/* * Signal handling for 32bit PPC and 32bit tasks on 64bit PPC * * PowerPC version * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * Copyright (C) 2001 IBM * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz) * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu) * * Derived from "arch/i386/kernel/signal.c" * Copyright (C) 1991, 1992 Linus Torvalds * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include #include #include #include #include #include #include #include #include #ifdef CONFIG_PPC64 #include #include #include #else #include #include #include #include #include #include #include #endif #include #include #include #include #include #ifdef CONFIG_PPC64 #include "ppc32.h" #include #else #include #include #endif #undef DEBUG_SIG #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) #ifdef CONFIG_PPC64 #define do_signal do_signal32 #define sys_sigsuspend compat_sys_sigsuspend #define sys_rt_sigsuspend compat_sys_rt_sigsuspend #define sys_rt_sigreturn compat_sys_rt_sigreturn #define sys_sigaction compat_sys_sigaction #define sys_swapcontext compat_sys_swapcontext #define sys_sigreturn compat_sys_sigreturn #define old_sigaction old_sigaction32 #define sigcontext sigcontext32 #define mcontext mcontext32 #define ucontext ucontext32 /* * Returning 0 means we return to userspace via * ret_from_except and thus restore all user * registers from *regs. This is what we need * to do when a signal has been delivered. */ #define GP_REGS_SIZE min(sizeof(elf_gregset_t32), sizeof(struct pt_regs32)) #undef __SIGNAL_FRAMESIZE #define __SIGNAL_FRAMESIZE __SIGNAL_FRAMESIZE32 #undef ELF_NVRREG #define ELF_NVRREG ELF_NVRREG32 /* * Functions for flipping sigsets (thanks to brain dead generic * implementation that makes things simple for little endian only) */ static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set) { compat_sigset_t cset; switch (_NSIG_WORDS) { case 4: cset.sig[5] = set->sig[3] & 0xffffffffull; cset.sig[7] = set->sig[3] >> 32; case 3: cset.sig[4] = set->sig[2] & 0xffffffffull; cset.sig[5] = set->sig[2] >> 32; case 2: cset.sig[2] = set->sig[1] & 0xffffffffull; cset.sig[3] = set->sig[1] >> 32; case 1: cset.sig[0] = set->sig[0] & 0xffffffffull; cset.sig[1] = set->sig[0] >> 32; } return copy_to_user(uset, &cset, sizeof(*uset)); } static inline int get_sigset_t(sigset_t *set, const compat_sigset_t __user *uset) { compat_sigset_t s32; if (copy_from_user(&s32, uset, sizeof(*uset))) return -EFAULT; /* * Swap the 2 words of the 64-bit sigset_t (they are stored * in the "wrong" endian in 32-bit user storage). */ switch (_NSIG_WORDS) { case 4: set->sig[3] = s32.sig[6] | (((long)s32.sig[7]) << 32); case 3: set->sig[2] = s32.sig[4] | (((long)s32.sig[5]) << 32); case 2: set->sig[1] = s32.sig[2] | (((long)s32.sig[3]) << 32); case 1: set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32); } return 0; } static inline int get_old_sigaction(struct k_sigaction *new_ka, struct old_sigaction __user *act) { compat_old_sigset_t mask; compat_uptr_t handler, restorer; if (get_user(handler, &act->sa_handler) || __get_user(restorer, &act->sa_restorer) || __get_user(new_ka->sa.sa_flags, &act->sa_flags) || __get_user(mask, &act->sa_mask)) return -EFAULT; new_ka->sa.sa_handler = compat_ptr(handler); new_ka->sa.sa_restorer = compat_ptr(restorer); siginitset(&new_ka->sa.sa_mask, mask); return 0; } #define to_user_ptr(p) ptr_to_compat(p) #define from_user_ptr(p) compat_ptr(p) static inline int save_general_regs(struct pt_regs *regs, struct mcontext __user *frame) { elf_greg_t64 *gregs = (elf_greg_t64 *)regs; int i; WARN_ON(!FULL_REGS(regs)); for (i = 0; i <= PT_RESULT; i ++) { if (i == 14 && !FULL_REGS(regs)) i = 32; if (__put_user((unsigned int)gregs[i], &frame->mc_gregs[i])) return -EFAULT; } return 0; } static inline int restore_general_regs(struct