diff options
Diffstat (limited to 'arch/um/sys-i386/signal.c')
| -rw-r--r-- | arch/um/sys-i386/signal.c | 382 |
1 files changed, 382 insertions, 0 deletions
diff --git a/arch/um/sys-i386/signal.c b/arch/um/sys-i386/signal.c new file mode 100644 index 00000000000..76ba87254b2 --- /dev/null +++ b/arch/um/sys-i386/signal.c @@ -0,0 +1,382 @@ +/* + * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com) + * Licensed under the GPL + */ + +#include "linux/signal.h" +#include "linux/ptrace.h" +#include "asm/current.h" +#include "asm/ucontext.h" +#include "asm/uaccess.h" +#include "asm/unistd.h" +#include "frame_kern.h" +#include "signal_user.h" +#include "sigcontext.h" +#include "registers.h" +#include "mode.h" + +#ifdef CONFIG_MODE_SKAS + +#include "skas.h" + +static int copy_sc_from_user_skas(struct pt_regs *regs, + struct sigcontext *from) +{ + struct sigcontext sc; + unsigned long fpregs[HOST_FP_SIZE]; + int err; + + err = copy_from_user(&sc, from, sizeof(sc)); + err |= copy_from_user(fpregs, sc.fpstate, sizeof(fpregs)); + if(err) + return(err); + + REGS_GS(regs->regs.skas.regs) = sc.gs; + REGS_FS(regs->regs.skas.regs) = sc.fs; + REGS_ES(regs->regs.skas.regs) = sc.es; + REGS_DS(regs->regs.skas.regs) = sc.ds; + REGS_EDI(regs->regs.skas.regs) = sc.edi; + REGS_ESI(regs->regs.skas.regs) = sc.esi; + REGS_EBP(regs->regs.skas.regs) = sc.ebp; + REGS_SP(regs->regs.skas.regs) = sc.esp; + REGS_EBX(regs->regs.skas.regs) = sc.ebx; + REGS_EDX(regs->regs.skas.regs) = sc.edx; + REGS_ECX(regs->regs.skas.regs) = sc.ecx; + REGS_EAX(regs->regs.skas.regs) = sc.eax; + REGS_IP(regs->regs.skas.regs) = sc.eip; + REGS_CS(regs->regs.skas.regs) = sc.cs; + REGS_EFLAGS(regs->regs.skas.regs) = sc.eflags; + REGS_SS(regs->regs.skas.regs) = sc.ss; + regs->regs.skas.fault_addr = sc.cr2; + regs->regs.skas.fault_type = FAULT_WRITE(sc.err); + regs->regs.skas.trap_type = sc.trapno; + + err = restore_fp_registers(userspace_pid[0], fpregs); + if(err < 0){ + printk("copy_sc_from_user_skas - PTRACE_SETFPREGS failed, " + "errno = %d\n", err); + return(1); + } + + return(0); +} + +int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp, + struct pt_regs *regs, unsigned long fault_addr, + int fault_type) +{ + struct sigcontext sc; + unsigned long fpregs[HOST_FP_SIZE]; + int err; + + sc.gs = REGS_GS(regs->regs.skas.regs); + sc.fs = REGS_FS(regs->regs.skas.regs); + sc.es = REGS_ES(regs->regs.skas.regs); + sc.ds = REGS_DS(regs->regs.skas.regs); + sc.edi = REGS_EDI(regs->regs.skas.regs); + sc.esi = REGS_ESI(regs->regs.skas.regs); + sc.ebp = REGS_EBP(regs->regs.skas.regs); + sc.esp = REGS_SP(regs->regs.skas.regs); + sc.ebx = REGS_EBX(regs->regs.skas.regs); + sc.edx = REGS_EDX(regs->regs.skas.regs); + sc.ecx = REGS_ECX(regs->regs.skas.regs); + sc.eax = REGS_EAX(regs->regs.skas.regs); + sc.eip = REGS_IP(regs->regs.skas.regs); + sc.cs = REGS_CS(regs->regs.skas.regs); + sc.eflags = REGS_EFLAGS(regs->regs.skas.regs); + sc.esp_at_signal = regs->regs.skas.regs[UESP]; + sc.ss = regs->regs.skas.regs[SS]; + sc.cr2 = fault_addr; + sc.err = TO_SC_ERR(fault_type); + sc.trapno = regs->regs.skas.trap_type; + + err = save_fp_registers(userspace_pid[0], fpregs); + if(err < 0){ + printk("copy_sc_to_user_skas - PTRACE_GETFPREGS failed, " + "errno = %d\n", err); + return(1); + } + to_fp = (to_fp ? to_fp : (struct _fpstate *) (to + 1)); + sc.fpstate = to_fp; + + if(err) + return(err); + + return(copy_to_user(to, &sc, sizeof(sc)) || + copy_to_user(to_fp, fpregs, sizeof(fpregs))); +} +#endif + +#ifdef CONFIG_MODE_TT + +/* These copy a sigcontext to/from userspace. They copy the fpstate pointer, + * blowing away the old, good one. So, that value is saved, and then restored + * after the sigcontext copy. In copy_from, the variable holding the saved + * fpstate pointer, and the sigcontext that it should be