diff options
Diffstat (limited to 'arch/x86/um/signal_64.c')
| -rw-r--r-- | arch/x86/um/signal_64.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/arch/x86/um/signal_64.c b/arch/x86/um/signal_64.c new file mode 100644 index 0000000..255b2ca --- /dev/null +++ b/arch/x86/um/signal_64.c @@ -0,0 +1,255 @@ +/* + * Copyright (C) 2003 PathScale, Inc. + * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + * Licensed under the GPL + */ + +#include <linux/personality.h> +#include <linux/ptrace.h> +#include <linux/kernel.h> +#include <asm/unistd.h> +#include <asm/uaccess.h> +#include <asm/ucontext.h> +#include "frame_kern.h" +#include "skas.h" + +static int copy_sc_from_user(struct pt_regs *regs, + struct sigcontext __user *from) +{ + struct sigcontext sc; + struct user_i387_struct fp; + void __user *buf; + int err; + + err = copy_from_user(&sc, from, sizeof(sc)); + if (err) + return err; + +#define GETREG(regno, regname) regs->regs.gp[HOST_##regno] = sc.regname + + GETREG(R8, r8); + GETREG(R9, r9); + GETREG(R10, r10); + GETREG(R11, r11); + GETREG(R12, r12); + GETREG(R13, r13); + GETREG(R14, r14); + GETREG(R15, r15); + GETREG(RDI, di); + GETREG(RSI, si); + GETREG(RBP, bp); + GETREG(RBX, bx); + GETREG(RDX, dx); + GETREG(RAX, ax); + GETREG(RCX, cx); + GETREG(SP, sp); + GETREG(IP, ip); + GETREG(EFLAGS, flags); + GETREG(CS, cs); +#undef GETREG + + buf = sc.fpstate; + + err = copy_from_user(&fp, buf, sizeof(struct user_i387_struct)); + if (err) + return 1; + + err = restore_fp_registers(userspace_pid[current_thread_info()->cpu], + (unsigned long *) &fp); + if (err < 0) { + printk(KERN_ERR "copy_sc_from_user - " + "restore_fp_registers failed, errno = %d\n", + -err); + return 1; + } + + return 0; +} + +static int copy_sc_to_user(struct sigcontext __user *to, + struct _fpstate __user *to_fp, struct pt_regs *regs, + unsigned long mask, unsigned long sp) +{ + struct faultinfo * fi = ¤t->thread.arch.faultinfo; + struct sigcontext sc; + struct user_i387_struct fp; + int err = 0; + memset(&sc, 0, sizeof(struct sigcontext)); + +#define PUTREG(regno, regname) sc.regname = regs->regs.gp[HOST_##regno] + + PUTREG(RDI, di); + PUTREG(RSI, si); + PUTREG(RBP, bp); + /* + * Must use original RSP, which is passed in, rather than what's in + * signal frame. + */ + sc.sp = sp; + PUTREG(RBX, bx); + PUTREG(RDX, dx); + PUTREG(RCX, cx); + PUTREG(RAX, ax); + PUTREG(R8, r8); + PUTREG(R9, r9); + PUTREG(R10, r10); + PUTREG(R11, r11); + PUTREG(R12, r12); + PUTREG(R13, r13); + PUTREG(R14, r14); + PUTREG(R15, r15); + PUTREG(CS, cs); /* XXX x86_64 doesn't do this */ + + sc.cr2 = fi->cr2; + sc.err = fi->error_code; + sc.trapno = fi->trap_no; + + PUTREG(IP, ip); + PUTREG(EFLAGS, flags); +#undef PUTREG + + sc.oldmask = mask; + + err = copy_to_user(to, &sc, sizeof(struct sigcontext)); + if (err) + return 1; + + err = save_fp_registers(userspace_pid[current_thread_info()->cpu], + (unsigned long *) &fp); + if (err < 0) { + printk(KERN_ERR "copy_sc_from_user - restore_fp_registers " + "failed, errno = %d\n", -err); + return 1; + } + + if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct))) + return 1; + + return err; +} + +struct rt_sigframe +{ + char __user *pretcode; + struct ucontext uc; + struct siginfo info; + struct _fpstate fpstate; +}; + +int setup_signal_stack_si(unsigned long stack_top, int sig, + struct k_sigaction *ka, struct pt_regs * regs, + siginfo_t *info, sigset_t *set) +{ + struct rt_sigframe __user *frame; + unsigned long save_sp = PT_REGS_RSP(regs); + int err = 0; + struct task_struct *me = current; + + frame = (struct rt_sigframe __user *) + round_down(stack_top - sizeof(struct rt_sigframe), 16); + /* Subtract 128 for a red zone and 8 for proper alignment */ + frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8); + + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) + goto out; + + if (ka->sa.sa_flags & SA_SIGINFO) { + err |= copy_siginfo_to_user(&frame->info, info); + if (err) + goto out; + } + + /* + * Update SP now because the page fault handler refuses to extend + * the stack if the faulting address is too far below the current + * SP, which frame now certainly is. If there's an error, the original + * value is restored on the way out. + * When writing the sigcontext to the stack, we have to write the + * original value, so that's passed to copy_sc_to_user, which does + * the right thing with it. + */ + PT_REGS_RSP(regs) = (unsigned long) frame; + + /* Create the ucontext. */ + err |= __put_user(0, &frame->uc.uc_flags); + err |= __put_user(0, &frame->uc.uc_link); + err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp); + err |= __put_user(sas_ss_flags(save_sp), + &frame->uc.uc_stack.ss_flags); + err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size); + err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs, + set->sig[0], save_sp); + err |= __put_user(&frame->fpstate, &frame->uc.uc_mcontext.fpstate); + if (sizeof(*set) == 16) { + __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]); + __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]); + } + else + err |= __copy_to_user(&frame->uc.uc_sigmask, set, + sizeof(*set)); + + /* + * Set up to return from userspace. If provided, use a stub + * already in userspace. + */ + /* x86-64 should always use SA_RESTORER. */ + if (ka->sa.sa_flags & SA_RESTORER) + err |= __put_user(ka->sa.sa_restorer, &frame->pretcode); + else + /* could use a vstub here */ + goto restore_sp; + + if (err) + goto restore_sp; + + /* Set up registers for signal handler */ + { + struct exec_domain *ed = current_thread_info()->exec_domain; + if (unlikely(ed && ed->signal_invmap && sig < 32)) + sig = ed->signal_invmap[sig]; + } + + PT_REGS_RDI(regs) = sig; + /* In case the signal handler was declared without prototypes */ + PT_REGS_RAX(regs) = 0; + + /* + * This also works for non SA_SIGINFO handlers because they expect the + * next argument after the signal number on the stack. + */ + PT_REGS_RSI(regs) = (unsigned long) &frame->info; + PT_REGS_RDX(regs) = (unsigned long) &frame->uc; + PT_REGS_RIP(regs) = (unsigned long) ka->sa.sa_handler; + out: + return err; + +restore_sp: + PT_REGS_RSP(regs) = save_sp; + return err; +} + +long sys_rt_sigreturn(struct pt_regs *regs) +{ + unsigned long sp = PT_REGS_SP(¤t->thread.regs); + struct rt_sigframe __user *frame = + (struct rt_sigframe __user *)(sp - 8); + struct ucontext __user *uc = &frame->uc; + sigset_t set; + + if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) + goto segfault; + + sigdelsetmask(&set, ~_BLOCKABLE); + set_current_blocked(&set); + + 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; +} |