pt_regs *regs, struct mcontext __user *sr) { elf_greg_t64 *gregs = (elf_greg_t64 *)regs; int i; for (i = 0; i <= PT_RESULT; i++) { if ((i == PT_MSR) || (i == PT_SOFTE)) continue; if (__get_user(gregs[i], &sr->mc_gregs[i])) return -EFAULT; } return 0; } #else /* CONFIG_PPC64 */ #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs)) static inline int put_sigset_t(sigset_t __user *uset, sigset_t *set) { return copy_to_user(uset, set, sizeof(*uset)); } static inline int get_sigset_t(sigset_t *set, const sigset_t __user *uset) { return copy_from_user(set, uset, sizeof(*uset)); } static inline int get_old_sigaction(struct k_sigaction *new_ka, struct old_sigaction __user *act) { old_sigset_t mask; if (!access_ok(VERIFY_READ, act, sizeof(*act)) || __get_user(new_ka->sa.sa_handler, &act->sa_handler) || __get_user(new_ka->sa.sa_restorer, &act->sa_restorer)) return -EFAULT; __get_user(new_ka->sa.sa_flags, &act->sa_flags); __get_user(mask, &act->sa_mask); siginitset(&new_ka->sa.sa_mask, mask); return 0; } #define to_user_ptr(p) ((unsigned long)(p)) #define from_user_ptr(p) ((void __user *)(p)) static inline int save_general_regs(struct pt_regs *regs, struct mcontext __user *frame) { WARN_ON(!FULL_REGS(regs)); return __copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE); } static inline int restore_general_regs(struct pt_regs *regs, struct mcontext __user *sr) { /* copy up to but not including MSR */ if (__copy_from_user(regs, &sr->mc_gregs, PT_MSR * sizeof(elf_greg_t))) return -EFAULT; /* copy from orig_r3 (the word after the MSR) up to the end */ if (__copy_from_user(®s->orig_gpr3, &sr->mc_gregs[PT_ORIG_R3], GP_REGS_SIZE - PT_ORIG_R3 * sizeof(elf_greg_t))) return -EFAULT; return 0; } #endif /* CONFIG_PPC64 */ int do_signal(sigset_t *oldset, struct pt_regs *regs); /* * Atomically swap in the new signal mask, and wait for a signal. */ long sys_sigsuspend(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_thread_flag(TIF_RESTORE_SIGMASK); return -ERESTARTNOHAND; } #ifdef CONFIG_PPC32 long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, int r5, int r6, int r7, int r8, struct pt_regs *regs) { return do_sigaltstack(uss, uoss, regs->gpr[1]); } #endif long sys_sigaction(int sig, struct old_sigaction __user *act, struct old_sigaction __user *oact) { struct k_sigaction new_ka, old_ka; int ret; #ifdef CONFIG_PPC64 if (sig < 0) sig = -sig; #endif if (act) { if (get_old_sigaction(&new_ka, act)) return -EFAULT; } ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); if (!ret && oact) { if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || __put_user(to_user_ptr(old_ka.sa.sa_handler), &oact->sa_handler) || __put_user(to_user_ptr(old_ka.sa.sa_restorer), &oact->sa_restorer) || __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) return -EFAULT; } return ret; } /* * When we have signals to deliver, we set up on the * user stack, going down from the original stack pointer: * a sigregs struct * a sigcontext struct * a gap of __SIGNAL_FRAMESIZE bytes * * Each of these things must be a multiple of 16 bytes in size. * */ struct sigregs { struct mcontext mctx; /* all the register values */ /* * Programs using the rs6000/xcoff abi can save up to 19 gp * regs and 18 fp regs below sp before decrementing it. */ int abigap[56]; }; /* We use the mc_pad field for the signal return trampoline. */ #define tramp mc_pad /* * When we have rt signals to deliver, we set up on the * user stack, going down from the original stack pointer: * one rt_sigframe struct (siginfo + ucontext + ABI gap) * a gap of __SIGNAL_FRAMESIZE+16 bytes * (the +16 is to get the siginfo and ucontext in the same * positions as in older kernels). * * Each of these things must be a multiple of 16 bytes in size. * */ struct rt_sigframe { #ifdef CONFIG_PPC64 compat_siginfo_t info; #else