97286a2b64
Impact: cleanup Introduce get_sigframe() like 32-bit to replace get_sigstack(). Move the i387 stuff into get_sigframe(). Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
904 lines
23 KiB
C
904 lines
23 KiB
C
/*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
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*
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* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
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* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
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* 2000-2002 x86-64 support by Andi Kleen
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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/tracehook.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/uaccess.h>
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#include <asm/processor.h>
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#include <asm/ucontext.h>
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#include <asm/i387.h>
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#include <asm/vdso.h>
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#ifdef CONFIG_X86_64
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#include <asm/proto.h>
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#include <asm/ia32_unistd.h>
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#include <asm/mce.h>
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#endif /* CONFIG_X86_64 */
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#include <asm/syscall.h>
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#include <asm/syscalls.h>
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#include <asm/sigframe.h>
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#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
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#define __FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \
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X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \
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X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \
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X86_EFLAGS_CF)
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#ifdef CONFIG_X86_32
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# define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF)
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#else
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# define FIX_EFLAGS __FIX_EFLAGS
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#endif
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#define COPY(x) do { \
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get_user_ex(regs->x, &sc->x); \
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} while (0)
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#define GET_SEG(seg) ({ \
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unsigned short tmp; \
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get_user_ex(tmp, &sc->seg); \
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tmp; \
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})
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#define COPY_SEG(seg) do { \
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regs->seg = GET_SEG(seg); \
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} while (0)
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#define COPY_SEG_CPL3(seg) do { \
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regs->seg = GET_SEG(seg) | 3; \
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} while (0)
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static int
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restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
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unsigned long *pax)
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{
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void __user *buf;
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unsigned int tmpflags;
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unsigned int err = 0;
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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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get_user_try {
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#ifdef CONFIG_X86_32
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set_user_gs(regs, GET_SEG(gs));
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COPY_SEG(fs);
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COPY_SEG(es);
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COPY_SEG(ds);
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#endif /* CONFIG_X86_32 */
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COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
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COPY(dx); COPY(cx); COPY(ip);
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#ifdef CONFIG_X86_64
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COPY(r8);
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COPY(r9);
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COPY(r10);
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COPY(r11);
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COPY(r12);
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COPY(r13);
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COPY(r14);
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COPY(r15);
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#endif /* CONFIG_X86_64 */
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#ifdef CONFIG_X86_32
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COPY_SEG_CPL3(cs);
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COPY_SEG_CPL3(ss);
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#else /* !CONFIG_X86_32 */
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/* Kernel saves and restores only the CS segment register on signals,
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* which is the bare minimum needed to allow mixed 32/64-bit code.
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* App's signal handler can save/restore other segments if needed. */
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COPY_SEG_CPL3(cs);
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#endif /* CONFIG_X86_32 */
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get_user_ex(tmpflags, &sc->flags);
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regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
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regs->orig_ax = -1; /* disable syscall checks */
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get_user_ex(buf, &sc->fpstate);
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err |= restore_i387_xstate(buf);
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get_user_ex(*pax, &sc->ax);
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} get_user_catch(err);
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return err;
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}
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static int
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setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
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struct pt_regs *regs, unsigned long mask)
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{
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int err = 0;
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put_user_try {
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#ifdef CONFIG_X86_32
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put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs);
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put_user_ex(regs->fs, (unsigned int __user *)&sc->fs);
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put_user_ex(regs->es, (unsigned int __user *)&sc->es);
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put_user_ex(regs->ds, (unsigned int __user *)&sc->ds);
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#endif /* CONFIG_X86_32 */
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put_user_ex(regs->di, &sc->di);
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put_user_ex(regs->si, &sc->si);
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put_user_ex(regs->bp, &sc->bp);
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put_user_ex(regs->sp, &sc->sp);
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put_user_ex(regs->bx, &sc->bx);
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put_user_ex(regs->dx, &sc->dx);
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put_user_ex(regs->cx, &sc->cx);
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put_user_ex(regs->ax, &sc->ax);
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#ifdef CONFIG_X86_64
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put_user_ex(regs->r8, &sc->r8);
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put_user_ex(regs->r9, &sc->r9);
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put_user_ex(regs->r10, &sc->r10);
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put_user_ex(regs->r11, &sc->r11);
