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linux/arch/m32r/kernel/signal.c
Hirokazu Takata 8e8ff02c0b [PATCH] m32r: Fix pt_regs for !COFNIG_ISA_DSP_LEVEL2 target 
This modification is required to fix debugging function for m32r targets
with !CONFIG_ISA_DSP_LEVEL2, by unifying 'struct pt_regs' and 'struct
sigcontext' size for all M32R ISA.

Some m32r processor core with !CONFIG_ISA_DSP_LEVEL2 configuration has only
single accumulator a0 (ex.  VDEC2 core, M32102 core, etc.), the others with
CONFIG_ISA_DSP_LEVEL2 has two accumulators, a0 and a1.

This means there are two variations of thread context.  So far, we reduced
and changed stackframe size at a syscall for their context size.  However,
this causes a problem that a GDB for processors with CONFIG_ISA_DSP_LEVEL2
cannot be used for processors with !CONFIG_ISA_DSP_LEVEL2.

From the viewpoint of GDB support, we should reduce such variation of
stackframe size for simplicity.

In this patch, dummy members are added to 'struct pt_regs' and 'struct
sigcontext' to adjust their size for !CONFIG_ISA_DSP_LEVEL2.

This modification is also a one step for a GDB update in future.
Currently, on the m32r, GDB can access process's context by using ptrace
functions in a simple way of register by register access.  By unifying
stackframe size, we have a possibility to make use of ptrace functions of
not only a single register access but also block register access,
PTRACE_{GETREGS,PUTREGS}.

However, for this purpose, we might have to modify stackframe structure
some more; for example, PSW (processor status word) register should be
pre-processed before pushing to stack at a syscall, and so on.  In this
case, we must update carefully both kernel and GDB at a time...

Signed-off-by: Hayato Fujiwara <fujiwara@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Cc: Kei Sakamoto <ksakamot@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-19 09:13:50 -07:00

