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![Paul Mundt](/assets/img/avatar_default.png)
The old ctrl in/out routines are non-portable and unsuitable for cross-platform use. While drivers/sh has already been sanitized, there is still quite a lot of code that is not. This converts the arch/sh/ bits over, which permits us to flag the routines as deprecated whilst still building with -Werror for the architecture code, and to ensure that future users are not added. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
659 lines
17 KiB
C
659 lines
17 KiB
C
/*
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* linux/arch/sh/kernel/signal.c
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*
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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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* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
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*
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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/tty.h>
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#include <linux/elf.h>
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#include <linux/personality.h>
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#include <linux/binfmts.h>
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#include <linux/freezer.h>
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#include <linux/io.h>
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#include <linux/tracehook.h>
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#include <asm/system.h>
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#include <asm/ucontext.h>
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#include <asm/uaccess.h>
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#include <asm/pgtable.h>
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#include <asm/cacheflush.h>
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#include <asm/syscalls.h>
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#include <asm/fpu.h>
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#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
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struct fdpic_func_descriptor {
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unsigned long text;
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unsigned long GOT;
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};
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/*
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* The following define adds a 64 byte gap between the signal
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* stack frame and previous contents of the stack. This allows
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* frame unwinding in a function epilogue but only if a frame
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* pointer is used in the function. This is necessary because
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* current gcc compilers (<4.3) do not generate unwind info on
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* SH for function epilogues.
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*/
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#define UNWINDGUARD 64
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/*
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* Atomically swap in the new signal mask, and wait for a signal.
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*/
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asmlinkage int
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sys_sigsuspend(old_sigset_t mask,
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unsigned long r5, unsigned long r6, unsigned long r7,
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struct pt_regs __regs)
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{
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mask &= _BLOCKABLE;
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spin_lock_irq(¤t->sighand->siglock);
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current->saved_sigmask = current->blocked;
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siginitset(¤t->blocked, mask);
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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current->state = TASK_INTERRUPTIBLE;
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schedule();
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set_restore_sigmask();
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return -ERESTARTNOHAND;
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}
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asmlinkage int
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sys_sigaction(int sig, const struct old_sigaction __user *act,
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struct old_sigaction __user *oact)
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{
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struct k_sigaction new_ka, old_ka;
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int ret;
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if (act) {
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old_sigset_t mask;
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if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
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__get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
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__get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
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return -EFAULT;
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__get_user(new_ka.sa.sa_flags, &act->sa_flags);
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__get_user(mask, &act->sa_mask);
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siginitset(&new_ka.sa.sa_mask, mask);
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}
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ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
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if (!ret && oact) {
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if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
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__put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
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__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
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return -EFAULT;
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__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
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__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
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}
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return ret;
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}
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asmlinkage int
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sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
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unsigned long r6, unsigned long r7,
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struct pt_regs __regs)
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{
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struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
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return do_sigaltstack(uss, uoss, regs->regs[15]);
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}
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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 MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */
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#if defined(CONFIG_CPU_SH2)
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#define TRAP_NOARG 0xc320 /* Syscall w/no args (NR in R3) */
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#else
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#define TRAP_NOARG 0xc310 /* Syscall w/no args (NR in R3) */
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#endif
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#define OR_R0_R0 0x200b /* or r0,r0 (insert to avoid hardware bug) */
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struct sigframe
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{
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struct sigcontext sc;
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unsigned long extramask[_NSIG_WORDS-1];
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u16 retcode[8];
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};
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struct rt_sigframe
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{
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struct siginfo info;
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struct ucontext uc;
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u16 retcode[8];
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};
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#ifdef CONFIG_SH_FPU
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static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
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{
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struct task_struct *tsk = current;
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if (!(boot_cpu_data.flags & CPU_HAS_FPU))
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return 0;
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set_used_math();
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return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0],
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sizeof(long)*(16*2+2));
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}
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static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
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struct pt_regs *regs)
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{
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struct task_struct *tsk = current;
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if (!(boot_cpu_data.flags & CPU_HAS_FPU))
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return 0;
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if (!used_math()) {
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__put_user(0, &sc->sc_ownedfp);
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return 0;
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}
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__put_user(1, &sc->sc_ownedfp);
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/* This will cause a "finit" to be triggered by the next
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attempted FPU operation by the 'current' process.
