forked from Minki/linux
6e61ee3b7a
As described ine6fa16ab9c("signal: sigprocmask() should do retarget_shared_pending()") the modification of current->blocked is incorrect as we need to check whether the signal we're about to block is pending in the shared queue. Also, use the new helper function introduced in commit5e6292c0f2("signal: add block_sigmask() for adding sigmask to current->blocked") which centralises the code for updating current->blocked after successfully delivering a signal and reduces the amount of duplicate code across architectures. In the past some architectures got this code wrong, so using this helper function should stop that from happening again. Acked-by: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
368 lines
9.2 KiB
C
368 lines
9.2 KiB
C
/*
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* Port on Texas Instruments TMS320C6x architecture
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*
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* Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
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* Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
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*
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* Updated for 2.6.34: Mark Salter <msalter@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/uaccess.h>
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#include <linux/syscalls.h>
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#include <linux/tracehook.h>
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#include <asm/ucontext.h>
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#include <asm/cacheflush.h>
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#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
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/*
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* Do a signal return, undo the signal stack.
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*/
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#define RETCODE_SIZE (9 << 2) /* 9 instructions = 36 bytes */
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struct rt_sigframe {
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struct siginfo __user *pinfo;
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void __user *puc;
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struct siginfo info;
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struct ucontext uc;
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unsigned long retcode[RETCODE_SIZE >> 2];
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};
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static int restore_sigcontext(struct pt_regs *regs,
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struct sigcontext __user *sc)
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{
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int err = 0;
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/* The access_ok check was done by caller, so use __get_user here */
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#define COPY(x) (err |= __get_user(regs->x, &sc->sc_##x))
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COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8);
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COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9);
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COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9);
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COPY(a16); COPY(a17); COPY(a18); COPY(a19);
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COPY(a20); COPY(a21); COPY(a22); COPY(a23);
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COPY(a24); COPY(a25); COPY(a26); COPY(a27);
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COPY(a28); COPY(a29); COPY(a30); COPY(a31);
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COPY(b16); COPY(b17); COPY(b18); COPY(b19);
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COPY(b20); COPY(b21); COPY(b22); COPY(b23);
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COPY(b24); COPY(b25); COPY(b26); COPY(b27);
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COPY(b28); COPY(b29); COPY(b30); COPY(b31);
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COPY(csr); COPY(pc);
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#undef COPY
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return err;
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}
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asmlinkage int do_rt_sigreturn(struct pt_regs *regs)
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{
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struct rt_sigframe __user *frame;
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sigset_t set;
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/*
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* Since we stacked the signal on a dword boundary,
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* 'sp' should be dword aligned here. If it's
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* not, then the user is trying to mess with us.
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*/
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if (regs->sp & 7)
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goto badframe;
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frame = (struct rt_sigframe __user *) ((unsigned long) regs->sp + 8);
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if (!access_ok(VERIFY_READ, 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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sigdelsetmask(&set, ~_BLOCKABLE);
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set_current_blocked(&set);
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if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
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goto badframe;
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return regs->a4;
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badframe:
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force_sig(SIGSEGV, current);
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return 0;
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}
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static int 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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err |= __put_user(mask, &sc->sc_mask);
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/* The access_ok check was done by caller, so use __put_user here */
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#define COPY(x) (err |= __put_user(regs->x, &sc->sc_##x))
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COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8);
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COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9);
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COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9);
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COPY(a16); COPY(a17); COPY(a18); COPY(a19);
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COPY(a20); COPY(a21); COPY(a22); COPY(a23);
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COPY(a24); COPY(a25); COPY(a26); COPY(a27);
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COPY(a28); COPY(a29); COPY(a30); COPY(a31);
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COPY(b16); COPY(b17); COPY(b18); COPY(b19);
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COPY(b20); COPY(b21); COPY(b22); COPY(b23);
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COPY(b24); COPY(b25); COPY(b26); COPY(b27);
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COPY(b28); COPY(b29); COPY(b30); COPY(b31);
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COPY(csr); COPY(pc);
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#undef COPY
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return err;
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}
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static inline void __user *get_sigframe(struct k_sigaction *ka,
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struct pt_regs *regs,
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unsigned long framesize)
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{
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unsigned long sp = regs->sp;
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/*
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* This is the X/Open sanctioned signal stack switching.