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put_user_ex(regs->r12, &sc->r12);
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put_user_ex(regs->r13, &sc->r13);
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put_user_ex(regs->r14, &sc->r14);
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put_user_ex(regs->r15, &sc->r15);
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#endif /* CONFIG_X86_64 */
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put_user_ex(current->thread.trap_no, &sc->trapno);
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put_user_ex(current->thread.error_code, &sc->err);
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put_user_ex(regs->ip, &sc->ip);
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#ifdef CONFIG_X86_32
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put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
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put_user_ex(regs->flags, &sc->flags);
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put_user_ex(regs->sp, &sc->sp_at_signal);
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put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
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#else /* !CONFIG_X86_32 */
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put_user_ex(regs->flags, &sc->flags);
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put_user_ex(regs->cs, &sc->cs);
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put_user_ex(0, &sc->gs);
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put_user_ex(0, &sc->fs);
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#endif /* CONFIG_X86_32 */
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put_user_ex(fpstate, &sc->fpstate);
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/* non-iBCS2 extensions.. */
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put_user_ex(mask, &sc->oldmask);
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put_user_ex(current->thread.cr2, &sc->cr2);
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} put_user_catch(err);
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return err;
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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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#ifdef CONFIG_X86_32
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static const struct {
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u16 poplmovl;
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u32 val;
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u16 int80;
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} __attribute__((packed)) retcode = {
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0xb858, /* popl %eax; movl $..., %eax */
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__NR_sigreturn,
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0x80cd, /* int $0x80 */
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};
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static const struct {
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u8 movl;
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u32 val;
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u16 int80;
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u8 pad;
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} __attribute__((packed)) rt_retcode = {
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0xb8, /* movl $..., %eax */
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__NR_rt_sigreturn,
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0x80cd, /* int $0x80 */
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0
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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, struct pt_regs *regs, size_t frame_size,
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void __user **fpstate)
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{
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unsigned long sp;
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/* Default to using normal stack */
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sp = regs->sp;
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/*
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* If we are on the alternate signal stack and would overflow it, don't.
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* Return an always-bogus address instead so we will die with SIGSEGV.
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*/
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if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
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return (void __user *) -1L;
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/* This is the X/Open sanctioned signal stack switching. */
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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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} else {
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/* This is the legacy signal stack switching. */
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if ((regs->ss & 0xffff) != __USER_DS &&
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!(ka->sa.sa_flags & SA_RESTORER) &&
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ka->sa.sa_restorer)
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sp = (unsigned long) ka->sa.sa_restorer;
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}
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if (used_math()) {
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sp = sp - sig_xstate_size;
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*fpstate = (void __user *) sp;
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if (save_i387_xstate(*fpstate) < 0)
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return (void __user *)-1L;
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}
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sp -= frame_size;
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/*
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* Align the stack pointer according to the i386 ABI,
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* i.e. so that on function entry ((sp + 4) & 15) == 0.
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*/
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sp = ((sp + 4) & -16ul) - 4;
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return (void __user *) sp;
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}
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static int
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__setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
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struct pt_regs *regs)
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{
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struct sigframe __user *frame;
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void __user *restorer;
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int err = 0;
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void __user *fpstate = NULL;
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frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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return -EFAULT;
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if (__put_user(sig, &frame->sig))
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return -EFAULT;
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if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
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return -EFAULT;
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if (_NSIG_WORDS > 1) {
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if (__copy_to_user(&frame->extramask, &set->sig[1],
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sizeof(frame->extramask)))
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return -EFAULT;
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}
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if (current->mm->context.vdso)
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restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
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else
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restorer = &frame->retcode;
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if (ka->sa.sa_flags & SA_RESTORER)
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restorer = ka->sa.sa_restorer;
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/* Set up to return from userspace. */
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err |= __put_user(restorer, &frame->pretcode);
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/*
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* This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
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*
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* WE DO NOT USE IT ANY MORE! It's only left here for historical
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* reasons and because gdb uses it as a signature to notice
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* signal handler stack frames.