restored to are both + * in the kernel, so we can just restore using an assignment. In copy_to, the + * saved pointer is in the kernel, but the sigcontext is in userspace, so we + * copy_to_user it. + */ +int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext *from, + int fpsize) +{ + struct _fpstate *to_fp, *from_fp; + unsigned long sigs; + int err; + + to_fp = to->fpstate; + from_fp = from->fpstate; + sigs = to->oldmask; + err = copy_from_user(to, from, sizeof(*to)); + to->oldmask = sigs; + to->fpstate = to_fp; + if(to_fp != NULL) + err |= copy_from_user(to_fp, from_fp, fpsize); + return(err); +} + +int copy_sc_to_user_tt(struct sigcontext *to, struct _fpstate *fp, + struct sigcontext *from, int fpsize) +{ + struct _fpstate *to_fp, *from_fp; + int err; + + to_fp = (fp ? fp : (struct _fpstate *) (to + 1)); + from_fp = from->fpstate; + err = copy_to_user(to, from, sizeof(*to)); + if(from_fp != NULL){ + err |= copy_to_user(&to->fpstate, &to_fp, sizeof(to->fpstate)); + err |= copy_to_user(to_fp, from_fp, fpsize); + } + return(err); +} +#endif + +static int copy_sc_from_user(struct pt_regs *to, void __user *from) +{ + int ret; + + ret = CHOOSE_MODE(copy_sc_from_user_tt(UPT_SC(&to->regs), from, + sizeof(struct _fpstate)), + copy_sc_from_user_skas(to, from)); + return(ret); +} + +static int copy_sc_to_user(struct sigcontext *to, struct _fpstate *fp, + struct pt_regs *from) +{ + return(CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs), + sizeof(*fp)), + copy_sc_to_user_skas(to, fp, from, + current->thread.cr2, + current->thread.err))); +} + +static int copy_ucontext_to_user(struct ucontext *uc, struct _fpstate *fp, + sigset_t *set, unsigned long sp) +{ + int err = 0; + + err |= put_user(current->sas_ss_sp, &uc->uc_stack.ss_sp); + err |= put_user(sas_ss_flags(sp), &uc->uc_stack.ss_flags); + err |= put_user(current->sas_ss_size, &uc->uc_stack.ss_size); + err |= copy_sc_to_user(&uc->uc_mcontext, fp, ¤t->thread.regs); + err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set)); + return(err); +} + +struct sigframe +{ + char *pretcode; + int sig; + struct sigcontext sc; + struct _fpstate fpstate; + unsigned long extramask[_NSIG_WORDS-1]; + char retcode[8]; +}; + +struct rt_sigframe +{ + char *pretcode; + int sig; + struct siginfo *pinfo; + void *puc; + struct siginfo info; + struct ucontext uc; + struct _fpstate fpstate; + char retcode[8]; +}; + +int setup_signal_stack_sc(unsigned long stack_top, int sig, + struct k_sigaction *ka, struct pt_regs *regs, + sigset_t *mask) +{ + struct sigframe __user *frame; + void *restorer; + int err = 0; + + stack_top &= -8UL; + frame = (struct sigframe *) stack_top - 1; + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) + return 1; + + restorer = (void *) frame->retcode; + if(ka->sa.sa_flags & SA_RESTORER) + restorer = ka->sa.sa_restorer; + + err |= __put_user(restorer, &frame->pretcode); + err |= __put_user(sig, &frame->sig); + err |= copy_sc_to_user(&frame->sc, NULL, regs); + err |= __put_user(mask->sig[0], &frame->sc.oldmask); + if (_NSIG_WORDS > 1) + err |= __copy_to_user(&frame->extramask, &mask->sig[1], + sizeof(frame->extramask)); + + /* + * This is popl %eax ; movl $,%eax ; int $0x80 + * + * WE DO NOT USE IT ANY MORE! It's only left here for historical + * reasons and because gdb uses it as a signature to notice + * signal handler stack frames. + */ + err |= __put_user(0xb858, (short __user *)(frame->retcode+0)); + err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2)); + err |= __put_user(0x80cd, (short __user *)(frame->retcode+6)); + + if(err) + return(err); + + PT_REGS_SP(regs) = (unsigned long) frame; + PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler; + PT_REGS_EAX(regs) = (unsigned long) sig; + PT_REGS_EDX(regs) = (unsigned long) 0; + PT_REGS_ECX(regs) = (unsigned long) 