struct siginfo info; #endif struct ucontext uc; /* * Programs using the rs6000/xcoff abi can save up to 19 gp * regs and 18 fp regs below sp before decrementing it. */ int abigap[56]; }; /* * Save the current user registers on the user stack. * We only save the altivec/spe registers if the process has used * altivec/spe instructions at some point. */ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, int sigret) { /* Make sure floating point registers are stored in regs */ flush_fp_to_thread(current); /* save general and floating-point registers */ if (save_general_regs(regs, frame) || __copy_to_user(&frame->mc_fregs, current->thread.fpr, ELF_NFPREG * sizeof(double))) return 1; #ifdef CONFIG_ALTIVEC /* save altivec registers */ if (current->thread.used_vr) { flush_altivec_to_thread(current); if (__copy_to_user(&frame->mc_vregs, current->thread.vr, ELF_NVRREG * sizeof(vector128))) return 1; /* set MSR_VEC in the saved MSR value to indicate that frame->mc_vregs contains valid data */ if (__put_user(regs->msr | MSR_VEC, &frame->mc_gregs[PT_MSR])) return 1; } /* else assert((regs->msr & MSR_VEC) == 0) */ /* We always copy to/from vrsave, it's 0 if we don't have or don't * use altivec. Since VSCR only contains 32 bits saved in the least * significant bits of a vector, we "cheat" and stuff VRSAVE in the * most significant bits of that same vector. --BenH */ if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32])) return 1; #endif /* CONFIG_ALTIVEC */ #ifdef CONFIG_SPE /* save spe registers */ if (current->thread.used_spe) { flush_spe_to_thread(current); if (__copy_to_user(&frame->mc_vregs, current->thread.evr, ELF_NEVRREG * sizeof(u32))) return 1; /* set MSR_SPE in the saved MSR value to indicate that frame->mc_vregs contains valid data */ if (__put_user(regs->msr | MSR_SPE, &frame->mc_gregs[PT_MSR])) return 1; } /* else assert((regs->msr & MSR_SPE) == 0) */ /* We always copy to/from spefscr */ if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs + ELF_NEVRREG)) return 1; #endif /* CONFIG_SPE */ if (sigret) { /* Set up the sigreturn trampoline: li r0,sigret; sc */ if (__put_user(0x38000000UL + sigret, &frame->tramp[0]) || __put_user(0x44000002UL, &frame->tramp[1])) return 1; flush_icache_range((unsigned long) &frame->tramp[0], (unsigned long) &frame->tramp[2]); } return 0; } /* * Restore the current user register values from the user stack, * (except for MSR). */ static long restore_user_regs(struct pt_regs *regs, struct mcontext __user *sr, int sig) { long err; unsigned int save_r2 = 0; unsigned long msr; /* * restore general registers but not including MSR or SOFTE. Also * take care of keeping r2 (TLS) intact if not a signal */ if (!sig) save_r2 = (unsigned int)regs->gpr[2]; err = restore_general_regs(regs, sr); err |= __get_user(msr, &sr->mc_gregs[PT_MSR]); if (!sig) regs->gpr[2] = (unsigned long) save_r2; if (err) return 1; /* if doing signal return, restore the previous little-endian mode */ if (sig) regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); /* * Do this before updating the thread state in * current->thread.fpr/vr/evr. That way, if we get preempted * and another task grabs the FPU/Altivec/SPE, it won't be * tempted to save the current CPU state into the thread_struct * and corrupt what we are writing there. */ discard_lazy_cpu_state(); /* force the process to reload the FP registers from current->thread when it next does FP instructions */ regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1); if (__copy_from_user(current->thread.fpr, &sr->mc_fregs, sizeof(sr->mc_fregs))) return 1; #ifdef CONFIG_ALTIVEC /* force the process to reload the altivec registers from current->thread when it next does altivec instructions */ regs->msr &= ~MSR_VEC; if (msr & MSR_VEC) { /* restore altivec registers from the stack */ if (__copy_from_user(current->thread.vr, &sr->mc_vregs, sizeof(sr->mc_vregs))) return 1; } else if (current->thread.used_vr) memset(current->thread.vr, 0, ELF_NVRREG * sizeof(vector128)); /* Always get VRSAVE back */ if (__get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32])) return 1; #endif /* CONFIG_ALTIVEC */ #ifdef CONFIG_SPE /* force the process to reload the spe registers from current->thread when it next does spe instructions */ regs->msr &= ~MSR_SPE; if (msr & MSR_SPE) { /* restore spe registers from the stack */ if (__copy_from_user(current->thread.evr, &sr->mc_vregs, ELF_NEVRREG * sizeof(u32))) return 1; } else if (current->thread.used_spe) memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32)); /* Always get SPEFSCR back */ if (__get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG)) return 1; #endif /* CONFIG_SPE */ return 0; } #ifdef CONFIG_PPC64 long compat_sys_rt_sigaction(int sig, const struct sigaction32 __user *act, struct sigaction32 __user *oact, size_t sigsetsize) { struct k_sigaction new_ka, old_ka; int ret; /* XXX: Don't preclude handling different sized sigset_t's. */ if (sigsetsize != sizeof(compat_sigset_t)) return -EINVAL; if (act) { compat_uptr_t handler; ret = get_user(handler, &act->sa_handler); new_ka.sa.sa_handler = compat_ptr(handler); ret |= get_sigset_t(&new_ka.sa.sa_mask, &act->sa_mask); ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags); if (ret) return -EFAULT; } ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); if (!ret && oact) { ret = put_user(to_user_ptr(old_ka.sa.sa_handler), &oact->sa_handler); ret |= put_sigset_t(&oact->sa_mask, &old_ka.sa.sa_mask); ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags); } return ret; } /* * Note: it is necessary to treat how as an unsigned int, with the * corresponding cast to a signed int to insure that the proper * conversion (sign extension) between the register representation * of a signed int (msr in 32-bit mode) and the register representation * of a signed int (msr in 64-bit mode) is performed. */ long compat_sys_rt_sigprocmask(u32 how, compat_sigset_t __user *set, compat_sigset_t __user *oset, size_t sigsetsize) { sigset_t s; sigset_t __user *up; int ret; mm_segment_t old_fs = get_fs(); if (set) { if (get_sigset_t(&s, set)) return -EFAULT; } set_fs(KERNEL_DS); /* This is valid because of the set_fs() */ up = (sigset_t __user *) &s; ret = sys_rt_sigprocmask((int)how, set ? up : NULL, oset ? up : NULL, sigsetsize); set_fs(old_fs); if (ret) return ret; if (oset) { if (put_sigset_t(oset, &s)) return -EFAULT; } return 0; } long compat_sys_rt_sigpending(compat_sigset_t __user *set, compat_size_t sigsetsize) { sigset_t s; int ret; mm_segment_t old_fs = get_fs(); set_fs(KERNEL_DS); /* The __user pointer cast is valid because of the set_fs() */ ret = sys_rt_sigpending((sigset_t __user *) &s, sigsetsize); set_fs(old_fs); if (!ret) { if (put_sigset_t(set, &s)) return -EFAULT; } return ret; } int copy_siginfo_to_user32(struct compat_siginfo __user *d, siginfo_t *s) { int err; if (!access_ok (VERIFY_WRITE, d, sizeof(*d))) return -EFAULT; /* If you change siginfo_t structure, please be sure * this code is fixed accordingly. * It should never copy any pad contained in the structure * to avoid security leaks, but must copy the generic * 3 ints plus the relevant union member. * This routine must convert siginfo from 64bit to 32bit as well * at the same time. */ err = __put_user(s->si_signo, &d->si_signo); err |= __put_user(s->si_errno, &d->si_errno); err |= __put_user((short)s->si_code, &d->si_code); if (s->si_code < 0) err |= __copy_to_user(&d->_sifields._pad, &s->_sifields._pad, SI_PAD_SIZE32); else switch(s->si_code >> 16) { case __SI_CHLD >> 16: err |= __put_user(s->si_pid, &d->si_pid); err |= __put_user(s->si_uid, &d->si_uid); err |= __put_user(s->si_utime, &d->si_utime); err |= __put_user(s->si_stime, &d->si_stime); err |= __put_user(s->si_status, &d->si_status); break; case __SI_FAULT >> 16: err |= __put_user((unsigned int)(unsigned long)s->si_addr, &d->si_addr); break; case __SI_POLL >> 16: err |= __put_user(s->si_band, &d->si_band); err |= __put_user(s->si_fd, &d->si_fd); break; case __SI_TIMER >> 16: err |= __put_user(s->si_tid, &d->si_tid); err |= __put_user(s->si_overrun, &d->si_overrun); err |= __put_user(s->si_int, &d->si_int); break; case __SI_RT >> 16: /* This is not generated by the kernel as of now. */ case __SI_MESGQ >> 16: err |= __put_user(s->si_int, &d->si_int); /* fallthrough */ case __SI_KILL >> 16: default: err |= __put_user(s->si_pid, &d->si_pid); err |= __put_user(s->si_uid, &d->si_uid); break; } return err; } #define copy_siginfo_to_user copy_siginfo_to_user32 /* * Note: it is necessary to treat pid and sig as unsigned ints, with the * corresponding cast to a signed int to insure that the proper conversion * (sign extension) between the register representation of a signed int * (msr in 32-bit mode) and the register representation of a signed int * (msr in 64-bit mode) is performed. */ long compat_sys_rt_sigqueueinfo(u32 pid, u32 sig, compat_siginfo_t __user *uinfo) { siginfo_t info; int ret; mm_segment_t old_fs = get_fs(); if (copy_from_user (&info, uinfo, 3*sizeof(int)) || copy_from_user (info._sifields._pad, uinfo->_sifields._pad, SI_PAD_SIZE32)) return -EFAULT; set_fs (KERNEL_DS); /* The __user pointer cast is valid becasuse of the set_fs() */ ret = sys_rt_sigqueueinfo((int)pid, (int)sig, (siginfo_t __user *) &info); set_fs (old_fs); return ret; } /* * Start Alternate signal stack support * * System Calls * sigaltatck compat_sys_sigaltstack */ int compat_sys_sigaltstack(u32 __new, u32 __old, int r5, int r6, int r7, int r8, struct pt_regs *regs) { stack_32_t __user * newstack = compat_ptr(__new); stack_32_t __user * oldstack = compat_ptr(__old); stack_t uss, uoss; int ret; mm_segment_t old_fs; unsigned long sp; compat_uptr_t ss_sp; /* * set sp to the user stack on entry to the system call * the system call router sets R9 to the saved registers */ sp = regs->gpr[1]; /* Put new stack info in local 64 bit stack struct */ if (newstack) { if (get_user(ss_sp, &newstack->ss_sp) || __get_user(uss.ss_flags, &newstack->ss_flags) || __get_user(uss.ss_size, &newstack->ss_size)) return -EFAULT; uss.ss_sp = compat_ptr(ss_sp); } old_fs = get_fs(); set_fs(KERNEL_DS); /* The __user pointer casts are valid because of the set_fs() */ ret = do_sigaltstack( newstack ? (stack_t __user *) &uss : NULL, oldstack ? (stack_t __user *) &uoss : NULL, sp); set_fs(old_fs); /* Copy the stack information to the user output buffer */ if (!ret && oldstack && (put_user(ptr_to_compat(uoss.ss_sp), &oldstack->ss_sp) || __put_user(uoss.ss_flags, &oldstack->ss_flags) || __put_user(uoss.ss_size, &oldstack->ss_size))) return -EFAULT; return ret; } #endif /* CONFIG_PPC64 */ /* * Restore the user process's signal mask */ #ifdef CONFIG_PPC64 extern void restore_sigmask(sigset_t *set); #else /* CONFIG_PPC64 */ static void restore_sigmask(sigset_t *set) { sigdelsetmask(set, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); current->blocked = *set; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); } #endif /* * Set up a signal frame for a "real-time" signal handler * (one which gets siginfo). */ static int handle_rt_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset, struct pt_regs *regs, unsigned long newsp) { struct rt_sigframe __user *rt_sf; struct mcontext __user *frame; unsigned long origsp = newsp; /* Set up Signal Frame */ /* Put a Real Time Context onto stack */ newsp -= sizeof(*rt_sf); rt_sf = (struct rt_sigframe __user *)newsp; /* create a stack frame for the caller of the