android_kernel_xiaomi_sm8350/arch/mips/kernel/signal.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

518 lines
13 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 1994 - 2000 Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
*/
#include <linux/config.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/personality.h>
#include <linux/smp.h>
#include <linux/smp_lock.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/compiler.h>
#include <asm/asm.h>
#include <linux/bitops.h>
#include <asm/cacheflush.h>
#include <asm/fpu.h>
#include <asm/sim.h>
#include <asm/uaccess.h>
#include <asm/ucontext.h>
#include <asm/cpu-features.h>
#include "signal-common.h"
#define DEBUG_SIG 0
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
static int do_signal(sigset_t *oldset, struct pt_regs *regs);
/*
* Atomically swap in the new signal mask, and wait for a signal.
*/
#ifdef CONFIG_TRAD_SIGNALS
save_static_function(sys_sigsuspend);
__attribute_used__ noinline static int
_sys_sigsuspend(nabi_no_regargs struct pt_regs regs)
{
sigset_t *uset, saveset, newset;
uset = (sigset_t *) regs.regs[4];
if (copy_from_user(&newset, uset, sizeof(sigset_t)))
return -EFAULT;
sigdelsetmask(&newset, ~_BLOCKABLE);
spin_lock_irq(&current->sighand->siglock);
saveset = current->blocked;
current->blocked = newset;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
regs.regs[2] = EINTR;
regs.regs[7] = 1;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(&saveset, &regs))
return -EINTR;
}
}
#endif
save_static_function(sys_rt_sigsuspend);
__attribute_used__ noinline static int
_sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
{
sigset_t *unewset, saveset, newset;
size_t sigsetsize;
/* XXX Don't preclude handling different sized sigset_t's. */
sigsetsize = regs.regs[5];
if (sigsetsize != sizeof(sigset_t))
return -EINVAL;
unewset = (sigset_t *) regs.regs[4];
if (copy_from_user(&newset, unewset, sizeof(newset)))
return -EFAULT;
sigdelsetmask(&newset, ~_BLOCKABLE);
spin_lock_irq(&current->sighand->siglock);
saveset = current->blocked;
current->blocked = newset;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
regs.regs[2] = EINTR;
regs.regs[7] = 1;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(&saveset, &regs))
return -EINTR;
}
}
#ifdef CONFIG_TRAD_SIGNALS
asmlinkage int sys_sigaction(int sig, const struct sigaction *act,
struct sigaction *oact)
{
struct k_sigaction new_ka, old_ka;
int ret;
int err = 0;
if (act) {
old_sigset_t mask;
if (!access_ok(VERIFY_READ, act, sizeof(*act)))
return -EFAULT;
err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
err |= __get_user(mask, &act->sa_mask.sig[0]);
if (err)
return -EFAULT;
siginitset(&new_ka.sa.sa_mask, mask);
}
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
if (!ret && oact) {
if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
return -EFAULT;
err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
err |= __put_user(0, &oact->sa_mask.sig[1]);
err |= __put_user(0, &oact->sa_mask.sig[2]);
err |= __put_user(0, &oact->sa_mask.sig[3]);
if (err)
return -EFAULT;
}
return ret;
}
#endif
asmlinkage int sys_sigaltstack(nabi_no_regargs struct pt_regs regs)
{
const stack_t *uss = (const stack_t *) regs.regs[4];
stack_t *uoss = (stack_t *) regs.regs[5];
unsigned long usp = regs.regs[29];
return do_sigaltstack(uss, uoss, usp);
}
#if PLAT_TRAMPOLINE_STUFF_LINE
#define __tramp __attribute__((aligned(PLAT_TRAMPOLINE_STUFF_LINE)))
#else
#define __tramp
#endif
#ifdef CONFIG_TRAD_SIGNALS
struct sigframe {
u32 sf_ass[4]; /* argument save space for o32 */
u32 sf_code[2] __tramp; /* signal trampoline */
struct sigcontext sf_sc __tramp;
sigset_t sf_mask;
};
#endif
struct rt_sigframe {
u32 rs_ass[4]; /* argument save space for o32 */
u32 rs_code[2] __tramp; /* signal trampoline */
struct siginfo rs_info __tramp;
struct ucontext rs_uc;
};
#ifdef CONFIG_TRAD_SIGNALS
save_static_function(sys_sigreturn);
__attribute_used__ noinline static void
_sys_sigreturn(nabi_no_regargs struct pt_regs regs)
{
struct sigframe *frame;
sigset_t blocked;
frame = (struct sigframe *) regs.regs[29];
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
goto badframe;
sigdelsetmask(&blocked, ~_BLOCKABLE);
spin_lock_irq(&current->sighand->siglock);
current->blocked = blocked;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
if (restore_sigcontext(&regs, &frame->sf_sc))
goto badframe;
/*
* Don't let your children do this ...
