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69be8f1896
kernel_optimize_test/arch/parisc/kernel/signal.c
Steven Rostedt 69be8f1896 [PATCH] convert signal handling of NODEFER to act like other Unix boxes. 
It has been reported that the way Linux handles NODEFER for signals is
not consistent with the way other Unix boxes handle it.  I've written a
program to test the behavior of how this flag affects signals and had
several reports from people who ran this on various Unix boxes,
confirming that Linux seems to be unique on the way this is handled.

The way NODEFER affects signals on other Unix boxes is as follows:

1) If NODEFER is set, other signals in sa_mask are still blocked.

2) If NODEFER is set and the signal is in sa_mask, then the signal is
still blocked. (Note: this is the behavior of all tested but Linux _and_
NetBSD 2.0 *).

The way NODEFER affects signals on Linux:

1) If NODEFER is set, other signals are _not_ blocked regardless of
sa_mask (Even NetBSD doesn't do this).

2) If NODEFER is set and the signal is in sa_mask, then the signal being
handled is not blocked.

The patch converts signal handling in all current Linux architectures to
the way most Unix boxes work.

Unix boxes that were tested:  DU4, AIX 5.2, Irix 6.5, NetBSD 2.0, SFU
3.5 on WinXP, AIX 5.3, Mac OSX, and of course Linux 2.6.13-rcX.

* NetBSD was the only other Unix to behave like Linux on point #2. The
main concern was brought up by point #1 which even NetBSD isn't like
Linux.  So with this patch, we leave NetBSD as the lonely one that
behaves differently here with #2.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-29 10:03:11 -07:00