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*/
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clear_used_math();
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unlazy_fpu(tsk, regs);
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return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu,
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sizeof(long)*(16*2+2));
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}
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#endif /* CONFIG_SH_FPU */
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static int
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restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_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->sc_##x)
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COPY(regs[1]);
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COPY(regs[2]); COPY(regs[3]);
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COPY(regs[4]); COPY(regs[5]);
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COPY(regs[6]); COPY(regs[7]);
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COPY(regs[8]); COPY(regs[9]);
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COPY(regs[10]); COPY(regs[11]);
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COPY(regs[12]); COPY(regs[13]);
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COPY(regs[14]); COPY(regs[15]);
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COPY(gbr); COPY(mach);
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COPY(macl); COPY(pr);
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COPY(sr); COPY(pc);
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#undef COPY
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#ifdef CONFIG_SH_FPU
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if (boot_cpu_data.flags & CPU_HAS_FPU) {
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int owned_fp;
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struct task_struct *tsk = current;
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regs->sr |= SR_FD; /* Release FPU */
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clear_fpu(tsk, regs);
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clear_used_math();
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__get_user (owned_fp, &sc->sc_ownedfp);
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if (owned_fp)
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err |= restore_sigcontext_fpu(sc);
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}
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#endif
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regs->tra = -1; /* disable syscall checks */
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err |= __get_user(*r0_p, &sc->sc_regs[0]);
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return err;
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}
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asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5,
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unsigned long r6, unsigned long r7,
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struct pt_regs __regs)
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{
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struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
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struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15];
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sigset_t set;
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int r0;
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/* Always make any pending restarted system calls return -EINTR */
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current_thread_info()->restart_block.fn = do_no_restart_syscall;
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if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
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goto badframe;
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if (__get_user(set.sig[0], &frame->sc.oldmask)
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|| (_NSIG_WORDS > 1
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&& __copy_from_user(&set.sig[1], &frame->extramask,
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sizeof(frame->extramask))))
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goto badframe;
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sigdelsetmask(&set, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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current->blocked = set;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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if (restore_sigcontext(regs, &frame->sc, &r0))
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goto badframe;
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return r0;
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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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asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5,
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unsigned long r6, unsigned long r7,
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struct pt_regs __regs)
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{
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struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
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struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15];
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sigset_t set;
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int r0;
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/* Always make any pending restarted system calls return -EINTR */
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current_thread_info()->restart_block.fn = do_no_restart_syscall;
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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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spin_lock_irq(¤t->sighand->siglock);
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current->blocked = set;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
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goto badframe;
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if (do_sigaltstack(&frame->uc.uc_stack, NULL,
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regs->regs[15]) == -EFAULT)
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goto badframe;
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return r0;
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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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/*
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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->sc_##x)
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COPY(regs[0]); COPY(regs[1]);
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COPY(regs[2]); COPY(regs[3]);
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COPY(regs[4]); COPY(regs[5]);
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COPY(regs[6]); COPY(regs[7]);
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COPY(regs[8]); COPY(regs[9]);
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COPY(regs[10]); COPY(regs[11]);
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COPY(regs[12]); COPY(regs[13]);
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COPY(regs[14]); COPY(regs[15]);
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COPY(gbr); COPY(mach);
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COPY(macl); COPY(pr);
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COPY(sr); COPY(pc);
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#undef COPY
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#ifdef CONFIG_SH_FPU
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err |= save_sigcontext_fpu(sc, regs);
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#endif
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/* non-iBCS2 extensions.. */
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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 k_sigaction *ka, unsigned long sp, size_t frame_size)
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{
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if (ka->sa.sa_flags & SA_ONSTACK) {
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if (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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return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul);
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}
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/* These symbols are defined with the addresses in the vsyscall page.
