diff options
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/powerpc/kernel/signal_64.c | 581 |
2 files changed, 582 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 601ddbf1c20..7a3e1155ac9 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -13,7 +13,7 @@ endif obj-y := semaphore.o cputable.o ptrace.o syscalls.o \ signal_32.o pmc.o obj-$(CONFIG_PPC64) += setup_64.o binfmt_elf32.o sys_ppc32.o \ - ptrace32.o systbl.o + signal_64.o ptrace32.o systbl.o obj-$(CONFIG_ALTIVEC) += vecemu.o vector.o obj-$(CONFIG_POWER4) += idle_power4.o obj-$(CONFIG_PPC_OF) += of_device.o diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c new file mode 100644 index 00000000000..ec9d0984b6a --- /dev/null +++ b/arch/powerpc/kernel/signal_64.c @@ -0,0 +1,581 @@ +/* + * linux/arch/ppc64/kernel/signal.c + * + * PowerPC version + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * + * 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 <linux/config.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/smp.h> +#include <linux/smp_lock.h> +#include <linux/kernel.h> +#include <linux/signal.h> +#include <linux/errno.h> +#include <linux/wait.h> +#include <linux/unistd.h> +#include <linux/stddef.h> +#include <linux/elf.h> +#include <linux/ptrace.h> +#include <linux/module.h> + +#include <asm/sigcontext.h> +#include <asm/ucontext.h> +#include <asm/uaccess.h> +#include <asm/pgtable.h> +#include <asm/ppcdebug.h> +#include <asm/unistd.h> +#include <asm/cacheflush.h> +#include <asm/vdso.h> + +#define DEBUG_SIG 0 + +#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) + +#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs)) +#define FP_REGS_SIZE sizeof(elf_fpregset_t) + +#define TRAMP_TRACEBACK 3 +#define TRAMP_SIZE 6 + +/* + * When we have signals to deliver, we set up on the user stack, + * going down from the original stack pointer: + * 1) a rt_sigframe struct which contains the ucontext + * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller + * frame for the signal handler. + */ + +struct rt_sigframe { + /* sys_rt_sigreturn requires the ucontext be the first field */ + struct ucontext uc; + unsigned long _unused[2]; + unsigned int tramp[TRAMP_SIZE]; + struct siginfo *pinfo; + void *puc; + struct siginfo info; + /* 64 bit ABI allows for 288 bytes below sp before decrementing it. */ + char abigap[288]; +} __attribute__ ((aligned (16))); + + +/* + * Atomically swap in the new signal mask, and wait for a signal. + */ +long sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, int p3, int p4, + int p6, int p7, struct pt_regs *regs) +{ + sigset_t saveset, newset; + + /* XXX: Don't preclude handling different sized sigset_t's. */ + if (sigsetsize != sizeof(sigset_t)) + return -EINVAL; + + if (copy_from_user(&newset, unewset, sizeof(newset))) + return -EFAULT; + sigdelsetmask(&newset, ~_BLOCKABLE); + + spin_lock_irq(¤t->sighand->siglock); + saveset = current->blocked; + current->blocked = newset; + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + regs->result = -EINTR; + regs->gpr[3] = EINTR; + regs->ccr |= 0x10000000; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(&saveset, regs)) + return 0; + } +} + +long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, unsigned long r5, + unsigned long r6, unsigned long r7, unsigned long r8, + struct pt_regs *regs) +{ + return do_sigaltstack(uss, uoss, regs->gpr[1]); +} + + +/* + * Set up the sigcontext for the signal frame. + */ + +static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, + int signr, sigset_t *set, unsigned long handler) +{ + /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the + * process never used altivec yet (MSR_VEC is zero in pt_regs of + * the context). This is very important because we must ensure we + * don't lose the VRSAVE content that may have been set prior to + * the process doing its first vector operation + * Userland shall check AT_HWCAP to know wether it can rely on the + * v_regs pointer or not + */ +#ifdef CONFIG_ALTIVEC + elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve + 15) & ~0xful); +#endif + long err = 0; + + flush_fp_to_thread(current); + + /* Make sure signal doesn't get spurrious FP exceptions */ + current->thread.fpscr.val = 0; + +#ifdef CONFIG_ALTIVEC + err |= __put_user(v_regs, &sc->v_regs); + + /* save altivec registers */ + if (current->thread.used_vr) { + flush_altivec_to_thread(current); + /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ + err |= __copy_to_user(v_regs, current->thread.vr, 33 * sizeof(vector128)); + /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg) + * contains valid data. + */ + regs->msr |= MSR_VEC; + } + /* We always copy to/from vrsave, it's 0 if we don't have or don't + * use altivec. + */ + err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); +#else /* CONFIG_ALTIVEC */ + err |= __put_user(0, &sc->v_regs); +#endif /* CONFIG_ALTIVEC */ + err |= __put_user(&sc->gp_regs, &sc->regs); + err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE); + err |= __copy_to_user(&sc->fp_regs, ¤t->thread.fpr, FP_REGS_SIZE); + err |= __put_user(signr, &sc->signal); + err |= __put_user(handler, &sc->handler); + if (set != NULL) + err |= __put_user(set->sig[0], &sc->oldmask); + + return err; +} + +/* + * Restore the sigcontext from the signal frame. + */ + +static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, + struct sigcontext __user *sc) +{ +#ifdef CONFIG_ALTIVEC + elf_vrreg_t __user *v_regs; +#endif + unsigned long err = 0; + unsigned long save_r13 = 0; + elf_greg_t *gregs = (elf_greg_t *)regs; +#ifdef CONFIG_ALTIVEC + unsigned long msr; +#endif + int i; + + /* If this is not a signal return, we preserve the TLS in r13 */ + if (!sig) + save_r13 = regs->gpr[13]; + + /* copy everything before MSR */ + err |= __copy_from_user(regs, &sc->gp_regs, + PT_MSR*sizeof(unsigned long)); + + /* skip MSR and SOFTE */ + for (i = PT_MSR+1; i <= PT_RESULT; i++) { + if (i == PT_SOFTE) + continue; + err |= __get_user(gregs[i], &sc->gp_regs[i]); + } + + if (!sig) + regs->gpr[13] = save_r13; + err |= __copy_from_user(¤t->thread.fpr, &sc->fp_regs, FP_REGS_SIZE); + if (set != NULL) + err |= __get_user(set->sig[0], &sc->oldmask); + +#ifdef CONFIG_ALTIVEC + err |= __get_user(v_regs, &sc->v_regs); + err |= __get_user(msr, &sc->gp_regs[PT_MSR]); + if (err) + return err; + /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ + if (v_regs != 0 && (msr & MSR_VEC) != 0) + err |= __copy_from_user(current->thread.vr, v_regs, + 33 * sizeof(vector128)); + else if (current->thread.used_vr) + memset(current->thread.vr, 0, 33 * sizeof(vector128)); + /* Always get VRSAVE back */ + if (v_regs != 0) + err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); + else + current->thread.vrsave = 0; +#endif /* CONFIG_ALTIVEC */ + +#ifndef CONFIG_SMP + preempt_disable(); + if (last_task_used_math == current) + last_task_used_math = NULL; + if (last_task_used_altivec == current) + last_task_used_altivec = NULL; + preempt_enable(); +#endif + /* Force reload of FP/VEC */ + regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC); + + return err; +} + +/* + * Allocate space for the signal frame + */ +static inline void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, + size_t frame_size) +{ + unsigned long newsp; + + /* Default to using normal stack */ + newsp = regs->gpr[1]; + + if (ka->sa.sa_flags & SA_ONSTACK) { + if (! on_sig_stack(regs->gpr[1])) + newsp = (current->sas_ss_sp + current->sas_ss_size); + } + + return (void __user *)((newsp - frame_size) & -16ul); +} + +/* + * Setup the trampoline code on the stack + */ +static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp) +{ + int i; + long err = 0; + + /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */ + err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]); + /* li r0, __NR_[rt_]sigreturn| */ + err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]); + /* sc */ + err |= __put_user(0x44000002UL, &tramp[2]); + + /* Minimal traceback info */ + for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++) + err |= __put_user(0, &tramp[i]); + + if (!err) + flush_icache_range((unsigned long) &tramp[0], + (unsigned long) &tramp[TRAMP_SIZE]); + + return err; +} + +/* + * Restore the user process's signal mask (also used by signal32.c) + */ +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); +} + + +/* + * Handle {get,set,swap}_context operations + */ +int sys_swapcontext(struct ucontext __user *old_ctx, + struct ucontext __user *new_ctx, + long ctx_size, long r6, long r7, long r8, struct pt_regs *regs) +{ + unsigned char tmp; + sigset_t set; + + /* 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)) + || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0) + || __copy_to_user(&old_ctx->uc_sigmask, + ¤t->blocked, sizeof(sigset_t))) + 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 (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set))) + do_exit(SIGSEGV); + restore_sigmask(&set); + if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext)) + do_exit(SIGSEGV); + + /* This returns like rt_sigreturn */ + return 0; +} + + +/* + * Do a signal return; undo the signal stack. + */ + +int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5, + unsigned long r6, unsigned long r7, unsigned long r8, + struct pt_regs *regs) +{ + struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1]; + sigset_t set; + + /* Always make any pending restarted system calls return -EINTR */ + current_thread_info()->restart_block.fn = do_no_restart_syscall; + + if (!access_ok(VERIFY_READ, uc, sizeof(*uc))) + goto badframe; + + if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) + goto badframe; + restore_sigmask(&set); + if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext)) + goto badframe; + + /* do_sigaltstack expects a __user pointer and won't modify + * what's in there anyway + */ + do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]); + + return regs->result; + +badframe: +#if DEBUG_SIG + printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n", + regs, uc, &uc->uc_mcontext); +#endif + force_sig(SIGSEGV, current); + return 0; +} + +static int setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info, + sigset_t *set, struct pt_regs *regs) +{ + /* Handler is *really* a pointer to the function descriptor for + * the signal routine. The first entry in the function + * descriptor is the entry address of signal and the second + * entry is the TOC value we need to use. + */ + func_descr_t __user *funct_desc_ptr; + struct rt_sigframe __user *frame; + unsigned long newsp = 0; + long err = 0; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) + goto badframe; + + err |= __put_user(&frame->info, &frame->pinfo); + err |= __put_user(&frame->uc, &frame->puc); + err |= copy_siginfo_to_user(&frame->info, info); + if (err) + goto badframe; + + /* Create the ucontext. */ + err |= __put_user(0, &frame->uc.uc_flags); + err |= __put_user(0, &frame->uc.uc_link); + err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); + err |= __put_user(sas_ss_flags(regs->gpr[1]), + &frame->uc.uc_stack.ss_flags); + err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); + err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, NULL, + (unsigned long)ka->sa.sa_handler); + err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); + if (err) + goto badframe; + + /* Set up to return from userspace. */ + if (vdso64_rt_sigtramp && current->thread.vdso_base) { + regs->link = current->thread.vdso_base + vdso64_rt_sigtramp; + } else { + err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]); + if (err) + goto badframe; + regs->link = (unsigned long) &frame->tramp[0]; + } + funct_desc_ptr = (func_descr_t __user *) ka->sa.sa_handler; + + /* Allocate a dummy caller frame for the signal handler. */ + newsp = (unsigned long)frame - __SIGNAL_FRAMESIZE; + err |= put_user(regs->gpr[1], (unsigned long __user *)newsp); + + /* Set up "regs" so we "return" to the signal handler. */ + err |= get_user(regs->nip, &funct_desc_ptr->entry); + regs->gpr[1] = newsp; + err |= get_user(regs->gpr[2], &funct_desc_ptr->toc); + regs->gpr[3] = signr; + regs->result = 0; + if (ka->sa.sa_flags & SA_SIGINFO) { + err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo); + err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc); + regs->gpr[6] = (unsigned long) frame; + } else { + regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext; + } + if (err) + goto badframe; + + if (test_thread_flag(TIF_SINGLESTEP)) + ptrace_notify(SIGTRAP); + + return 1; + +badframe: +#if DEBUG_SIG + printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n", + regs, frame, newsp); +#endif + force_sigsegv(signr, current); + return 0; +} + + +/* + * 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) +{ + int ret; + + /* Set up Signal Frame */ + ret = setup_rt_frame(sig, ka, info, oldset, regs); + + 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,sig); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + } + + return ret; +} + +static inline void syscall_restart(struct pt_regs *regs, struct k_sigaction *ka) +{ + switch ((int)regs->result) { + case -ERESTART_RESTARTBLOCK: + case -ERESTARTNOHAND: + /* ERESTARTNOHAND means that the syscall should only be + * restarted if there was no handler for the signal, and since + * we only get here if there is a handler, we dont restart. + */ + regs->result = -EINTR; + break; + case -ERESTARTSYS: + /* ERESTARTSYS means to restart the syscall if there is no + * handler or the handler was registered with SA_RESTART + */ + if (!(ka->sa.sa_flags & SA_RESTART)) { + regs->result = -EINTR; + break; + } + /* fallthrough */ + case -ERESTARTNOINTR: + /* ERESTARTNOINTR means that the syscall should be + * called again after the signal handler returns. + */ + regs->gpr[3] = regs->orig_gpr3; + regs->nip -= 4; + regs->result = 0; + break; + } +} + +/* + * 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; + int signr; + struct k_sigaction ka; + + /* + * If the current thread is 32 bit - invoke the + * 32 bit signal handling code + */ + if (test_thread_flag(TIF_32BIT)) + return do_signal32(oldset, regs); + + if (!oldset) + oldset = ¤t->blocked; + + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + if (signr > 0) { + /* Whee! Actually deliver the signal. */ + if (TRAP(regs) == 0x0C00) + syscall_restart(regs, &ka); + + /* + * 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); + + return handle_signal(signr, &ka, &info, oldset, regs); + } + + if (TRAP(regs) == 0x0C00) { /* System Call! */ + if ((int)regs->result == -ERESTARTNOHAND || + (int)regs->result == -ERESTARTSYS || + (int)regs->result == -ERESTARTNOINTR) { + regs->gpr[3] = regs->orig_gpr3; + regs->nip -= 4; /* Back up & retry system call */ + regs->result = 0; + } else if ((int)regs->result == -ERESTART_RESTARTBLOCK) { + regs->gpr[0] = __NR_restart_syscall; + regs->nip -= 4; + regs->result = 0; + } + } + + return 0; +} +EXPORT_SYMBOL(do_signal); |