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*/
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err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);
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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->sp = (unsigned long)frame;
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regs->ip = (unsigned long)ka->sa.sa_handler;
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regs->ax = (unsigned long)sig;
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regs->dx = 0;
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regs->cx = 0;
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regs->ds = __USER_DS;
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regs->es = __USER_DS;
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regs->ss = __USER_DS;
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regs->cs = __USER_CS;
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return 0;
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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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void __user *restorer;
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int err = 0;
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void __user *fpstate = NULL;
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frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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return -EFAULT;
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put_user_try {
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put_user_ex(sig, &frame->sig);
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put_user_ex(&frame->info, &frame->pinfo);
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put_user_ex(&frame->uc, &frame->puc);
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err |= copy_siginfo_to_user(&frame->info, info);
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/* Create the ucontext. */
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if (cpu_has_xsave)
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put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
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else
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put_user_ex(0, &frame->uc.uc_flags);
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put_user_ex(0, &frame->uc.uc_link);
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put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
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put_user_ex(sas_ss_flags(regs->sp),
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&frame->uc.uc_stack.ss_flags);
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put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
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err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
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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. */
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restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
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if (ka->sa.sa_flags & SA_RESTORER)
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restorer = ka->sa.sa_restorer;
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put_user_ex(restorer, &frame->pretcode);
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/*
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* This is movl $__NR_rt_sigreturn, %ax ; int $0x80
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*
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* WE DO NOT USE IT ANY MORE! It's only left here for historical
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* reasons and because gdb uses it as a signature to notice
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* signal handler stack frames.
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*/
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put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
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} put_user_catch(err);
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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->sp = (unsigned long)frame;
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regs->ip = (unsigned long)ka->sa.sa_handler;
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regs->ax = (unsigned long)sig;
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regs->dx = (unsigned long)&frame->info;
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regs->cx = (unsigned long)&frame->uc;
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regs->ds = __USER_DS;
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regs->es = __USER_DS;
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regs->ss = __USER_DS;
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regs->cs = __USER_CS;
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return 0;
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}
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#else /* !CONFIG_X86_32 */
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/*
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* Determine which stack to use..
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*/
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static void __user *
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get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
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void __user **fpstate)
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{
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unsigned long sp;
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/* Default to using normal stack - redzone */
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sp = regs->sp - 128;
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/* This is the X/Open sanctioned signal stack switching. */
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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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if (used_math()) {
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sp -= sig_xstate_size;
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*fpstate = (void __user *)round_down(sp, 64);
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if (save_i387_xstate(*fpstate) < 0)
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return (void __user *) -1L;
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sp -= frame_size;
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return (void __user *)round_down(sp, 16) - 8;
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}
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sp -= frame_size;
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return (void __user *)round_down(sp, 64) - 8;
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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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void __user *fp = NULL;
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int err = 0;
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struct task_struct *me = current;
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frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe), &fp);
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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return -EFAULT;
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if (ka->sa.sa_flags & SA_SIGINFO) {
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if (copy_siginfo_to_user(&frame->info, info))
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return -EFAULT;
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}
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put_user_try {
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/* Create the ucontext. */
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if (cpu_has_xsave)
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put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
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else
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put_user_ex(0, &frame->uc.uc_flags);
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put_user_ex(0, &frame->uc.uc_link);
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put_user_ex(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
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put_user_ex(sas_ss_flags(regs->sp),
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&frame->uc.uc_stack.ss_flags);
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put_user_ex(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
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err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, 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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/* x86-64 should always use SA_RESTORER. */
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if (ka->sa.sa_flags & SA_RESTORER) {
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put_user_ex(ka->sa.sa_restorer, &frame->pretcode);
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} else {
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/* could use a vstub here */
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err |= -EFAULT;
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}
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} put_user_catch(err);
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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->di = sig;
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/* In case the signal handler was declared without prototypes */
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regs->ax = 0;
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/* This also works for non SA_SIGINFO handlers because they expect the
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next argument after the signal number on the stack. */
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regs->si = (unsigned long)&frame->info;
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regs->dx = (unsigned long)&frame->uc;
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regs->ip = (unsigned long) ka->sa.sa_handler;
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regs->sp = (unsigned long)frame;
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/* Set up the CS register to run signal handlers in 64-bit mode,
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even if the handler happens to be interrupting 32-bit code. */
|
|
regs->cs = __USER_CS;
|
|
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_X86_32 */
|
|
|
|
#ifdef CONFIG_X86_32
|
|
/*
|
|
* Atomically swap in the new signal mask, and wait for a signal.