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See vsyscall-trapa.S. */
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extern void __kernel_sigreturn(void);
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extern void __kernel_rt_sigreturn(void);
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static int setup_frame(int sig, struct k_sigaction *ka,
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sigset_t *set, struct pt_regs *regs)
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{
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struct sigframe __user *frame;
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int err = 0;
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int signal;
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frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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goto give_sigsegv;
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signal = current_thread_info()->exec_domain
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&& current_thread_info()->exec_domain->signal_invmap
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&& sig < 32
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? current_thread_info()->exec_domain->signal_invmap[sig]
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: sig;
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err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
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if (_NSIG_WORDS > 1)
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err |= __copy_to_user(frame->extramask, &set->sig[1],
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sizeof(frame->extramask));
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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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if (ka->sa.sa_flags & SA_RESTORER) {
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regs->pr = (unsigned long) ka->sa.sa_restorer;
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#ifdef CONFIG_VSYSCALL
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} else if (likely(current->mm->context.vdso)) {
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regs->pr = VDSO_SYM(&__kernel_sigreturn);
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#endif
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} else {
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/* Generate return code (system call to sigreturn) */
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err |= __put_user(MOVW(7), &frame->retcode[0]);
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err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
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err |= __put_user(OR_R0_R0, &frame->retcode[2]);
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err |= __put_user(OR_R0_R0, &frame->retcode[3]);
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err |= __put_user(OR_R0_R0, &frame->retcode[4]);
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err |= __put_user(OR_R0_R0, &frame->retcode[5]);
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err |= __put_user(OR_R0_R0, &frame->retcode[6]);
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err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
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regs->pr = (unsigned long) frame->retcode;
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flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
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}
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if (err)
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goto give_sigsegv;
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/* Set up registers for signal handler */
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regs->regs[15] = (unsigned long) frame;
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regs->regs[4] = signal; /* Arg for signal handler */
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regs->regs[5] = 0;
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regs->regs[6] = (unsigned long) &frame->sc;
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if (current->personality & FDPIC_FUNCPTRS) {
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struct fdpic_func_descriptor __user *funcptr =
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(struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
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__get_user(regs->pc, &funcptr->text);
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__get_user(regs->regs[12], &funcptr->GOT);
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} else
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regs->pc = (unsigned long)ka->sa.sa_handler;
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set_fs(USER_DS);
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pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
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current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
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return 0;
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give_sigsegv:
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force_sigsegv(sig, current);
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return -EFAULT;
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}
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static int setup_rt_frame(int sig, 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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int err = 0;
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int signal;
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frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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goto give_sigsegv;
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signal = current_thread_info()->exec_domain
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&& current_thread_info()->exec_domain->signal_invmap
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&& sig < 32
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? current_thread_info()->exec_domain->signal_invmap[sig]
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: sig;
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err |= copy_siginfo_to_user(&frame->info, 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 |= __put_user((void *)current->sas_ss_sp,
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&frame->uc.uc_stack.ss_sp);