0; + + if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED)) + ptrace_notify(SIGTRAP); + return(0); +} + +int setup_signal_stack_si(unsigned long stack_top, int sig, + struct k_sigaction *ka, struct pt_regs *regs, + siginfo_t *info, sigset_t *mask) +{ + struct rt_sigframe __user *frame; + void *restorer; + int err = 0; + + stack_top &= -8UL; + frame = (struct rt_sigframe *) stack_top - 1; + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) + return 1; + + restorer = (void *) frame->retcode; + if(ka->sa.sa_flags & SA_RESTORER) + restorer = ka->sa.sa_restorer; + + err |= __put_user(restorer, &frame->pretcode); + err |= __put_user(sig, &frame->sig); + err |= __put_user(&frame->info, &frame->pinfo); + err |= __put_user(&frame->uc, &frame->puc); + err |= copy_siginfo_to_user(&frame->info, info); + err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask, + PT_REGS_SP(regs)); + + /* + * This is movl $,%eax ; int $0x80 + * + * WE DO NOT USE IT ANY MORE! It's only left here for historical + * reasons and because gdb uses it as a signature to notice + * signal handler stack frames. + */ + err |= __put_user(0xb8, (char __user *)(frame->retcode+0)); + err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1)); + err |= __put_user(0x80cd, (short __user *)(frame->retcode+5)); + + if(err) + return(err); + + PT_REGS_SP(regs) = (unsigned long) frame; + PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler; + PT_REGS_EAX(regs) = (unsigned long) sig; + PT_REGS_EDX(regs) = (unsigned long) &frame->info; + PT_REGS_ECX(regs) = (unsigned long) &frame->uc; + + if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED)) + ptrace_notify(SIGTRAP); + return(0); +} + +long sys_sigreturn(struct pt_regs regs) +{ + unsigned long sp = PT_REGS_SP(¤t->thread.regs); + struct sigframe __user *frame = (struct sigframe *)(sp - 8); + sigset_t set; + struct sigcontext __user *sc = &frame->sc; + unsigned long __user *oldmask = &sc->oldmask; + unsigned long __user *extramask = frame->extramask; + int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long); + + if(copy_from_user(&set.sig[0], oldmask, sizeof(&set.sig[0])) || + copy_from_user(&set.sig[1], extramask, sig_size)) + goto segfault; + + sigdelsetmask(&set, ~_BLOCKABLE); + + spin_lock_irq(¤t->sighand->siglock); + current->blocked = set; + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + if(copy_sc_from_user(¤t->thread.regs, sc)) + goto segfault; + + /* Avoid ERESTART handling */ + PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1; + return(PT_REGS_SYSCALL_RET(¤t->thread.regs)); + + segfault: + force_sig(SIGSEGV, current); + return 0; +} + +long sys_rt_sigreturn(struct pt_regs regs) +{ + unsigned long __user sp = PT_REGS_SP(¤t->thread.regs); + struct rt_sigframe __user *frame = (struct rt_sigframe *) (sp - 4); + sigset_t set; + struct ucontext __user *uc = &frame->uc; + int sig_size = _NSIG_WORDS * sizeof(unsigned long); + + if(copy_from_user(&set, &uc->uc_sigmask, sig_size)) + goto segfault; + + sigdelsetmask(&set, ~_BLOCKABLE); + + spin_lock_irq(¤t->sighand->siglock); + current->blocked = set; + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + if(copy_sc_from_user(¤t->thread.regs, &uc->uc_mcontext)) + goto segfault; + + /* Avoid ERESTART handling */ + PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1; + return(PT_REGS_SYSCALL_RET(¤t->thread.regs)); + + segfault: + force_sig(SIGSEGV, current); + return 0; +} + +/* + * Overrides for Emacs so that we follow Linus's tabbing style. + * Emacs will notice this stuff at the end of the file and automatically + * adjust the settings for this buffer only. This must remain at the end + * of the file. + * --------------------------------------------------------------------------- + * Local variables: + * c-file-style: "linux" + * End: + */ |