android_kernel_motorola_sm6225/arch/v850/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

525 lines
14 KiB
C

/*
* arch/v850/kernel/signal.c -- Signal handling
*
* Copyright (C) 2001,02,03 NEC Electronics Corporation
* Copyright (C) 2001,02,03 Miles Bader <miles@gnu.org>
* Copyright (C) 1999,2000,2002 Niibe Yutaka & Kaz Kojima
* Copyright (C) 1991,1992 Linus Torvalds
*
* 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.
*
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
*
* This file was derived from the sh version, arch/sh/kernel/signal.c
*/
#include <linux/mm.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/stddef.h>
#include <linux/personality.h>
#include <linux/tty.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/thread_info.h>
#include <asm/cacheflush.h>
#define DEBUG_SIG 0
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
/*
* Atomically swap in the new signal mask, and wait for a signal.
*/
asmlinkage int
sys_sigsuspend(old_sigset_t mask, 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->gpr[GPR_RVAL] = -EINTR;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(regs, &saveset))
return -EINTR;
}
}
asmlinkage int
sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
struct pt_regs *regs)
{
sigset_t saveset, newset;
/* XXX: Don't preclude handling different sized sigset_t's. */
if (sigsetsize != sizeof(sigset_t))
return -EINVAL;
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->gpr[GPR_RVAL] = -EINTR;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(regs, &saveset))
return -EINTR;
}
}
asmlinkage int
sys_sigaction(int sig, const struct old_sigaction *act,
struct old_sigaction *oact)
{
struct k_sigaction new_ka, old_ka;
int ret;
if (act) {
old_sigset_t mask;
if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
__get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
__get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
return -EFAULT;
__get_user(new_ka.sa.sa_flags, &act->sa_flags);
__get_user(mask, &act->sa_mask);
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)) ||
__put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
return -EFAULT;
__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
}
return ret;
}
asmlinkage int
sys_sigaltstack(const stack_t *uss, stack_t *uoss,
struct pt_regs *regs)
{
return do_sigaltstack(uss, uoss, regs->gpr[GPR_SP]);
}
/*
* Do a signal return; undo the signal stack.
*/
struct sigframe
{
struct sigcontext sc;
unsigned long extramask[_NSIG_WORDS-1];
unsigned long tramp[2]; /* signal trampoline */
};
struct rt_sigframe
{
struct siginfo info;
struct ucontext uc;
unsigned long tramp[2]; /* signal trampoline */
};
static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *rval_p)
{
unsigned int err = 0;
#define COPY(x) err |= __get_user(regs->x, &sc->regs.x)
COPY(gpr[0]); COPY(gpr[1]); COPY(gpr[2]); COPY(gpr[3]);
COPY(gpr[4]); COPY(gpr[5]); COPY(gpr[6]); COPY(gpr[7]);
COPY(gpr[8]); COPY(gpr[9]); COPY(gpr[10]); COPY(gpr[11]);
COPY(gpr[12]); COPY(gpr[13]); COPY(gpr[14]); COPY(gpr[15]);
COPY(gpr[16]); COPY(gpr[17]); COPY(gpr[18]); COPY(gpr[19]);
COPY(gpr[20]); COPY(gpr[21]); COPY(gpr[22]); COPY(gpr[23]);
COPY(gpr[24]); COPY(gpr[25]); COPY(gpr[26]); COPY(gpr[27]);
COPY(gpr[28]); COPY(gpr[29]); COPY(gpr[30]); COPY(gpr[31]);
COPY(pc); COPY(psw);
COPY(ctpc); COPY(ctpsw); COPY(ctbp);
#undef COPY
return err;
}
asmlinkage int sys_sigreturn(struct pt_regs *regs)
{
struct sigframe *frame = (struct sigframe *)regs->gpr[GPR_SP];
sigset_t set;
int rval;
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__get_user(set.sig[0], &frame->sc.oldmask)
|| (_NSIG_WORDS > 1
&& __copy_from_user(&set.sig[1], &frame->extramask,
sizeof(frame->extramask))))
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->sc, &rval))
goto badframe;
return rval;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
{
struct rt_sigframe *frame = (struct rt_sigframe *)regs->gpr[GPR_SP];
sigset_t set;
stack_t st;
int rval;
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);
spin_lock_irq(&current->sighand->siglock);
current->blocked = set;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval))
goto badframe;
if (__copy_from_user(&st, &frame->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->gpr[GPR_SP]);
return rval;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* Set up a signal frame.
