.ss_size)
|| __put_user((u32)(u64)&rt_sf->uc.uc_mcontext, &rt_sf->uc.uc_regs)
|| __copy_to_user(&rt_sf->uc.uc_sigmask, &c_oldset, sizeof(c_oldset)))
goto badframe;
/* Save user registers on the stack */
frame = &rt_sf->uc.uc_mcontext;
if (put_user(regs->gpr[1], (u32 __user *)newsp))
goto badframe;
if (vdso32_rt_sigtramp && current->thread.vdso_base) {
if (save_user_regs(regs, frame, 0))
goto badframe;
regs->link = current->thread.vdso_base + vdso32_rt_sigtramp;
} else {
if (save_user_regs(regs, frame, __NR_rt_sigreturn))
goto badframe;
regs->link = (unsigned long) frame->tramp;
}
regs->gpr[1] = (unsigned long) newsp;
regs->gpr[3] = sig;
regs->gpr[4] = (unsigned long) &rt_sf->info;
regs->gpr[5] = (unsigned long) &rt_sf->uc;
regs->gpr[6] = (unsigned long) rt_sf;
regs->nip = (unsigned long) ka->sa.sa_handler;
regs->trap = 0;
regs->result = 0;
if (test_thread_flag(TIF_SINGLESTEP))
ptrace_notify(SIGTRAP);
return 1;
badframe:
#if DEBUG_SIG
printk("badframe in handle_rt_signal, regs=%p frame=%p newsp=%lx\n",
regs, frame, newsp);
#endif
force_sigsegv(sig, current);
return 0;
}
static long do_setcontext32(struct ucontext32 __user *ucp, struct pt_regs *regs, int sig)
{
compat_sigset_t c_set;
sigset_t set;
u32 mcp;
if (__copy_from_user(&c_set, &ucp->uc_sigmask, sizeof(c_set))
|| __get_user(mcp, &ucp->uc_regs))
return -EFAULT;
sigset_from_compat(&set, &c_set);
restore_sigmask(&set);
if (restore_user_regs(regs, (struct mcontext32 __user *)(u64)mcp, sig))
return -EFAULT;
return 0;
}
/*
* Handle {get,set,swap}_context operations for 32 bits processes
*/
long sys32_swapcontext(struct ucontext32 __user *old_ctx,
struct ucontext32 __user *new_ctx,
int ctx_size, int r6, int r7, int r8, struct pt_regs *regs)
{
unsigned char tmp;
compat_sigset_t c_set;
/* Context size is for future use. Right now, we only make sure
* we are passed something we understand
*/
if (ctx_size < sizeof(struct ucontext32))
return -EINVAL;
if (old_ctx != NULL) {
compat_from_sigset(&c_set, &current->blocked);
if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx))
|| save_user_regs(regs, &old_ctx->uc_mcontext, 0)
|| __copy_to_user(&old_ctx->uc_sigmask, &c_set, sizeof(c_set))
|| __put_user((u32)(u64)&old_ctx->uc_mcontext, &old_ctx->uc_regs))
return -EFAULT;
}
if (new_ctx == NULL)
return 0;
if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx))
|| __get_user(tmp, (u8 __user *) new_ctx)
|| __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1))
return -EFAULT;
/*
* If we get a fault copying the context into the kernel's
* image of the user's registers, we can't just return -EFAULT
* because the user's registers will be corrupted. For instance
* the NIP value may have been updated but not some of the
* other registers. Given that we have done the access_ok
* and successfully read the first and last bytes of the region
* above, this should only happen in an out-of-memory situation
* or if another thread unmaps the region containing the context.
* We kill the task with a SIGSEGV in this situation.
*/
if (do_setcontext32(new_ctx, regs, 0))
do_exit(SIGSEGV);
return 0;
}
long sys32_rt_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
struct pt_regs *regs)
{
struct rt_sigframe32 __user *rt_sf;
int ret;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
rt_sf = (struct rt_sigframe32 __user *)
(regs->gpr[1] + __SIGNAL_FRAMESIZE32 + 16);
if (!access_ok(VERIFY_READ, rt_sf, sizeof(*rt_sf)))
goto bad;
if (do_setcontext32(&rt_sf->uc, regs, 1))
goto bad;
/*
* It's not clear whether or why it is desirable to save the
* sigaltstack setting on signal delivery and restore it on
* signal return. But other architectures do this and we have
* always done it up until now so it is probably better not to
* change it. -- paulus
* We use the sys32_ version that does the 32/64 bits conversion
* and takes userland pointer directly. What about error checking ?
* nobody does any...
