292 lines
8.0 KiB
C
292 lines
8.0 KiB
C
/*
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* Copyright (C) 2003 PathScale, Inc.
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* Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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* Licensed under the GPL
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*/
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#include <linux/personality.h>
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#include <linux/ptrace.h>
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#include <asm/unistd.h>
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#include <asm/uaccess.h>
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#include <asm/ucontext.h>
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#include "frame_kern.h"
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#include "skas.h"
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void copy_sc(struct uml_pt_regs *regs, void *from)
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{
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struct sigcontext *sc = from;
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#define GETREG(regs, regno, sc, regname) \
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(regs)->gp[(regno) / sizeof(unsigned long)] = (sc)->regname
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GETREG(regs, R8, sc, r8);
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GETREG(regs, R9, sc, r9);
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GETREG(regs, R10, sc, r10);
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GETREG(regs, R11, sc, r11);
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GETREG(regs, R12, sc, r12);
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GETREG(regs, R13, sc, r13);
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GETREG(regs, R14, sc, r14);
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GETREG(regs, R15, sc, r15);
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GETREG(regs, RDI, sc, di);
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GETREG(regs, RSI, sc, si);
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GETREG(regs, RBP, sc, bp);
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GETREG(regs, RBX, sc, bx);
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GETREG(regs, RDX, sc, dx);
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GETREG(regs, RAX, sc, ax);
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GETREG(regs, RCX, sc, cx);
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GETREG(regs, RSP, sc, sp);
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GETREG(regs, RIP, sc, ip);
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GETREG(regs, EFLAGS, sc, flags);
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GETREG(regs, CS, sc, cs);
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#undef GETREG
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}
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static int copy_sc_from_user(struct pt_regs *regs,
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struct sigcontext __user *from,
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struct _fpstate __user *fpp)
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{
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struct user_i387_struct fp;
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int err = 0;
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#define GETREG(regs, regno, sc, regname) \
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__get_user((regs)->regs.gp[(regno) / sizeof(unsigned long)], \
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&(sc)->regname)
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err |= GETREG(regs, R8, from, r8);
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err |= GETREG(regs, R9, from, r9);
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err |= GETREG(regs, R10, from, r10);
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err |= GETREG(regs, R11, from, r11);
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err |= GETREG(regs, R12, from, r12);
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err |= GETREG(regs, R13, from, r13);
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err |= GETREG(regs, R14, from, r14);
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err |= GETREG(regs, R15, from, r15);
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err |= GETREG(regs, RDI, from, di);
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err |= GETREG(regs, RSI, from, si);
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err |= GETREG(regs, RBP, from, bp);
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err |= GETREG(regs, RBX, from, bx);
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err |= GETREG(regs, RDX, from, dx);
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err |= GETREG(regs, RAX, from, ax);
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err |= GETREG(regs, RCX, from, cx);
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err |= GETREG(regs, RSP, from, sp);
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err |= GETREG(regs, RIP, from, ip);
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err |= GETREG(regs, EFLAGS, from, flags);
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err |= GETREG(regs, CS, from, cs);
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if (err)
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return 1;
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#undef GETREG
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err = copy_from_user(&fp, fpp, sizeof(struct user_i387_struct));
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if (err)
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return 1;
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err = restore_fp_registers(userspace_pid[current_thread->cpu],
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(unsigned long *) &fp);
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if (err < 0) {
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printk(KERN_ERR "copy_sc_from_user - "
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"restore_fp_registers failed, errno = %d\n",
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-err);
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return 1;
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}
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return 0;
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}
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static int copy_sc_to_user(struct sigcontext __user *to,
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struct _fpstate __user *to_fp, struct pt_regs *regs,
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unsigned long mask, unsigned long sp)
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{
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struct faultinfo * fi = ¤t->thread.arch.faultinfo;
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struct user_i387_struct fp;
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int err = 0;
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err |= __put_user(0, &to->gs);
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err |= __put_user(0, &to->fs);
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#define PUTREG(regs, regno, sc, regname) \
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__put_user((regs)->regs.gp[(regno) / sizeof(unsigned long)], \
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&(sc)->regname)
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err |= PUTREG(regs, RDI, to, di);
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err |= PUTREG(regs, RSI, to, si);
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err |= PUTREG(regs, RBP, to, bp);
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/*
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* Must use orignal RSP, which is passed in, rather than what's in
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* the pt_regs, because that's already been updated to point at the
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* signal frame.