664 lines
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/*
* linux/arch/parisc/kernel/signal.c: Architecture-specific signal
* handling support.
*
* Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
* Copyright (C) 2000 Linuxcare, Inc.
*
* Based on the ia64, i386, and alpha versions.
*
* Like the IA-64, we are a recent enough port (we are *starting*
* with glibc2.2) that we do not need to support the old non-realtime
* Linux signals. Therefore we don't. HP/UX signals will go in
* arch/parisc/hpux/signal.c when we figure out how to do them.
*/
#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/ptrace.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/compat.h>
#include <linux/elf.h>
#include <linux/personality.h>
#include <asm/ucontext.h>
#include <asm/rt_sigframe.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/cacheflush.h>
#include <asm/offsets.h>
#ifdef CONFIG_COMPAT
#include <linux/compat.h>
#include "signal32.h"
#endif
#define DEBUG_SIG 0
#define DEBUG_SIG_LEVEL 2
#if DEBUG_SIG
#define DBG(LEVEL, ...) \
((DEBUG_SIG_LEVEL >= LEVEL) \
? printk(__VA_ARGS__) : (void) 0)
#else
#define DBG(LEVEL, ...)
#endif
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
/* gcc will complain if a pointer is cast to an integer of different
* size. If you really need to do this (and we do for an ELF32 user
* application in an ELF64 kernel) then you have to do a cast to an
* integer of the same size first. The A() macro accomplishes
* this. */
#define A(__x) ((unsigned long)(__x))
int do_signal(sigset_t *oldset, struct pt_regs *regs, int in_syscall);
/*
* Atomically swap in the new signal mask, and wait for a signal.
*/
#ifdef __LP64__
#include "sys32.h"
#endif
asmlinkage int
sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs)
{
sigset_t saveset, newset;
#ifdef __LP64__
compat_sigset_t newset32;
if(personality(current->personality) == PER_LINUX32){
/* XXX: Don't preclude handling different sized sigset_t's. */
if (sigsetsize != sizeof(compat_sigset_t))
return -EINVAL;
if (copy_from_user(&newset32, (compat_sigset_t __user *)unewset, sizeof(newset32)))
return -EFAULT;
sigset_32to64(&newset,&newset32);
} else
#endif
{
/* 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->gr[28] = -EINTR;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(&saveset, regs, 1))
return -EINTR;
}
}
/*
* Do a signal return - restore sigcontext.
*/
/* Trampoline for calling rt_sigreturn() */
#define INSN_LDI_R25_0 0x34190000 /* ldi 0,%r25 (in_syscall=0) */
#define INSN_LDI_R25_1 0x34190002 /* ldi 1,%r25 (in_syscall=1) */
#define INSN_LDI_R20 0x3414015a /* ldi __NR_rt_sigreturn,%r20 */
#define INSN_BLE_SR2_R0 0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */
#define INSN_NOP 0x08000240 /* nop */
/* For debugging */
#define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */
static long
restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
{
long err = 0;
err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr));
err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr));
err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq));
err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq));
err |= __get_user(regs->sar, &sc->sc_sar);
DBG(2,"restore_sigcontext: iaoq is 0x%#lx / 0x%#lx\n",
regs->iaoq[0],regs->iaoq[1]);
DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]);
return err;
}
void
sys_rt_sigreturn(struct pt_regs *regs, int in_syscall)
{
struct rt_sigframe __user *frame;
struct siginfo si;
sigset_t set;
unsigned long usp = (regs->gr[30] & ~(0x01UL));
unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE;
#ifdef __LP64__
compat_sigset_t compat_set;
struct compat_rt_sigframe __user * compat_frame;
if(personality(current->personality) == PER_LINUX32)
sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
#endif
/* Unwind the user stack to get the rt_sigframe structure. */
frame = (struct rt_sigframe __user *)
(usp - sigframe_size);
DBG(2,"sys_rt_sigreturn: frame is %p\n", frame);
#ifdef __LP64__
compat_frame = (struct compat_rt_sigframe __user *)frame;
if(personality(current->personality) == PER_LINUX32){
DBG(2,"sys_rt_sigreturn: ELF32 process.\n");
if (__copy_from_user(&compat_set, &compat_frame->uc.uc_sigmask, sizeof(compat_set)))
goto give_sigsegv;
sigset_32to64(&set,&compat_set);
} else
#endif
{
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto give_sigsegv;
}
sigdelsetmask(&set, ~_BLOCKABLE);