|
|
*/
|
|
asmlinkage int
|
|
sys_sigsuspend(int history0, int history1, old_sigset_t mask)
|
|
{
|
|
mask &= _BLOCKABLE;
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
current->saved_sigmask = current->blocked;
|
|
siginitset(¤t->blocked, mask);
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
|
|
current->state = TASK_INTERRUPTIBLE;
|
|
schedule();
|
|
set_restore_sigmask();
|
|
|
|
return -ERESTARTNOHAND;
|
|
}
|
|
|
|
asmlinkage int
|
|
sys_sigaction(int sig, const struct old_sigaction __user *act,
|
|
struct old_sigaction __user *oact)
|
|
{
|
|
struct k_sigaction new_ka, old_ka;
|
|
int ret = 0;
|
|
|
|
if (act) {
|
|
old_sigset_t mask;
|
|
|
|
if (!access_ok(VERIFY_READ, act, sizeof(*act)))
|
|
return -EFAULT;
|
|
|
|
get_user_try {
|
|
get_user_ex(new_ka.sa.sa_handler, &act->sa_handler);
|
|
get_user_ex(new_ka.sa.sa_flags, &act->sa_flags);
|
|
get_user_ex(mask, &act->sa_mask);
|
|
get_user_ex(new_ka.sa.sa_restorer, &act->sa_restorer);
|
|
} get_user_catch(ret);
|
|
|
|
if (ret)
|
|
return -EFAULT;
|
|
siginitset(&new_ka.sa.sa_mask, mask);
|
|
}
|
|
|
|
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
|
|
|
|
if (!ret && oact) {
|
|
if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
|
|
return -EFAULT;
|
|
|
|
put_user_try {
|
|
put_user_ex(old_ka.sa.sa_handler, &oact->sa_handler);
|
|
put_user_ex(old_ka.sa.sa_flags, &oact->sa_flags);
|
|
put_user_ex(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
|
|
put_user_ex(old_ka.sa.sa_restorer, &oact->sa_restorer);
|
|
} put_user_catch(ret);
|
|
|
|
if (ret)
|
|
return -EFAULT;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
#endif /* CONFIG_X86_32 */
|
|
|
|
#ifdef CONFIG_X86_32
|
|
int sys_sigaltstack(struct pt_regs *regs)
|
|
{
|
|
const stack_t __user *uss = (const stack_t __user *)regs->bx;
|
|
stack_t __user *uoss = (stack_t __user *)regs->cx;
|
|
|
|
return do_sigaltstack(uss, uoss, regs->sp);
|
|
}
|
|
#else /* !CONFIG_X86_32 */
|
|
asmlinkage long
|
|
sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
|
|
struct pt_regs *regs)
|
|
{
|
|
return do_sigaltstack(uss, uoss, regs->sp);
|
|
}
|
|
#endif /* CONFIG_X86_32 */
|
|
|
|
/*
|
|
* Do a signal return; undo the signal stack.