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err |= __put_user(sas_ss_flags(regs->regs[15]),
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&frame->uc.uc_stack.ss_flags);
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err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
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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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if (ka->sa.sa_flags & SA_RESTORER) {
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regs->pr = (unsigned long) ka->sa.sa_restorer;
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#ifdef CONFIG_VSYSCALL
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} else if (likely(current->mm->context.vdso)) {
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regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
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#endif
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} else {
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/* Generate return code (system call to rt_sigreturn) */
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err |= __put_user(MOVW(7), &frame->retcode[0]);
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err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
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err |= __put_user(OR_R0_R0, &frame->retcode[2]);
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err |= __put_user(OR_R0_R0, &frame->retcode[3]);
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err |= __put_user(OR_R0_R0, &frame->retcode[4]);
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err |= __put_user(OR_R0_R0, &frame->retcode[5]);
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err |= __put_user(OR_R0_R0, &frame->retcode[6]);
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err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
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regs->pr = (unsigned long) frame->retcode;
|
|
flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
|
|
}
|
|
|
|
if (err)
|
|
goto give_sigsegv;
|
|
|
|
/* Set up registers for signal handler */
|
|
regs->regs[15] = (unsigned long) frame;
|
|
regs->regs[4] = signal; /* Arg for signal handler */
|
|
regs->regs[5] = (unsigned long) &frame->info;
|
|
regs->regs[6] = (unsigned long) &frame->uc;
|
|
|
|
if (current->personality & FDPIC_FUNCPTRS) {
|
|
struct fdpic_func_descriptor __user *funcptr =
|
|
(struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
|
|
|
|
__get_user(regs->pc, &funcptr->text);
|
|
__get_user(regs->regs[12], &funcptr->GOT);
|
|
} else
|
|
regs->pc = (unsigned long)ka->sa.sa_handler;
|
|
|
|
set_fs(USER_DS);
|
|
|
|
pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
|
|
current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
|
|
|
|
return 0;
|
|
|
|
give_sigsegv:
|
|
force_sigsegv(sig, current);
|
|
return -EFAULT;
|
|
}
|
|
|
|
static inline void
|
|
handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs,
|
|
struct sigaction *sa)
|
|
{
|
|
/* If we're not from a syscall, bail out */
|
|
if (regs->tra < 0)
|
|
return;
|
|
|
|
/* check for system call restart.. */
|
|
switch (regs->regs[0]) {
|
|
case -ERESTART_RESTARTBLOCK:
|
|
case -ERESTARTNOHAND:
|
|
no_system_call_restart:
|
|
regs->regs[0] = -EINTR;
|
|
break;
|
|
|
|
case -ERESTARTSYS:
|
|
if (!(sa->sa_flags & SA_RESTART))
|
|
goto no_system_call_restart;
|
|
/* fallthrough */
|
|
case -ERESTARTNOINTR:
|
|
regs->regs[0] = save_r0;
|
|
regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* OK, we're invoking a handler
|
|
*/
|
|
static int
|
|
handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
|
|
sigset_t *oldset, struct pt_regs *regs, unsigned int save_r0)
|
|
{
|
|
int ret;
|
|
|
|
/* Set up the stack frame */
|
|
if (ka->sa.sa_flags & SA_SIGINFO)
|
|
ret = setup_rt_frame(sig, ka, info, oldset, regs);
|
|
else
|
|
ret = setup_frame(sig, ka, oldset, regs);
|
|
|
|
if (ka->sa.sa_flags & SA_ONESHOT)
|
|
ka->sa.sa_handler = SIG_DFL;
|
|
|
|
if (ret == 0) {
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
|
|
if (!(ka->sa.sa_flags & SA_NODEFER))
|
|
sigaddset(¤t->blocked,sig);
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static void do_signal(struct pt_regs *regs, unsigned int save_r0)
|
|
{
|
|
siginfo_t info;
|
|
int signr;
|
|
struct k_sigaction ka;
|
|
sigset_t *oldset;
|
|
|
|
/*
|
|
* 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;
|
|
|
|
if (try_to_freeze())
|
|
goto no_signal;
|
|
|
|
if (current_thread_info()->status & TS_RESTORE_SIGMASK)
|
|
oldset = ¤t->saved_sigmask;
|
|
else
|
|
oldset = ¤t->blocked;
|
|
|
|
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
|
|
if (signr > 0) {
|
|
handle_syscall_restart(save_r0, regs, &ka.sa);
|
|
|
|
/* Whee! Actually deliver the signal. */
|
|
if (handle_signal(signr, &ka, &info, oldset,
|
|
regs, save_r0) == 0) {
|
|
/*
|
|
* A signal was successfully delivered; the saved
|
|
* sigmask will have been stored in the signal frame,
|
|
* and will be restored by sigreturn, so we can simply
|
|
* clear the TS_RESTORE_SIGMASK flag
|
|
*/
|
|
current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
|
|
|
|
tracehook_signal_handler(signr, &info, &ka, regs,
|
|
test_thread_flag(TIF_SINGLESTEP));
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
no_signal:
|
|
/* Did we come from a system call? */
|
|
if (regs->tra >= 0) {
|
|
/* Restart the system call - no handlers present */
|
|
if (regs->regs[0] == -ERESTARTNOHAND ||
|
|
regs->regs[0] == -ERESTARTSYS ||
|
|
regs->regs[0] == -ERESTARTNOINTR) {
|
|
regs->regs[0] = save_r0;
|
|
regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
|
|
} else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
|
|
regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
|
|
regs->regs[3] = __NR_restart_syscall;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If there's no signal to deliver, we just put the saved sigmask
|
|
* back.
|
|
*/
|
|
if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
|
|
current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
|
|
sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
|
|
}
|
|
}
|
|
|
|
asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
|
|
unsigned long thread_info_flags)
|
|
{
|
|
/* deal with pending signal delivery */
|
|
if (thread_info_flags & _TIF_SIGPENDING)
|
|
do_signal(regs, save_r0);
|
|
|
|
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
|
|
clear_thread_flag(TIF_NOTIFY_RESUME);
|
|
tracehook_notify_resume(regs);
|
|
if (current->replacement_session_keyring)
|
|
key_replace_session_keyring();
|
|
}
|
|
}
|