spin_lock_irq(&current->sighand->siglock);
current->blocked = set;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
/* Good thing we saved the old gr[30], eh? */
#ifdef __LP64__
if(personality(current->personality) == PER_LINUX32){
DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n",
&compat_frame->uc.uc_mcontext);
// FIXME: Load upper half from register file
if (restore_sigcontext32(&compat_frame->uc.uc_mcontext,
&compat_frame->regs, regs))
goto give_sigsegv;
DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n",
usp, &compat_frame->uc.uc_stack);
if (do_sigaltstack32(&compat_frame->uc.uc_stack, NULL, usp) == -EFAULT)
goto give_sigsegv;
} else
#endif
{
DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n",
&frame->uc.uc_mcontext);
if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
goto give_sigsegv;
DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n",
usp, &frame->uc.uc_stack);
if (do_sigaltstack(&frame->uc.uc_stack, NULL, usp) == -EFAULT)
goto give_sigsegv;
}
/* If we are on the syscall path IAOQ will not be restored, and
* if we are on the interrupt path we must not corrupt gr31.
*/
if (in_syscall)
regs->gr[31] = regs->iaoq[0];
#if DEBUG_SIG
DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]);
show_regs(regs);
#endif
return;
give_sigsegv:
DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n");
si.si_signo = SIGSEGV;
si.si_errno = 0;
si.si_code = SI_KERNEL;
si.si_pid = current->pid;
si.si_uid = current->uid;
si.si_addr = &frame->uc;
force_sig_info(SIGSEGV, &si, current);
return;
}
/*
* Set up a signal frame.
*/
static inline void __user *
get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
{
/*FIXME: ELF32 vs. ELF64 has different frame_size, but since we
don't use the parameter it doesn't matter */
DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n",
(unsigned long)ka, sp, frame_size);
if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp))
sp = current->sas_ss_sp; /* Stacks grow up! */
DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp);
return (void __user *) sp; /* Stacks grow up. Fun. */
}
static long
setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall)
{
unsigned long flags = 0;
long err = 0;
if (on_sig_stack((unsigned long) sc))
flags |= PARISC_SC_FLAG_ONSTACK;
if (in_syscall) {
flags |= PARISC_SC_FLAG_IN_SYSCALL;
/* regs->iaoq is undefined in the syscall return path */
err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]);
err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]);
err |= __put_user(regs->sr[3], &sc->sc_iasq[0]);
err |= __put_user(regs->sr[3], &sc->sc_iasq[1]);
DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n",
regs->gr[31], regs->gr[31]+4);
} else {
err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq));
err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq));
DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n",
regs->iaoq[0], regs->iaoq[1]);
}
err |= __put_user(flags, &sc->sc_flags);
err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr));
err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr));
err |= __put_user(regs->sar, &sc->sc_sar);
DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]);
return err;
}
static long
setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs, int in_syscall)
{
struct rt_sigframe __user *frame;
unsigned long rp, usp;
unsigned long haddr, sigframe_size;
struct siginfo si;
int err = 0;
#ifdef __LP64__
compat_int_t compat_val;
struct compat_rt_sigframe __user * compat_frame;
compat_sigset_t compat_set;
#endif
usp = (regs->gr[30] & ~(0x01UL));
/*FIXME: frame_size parameter is unused, remove it. */
frame = get_sigframe(ka, usp, sizeof(*frame));
DBG(1,"SETUP_RT_FRAME: START\n");
DBG(1,"setup_rt_frame: frame %p info %p\n", frame, info);
#ifdef __LP64__
compat_frame = (struct compat_rt_sigframe __user *)frame;
if(personality(current->personality) == PER_LINUX32) {
DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info);
err |= compat_copy_siginfo_to_user(&compat_frame->info, info);
DBG(1,"SETUP_RT_FRAME: 1\n");
compat_val = (compat_int_t)current->sas_ss_sp;
err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_sp);
DBG(1,"SETUP_RT_FRAME: 2\n");
compat_val = (compat_int_t)current->sas_ss_size;
err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_size);
DBG(1,"SETUP_RT_FRAME: 3\n");
compat_val = sas_ss_flags(regs->gr[30]);
