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315 lines
7.9 KiB
315 lines
7.9 KiB
/* |
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* Signal handling |
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* |
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* Copyright (C) 2008-2009 Michal Simek <[email protected]> |
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* Copyright (C) 2008-2009 PetaLogix |
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* Copyright (C) 2003,2004 John Williams <[email protected]> |
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* Copyright (C) 2001 NEC Corporation |
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* Copyright (C) 2001 Miles Bader <[email protected]> |
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* Copyright (C) 1999,2000 Niibe Yutaka & Kaz Kojima |
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* Copyright (C) 1991,1992 Linus Torvalds |
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* |
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* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson |
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* |
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* This file was was derived from the sh version, arch/sh/kernel/signal.c |
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* |
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* This file is subject to the terms and conditions of the GNU General |
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* Public License. See the file COPYING in the main directory of this |
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* archive for more details. |
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*/ |
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#include <linux/sched.h> |
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#include <linux/mm.h> |
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#include <linux/smp.h> |
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#include <linux/kernel.h> |
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#include <linux/signal.h> |
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#include <linux/errno.h> |
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#include <linux/wait.h> |
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#include <linux/ptrace.h> |
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#include <linux/unistd.h> |
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#include <linux/stddef.h> |
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#include <linux/personality.h> |
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#include <linux/percpu.h> |
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#include <linux/linkage.h> |
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#include <linux/tracehook.h> |
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#include <asm/entry.h> |
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#include <asm/ucontext.h> |
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#include <linux/uaccess.h> |
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#include <linux/syscalls.h> |
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#include <asm/cacheflush.h> |
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#include <asm/syscalls.h> |
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/* |
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* Do a signal return; undo the signal stack. |
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*/ |
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struct sigframe { |
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struct sigcontext sc; |
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unsigned long extramask[_NSIG_WORDS-1]; |
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unsigned long tramp[2]; /* signal trampoline */ |
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}; |
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struct rt_sigframe { |
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struct siginfo info; |
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struct ucontext uc; |
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unsigned long tramp[2]; /* signal trampoline */ |
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}; |
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static int restore_sigcontext(struct pt_regs *regs, |
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struct sigcontext __user *sc, int *rval_p) |
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{ |
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unsigned int err = 0; |
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#define COPY(x) {err |= __get_user(regs->x, &sc->regs.x); } |
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COPY(r0); |
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COPY(r1); |
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COPY(r2); COPY(r3); COPY(r4); COPY(r5); |
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COPY(r6); COPY(r7); COPY(r8); COPY(r9); |
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COPY(r10); COPY(r11); COPY(r12); COPY(r13); |
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COPY(r14); COPY(r15); COPY(r16); COPY(r17); |
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COPY(r18); COPY(r19); COPY(r20); COPY(r21); |
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COPY(r22); COPY(r23); COPY(r24); COPY(r25); |
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COPY(r26); COPY(r27); COPY(r28); COPY(r29); |
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COPY(r30); COPY(r31); |
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COPY(pc); COPY(ear); COPY(esr); COPY(fsr); |
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#undef COPY |
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*rval_p = regs->r3; |
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return err; |
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} |
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asmlinkage long sys_rt_sigreturn(struct pt_regs *regs) |
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{ |
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struct rt_sigframe __user *frame = |
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(struct rt_sigframe __user *)(regs->r1); |
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sigset_t set; |
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int rval; |
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/* Always make any pending restarted system calls return -EINTR */ |
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current->restart_block.fn = do_no_restart_syscall; |
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if (!access_ok(frame, sizeof(*frame))) |
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goto badframe; |
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if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) |
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goto badframe; |
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set_current_blocked(&set); |
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if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval)) |
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goto badframe; |
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if (restore_altstack(&frame->uc.uc_stack)) |
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goto badframe; |
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return rval; |
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badframe: |
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force_sig(SIGSEGV); |
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return 0; |
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} |
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/* |
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* Set up a signal frame. |
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*/ |
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static int |
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setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, |
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unsigned long mask) |
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{ |
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int err = 0; |
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#define COPY(x) {err |= __put_user(regs->x, &sc->regs.x); } |
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COPY(r0); |
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COPY(r1); |
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COPY(r2); COPY(r3); COPY(r4); COPY(r5); |
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COPY(r6); COPY(r7); COPY(r8); COPY(r9); |
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COPY(r10); COPY(r11); COPY(r12); COPY(r13); |
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COPY(r14); COPY(r15); COPY(r16); COPY(r17); |
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COPY(r18); COPY(r19); COPY(r20); COPY(r21); |
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COPY(r22); COPY(r23); COPY(r24); COPY(r25); |
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COPY(r26); COPY(r27); COPY(r28); COPY(r29); |
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COPY(r30); COPY(r31); |
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COPY(pc); COPY(ear); COPY(esr); COPY(fsr); |
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#undef COPY |
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err |= __put_user(mask, &sc->oldmask); |
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return err; |
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} |
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/* |
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* Determine which stack to use.. |
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*/ |
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static inline void __user * |
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get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size) |
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{ |
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/* Default to using normal stack */ |
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unsigned long sp = sigsp(regs->r1, ksig); |
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return (void __user *)((sp - frame_size) & -8UL); |
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} |
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static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, |
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struct pt_regs *regs) |
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{ |
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struct rt_sigframe __user *frame; |
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int err = 0, sig = ksig->sig; |
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unsigned long address = 0; |
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pmd_t *pmdp; |
