4d338e1acc
misc sparse annotations Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
407 lines
12 KiB
C
407 lines
12 KiB
C
/*
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* Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
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* Licensed under the GPL
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*/
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#include "linux/signal.h"
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#include "linux/ptrace.h"
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#include "asm/current.h"
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#include "asm/ucontext.h"
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#include "asm/uaccess.h"
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#include "asm/unistd.h"
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#include "frame_kern.h"
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#include "sigcontext.h"
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#include "registers.h"
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#include "mode.h"
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#ifdef CONFIG_MODE_SKAS
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#include "skas.h"
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static int copy_sc_from_user_skas(struct pt_regs *regs,
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struct sigcontext __user *from)
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{
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struct sigcontext sc;
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unsigned long fpregs[HOST_FP_SIZE];
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int err;
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err = copy_from_user(&sc, from, sizeof(sc));
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err |= copy_from_user(fpregs, sc.fpstate, sizeof(fpregs));
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if(err)
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return(err);
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REGS_GS(regs->regs.skas.regs) = sc.gs;
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REGS_FS(regs->regs.skas.regs) = sc.fs;
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REGS_ES(regs->regs.skas.regs) = sc.es;
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REGS_DS(regs->regs.skas.regs) = sc.ds;
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REGS_EDI(regs->regs.skas.regs) = sc.edi;
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REGS_ESI(regs->regs.skas.regs) = sc.esi;
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REGS_EBP(regs->regs.skas.regs) = sc.ebp;
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REGS_SP(regs->regs.skas.regs) = sc.esp;
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REGS_EBX(regs->regs.skas.regs) = sc.ebx;
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REGS_EDX(regs->regs.skas.regs) = sc.edx;
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REGS_ECX(regs->regs.skas.regs) = sc.ecx;
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REGS_EAX(regs->regs.skas.regs) = sc.eax;
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REGS_IP(regs->regs.skas.regs) = sc.eip;
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REGS_CS(regs->regs.skas.regs) = sc.cs;
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REGS_EFLAGS(regs->regs.skas.regs) = sc.eflags;
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REGS_SS(regs->regs.skas.regs) = sc.ss;
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err = restore_fp_registers(userspace_pid[0], fpregs);
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if(err < 0){
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printk("copy_sc_from_user_skas - PTRACE_SETFPREGS failed, "
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"errno = %d\n", 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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int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate __user *to_fp,
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struct pt_regs *regs, unsigned long sp)
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{
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struct sigcontext sc;
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unsigned long fpregs[HOST_FP_SIZE];
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struct faultinfo * fi = ¤t->thread.arch.faultinfo;
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int err;
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sc.gs = REGS_GS(regs->regs.skas.regs);
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sc.fs = REGS_FS(regs->regs.skas.regs);
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sc.es = REGS_ES(regs->regs.skas.regs);
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sc.ds = REGS_DS(regs->regs.skas.regs);
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sc.edi = REGS_EDI(regs->regs.skas.regs);
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sc.esi = REGS_ESI(regs->regs.skas.regs);
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sc.ebp = REGS_EBP(regs->regs.skas.regs);
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sc.esp = sp;
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sc.ebx = REGS_EBX(regs->regs.skas.regs);
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sc.edx = REGS_EDX(regs->regs.skas.regs);
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sc.ecx = REGS_ECX(regs->regs.skas.regs);
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sc.eax = REGS_EAX(regs->regs.skas.regs);
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sc.eip = REGS_IP(regs->regs.skas.regs);
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sc.cs = REGS_CS(regs->regs.skas.regs);
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sc.eflags = REGS_EFLAGS(regs->regs.skas.regs);
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sc.esp_at_signal = regs->regs.skas.regs[UESP];
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sc.ss = regs->regs.skas.regs[SS];
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sc.cr2 = fi->cr2;
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sc.err = fi->error_code;
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sc.trapno = fi->trap_no;
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err = save_fp_registers(userspace_pid[0], fpregs);
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if(err < 0){
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printk("copy_sc_to_user_skas - PTRACE_GETFPREGS failed, "
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"errno = %d\n", err);
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return(1);
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}
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to_fp = (to_fp ? to_fp : (struct _fpstate __user *) (to + 1));
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sc.fpstate = to_fp;
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if(err)
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return(err);
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return(copy_to_user(to, &sc, sizeof(sc)) ||
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copy_to_user(to_fp, fpregs, sizeof(fpregs)));
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}
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#endif
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#ifdef CONFIG_MODE_TT
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/* These copy a sigcontext to/from userspace. They copy the fpstate pointer,
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* blowing away the old, good one. So, that value is saved, and then restored
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* after the sigcontext copy. In copy_from, the variable holding the saved
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* fpstate pointer, and the sigcontext that it should be restored to are both
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* in the kernel, so we can just restore using an assignment. In copy_to, the
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* saved pointer is in the kernel, but the sigcontext is in userspace, so we
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* copy_to_user it.
