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authorStephen Rothwell <sfr@canb.auug.org.au>2005-11-03 15:26:23 +1100
committerStephen Rothwell <sfr@canb.auug.org.au>2005-11-03 16:03:20 +1100
commit62f4f47da64a10630d5f6dabc616477b0e09b612 (patch)
treecae7fc8698e2e8c18ad7e81a4c01c645757c53a6 /arch/powerpc/kernel/signal_64.c
parentda80d460bf4606671df3ba53408f45ab848e67ba (diff)
powerpc: move ppc64/kernel/signal.c to arch/powerpc
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Diffstat (limited to 'arch/powerpc/kernel/signal_64.c')
-rw-r--r--arch/powerpc/kernel/signal_64.c581
1 files changed, 581 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
new file mode 100644
index 000000000000..ec9d0984b6a0
--- /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(&current->sighand->siglock);
+ saveset = current->blocked;
+ current->blocked = newset;
+ recalc_sigpending();
+ spin_unlock_irq(&current->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, &current->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(&current->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(&current->sighand->siglock);
+ current->blocked = *set;
+ recalc_sigpending();
+ spin_unlock_irq(&current->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,
+ &current->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(&current->sighand->siglock);
+ sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
+ if (!(ka->sa.sa_flags & SA_NODEFER))
+ sigaddset(&current->blocked,sig);
+ recalc_sigpending();
+ spin_unlock_irq(&current->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 = &current->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);