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pte_t *ptep; |
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frame = get_sigframe(ksig, regs, sizeof(*frame)); |
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if (!access_ok(frame, sizeof(*frame))) |
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return -EFAULT; |
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if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
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err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
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/* Create the ucontext. */ |
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err |= __put_user(0, &frame->uc.uc_flags); |
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err |= __put_user(NULL, &frame->uc.uc_link); |
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err |= __save_altstack(&frame->uc.uc_stack, regs->r1); |
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err |= setup_sigcontext(&frame->uc.uc_mcontext, |
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regs, set->sig[0]); |
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err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
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/* Set up to return from userspace. If provided, use a stub |
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already in userspace. */ |
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/* minus 8 is offset to cater for "rtsd r15,8" */ |
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/* addi r12, r0, __NR_sigreturn */ |
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err |= __put_user(0x31800000 | __NR_rt_sigreturn , |
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frame->tramp + 0); |
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/* brki r14, 0x8 */ |
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err |= __put_user(0xb9cc0008, frame->tramp + 1); |
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/* Return from sighandler will jump to the tramp. |
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Negative 8 offset because return is rtsd r15, 8 */ |
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regs->r15 = ((unsigned long)frame->tramp)-8; |
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address = ((unsigned long)frame->tramp); |
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pmdp = pmd_off(current->mm, address); |
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preempt_disable(); |
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ptep = pte_offset_map(pmdp, address); |
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if (pte_present(*ptep)) { |
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address = (unsigned long) page_address(pte_page(*ptep)); |
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/* MS: I need add offset in page */ |
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address += ((unsigned long)frame->tramp) & ~PAGE_MASK; |
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/* MS address is virtual */ |
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address = __virt_to_phys(address); |
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invalidate_icache_range(address, address + 8); |
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flush_dcache_range(address, address + 8); |
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} |
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pte_unmap(ptep); |
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preempt_enable(); |
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if (err) |
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return -EFAULT; |
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/* Set up registers for signal handler */ |
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regs->r1 = (unsigned long) frame; |
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/* Signal handler args: */ |
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regs->r5 = sig; /* arg 0: signum */ |
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regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */ |
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regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */ |
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/* Offset to handle microblaze rtid r14, 0 */ |
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regs->pc = (unsigned long)ksig->ka.sa.sa_handler; |
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#ifdef DEBUG_SIG |
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pr_info("SIG deliver (%s:%d): sp=%p pc=%08lx\n", |
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current->comm, current->pid, frame, regs->pc); |
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#endif |
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return 0; |
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} |
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/* Handle restarting system calls */ |
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static inline void |
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handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler) |
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{ |
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switch (regs->r3) { |
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case -ERESTART_RESTARTBLOCK: |
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case -ERESTARTNOHAND: |
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if (!has_handler) |
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goto do_restart; |
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regs->r3 = -EINTR; |
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break; |
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case -ERESTARTSYS: |
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if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) { |
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regs->r3 = -EINTR; |
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break; |
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} |
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fallthrough; |
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case -ERESTARTNOINTR: |
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do_restart: |
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/* offset of 4 bytes to re-execute trap (brki) instruction */ |
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regs->pc -= 4; |
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break; |
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} |
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} |
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/* |
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* OK, we're invoking a handler |
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*/ |
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static void |
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handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
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{ |
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sigset_t *oldset = sigmask_to_save(); |
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int ret; |
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/* Set up the stack frame */ |
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ret = setup_rt_frame(ksig, oldset, regs); |
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signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP)); |
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} |
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/* |
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* Note that 'init' is a special process: it doesn't get signals it doesn't |
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* want to handle. Thus you cannot kill init even with a SIGKILL even by |
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* mistake. |
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* |
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* Note that we go through the signals twice: once to check the signals that |
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* the kernel can handle, and then we build all the user-level signal handling |
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* stack-frames in one go after that. |
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*/ |
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static void do_signal(struct pt_regs *regs, int in_syscall) |
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{ |
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struct ksignal ksig; |
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#ifdef DEBUG_SIG |
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pr_info("do signal: %p %d\n", regs, in_syscall); |
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pr_info("do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1, |
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regs->r12, current_thread_info()->flags); |
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#endif |
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if (get_signal(&ksig)) { |
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/* Whee! Actually deliver the signal. */ |
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if (in_syscall) |
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handle_restart(regs, &ksig.ka, 1); |
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handle_signal(&ksig, regs); |
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return; |
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} |
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if (in_syscall) |
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handle_restart(regs, NULL, 0); |
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/* |
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* If there's no signal to deliver, we just put the saved sigmask |
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* back. |
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*/ |
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restore_saved_sigmask(); |
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} |
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asmlinkage void do_notify_resume(struct pt_regs *regs, int in_syscall) |
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{ |
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if (test_thread_flag(TIF_SIGPENDING) || |
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test_thread_flag(TIF_NOTIFY_SIGNAL)) |
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do_signal(regs, in_syscall); |
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if (test_thread_flag(TIF_NOTIFY_RESUME)) |
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tracehook_notify_resume(regs); |
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}
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