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*/
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int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext __user *from,
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int fpsize)
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{
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struct _fpstate *to_fp;
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struct _fpstate __user *from_fp;
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unsigned long sigs;
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int err;
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to_fp = to->fpstate;
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sigs = to->oldmask;
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err = copy_from_user(to, from, sizeof(*to));
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from_fp = to->fpstate;
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to->oldmask = sigs;
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to->fpstate = to_fp;
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if(to_fp != NULL)
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err |= copy_from_user(to_fp, from_fp, fpsize);
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return(err);
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}
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int copy_sc_to_user_tt(struct sigcontext *to, struct _fpstate __user *fp,
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struct sigcontext *from, int fpsize, unsigned long sp)
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{
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struct _fpstate __user *to_fp;
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struct _fpstate *from_fp;
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int err;
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to_fp = (fp ? fp : (struct _fpstate __user *) (to + 1));
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from_fp = from->fpstate;
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err = copy_to_user(to, from, sizeof(*to));
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/* The SP in the sigcontext is the updated one for the signal
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* delivery. The sp passed in is the original, and this needs
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* to be restored, so we stick it in separately.
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*/
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err |= copy_to_user(&SC_SP(to), sp, sizeof(sp));
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if(from_fp != NULL){
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err |= copy_to_user(&to->fpstate, &to_fp, sizeof(to->fpstate));
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err |= copy_to_user(to_fp, from_fp, fpsize);
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}
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return err;
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}
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#endif
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static int copy_sc_from_user(struct pt_regs *to, void __user *from)
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{
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int ret;
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ret = CHOOSE_MODE(copy_sc_from_user_tt(UPT_SC(&to->regs), from,
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sizeof(struct _fpstate)),
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copy_sc_from_user_skas(to, from));
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return(ret);
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}
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static int copy_sc_to_user(struct sigcontext *to, struct _fpstate __user *fp,
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struct pt_regs *from, unsigned long sp)
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{
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return(CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs),
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sizeof(*fp), sp),
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copy_sc_to_user_skas(to, fp, from, sp)));
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}
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static int copy_ucontext_to_user(struct ucontext __user *uc, struct _fpstate __user *fp,
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sigset_t *set, unsigned long sp)
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{
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int err = 0;
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err |= put_user(current->sas_ss_sp, &uc->uc_stack.ss_sp);
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err |= put_user(sas_ss_flags(sp), &uc->uc_stack.ss_flags);
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err |= put_user(current->sas_ss_size, &uc->uc_stack.ss_size);
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err |= copy_sc_to_user(&uc->uc_mcontext, fp, ¤t->thread.regs, sp);
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err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
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return(err);
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}
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struct sigframe
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{
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char __user *pretcode;
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int sig;
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struct sigcontext sc;
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struct _fpstate fpstate;
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unsigned long extramask[_NSIG_WORDS-1];
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char retcode[8];
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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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int sig;
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struct siginfo __user *pinfo;
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void __user *puc;
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struct siginfo info;
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struct ucontext uc;
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struct _fpstate fpstate;
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char retcode[8];
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};
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int setup_signal_stack_sc(unsigned long stack_top, int sig,
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struct k_sigaction *ka, struct pt_regs *regs,
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sigset_t *mask)
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{
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struct sigframe __user *frame;
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void __user *restorer;
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unsigned long save_sp = PT_REGS_SP(regs);
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int err = 0;
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stack_top &= -8UL;
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frame = (struct sigframe __user *) stack_top - 1;
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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return 1;
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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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/* 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_SP(regs) = (unsigned long) frame;
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err |= __put_user(restorer, &frame->pretcode);
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err |= __put_user(sig, &frame->sig);