*/
sys32_sigaltstack((u32)(u64)&rt_sf->uc.uc_stack, 0, 0, 0, 0, 0, regs);
ret = regs->result;
return ret;
bad:
force_sig(SIGSEGV, current);
return 0;
}
/*
* OK, we're invoking a handler
*/
static int handle_signal32(unsigned long sig, struct k_sigaction *ka,
siginfo_t *info, sigset_t *oldset,
struct pt_regs * regs, unsigned long newsp)
{
struct sigcontext32 __user *sc;
struct sigregs32 __user *frame;
unsigned long origsp = newsp;
/* Set up Signal Frame */
newsp -= sizeof(struct sigregs32);
frame = (struct sigregs32 __user *) newsp;
/* Put a sigcontext on the stack */
newsp -= sizeof(*sc);
sc = (struct sigcontext32 __user *) newsp;
/* create a stack frame for the caller of the handler */
newsp -= __SIGNAL_FRAMESIZE32;
if (!access_ok(VERIFY_WRITE, (void __user *) newsp, origsp - newsp))
goto badframe;
#if _NSIG != 64
#error "Please adjust handle_signal32()"
#endif
if (__put_user((u32)(u64)ka->sa.sa_handler, &sc->handler)
|| __put_user(oldset->sig[0], &sc->oldmask)
|| __put_user((oldset->sig[0] >> 32), &sc->_unused[3])
|| __put_user((u32)(u64)frame, &sc->regs)
|| __put_user(sig, &sc->signal))
goto badframe;
if (vdso32_sigtramp && current->thread.vdso_base) {
if (save_user_regs(regs, &frame->mctx, 0))
goto badframe;
regs->link = current->thread.vdso_base + vdso32_sigtramp;
} else {
if (save_user_regs(regs, &frame->mctx, __NR_sigreturn))
goto badframe;
regs->link = (unsigned long) frame->mctx.tramp;
}
if (put_user(regs->gpr[1], (u32 __user *)newsp))
goto badframe;
regs->gpr[1] = (unsigned long) newsp;
regs->gpr[3] = sig;
regs->gpr[4] = (unsigned long) sc;
regs->nip = (unsigned long) ka->sa.sa_handler;
regs->trap = 0;
regs->result = 0;
if (test_thread_flag(TIF_SINGLESTEP))
ptrace_notify(SIGTRAP);
return 1;
badframe:
#if DEBUG_SIG
printk("badframe in handle_signal, regs=%p frame=%x newsp=%x\n",
regs, frame, *newspp);
#endif
force_sigsegv(sig, current);
return 0;
}
/*
* Do a signal return; undo the signal stack.
*/
long sys32_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
struct pt_regs *regs)
{
struct sigcontext32 __user *sc;
struct sigcontext32 sigctx;
struct mcontext32 __user *sr;
sigset_t set;
int ret;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
sc = (struct sigcontext32 __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE32);
if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
goto badframe;
/*
* Note that PPC32 puts the upper 32 bits of the sigmask in the
* unused part of the signal stackframe
*/
set.sig[0] = sigctx.oldmask + ((long)(sigctx._unused[3]) << 32);
restore_sigmask(&set);
sr = (struct mcontext32 __user *)(u64)sigctx.regs;
if (!access_ok(VERIFY_READ, sr, sizeof(*sr))
|| restore_user_regs(regs, sr, 1))
goto badframe;
ret = regs->result;
return ret;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* Start of do_signal32 routine
*
* This routine gets control when a pending signal needs to be processed
* in the 32 bit target thread -
*
* It handles both rt and non-rt signals
*/
/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
* mistake.
*/
int do_signal32(sigset_t *oldset, struct pt_regs *regs)
{
siginfo_t info;
unsigned int frame, newsp;
int signr, ret;
struct k_sigaction ka;
if (!oldset)
oldset = &current->blocked;
newsp = frame = 0;
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (TRAP(regs) == 0x0C00 /* System Call! */
&& regs->ccr & 0x10000000 /* error signalled */
&& ((ret = regs->gpr[3]) == ERESTARTSYS
|| ret == ERESTARTNOHAND || ret == ERESTARTNOINTR
|| ret == ERESTART_RESTARTBLOCK)) {
if (signr > 0
&& (ret == ERESTARTNOHAND || ret == ERESTART_RESTARTBLOCK
|| (ret == ERESTARTSYS
&& !(ka.sa.sa_flags & SA_RESTART)))) {
/* make the system call return an EINTR error */
regs->result = -EINTR;
regs->gpr[3] = EINTR;
/* note that the cr0.SO bit is already set */
} else {
regs->nip -= 4; /* Back up & retry system call */
regs->result = 0;
regs->trap = 0;
if (ret == ERESTART_RESTARTBLOCK)
regs->gpr[0] = __NR_restart_syscall;
else
regs->gpr[3] = regs->orig_gpr3;
}
}
if (signr == 0)
return 0; /* no signals delivered */
if ((ka.sa.sa_flags & SA_ONSTACK) && current->sas_ss_size
&& (!on_sig_stack(regs->gpr[1])))
newsp = (current->sas_ss_sp + current->sas_ss_size);
else
newsp = regs->gpr[1];
newsp &= ~0xfUL;
/* Whee! Actually deliver the signal. */
if (ka.sa.sa_flags & SA_SIGINFO)
ret = handle_rt_signal32(signr, &ka, &info, oldset, regs, newsp);
else
ret = handle_signal32(signr, &ka, &info, oldset, regs, newsp);
if (ret) {
spin_lock_irq(&current->sighand->siglock);
sigorsets(&current->blocked, &current->blocked,
&ka.sa.sa_mask);
if (!(ka.sa.sa_flags & SA_NODEFER))
sigaddset(&current->blocked, signr);
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
}
return ret;
}
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