*/
if (current_thread_info()->flags & TIF_SYSCALL_TRACE)
do_syscall_trace(&regs, 1);
__asm__ __volatile__(
"move\t$29, %0\n\t"
"j\tsyscall_exit"
:/* no outputs */
:"r" (&regs));
/* Unreached */
badframe:
force_sig(SIGSEGV, current);
}
#endif
save_static_function(sys_rt_sigreturn);
__attribute_used__ noinline static void
_sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
{
struct rt_sigframe *frame;
sigset_t set;
stack_t st;
frame = (struct rt_sigframe *) regs.regs[29];
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
goto badframe;
sigdelsetmask(&set, ~_BLOCKABLE);
spin_lock_irq(&current->sighand->siglock);
current->blocked = set;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
if (restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext))
goto badframe;
if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
goto badframe;
/* It is more difficult to avoid calling this function than to
call it and ignore errors. */
do_sigaltstack(&st, NULL, regs.regs[29]);
/*
* Don't let your children do this ...
*/
__asm__ __volatile__(
"move\t$29, %0\n\t"
"j\tsyscall_exit"
:/* no outputs */
:"r" (&regs));
/* Unreached */
badframe:
force_sig(SIGSEGV, current);
}
#ifdef CONFIG_TRAD_SIGNALS
static void inline setup_frame(struct k_sigaction * ka, struct pt_regs *regs,
int signr, sigset_t *set)
{
struct sigframe *frame;
int err = 0;
frame = get_sigframe(ka, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
goto give_sigsegv;
/*
* Set up the return code ...
*
* li v0, __NR_sigreturn
* syscall
*/
if (PLAT_TRAMPOLINE_STUFF_LINE)
__clear_user(frame->sf_code, PLAT_TRAMPOLINE_STUFF_LINE);
err |= __put_user(0x24020000 + __NR_sigreturn, frame->sf_code + 0);
err |= __put_user(0x0000000c , frame->sf_code + 1);
flush_cache_sigtramp((unsigned long) frame->sf_code);
err |= setup_sigcontext(regs, &frame->sf_sc);
err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
if (err)
goto give_sigsegv;
/*
* Arguments to signal handler:
*
* a0 = signal number
* a1 = 0 (should be cause)
* a2 = pointer to struct sigcontext
*
* $25 and c0_epc point to the signal handler, $29 points to the
* struct sigframe.
*/
regs->regs[ 4] = signr;
regs->regs[ 5] = 0;
regs->regs[ 6] = (unsigned long) &frame->sf_sc;
regs->regs[29] = (unsigned long) frame;
regs->regs[31] = (unsigned long) frame->sf_code;
regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
current->comm, current->pid,
frame, regs->cp0_epc, frame->regs[31]);
#endif
return;
give_sigsegv:
force_sigsegv(signr, current);
}
#endif
static void inline setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs,
int signr, sigset_t *set, siginfo_t *info)
{
struct rt_sigframe *frame;
int err = 0;
frame = get_sigframe(ka, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
goto give_sigsegv;
/*
* Set up the return code ...
*
* li v0, __NR_rt_sigreturn
* syscall
*/
if (PLAT_TRAMPOLINE_STUFF_LINE)
__clear_user(frame->rs_code, PLAT_TRAMPOLINE_STUFF_LINE);
err |= __put_user(0x24020000 + __NR_rt_sigreturn, frame->rs_code + 0);
err |= __put_user(0x0000000c , frame->rs_code + 1);
flush_cache_sigtramp((unsigned long) frame->rs_code);
/* Create siginfo. */
err |= copy_siginfo_to_user(&frame->rs_info, info);
/* Create the ucontext. */
err |= __put_user(0, &frame->rs_uc.uc_flags);
err |= __put_user(0, &frame->rs_uc.uc_link);
err |= __put_user((void *)current->sas_ss_sp,
&frame->rs_uc.uc_stack.ss_sp);
err |= __put_user(sas_ss_flags(regs->regs[29]),
&frame->rs_uc.uc_stack.ss_flags);
err |= __put_user(current->sas_ss_size,
&frame->rs_uc.uc_stack.ss_size);
err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
if (err)
goto give_sigsegv;
/*
* Arguments to signal handler:
*
* a0 = signal number
* a1 = 0 (should be cause)
* a2 = pointer to ucontext
*
* $25 and c0_epc point to the signal handler, $29 points to
* the struct rt_sigframe.