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*/
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err |= __put_user(sp, &to->sp);
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err |= PUTREG(regs, RBX, to, bx);
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err |= PUTREG(regs, RDX, to, dx);
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err |= PUTREG(regs, RCX, to, cx);
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err |= PUTREG(regs, RAX, to, ax);
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err |= PUTREG(regs, R8, to, r8);
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err |= PUTREG(regs, R9, to, r9);
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err |= PUTREG(regs, R10, to, r10);
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err |= PUTREG(regs, R11, to, r11);
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err |= PUTREG(regs, R12, to, r12);
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err |= PUTREG(regs, R13, to, r13);
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err |= PUTREG(regs, R14, to, r14);
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err |= PUTREG(regs, R15, to, r15);
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err |= PUTREG(regs, CS, to, cs); /* XXX x86_64 doesn't do this */
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err |= __put_user(fi->cr2, &to->cr2);
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err |= __put_user(fi->error_code, &to->err);
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err |= __put_user(fi->trap_no, &to->trapno);
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err |= PUTREG(regs, RIP, to, ip);
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err |= PUTREG(regs, EFLAGS, to, flags);
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#undef PUTREG
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err |= __put_user(mask, &to->oldmask);
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if (err)
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return 1;
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err = save_fp_registers(userspace_pid[current_thread->cpu],
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(unsigned long *) &fp);
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if (err < 0) {
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printk(KERN_ERR "copy_sc_from_user - restore_fp_registers "
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"failed, errno = %d\n", -err);
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return 1;
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}
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if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
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return 1;
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return err;
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}
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struct rt_sigframe
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{
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char __user *pretcode;
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struct ucontext uc;
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struct siginfo info;
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struct _fpstate fpstate;
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};
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#define round_down(m, n) (((m) / (n)) * (n))
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int setup_signal_stack_si(unsigned long stack_top, int sig,
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struct k_sigaction *ka, struct pt_regs * regs,
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siginfo_t *info, sigset_t *set)
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{
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struct rt_sigframe __user *frame;
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unsigned long save_sp = PT_REGS_RSP(regs);
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int err = 0;
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struct task_struct *me = current;
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frame = (struct rt_sigframe __user *)
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round_down(stack_top - sizeof(struct rt_sigframe), 16);
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/* Subtract 128 for a red zone and 8 for proper alignment */
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frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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goto out;
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if (ka->sa.sa_flags & SA_SIGINFO) {
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err |= copy_siginfo_to_user(&frame->info, info);
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if (err)
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goto out;
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}
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/*
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* Update SP now because the page fault handler refuses to extend
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* the stack if the faulting address is too far below the current
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* SP, which frame now certainly is. If there's an error, the original
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* value is restored on the way out.
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* When writing the sigcontext to the stack, we have to write the
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* original value, so that's passed to copy_sc_to_user, which does
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* the right thing with it.
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*/
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PT_REGS_RSP(regs) = (unsigned long) frame;
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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(0, &frame->uc.uc_link);
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err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
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err |= __put_user(sas_ss_flags(save_sp),
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&frame->uc.uc_stack.ss_flags);
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err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
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err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
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set->sig[0], save_sp);
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err |= __put_user(&frame->fpstate, &frame->uc.uc_mcontext.fpstate);
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if (sizeof(*set) == 16) {
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__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
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__put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
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}
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else
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err |= __copy_to_user(&frame->uc.uc_sigmask, set,
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sizeof(*set));
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/*
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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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*/
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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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err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
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else
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/* could use a vstub here */
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goto restore_sp;
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if (err)
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goto restore_sp;
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/* Set up registers for signal handler */
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{
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struct exec_domain *ed = current_thread_info()->exec_domain;
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if (unlikely(ed && ed->signal_invmap && sig < 32))
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sig = ed->signal_invmap[sig];
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}
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PT_REGS_RDI(regs) = sig;
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/* In case the signal handler was declared without prototypes */
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PT_REGS_RAX(regs) = 0;
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/*
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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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*/
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PT_REGS_RSI(regs) = (unsigned long) &frame->info;
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PT_REGS_RDX(regs) = (unsigned long) &frame->uc;
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PT_REGS_RIP(regs) = (unsigned long) ka->sa.sa_handler;
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out:
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return err;
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restore_sp:
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PT_REGS_RSP(regs) = save_sp;
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return err;
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}
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long sys_rt_sigreturn(struct pt_regs *regs)
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{
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unsigned long sp = PT_REGS_SP(¤t->thread.regs);
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struct rt_sigframe __user *frame =
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(struct rt_sigframe __user *)(sp - 8);
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struct ucontext __user *uc = &frame->uc;
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sigset_t set;
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if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
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goto segfault;
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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 (copy_sc_from_user(¤t->thread.regs, &uc->uc_mcontext,
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&frame->fpstate))
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goto segfault;
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/* Avoid ERESTART handling */
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PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1;
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return PT_REGS_SYSCALL_RET(¤t->thread.regs);
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segfault:
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force_sig(SIGSEGV, current);
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return 0;
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}
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