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err |= copy_sc_to_user(&frame->sc, NULL, regs, save_sp);
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err |= __put_user(mask->sig[0], &frame->sc.oldmask);
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if (_NSIG_WORDS > 1)
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err |= __copy_to_user(&frame->extramask, &mask->sig[1],
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sizeof(frame->extramask));
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/*
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* This is popl %eax ; movl $,%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(0xb858, (short __user *)(frame->retcode+0));
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err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
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err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
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if(err)
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goto err;
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PT_REGS_SP(regs) = (unsigned long) frame;
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PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
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PT_REGS_EAX(regs) = (unsigned long) sig;
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PT_REGS_EDX(regs) = (unsigned long) 0;
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PT_REGS_ECX(regs) = (unsigned long) 0;
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if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
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ptrace_notify(SIGTRAP);
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return 0;
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err:
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PT_REGS_SP(regs) = save_sp;
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return err;
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}
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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 *mask)
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{
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struct rt_sigframe __user *frame;
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void __user *restorer;
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unsigned long save_sp = PT_REGS_SP(regs);
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int err = 0;
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stack_top &= -8UL;
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frame = (struct rt_sigframe __user *) stack_top - 1;
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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return 1;
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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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/* See comment above about why this is here */
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PT_REGS_SP(regs) = (unsigned long) frame;
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err |= __put_user(restorer, &frame->pretcode);
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err |= __put_user(sig, &frame->sig);
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err |= __put_user(&frame->info, &frame->pinfo);
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err |= __put_user(&frame->uc, &frame->puc);
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err |= copy_siginfo_to_user(&frame->info, info);
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err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
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save_sp);
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/*
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* This is movl $,%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(0xb8, (char __user *)(frame->retcode+0));
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err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
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err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
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if(err)
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goto err;
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PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
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PT_REGS_EAX(regs) = (unsigned long) sig;
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PT_REGS_EDX(regs) = (unsigned long) &frame->info;
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PT_REGS_ECX(regs) = (unsigned long) &frame->uc;
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if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
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ptrace_notify(SIGTRAP);
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return 0;
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err:
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PT_REGS_SP(regs) = save_sp;
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return err;
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}
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long sys_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 sigframe __user *frame = (struct sigframe __user *)(sp - 8);
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sigset_t set;
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struct sigcontext __user *sc = &frame->sc;
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unsigned long __user *oldmask = &sc->oldmask;
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unsigned long __user *extramask = frame->extramask;
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int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
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if(copy_from_user(&set.sig[0], oldmask, sizeof(set.sig[0])) ||
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copy_from_user(&set.sig[1], extramask, sig_size))
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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, sc))
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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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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 = (struct rt_sigframe __user *) (sp - 4);
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sigset_t set;
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struct ucontext __user *uc = &frame->uc;
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int sig_size = _NSIG_WORDS * sizeof(unsigned long);
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if(copy_from_user(&set, &uc->uc_sigmask, sig_size))
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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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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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/*
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* Overrides for Emacs so that we follow Linus's tabbing style.
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* Emacs will notice this stuff at the end of the file and automatically
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* adjust the settings for this buffer only. This must remain at the end
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* of the file.
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* ---------------------------------------------------------------------------
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* Local variables:
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* c-file-style: "linux"
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* End:
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*/
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