*/
static int
setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
unsigned long mask)
{
int err = 0;
#define COPY(x) err |= __put_user(regs->x, &sc->regs.x)
COPY(gpr[0]); COPY(gpr[1]); COPY(gpr[2]); COPY(gpr[3]);
COPY(gpr[4]); COPY(gpr[5]); COPY(gpr[6]); COPY(gpr[7]);
COPY(gpr[8]); COPY(gpr[9]); COPY(gpr[10]); COPY(gpr[11]);
COPY(gpr[12]); COPY(gpr[13]); COPY(gpr[14]); COPY(gpr[15]);
COPY(gpr[16]); COPY(gpr[17]); COPY(gpr[18]); COPY(gpr[19]);
COPY(gpr[20]); COPY(gpr[21]); COPY(gpr[22]); COPY(gpr[23]);
COPY(gpr[24]); COPY(gpr[25]); COPY(gpr[26]); COPY(gpr[27]);
COPY(gpr[28]); COPY(gpr[29]); COPY(gpr[30]); COPY(gpr[31]);
COPY(pc); COPY(psw);
COPY(ctpc); COPY(ctpsw); COPY(ctbp);
#undef COPY
err |= __put_user(mask, &sc->oldmask);
return err;
}
/*
* Determine which stack to use..
*/
static inline void *
get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
{
/* Default to using normal stack */
unsigned long sp = regs->gpr[GPR_SP];
if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp))
sp = current->sas_ss_sp + current->sas_ss_size;
return (void *)((sp - frame_size) & -8UL);
}
static void setup_frame(int sig, struct k_sigaction *ka,
sigset_t *set, struct pt_regs *regs)
{
struct sigframe *frame;
int err = 0;
int signal;
frame = get_sigframe(ka, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
signal = current_thread_info()->exec_domain
&& current_thread_info()->exec_domain->signal_invmap
&& sig < 32
? current_thread_info()->exec_domain->signal_invmap[sig]
: sig;
err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
if (_NSIG_WORDS > 1) {
err |= __copy_to_user(frame->extramask, &set->sig[1],
sizeof(frame->extramask));
}
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa.sa_flags & SA_RESTORER) {
regs->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer;
} else {
/* Note, these encodings are _little endian_! */
/* addi __NR_sigreturn, r0, r12 */
err |= __put_user(0x6600 | (__NR_sigreturn << 16),
frame->tramp + 0);
/* trap 0 */
err |= __put_user(0x010007e0,
frame->tramp + 1);
regs->gpr[GPR_LP] = (unsigned long)frame->tramp;
flush_cache_sigtramp (regs->gpr[GPR_LP]);
}
if (err)
goto give_sigsegv;
/* Set up registers for signal handler. */
regs->pc = (v850_reg_t) ka->sa.sa_handler;
regs->gpr[GPR_SP] = (v850_reg_t)frame;
/* Signal handler args: */
regs->gpr[GPR_ARG0] = signal; /* arg 0: signum */
regs->gpr[GPR_ARG1] = (v850_reg_t)&frame->sc;/* arg 1: sigcontext */
set_fs(USER_DS);
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=%p pc=%08lx ra=%08lx\n",
current->comm, current->pid, frame, regs->pc, );
#endif
return;
give_sigsegv:
force_sigsegv(sig, current);
}
static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs)
{
struct rt_sigframe *frame;
int err = 0;
int signal;
frame = get_sigframe(ka, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
signal = current_thread_info()->exec_domain
&& current_thread_info()->exec_domain->signal_invmap
&& sig < 32
? current_thread_info()->exec_domain->signal_invmap[sig]
: sig;
err |= copy_siginfo_to_user(&frame->info, info);
/* Create the ucontext. */
err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
err |= __put_user((void *)current->sas_ss_sp,
&frame->uc.uc_stack.ss_sp);