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*/
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if ((ka->sa.sa_flags & SA_ONSTACK) && sas_ss_flags(sp) == 0)
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sp = current->sas_ss_sp + current->sas_ss_size;
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/*
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* No matter what happens, 'sp' must be dword
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* aligned. Otherwise, nasty things will happen
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*/
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return (void __user *)((sp - framesize) & ~7);
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}
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static int setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info,
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sigset_t *set, struct pt_regs *regs)
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{
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struct rt_sigframe __user *frame;
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unsigned long __user *retcode;
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int err = 0;
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frame = get_sigframe(ka, regs, sizeof(*frame));
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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goto segv_and_exit;
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err |= __put_user(&frame->info, &frame->pinfo);
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err |= __put_user(&frame->uc, &frame->puc);
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err |= copy_siginfo_to_user(&frame->info, info);
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/* Clear all the bits of the ucontext we don't use. */
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err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
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err |= setup_sigcontext(&frame->uc.uc_mcontext, 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 */
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retcode = (unsigned long __user *) &frame->retcode;
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/* The access_ok check was done above, so use __put_user here */
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#define COPY(x) (err |= __put_user(x, retcode++))
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COPY(0x0000002AUL | (__NR_rt_sigreturn << 7));
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/* MVK __NR_rt_sigreturn,B0 */
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COPY(0x10000000UL); /* SWE */
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COPY(0x00006000UL); /* NOP 4 */
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COPY(0x00006000UL); /* NOP 4 */
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COPY(0x00006000UL); /* NOP 4 */
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COPY(0x00006000UL); /* NOP 4 */
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COPY(0x00006000UL); /* NOP 4 */
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COPY(0x00006000UL); /* NOP 4 */
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COPY(0x00006000UL); /* NOP 4 */
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#undef COPY
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if (err)
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goto segv_and_exit;
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flush_icache_range((unsigned long) &frame->retcode,
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(unsigned long) &frame->retcode + RETCODE_SIZE);
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retcode = (unsigned long __user *) &frame->retcode;
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/* Change user context to branch to signal handler */
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regs->sp = (unsigned long) frame - 8;
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regs->b3 = (unsigned long) retcode;
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regs->pc = (unsigned long) ka->sa.sa_handler;
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/* Give the signal number to the handler */
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regs->a4 = signr;
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/*
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* For realtime signals we must also set the second and third
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* arguments for the signal handler.
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* -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
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*/
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regs->b4 = (unsigned long)&frame->info;
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regs->a6 = (unsigned long)&frame->uc;
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return 0;
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segv_and_exit:
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force_sigsegv(signr, current);
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return -EFAULT;
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}
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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->a4) {
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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->a4 = -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->a4 = -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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regs->a4 = regs->orig_a4;
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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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* handle the actual delivery of a signal to userspace
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*/
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static int handle_signal(int sig,
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siginfo_t *info, struct k_sigaction *ka,
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sigset_t *oldset, struct pt_regs *regs,
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int syscall)
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{
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int ret;
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/* Are we from a system call? */
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if (syscall) {
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/* If so, check system call restarting.. */
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switch (regs->a4) {
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case -ERESTART_RESTARTBLOCK:
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case -ERESTARTNOHAND:
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regs->a4 = -EINTR;
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break;
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case -ERESTARTSYS:
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if (!(ka->sa.sa_flags & SA_RESTART)) {
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regs->a4 = -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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regs->a4 = regs->orig_a4;
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regs->pc -= 4;
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}
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}
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/* Set up the stack frame */
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ret = setup_rt_frame(sig, ka, info, oldset, regs);
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if (ret == 0)
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block_sigmask(ka, sig);
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return ret;
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}
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/*
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* handle a potential signal
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*/
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static void do_signal(struct pt_regs *regs, int syscall)
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{
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struct k_sigaction ka;
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siginfo_t info;
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sigset_t *oldset;
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int signr;
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/* we want the common case to go fast, which is why we may in certain
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* cases get here from kernel mode */
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if (!user_mode(regs))
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return;
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if (test_thread_flag(TIF_RESTORE_SIGMASK))
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oldset = ¤t->saved_sigmask;
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else
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oldset = ¤t->blocked;
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signr = get_signal_to_deliver(&info, &ka, regs, NULL);
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if (signr > 0) {
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if (handle_signal(signr, &info, &ka, oldset,
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regs, syscall) == 0) {
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/* a signal was successfully delivered; the saved
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* sigmask will have been stored in the signal frame,
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* and will be restored by sigreturn, so we can simply
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* clear the TIF_RESTORE_SIGMASK flag */
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if (test_thread_flag(TIF_RESTORE_SIGMASK))
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clear_thread_flag(TIF_RESTORE_SIGMASK);
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tracehook_signal_handler(signr, &info, &ka, regs, 0);
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}
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return;
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}
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/* did we come from a system call? */
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if (syscall) {
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/* restart the system call - no handlers present */
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switch (regs->a4) {
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case -ERESTARTNOHAND:
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case -ERESTARTSYS:
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case -ERESTARTNOINTR:
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regs->a4 = regs->orig_a4;
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regs->pc -= 4;
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break;
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case -ERESTART_RESTARTBLOCK:
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regs->a4 = regs->orig_a4;
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regs->b0 = __NR_restart_syscall;
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regs->pc -= 4;
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break;
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}
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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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if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
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clear_thread_flag(TIF_RESTORE_SIGMASK);
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sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
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}
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}
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/*
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* notification of userspace execution resumption
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* - triggered by current->work.notify_resume
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*/
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asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags,
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int syscall)
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{
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/* deal with pending signal delivery */
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if (thread_info_flags & ((1 << TIF_SIGPENDING) |
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(1 << TIF_RESTORE_SIGMASK)))
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do_signal(regs, syscall);
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if (thread_info_flags & (1 << TIF_NOTIFY_RESUME)) {
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clear_thread_flag(TIF_NOTIFY_RESUME);
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tracehook_notify_resume(regs);
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if (current->replacement_session_keyring)
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key_replace_session_keyring();
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}
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}
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