err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_flags);
DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc);
DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext);
err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext,
&compat_frame->regs, regs, in_syscall);
sigset_64to32(&compat_set,set);
err |= __copy_to_user(&compat_frame->uc.uc_sigmask, &compat_set, sizeof(compat_set));
} else
#endif
{
DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info);
err |= copy_siginfo_to_user(&frame->info, info);
err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
err |= __put_user(sas_ss_flags(regs->gr[30]),
&frame->uc.uc_stack.ss_flags);
DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc);
DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext);
err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall);
/* FIXME: Should probably be converted aswell for the compat case */
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. The first words of tramp are used to
save the previous sigrestartblock trampoline that might be
on the stack. We start the sigreturn trampoline at
SIGRESTARTBLOCK_TRAMP+X. */
err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0,
&frame->tramp[SIGRESTARTBLOCK_TRAMP+0]);
err |= __put_user(INSN_LDI_R20,
&frame->tramp[SIGRESTARTBLOCK_TRAMP+1]);
err |= __put_user(INSN_BLE_SR2_R0,
&frame->tramp[SIGRESTARTBLOCK_TRAMP+2]);
err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]);
#if DEBUG_SIG
/* Assert that we're flushing in the correct space... */
{
int sid;
asm ("mfsp %%sr3,%0" : "=r" (sid));
DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n",
sid, frame->tramp);
}
#endif
flush_user_dcache_range((unsigned long) &frame->tramp[0],
(unsigned long) &frame->tramp[TRAMP_SIZE]);
flush_user_icache_range((unsigned long) &frame->tramp[0],
(unsigned long) &frame->tramp[TRAMP_SIZE]);
/* TRAMP Words 0-4, Lenght 5 = SIGRESTARTBLOCK_TRAMP
* TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP
* So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP
*/
rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP];
if (err)
goto give_sigsegv;
haddr = A(ka->sa.sa_handler);
/* The sa_handler may be a pointer to a function descriptor */
#ifdef __LP64__
if(personality(current->personality) == PER_LINUX32) {
#endif
if (haddr & PA_PLABEL_FDESC) {
Elf32_Fdesc fdesc;
Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3);
err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
if (err)
goto give_sigsegv;
haddr = fdesc.addr;
regs->gr[19] = fdesc.gp;
}
#ifdef __LP64__
} else {
Elf64_Fdesc fdesc;
Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3);
err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
if (err)
goto give_sigsegv;
haddr = fdesc.addr;
regs->gr[19] = fdesc.gp;
DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n",
haddr, regs->gr[19], in_syscall);
}
#endif
/* The syscall return path will create IAOQ values from r31.
*/
sigframe_size = PARISC_RT_SIGFRAME_SIZE;
#ifdef __LP64__
if(personality(current->personality) == PER_LINUX32)
sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
#endif
if (in_syscall) {
regs->gr[31] = haddr;
#ifdef __LP64__
if(personality(current->personality) == PER_LINUX)
sigframe_size |= 1;
#endif
} else {
unsigned long psw = USER_PSW;
#ifdef __LP64__
if(personality(current->personality) == PER_LINUX)
psw |= PSW_W;
#endif
/* If we are singlestepping, arrange a trap to be delivered
when we return to userspace. Note the semantics -- we
should trap before the first insn in the handler is
executed. Ref:
http://sources.redhat.com/ml/gdb/2004-11/msg00245.html
*/
if (pa_psw(current)->r) {
pa_psw(current)->r = 0;
psw |= PSW_R;
mtctl(-1, 0);
}
regs->gr[0] = psw;
regs->iaoq[0] = haddr | 3;
regs->iaoq[1] = regs->iaoq[0] + 4;
}
regs->gr[2] = rp; /* userland return pointer */
regs->gr[26] = sig; /* signal number */
#ifdef __LP64__
if(personality(current->personality) == PER_LINUX32){
regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */
regs->gr[24] = A(&compat_frame->uc); /* ucontext pointer */
} else
#endif
{
regs->gr[25] = A(&frame->info); /* siginfo pointer */
regs->gr[24] = A(&frame->uc); /* ucontext pointer */
}
DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n",
regs->gr[30], sigframe_size,
regs->gr[30] + sigframe_size);
/* Raise the user stack pointer to make a proper call frame. */
regs->gr[30] = (A(frame) + sigframe_size);
DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n",