436 lines
9.9 KiB
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/*
* linux/arch/m32r/kernel/signal.c
*
* Copyright (c) 2003 Hitoshi Yamamoto
*
* Taken from i386 version.
* Copyright (C) 1991, 1992 Linus Torvalds
*
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
*/
#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/errno.h>
#include <linux/wait.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/suspend.h>
#include <asm/cacheflush.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#define DEBUG_SIG 0
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
int do_signal(struct pt_regs *, sigset_t *);
asmlinkage int
sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
unsigned long r2, unsigned long r3, unsigned long r4,
unsigned long r5, unsigned long r6, 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->r0 = -EINTR;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(regs, &saveset))
return regs->r0;
}
}
asmlinkage int
sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
unsigned long r2, unsigned long r3, unsigned long r4,
unsigned long r5, unsigned long r6, struct pt_regs *regs)
{
return do_sigaltstack(uss, uoss, regs->spu);
}
/*
* Do a signal return; undo the signal stack.
*/
struct rt_sigframe
{
int sig;
struct siginfo *pinfo;
void *puc;
struct siginfo info;
struct ucontext uc;
// struct _fpstate fpstate;
};
static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
int *r0_p)
{
unsigned int err = 0;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
COPY(r4);
COPY(r5);
COPY(r6);
COPY(pt_regs);
/* COPY(r0); Skip r0 */
COPY(r1);
COPY(r2);
COPY(r3);
COPY(r7);
COPY(r8);
COPY(r9);
COPY(r10);
COPY(r11);
COPY(r12);
#if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
COPY(acc0h);
COPY(acc0l);
COPY(acc1h);
COPY(acc1l);
#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
COPY(acch);
COPY(accl);
COPY(dummy_acc1h);
COPY(dummy_acc1l);
#else
#error unknown isa configuration
#endif
COPY(psw);
COPY(bpc);
COPY(bbpsw);
COPY(bbpc);
COPY(spu);
COPY(fp);
COPY(lr);
COPY(spi);
#undef COPY
regs->syscall_nr = -1; /* disable syscall checks */
err |= __get_user(*r0_p, &sc->sc_r0);
return err;
}
asmlinkage int
sys_rt_sigreturn(unsigned long r0, unsigned long r1,
unsigned long r2, unsigned long r3, unsigned long r4,
unsigned long r5, unsigned long r6, struct pt_regs *regs)
{
struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
sigset_t set;
int result;
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, &result))
goto badframe;
if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
goto badframe;
return result;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* Set up a signal frame.
*/
static int
setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
unsigned long mask)
{
int err = 0;
#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
COPY(r4);
COPY(r5);
COPY(r6);
COPY(pt_regs);
COPY(r0);
COPY(r1);
COPY(r2);
COPY(r3);
COPY(r7);
COPY(r8);
COPY(r9);
COPY(r10);
COPY(r11);
COPY(r12);
#if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
COPY(acc0h);
COPY(acc0l);
COPY(acc1h);
COPY(acc1l);
#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
COPY(acch);
COPY(accl);
COPY(dummy_acc1h);
COPY(dummy_acc1l);
#else
#error unknown isa configuration
#endif
COPY(psw);
COPY(bpc);
COPY(bbpsw);
COPY(bbpc);
COPY(spu);
COPY(fp);
COPY(lr);
COPY(spi);
#undef COPY
err |= __put_user(mask, &sc->oldmask);
return err;
}
/*
* Determine which stack to use..
*/
static inline void __user *
get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
{
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa.sa_flags & SA_ONSTACK) {
if (sas_ss_flags(sp) == 0)
sp = current->sas_ss_sp + current->sas_ss_size;
}
return (void __user *)((sp - frame_size) & -8ul);
}
static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
int err = 0;
int signal;
frame = get_sigframe(ka, regs->spu, 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 |= __put_user(signal, &frame->sig);
if (err)
goto give_sigsegv;
err |= __put_user(&frame->info, &frame->pinfo);
err |= __put_user(&frame->uc, &frame->puc);
err |= copy_siginfo_to_user(&frame->info, info);
if (err)
goto give_sigsegv;
/* Create the ucontext. */
err |= __put_user(0, &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->spu),
&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));
if (err)
goto give_sigsegv;
/* Set up to return from userspace. */
regs->lr = (unsigned long)ka->sa.sa_restorer;
/* Set up registers for signal handler */
regs->spu = (unsigned long)frame;
regs->r0 = signal; /* Arg for signal handler */
regs->r1 = (unsigned long)&frame->info;
regs->r2 = (unsigned long)&frame->uc;
regs->bpc = (unsigned long)ka->sa.sa_handler;
set_fs(USER_DS);
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
current->comm, current->pid, frame, regs->pc);
#endif
return;
give_sigsegv:
force_sigsegv(sig, current);
}
/*
* OK, we're invoking a handler
*/
static void
handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *oldset, struct pt_regs *regs)
{
unsigned short inst;
/* Are we from a system call? */
if (regs->syscall_nr >= 0) {
/* If so, check system call restarting.. */
switch (regs->r0) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
regs->r0 = -EINTR;
break;
case -ERESTARTSYS:
if (!(ka->sa.sa_flags & SA_RESTART)) {
regs->r0 = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
regs->r0 = regs->orig_r0;
inst = *(unsigned short *)(regs->bpc - 2);
if ((inst & 0xfff0) == 0x10f0) /* trap ? */
regs->bpc -= 2;
else
regs->bpc -= 4;
}
}
/* Set up the stack frame */
setup_rt_frame(sig, ka, info, oldset, regs);
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,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.
*/
int do_signal(struct pt_regs *regs, sigset_t *oldset)
{
siginfo_t info;
int signr;
struct k_sigaction ka;
unsigned short inst;
/*
* 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())
goto no_signal;
if (!oldset)
oldset = &current->blocked;
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
/* Reenable any watchpoints before delivering the
* signal to user space. The processor register will
* have been cleared if the watchpoint triggered
* inside the kernel.
*/
/* Whee! Actually deliver the signal. */
handle_signal(signr, &ka, &info, oldset, regs);
return 1;
}
no_signal:
/* Did we come from a system call? */
if (regs->syscall_nr >= 0) {
/* Restart the system call - no handlers present */
if (regs->r0 == -ERESTARTNOHAND ||
regs->r0 == -ERESTARTSYS ||
regs->r0 == -ERESTARTNOINTR) {
regs->r0 = regs->orig_r0;
inst = *(unsigned short *)(regs->bpc - 2);
if ((inst & 0xfff0) == 0x10f0) /* trap ? */
regs->bpc -= 2;
else
regs->bpc -= 4;
}
if (regs->r0 == -ERESTART_RESTARTBLOCK){
regs->r0 = regs->orig_r0;
regs->r7 = __NR_restart_syscall;
inst = *(unsigned short *)(regs->bpc - 2);
if ((inst & 0xfff0) == 0x10f0) /* trap ? */
regs->bpc -= 2;
else
regs->bpc -= 4;
}
}
return 0;
}
/*
* notification of userspace execution resumption
* - triggered by current->work.notify_resume
*/
void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
__u32 thread_info_flags)
{
/* Pending single-step? */
if (thread_info_flags & _TIF_SINGLESTEP)
clear_thread_flag(TIF_SINGLESTEP);
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs,oldset);
clear_thread_flag(TIF_IRET);
}
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