err |= __put_user(sas_ss_flags(regs->gpr[GPR_SP]),
&frame->uc.uc_stack.ss_flags);
err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
err |= setup_sigcontext(&frame->uc.uc_mcontext,
regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa.sa_flags & SA_RESTORER) {
regs->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer;
} else {
/* Note, these encodings are _little endian_! */
/* addi __NR_sigreturn, r0, r12 */
err |= __put_user(0x6600 | (__NR_sigreturn << 16),
frame->tramp + 0);
/* trap 0 */
err |= __put_user(0x010007e0,
frame->tramp + 1);
regs->gpr[GPR_LP] = (unsigned long)frame->tramp;
flush_cache_sigtramp (regs->gpr[GPR_LP]);
}
if (err)
goto give_sigsegv;
/* Set up registers for signal handler. */
regs->pc = (v850_reg_t) ka->sa.sa_handler;
regs->gpr[GPR_SP] = (v850_reg_t)frame;
/* Signal handler args: */
regs->gpr[GPR_ARG0] = signal; /* arg 0: signum */
regs->gpr[GPR_ARG1] = (v850_reg_t)&frame->info; /* arg 1: siginfo */
regs->gpr[GPR_ARG2] = (v850_reg_t)&frame->uc; /* arg 2: ucontext */
set_fs(USER_DS);
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
current->comm, current->pid, frame, regs->pc, regs->pr);
#endif
return;
give_sigsegv:
force_sigsegv(sig, current);
}
/*
* OK, we're invoking a handler
*/
static void
handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
sigset_t *oldset, struct pt_regs * regs)
{
/* Are we from a system call? */
if (PT_REGS_SYSCALL (regs)) {
/* If so, check system call restarting.. */
switch (regs->gpr[GPR_RVAL]) {
case -ERESTART_RESTARTBLOCK:
current_thread_info()->restart_block.fn =
do_no_restart_syscall;
/* fall through */
case -ERESTARTNOHAND:
regs->gpr[GPR_RVAL] = -EINTR;
break;
case -ERESTARTSYS:
if (!(ka->sa.sa_flags & SA_RESTART)) {
regs->gpr[GPR_RVAL] = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
regs->gpr[12] = PT_REGS_SYSCALL (regs);
regs->pc -= 4; /* Size of `trap 0' insn. */
}
PT_REGS_SET_SYSCALL (regs, 0);
}
/* Set up the stack frame */
if (ka->sa.sa_flags & SA_SIGINFO)
setup_rt_frame(sig, ka, info, oldset, regs);
else
setup_frame(sig, ka, oldset, regs);
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);
}
}
/*
* 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.
*
* Note that we go through the signals twice: once to check the signals that
* the kernel can handle, and then we build all the user-level signal handling
* stack-frames in one go after that.
*/
int do_signal(struct pt_regs *regs, sigset_t *oldset)
{
siginfo_t info;
int signr;
struct k_sigaction ka;
/*
* 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 (!oldset)
oldset = &current->blocked;
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
/* Whee! Actually deliver the signal. */
handle_signal(signr, &info, &ka, oldset, regs);
return 1;
}
/* Did we come from a system call? */
if (PT_REGS_SYSCALL (regs)) {
int rval = (int)regs->gpr[GPR_RVAL];
/* Restart the system call - no handlers present */
if (rval == -ERESTARTNOHAND
|| rval == -ERESTARTSYS
|| rval == -ERESTARTNOINTR)
{
regs->gpr[12] = PT_REGS_SYSCALL (regs);
regs->pc -= 4; /* Size of `trap 0' insn. */
}
else if (rval == -ERESTART_RESTARTBLOCK) {
regs->gpr[12] = __NR_restart_syscall;
regs->pc -= 4; /* Size of `trap 0' insn. */
}
}
return 0;
}