current->comm, current->pid, frame, regs->gr[30],
regs->iaoq[0], regs->iaoq[1], rp);
return 1;
give_sigsegv:
DBG(1,"setup_rt_frame: sending SIGSEGV\n");
if (sig == SIGSEGV)
ka->sa.sa_handler = SIG_DFL;
si.si_signo = SIGSEGV;
si.si_errno = 0;
si.si_code = SI_KERNEL;
si.si_pid = current->pid;
si.si_uid = current->uid;
si.si_addr = frame;
force_sig_info(SIGSEGV, &si, current);
return 0;
}
/*
* OK, we're invoking a handler.
*/
static long
handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
sigset_t *oldset, struct pt_regs *regs, int in_syscall)
{
DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n",
sig, ka, info, oldset, regs);
/* Set up the stack frame */
if (!setup_rt_frame(sig, ka, info, oldset, regs, in_syscall))
return 0;
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);
return 1;
}
/*
* 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.
*
* We need to be able to restore the syscall arguments (r21-r26) to
* restart syscalls. Thus, the syscall path should save them in the
* pt_regs structure (it's okay to do so since they are caller-save
* registers). As noted below, the syscall number gets restored for
* us due to the magic of delayed branching.
*/
asmlinkage int
do_signal(sigset_t *oldset, struct pt_regs *regs, int in_syscall)
{
siginfo_t info;
struct k_sigaction ka;
int signr;
DBG(1,"\ndo_signal: oldset=0x%p, regs=0x%p, sr7 %#lx, in_syscall=%d\n",
oldset, regs, regs->sr[7], in_syscall);
/* Everyone else checks to see if they are in kernel mode at
this point and exits if that's the case. I'm not sure why
we would be called in that case, but for some reason we
are. */
if (!oldset)
oldset = &current->blocked;
DBG(1,"do_signal: oldset %08lx / %08lx\n",
oldset->sig[0], oldset->sig[1]);
/* May need to force signal if handle_signal failed to deliver */
while (1) {
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]);
if (signr <= 0)
break;
/* Restart a system call if necessary. */
if (in_syscall) {
/* Check the return code */
switch (regs->gr[28]) {
case -ERESTART_RESTARTBLOCK:
current_thread_info()->restart_block.fn = do_no_restart_syscall;
case -ERESTARTNOHAND:
DBG(1,"ERESTARTNOHAND: returning -EINTR\n");
regs->gr[28] = -EINTR;
break;
case -ERESTARTSYS:
if (!(ka.sa.sa_flags & SA_RESTART)) {
DBG(1,"ERESTARTSYS: putting -EINTR\n");
regs->gr[28] = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
/* A syscall is just a branch, so all
we have to do is fiddle the return pointer. */
regs->gr[31] -= 8; /* delayed branching */
/* Preserve original r28. */
regs->gr[28] = regs->orig_r28;
break;
}
}
/* Whee! Actually deliver the signal. If the
delivery failed, we need to continue to iterate in
this loop so we can deliver the SIGSEGV... */
if (handle_signal(signr, &info, &ka, oldset, regs, in_syscall)) {
DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n",
regs->gr[28]);
return 1;
}
}
/* end of while(1) looping forever if we can't force a signal */
/* Did we come from a system call? */
if (in_syscall) {
/* Restart the system call - no handlers present */
if (regs->gr[28] == -ERESTART_RESTARTBLOCK) {
unsigned int *usp = (unsigned int *)regs->gr[30];
/* Setup a trampoline to restart the syscall
* with __NR_restart_syscall
*
* 0: <return address (orig r31)>
* 4: <2nd half for 64-bit>
* 8: ldw 0(%sp), %r31
* 12: be 0x100(%sr2, %r0)
* 16: ldi __NR_restart_syscall, %r20
*/
#ifndef __LP64__
put_user(regs->gr[31], &usp[0]);
put_user(0x0fc0109f, &usp[2]);
#else
put_user(regs->gr[31] >> 32, &usp[0]);
put_user(regs->gr[31] & 0xffffffff, &usp[1]);
put_user(0x0fc010df, &usp[2]);
#endif
put_user(0xe0008200, &usp[3]);
put_user(0x34140000, &usp[4]);
/* Stack is 64-byte aligned, and we only
* need to flush 1 cache line */
asm("fdc 0(%%sr3, %0)\n"
"fic 0(%%sr3, %0)\n"
"sync\n"
: : "r"(regs->gr[30]));
regs->gr[31] = regs->gr[30] + 8;
/* Preserve original r28. */
regs->gr[28] = regs->orig_r28;
} else if (regs->gr[28] == -ERESTARTNOHAND ||
regs->gr[28] == -ERESTARTSYS ||
regs->gr[28] == -ERESTARTNOINTR) {
/* Hooray for delayed branching. We don't
have to restore %r20 (the system call
number) because it gets loaded in the delay
slot of the branch external instruction. */
regs->gr[31] -= 8;
/* Preserve original r28. */
regs->gr[28] = regs->orig_r28;
}
}
DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n",
regs->gr[28]);
return 0;
}
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