*/
regs->regs[ 4] = signr;
regs->regs[ 5] = (unsigned long) &frame->rs_info;
regs->regs[ 6] = (unsigned long) &frame->rs_uc;
regs->regs[29] = (unsigned long) frame;
regs->regs[31] = (unsigned long) frame->rs_code;
regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
current->comm, current->pid,
frame, regs->cp0_epc, regs->regs[31]);
#endif
return;
give_sigsegv:
force_sigsegv(signr, current);
}
extern void setup_rt_frame_n32(struct k_sigaction * ka,
struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info);
static inline void handle_signal(unsigned long sig, siginfo_t *info,
struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs)
{
switch(regs->regs[0]) {
case ERESTART_RESTARTBLOCK:
case ERESTARTNOHAND:
regs->regs[2] = EINTR;
break;
case ERESTARTSYS:
if(!(ka->sa.sa_flags & SA_RESTART)) {
regs->regs[2] = EINTR;
break;
}
/* fallthrough */
case ERESTARTNOINTR: /* Userland will reload $v0. */
regs->regs[7] = regs->regs[26];
regs->cp0_epc -= 8;
}
regs->regs[0] = 0; /* Don't deal with this again. */
#ifdef CONFIG_TRAD_SIGNALS
if (ka->sa.sa_flags & SA_SIGINFO) {
#else
if (1) {
#endif
#ifdef CONFIG_MIPS32_N32
if ((current->thread.mflags & MF_ABI_MASK) == MF_N32)
setup_rt_frame_n32 (ka, regs, sig, oldset, info);
else
#endif
setup_rt_frame(ka, regs, sig, oldset, info);
}
#ifdef CONFIG_TRAD_SIGNALS
else
setup_frame(ka, regs, sig, oldset);
#endif
if (!(ka->sa.sa_flags & SA_NODEFER)) {
spin_lock_irq(&current->sighand->siglock);
sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
sigaddset(&current->blocked,sig);
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
}
}
extern int do_signal32(sigset_t *oldset, struct pt_regs *regs);
extern int do_irix_signal(sigset_t *oldset, struct pt_regs *regs);
static int do_signal(sigset_t *oldset, struct pt_regs *regs)
{
struct k_sigaction ka;
siginfo_t info;
int signr;
#ifdef CONFIG_BINFMT_ELF32
if ((current->thread.mflags & MF_ABI_MASK) == MF_O32) {
return do_signal32(oldset, regs);
}
#endif
/*
* We want the common case to go fast, which is why we may in certain
* cases get here from kernel mode. Just return without doing anything
* if so.
*/
if (!user_mode(regs))
return 1;
if (try_to_freeze(0))
goto no_signal;
if (!oldset)
oldset = &current->blocked;
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
handle_signal(signr, &info, &ka, oldset, regs);
return 1;
}
no_signal:
/*
* Who's code doesn't conform to the restartable syscall convention
* dies here!!! The li instruction, a single machine instruction,
* must directly be followed by the syscall instruction.
*/
if (regs->regs[0]) {
if (regs->regs[2] == ERESTARTNOHAND ||
regs->regs[2] == ERESTARTSYS ||
regs->regs[2] == ERESTARTNOINTR) {
regs->regs[7] = regs->regs[26];
regs->cp0_epc -= 8;
}
if (regs->regs[2] == ERESTART_RESTARTBLOCK) {
regs->regs[2] = __NR_restart_syscall;
regs->regs[7] = regs->regs[26];
regs->cp0_epc -= 4;
}
}
return 0;
}
/*
* notification of userspace execution resumption
* - triggered by current->work.notify_resume
*/
asmlinkage void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
__u32 thread_info_flags)
{
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING) {
#ifdef CONFIG_BINFMT_ELF32
if (likely((current->thread.mflags & MF_ABI_MASK) == MF_O32)) {
do_signal32(oldset, regs);
return;
}
#endif
#ifdef CONFIG_BINFMT_IRIX
if (unlikely(current->personality != PER_LINUX)) {
do_irix_signal(oldset, regs);
return;
}
#endif
do_signal(oldset, regs);
}
}