|
|
*/
|
|
#ifdef CONFIG_X86_32
|
|
unsigned long sys_sigreturn(struct pt_regs *regs)
|
|
{
|
|
struct sigframe __user *frame;
|
|
unsigned long ax;
|
|
sigset_t set;
|
|
|
|
frame = (struct sigframe __user *)(regs->sp - 8);
|
|
|
|
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
|
|
goto badframe;
|
|
if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1
|
|
&& __copy_from_user(&set.sig[1], &frame->extramask,
|
|
sizeof(frame->extramask))))
|
|
goto badframe;
|
|
|
|
sigdelsetmask(&set, ~_BLOCKABLE);
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
current->blocked = set;
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
|
|
if (restore_sigcontext(regs, &frame->sc, &ax))
|
|
goto badframe;
|
|
return ax;
|
|
|
|
badframe:
|
|
signal_fault(regs, frame, "sigreturn");
|
|
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_X86_32 */
|
|
|
|
long sys_rt_sigreturn(struct pt_regs *regs)
|
|
{
|
|
struct rt_sigframe __user *frame;
|
|
unsigned long ax;
|
|
sigset_t set;
|
|
|
|
frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
|
|
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
|
|
goto badframe;
|
|
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
|
|
goto badframe;
|
|
|
|
sigdelsetmask(&set, ~_BLOCKABLE);
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
current->blocked = set;
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
|
|
if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
|
|
goto badframe;
|
|
|
|
if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
|
|
goto badframe;
|
|
|
|
return ax;
|
|
|
|
badframe:
|
|
signal_fault(regs, frame, "rt_sigreturn");
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* OK, we're invoking a handler:
|
|
*/
|
|
static int signr_convert(int sig)
|
|
{
|
|
#ifdef CONFIG_X86_32
|
|
struct thread_info *info = current_thread_info();
|
|
|
|
if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32)
|
|
return info->exec_domain->signal_invmap[sig];
|
|
#endif /* CONFIG_X86_32 */
|
|
return sig;
|
|
}
|
|
|
|
#ifdef CONFIG_X86_32
|
|
|
|
#define is_ia32 1
|
|
#define ia32_setup_frame __setup_frame
|
|
#define ia32_setup_rt_frame __setup_rt_frame
|
|
|
|
#else /* !CONFIG_X86_32 */
|
|
|
|
#ifdef CONFIG_IA32_EMULATION
|
|
#define is_ia32 test_thread_flag(TIF_IA32)
|
|
#else /* !CONFIG_IA32_EMULATION */
|
|
#define is_ia32 0
|
|
#endif /* CONFIG_IA32_EMULATION */
|
|
|
|
int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
|
|
sigset_t *set, struct pt_regs *regs);
|
|
int ia32_setup_frame(int sig, struct k_sigaction *ka,
|
|
sigset_t *set, struct pt_regs *regs);
|
|
|
|
#endif /* CONFIG_X86_32 */
|
|
|
|
static int
|
|
setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
|
|
sigset_t *set, struct pt_regs *regs)
|
|
{
|
|
int usig = signr_convert(sig);
|
|
int ret;
|
|
|
|
/* Set up the stack frame */
|
|
if (is_ia32) {
|
|
if (ka->sa.sa_flags & SA_SIGINFO)
|
|
ret = ia32_setup_rt_frame(usig, ka, info, set, regs);
|
|
else
|
|
ret = ia32_setup_frame(usig, ka, set, regs);
|
|
} else
|
|
ret = __setup_rt_frame(sig, ka, info, set, regs);
|
|
|
|
if (ret) {
|
|
force_sigsegv(sig, current);
|
|
return -EFAULT;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
|
|
sigset_t *oldset, struct pt_regs *regs)
|
|
{
|
|
int ret;
|
|
|
|
/* Are we from a system call? */
|
|
if (syscall_get_nr(current, regs) >= 0) {
|
|
/* If so, check system call restarting.. */
|
|
switch (syscall_get_error(current, regs)) {
|
|
case -ERESTART_RESTARTBLOCK:
|
|
case -ERESTARTNOHAND:
|
|
regs->ax = -EINTR;
|
|
break;
|
|
|
|
case -ERESTARTSYS:
|
|
if (!(ka->sa.sa_flags & SA_RESTART)) {
|
|
regs->ax = -EINTR;
|
|
break;
|
|
}
|
|
/* fallthrough */
|
|
case -ERESTARTNOINTR:
|
|
regs->ax = regs->orig_ax;
|
|
regs->ip -= 2;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
|
|
* flag so that register information in the sigcontext is correct.
|
|
*/
|
|
if (unlikely(regs->flags & X86_EFLAGS_TF) &&
|
|
likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
|
|
regs->flags &= ~X86_EFLAGS_TF;
|
|
|
|
ret = setup_rt_frame(sig, ka, info, oldset, regs);
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
#ifdef CONFIG_X86_64
|
|
/*
|
|
* This has nothing to do with segment registers,
|
|
* despite the name. This magic affects uaccess.h
|
|
* macros' behavior. Reset it to the normal setting.