handler */ newsp -= __SIGNAL_FRAMESIZE + 16; if (!access_ok(VERIFY_WRITE, (void __user *)newsp, origsp - newsp)) goto badframe; /* Put the siginfo & fill in most of the ucontext */ if (copy_siginfo_to_user(&rt_sf->info, info) || __put_user(0, &rt_sf->uc.uc_flags) || __put_user(0, &rt_sf->uc.uc_link) || __put_user(current->sas_ss_sp, &rt_sf->uc.uc_stack.ss_sp) || __put_user(sas_ss_flags(regs->gpr[1]), &rt_sf->uc.uc_stack.ss_flags) || __put_user(current->sas_ss_size, &rt_sf->uc.uc_stack.ss_size) || __put_user(to_user_ptr(&rt_sf->uc.uc_mcontext), &rt_sf->uc.uc_regs) || put_sigset_t(&rt_sf->uc.uc_sigmask, oldset)) goto badframe; /* Save user registers on the stack */ frame = &rt_sf->uc.uc_mcontext; if (vdso32_rt_sigtramp && current->mm->context.vdso_base) { if (save_user_regs(regs, frame, 0)) goto badframe; regs->link = current->mm->context.vdso_base + vdso32_rt_sigtramp; } else { if (save_user_regs(regs, frame, __NR_rt_sigreturn)) goto badframe; regs->link = (unsigned long) frame->tramp; } current->thread.fpscr.val = 0; /* turn off all fp exceptions */ if (put_user(regs->gpr[1], (u32 __user *)newsp)) goto badframe; regs->gpr[1] = newsp; regs->gpr[3] = sig; regs->gpr[4] = (unsigned long) &rt_sf->info; regs->gpr[5] = (unsigned long) &rt_sf->uc; regs->gpr[6] = (unsigned long) rt_sf; regs->nip = (unsigned long) ka->sa.sa_handler; /* enter the signal handler in big-endian mode */ regs->msr &= ~MSR_LE; regs->trap = 0; return 1; badframe: #ifdef DEBUG_SIG printk("badframe in handle_rt_signal, regs=%p frame=%p newsp=%lx\n", regs, frame, newsp); #endif force_sigsegv(sig, current); return 0; } static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig) { sigset_t set; struct mcontext __user *mcp; if (get_sigset_t(&set, &ucp->uc_sigmask)) return -EFAULT; #ifdef CONFIG_PPC64 { u32 cmcp; if (__get_user(cmcp, &ucp->uc_regs)) return -EFAULT; mcp = (struct mcontext __user *)(u64)cmcp; } #else if (__get_user(mcp, &ucp->uc_regs)) return -EFAULT; #endif restore_sigmask(&set); if (restore_user_regs(regs, mcp, sig)) return -EFAULT; return 0; } long sys_swapcontext(struct ucontext __user *old_ctx, struct ucontext __user *new_ctx, int ctx_size, int r6, int r7, int r8, struct pt_regs *regs) { unsigned char tmp; /* Context size is for future use. Right now, we only make sure * we are passed something we understand */ if (ctx_size < sizeof(struct ucontext)) return -EINVAL; if (old_ctx != NULL) { if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx)) || save_user_regs(regs, &old_ctx->uc_mcontext, 0) || put_sigset_t(&old_ctx->uc_sigmask, ¤t->blocked) || __put_user(to_user_ptr(&old_ctx->uc_mcontext), &old_ctx->uc_regs)) return -EFAULT; } if (new_ctx == NULL) return 0; if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx)) || __get_user(tmp, (u8 __user *) new_ctx) || __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1)) return -EFAULT; /* * If we get a fault copying the context into the kernel's * image of the user's registers, we can't just return -EFAULT * because the user's registers will be corrupted. For instance * the NIP value may have been updated but not some of the * other registers. Given that we have done the access_ok * and successfully read the first and last bytes of the region * above, this should only happen in an out-of-memory situation * or if another thread unmaps the region containing the context. * We kill the task with a SIGSEGV in this situation. */ if (do_setcontext(new_ctx, regs, 0)) do_exit(SIGSEGV); set_thread_flag(TIF_RESTOREALL); return 0; } long sys_rt_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8, struct pt_regs *regs) { struct rt_sigframe __user *rt_sf; /* Always make any pending restarted system calls return -EINTR */ current_thread_info()->restart_block.fn = do_no_restart_syscall; rt_sf = (struct rt_sigframe __user *) (regs->gpr[1] + __SIGNAL_FRAMESIZE + 16); if (!access_ok(VERIFY_READ, rt_sf, sizeof(*rt_sf))) goto bad; if (do_setcontext(&rt_sf->uc, regs, 1)) goto bad; /* * It's not clear whether or why it is desirable to save the * sigaltstack setting on signal delivery and restore it on * signal return. But other architectures do this and we have * always done it up until now so it is probably better not to * change it. -- paulus */ #ifdef CONFIG_PPC64 /* * We use the compat_sys_ version that does the 32/64 bits conversion * and takes userland pointer directly. What about error checking ? * nobody does any... */ compat_sys_sigaltstack((u32)(u64)&rt_sf->uc.uc_stack, 0, 0, 0, 0, 0, regs); #else do_sigaltstack(&rt_sf->uc.uc_stack, NULL, regs->gpr[1]); #endif set_thread_flag(TIF_RESTOREALL); return 0; bad: force_sig(SIGSEGV, current); return 0; } #ifdef CONFIG_PPC32 int sys_debug_setcontext(struct ucontext __user *ctx, int ndbg, struct sig_dbg_op __user *dbg, int r6, int r7, int r8, struct pt_regs *regs) { struct sig_dbg_op op; int i; unsigned long new_msr = regs->msr; #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) unsigned long new_dbcr0 = current->thread.dbcr0; #endif for (i=0; imsr = new_msr; #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) current->thread.dbcr0 = new_dbcr0; #endif /* * If we get a fault copying the context into the kernel's * image of the user's registers, we can't just return -EFAULT * because the user's registers will be corrupted. For instance * the NIP value may have been updated but not some of the * other registers. Given that we have done the access_ok * and successfully read the first and last bytes of the region * above, this should only happen in an out-of-memory situation * or if another thread unmaps the region containing the context. * We kill the task with a SIGSEGV in this situation. */ if (do_setcontext(ctx, regs, 1)) { force_sig(SIGSEGV, current); goto out; } /* * It's not clear whether or why it is desirable to save the * sigaltstack setting on signal delivery and restore it on * signal return. But other architectures do this and we have * always done it up until now so it is probably better not to * change it. -- paulus */ do_sigaltstack(&ctx->uc_stack, NULL, regs->gpr[1]); set_thread_flag(TIF_RESTOREALL); out: return 0; } #endif /* * OK, we're invoking a handler */ static int handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset, struct pt_regs *regs, unsigned long newsp) { struct sigcontext __user *sc; struct sigregs __user *frame; unsigned long origsp = newsp; /* Set up Signal Frame */ newsp -= sizeof(struct sigregs); frame = (struct sigregs __user *) newsp; /* Put a sigcontext on the stack */ newsp -= sizeof(*sc); sc = (struct sigcontext __user *) newsp; /* create a stack frame for the caller of the handler */ newsp -= __SIGNAL_FRAMESIZE; if (!access_ok(VERIFY_WRITE, (void __user *) newsp, origsp - newsp)) goto badframe; #if _NSIG != 64 #error "Please adjust handle_signal()" #endif if (__put_user(to_user_ptr(ka->sa.sa_handler), &sc->handler) || __put_user(oldset->sig[0], &sc->oldmask) #ifdef CONFIG_PPC64 || __put_user((oldset->sig[0] >> 32), &sc->_unused[3]) #else || __put_user(oldset->sig[1], &sc->_unused[3]) #endif || __put_user(to_user_ptr(frame), &sc->regs) || __put_user(sig, &sc->signal)) goto badframe; if (vdso32_sigtramp && current->mm->context.vdso_base) { if (save_user_regs(regs, &frame->mctx, 0)) goto badframe; regs->link = current->mm->context.vdso_base + vdso32_sigtramp; } else { if (save_user_regs(regs, &frame->mctx, __NR_sigreturn)) goto badframe; regs->link = (unsigned long) frame->mctx.tramp; } current->thread.fpscr.val = 0; /* turn off all fp exceptions */ if (put_user(regs->gpr[1], (u32 __user *)newsp)) goto badframe; regs->gpr[1] = newsp; regs->gpr[3] = sig; regs->gpr[4] = (unsigned long) sc; regs->nip = (unsigned long) ka->sa.sa_handler; /* enter the signal handler in big-endian mode */ regs->msr &= ~MSR_LE; regs->trap = 0; return 1; badframe: #ifdef DEBUG_SIG printk("badframe in handle_signal, regs=%p frame=%p newsp=%lx\n", regs, frame, newsp); #endif force_sigsegv(sig, current); return 0; } /* * Do a signal return; undo the signal stack. */ long sys_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8, struct pt_regs *regs) { struct sigcontext __user *sc; struct sigcontext sigctx; struct mcontext __user *sr; sigset_t set; /* Always make any pending restarted system calls return -EINTR */ current_thread_info()->restart_block.fn = do_no_restart_syscall; sc = (struct sigcontext __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE); if (copy_from_user(&sigctx, sc, sizeof(sigctx))) goto badframe; #ifdef CONFIG_PPC64 /* * Note that PPC32 puts the upper 32 bits of the sigmask in the * unused part of the signal stackframe */ set.sig[0] = sigctx.oldmask + ((long)(sigctx._unused[3]) << 32); #else set.sig[0] = sigctx.oldmask; set.sig[1] = sigctx._unused[3]; #endif restore_sigmask(&set); sr = (struct mcontext __user *)from_user_ptr(sigctx.regs); if (!access_ok(VERIFY_READ, sr, sizeof(*sr)) || restore_user_regs(regs, sr, 1)) goto badframe; set_thread_flag(TIF_RESTOREALL); return 0; badframe: force_sig(SIGSEGV, current); return 0; } /* * 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. */ int do_signal(sigset_t *oldset, struct pt_regs *regs) { siginfo_t info; struct k_sigaction ka; unsigned int newsp; int signr, ret; #ifdef CONFIG_PPC32 if (try_to_freeze()) { signr = 0; if (!signal_pending(current)) goto no_signal; } #endif if (test_thread_flag(TIF_RESTORE_SIGMASK)) oldset = ¤t->saved_sigmask; else if (!oldset) oldset = ¤t->blocked; signr = get_signal_to_deliver(&info, &ka, regs, NULL); #ifdef CONFIG_PPC32 no_signal: #endif if (TRAP(regs) == 0x0C00 /* System Call! */ && regs->ccr & 0x10000000 /* error signalled */ && ((ret = regs->gpr[3]) == ERESTARTSYS || ret == ERESTARTNOHAND || ret == ERESTARTNOINTR || ret == ERESTART_RESTARTBLOCK)) { if (signr > 0 && (ret == ERESTARTNOHAND || ret == ERESTART_RESTARTBLOCK || (ret == ERESTARTSYS && !(ka.sa.sa_flags & SA_RESTART)))) { /* make the system call return an EINTR error */ regs->result = -EINTR; regs->gpr[3] = EINTR; /* note that the cr0.SO bit is already set */ } else { regs->nip -= 4; /* Back up & retry system call */ regs->result = 0; regs->trap = 0; if (ret == ERESTART_RESTARTBLOCK) regs->gpr[0] = __NR_restart_syscall; else regs->gpr[3] = regs->orig_gpr3; } } if (signr == 0) { /* No signal to deliver -- put the saved sigmask back */ if (test_thread_flag(TIF_RESTORE_SIGMASK)) { clear_thread_flag(TIF_RESTORE_SIGMASK); sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); } return 0; /* no signals delivered */ } if ((ka.sa.sa_flags & SA_ONSTACK) && current->sas_ss_size && !on_sig_stack(regs->gpr[1])) newsp = current->sas_ss_sp + current->sas_ss_size; else newsp = regs->gpr[1]; newsp &= ~0xfUL; #ifdef CONFIG_PPC64 /* * Reenable the DABR before delivering the signal to * user space. The DABR will have been cleared if it * triggered inside the kernel. */ if (current->thread.dabr) set_dabr(current->thread.dabr); #endif /* Whee! Actually deliver the signal. */ if (ka.sa.sa_flags & SA_SIGINFO) ret = handle_rt_signal(signr, &ka, &info, oldset, regs, newsp); else ret = handle_signal(signr, &ka, &info, oldset, regs, newsp); if (ret) { 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, signr); recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); /* A signal was successfully delivered; the saved sigmask is in its frame, and we can clear the TIF_RESTORE_SIGMASK flag */ if (test_thread_flag(TIF_RESTORE_SIGMASK)) clear_thread_flag(TIF_RESTORE_SIGMASK); } return ret; }