|
|
*/
|
|
set_fs(USER_DS);
|
|
#endif
|
|
|
|
/*
|
|
* Clear the direction flag as per the ABI for function entry.
|
|
*/
|
|
regs->flags &= ~X86_EFLAGS_DF;
|
|
|
|
/*
|
|
* Clear TF when entering the signal handler, but
|
|
* notify any tracer that was single-stepping it.
|
|
* The tracer may want to single-step inside the
|
|
* handler too.
|
|
*/
|
|
regs->flags &= ~X86_EFLAGS_TF;
|
|
|
|
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);
|
|
|
|
tracehook_signal_handler(sig, info, ka, regs,
|
|
test_thread_flag(TIF_SINGLESTEP));
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_X86_32
|
|
#define NR_restart_syscall __NR_restart_syscall
|
|
#else /* !CONFIG_X86_32 */
|
|
#define NR_restart_syscall \
|
|
test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
|
|
#endif /* CONFIG_X86_32 */
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static void do_signal(struct pt_regs *regs)
|
|
{
|
|
struct k_sigaction ka;
|
|
siginfo_t info;
|
|
int signr;
|
|
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.
|
|
* X86_32: vm86 regs switched out by assembly code before reaching
|
|
* here, so testing against kernel CS suffices.
|
|
*/
|
|
if (!user_mode(regs))
|
|
return;
|
|
|
|
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) {
|
|
/*
|
|
* Re-enable any watchpoints before delivering the
|
|
* signal to user space. The processor register will
|
|
* have been cleared if the watchpoint triggered
|
|
* inside the kernel.
|
|
*/
|
|
if (current->thread.debugreg7)
|
|
set_debugreg(current->thread.debugreg7, 7);
|
|
|
|
/* Whee! Actually deliver the signal. */
|
|
if (handle_signal(signr, &info, &ka, oldset, regs) == 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;
|
|
}
|
|
return;
|
|
}
|
|
|
|
/* Did we come from a system call? */
|
|
if (syscall_get_nr(current, regs) >= 0) {
|
|
/* Restart the system call - no handlers present */
|
|
switch (syscall_get_error(current, regs)) {
|
|
case -ERESTARTNOHAND:
|
|
case -ERESTARTSYS:
|
|
case -ERESTARTNOINTR:
|
|
regs->ax = regs->orig_ax;
|
|
regs->ip -= 2;
|
|
break;
|
|
|
|
case -ERESTART_RESTARTBLOCK:
|
|
regs->ax = NR_restart_syscall;
|
|
regs->ip -= 2;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* notification of userspace execution resumption
|
|
* - triggered by the TIF_WORK_MASK flags
|
|
*/
|
|
void
|
|
do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
|
|
{
|
|
#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
|
|
/* notify userspace of pending MCEs */
|
|
if (thread_info_flags & _TIF_MCE_NOTIFY)
|
|
mce_notify_user();
|
|
#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
|
|
|
|
/* deal with pending signal delivery */
|
|
if (thread_info_flags & _TIF_SIGPENDING)
|
|
do_signal(regs);
|
|
|
|
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
|
|
clear_thread_flag(TIF_NOTIFY_RESUME);
|
|
tracehook_notify_resume(regs);
|
|
}
|
|
|
|
#ifdef CONFIG_X86_32
|
|
clear_thread_flag(TIF_IRET);
|
|
#endif /* CONFIG_X86_32 */
|
|
}
|
|
|
|
void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
|
|
{
|
|
struct task_struct *me = current;
|
|
|
|
if (show_unhandled_signals && printk_ratelimit()) {
|
|
printk("%s"
|
|
"%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
|
|
task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
|
|
me->comm, me->pid, where, frame,
|
|
regs->ip, regs->sp, regs->orig_ax);
|
|
print_vma_addr(" in ", regs->ip);
|
|
printk(KERN_CONT "\n");
|
|
}
|
|
|
|
force_sig(SIGSEGV, me);
|
|
}
|