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-rw-r--r--arch/tile/kernel/signal.c409
1 files changed, 409 insertions, 0 deletions
diff --git a/arch/tile/kernel/signal.c b/arch/tile/kernel/signal.c
new file mode 100644
index 000000000..87299a6cf
--- /dev/null
+++ b/arch/tile/kernel/signal.c
@@ -0,0 +1,409 @@
+/*
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * 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, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.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/personality.h>
+#include <linux/suspend.h>
+#include <linux/ptrace.h>
+#include <linux/elf.h>
+#include <linux/compat.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+#include <asm/processor.h>
+#include <asm/ucontext.h>
+#include <asm/sigframe.h>
+#include <asm/syscalls.h>
+#include <asm/vdso.h>
+#include <arch/interrupts.h>
+
+#define DEBUG_SIG 0
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+
+int restore_sigcontext(struct pt_regs *regs,
+ struct sigcontext __user *sc)
+{
+ int err;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ /*
+ * Enforce that sigcontext is like pt_regs, and doesn't mess
+ * up our stack alignment rules.
+ */
+ BUILD_BUG_ON(sizeof(struct sigcontext) != sizeof(struct pt_regs));
+ BUILD_BUG_ON(sizeof(struct sigcontext) % 8 != 0);
+ err = __copy_from_user(regs, sc, sizeof(*regs));
+
+ /* Ensure that the PL is always set to USER_PL. */
+ regs->ex1 = PL_ICS_EX1(USER_PL, EX1_ICS(regs->ex1));
+
+ regs->faultnum = INT_SWINT_1_SIGRETURN;
+
+ return err;
+}
+
+void signal_fault(const char *type, struct pt_regs *regs,
+ void __user *frame, int sig)
+{
+ trace_unhandled_signal(type, regs, (unsigned long)frame, SIGSEGV);
+ force_sigsegv(sig, current);
+}
+
+/* The assembly shim for this function arranges to ignore the return value. */
+SYSCALL_DEFINE0(rt_sigreturn)
+{
+ struct pt_regs *regs = current_pt_regs();
+ struct rt_sigframe __user *frame =
+ (struct rt_sigframe __user *)(regs->sp);
+ sigset_t set;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+ if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
+ goto badframe;
+
+ if (restore_altstack(&frame->uc.uc_stack))
+ goto badframe;
+
+ return 0;
+
+badframe:
+ signal_fault("bad sigreturn frame", regs, frame, 0);
+ return 0;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
+{
+ return __copy_to_user(sc, regs, sizeof(*regs));
+}
+
+/*
+ * Determine which stack to use..
+ */
+static inline void __user *get_sigframe(struct k_sigaction *ka,
+ struct pt_regs *regs,
+ size_t frame_size)
+{
+ unsigned long sp;
+
+ /* Default to using normal stack */
+ sp = regs->sp;
+
+ /*
+ * If we are on the alternate signal stack and would overflow
+ * it, don't. Return an always-bogus address instead so we
+ * will die with SIGSEGV.
+ */
+ if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
+ return (void __user __force *)-1UL;
+
+ /* This is the X/Open sanctioned signal stack switching. */
+ if (ka->sa.sa_flags & SA_ONSTACK) {
+ if (sas_ss_flags(sp) == 0)
+ sp = current->sas_ss_sp + current->sas_ss_size;
+ }
+
+ sp -= frame_size;
+ /*
+ * Align the stack pointer according to the TILE ABI,
+ * i.e. so that on function entry (sp & 15) == 0.
+ */
+ sp &= -16UL;
+ return (void __user *) sp;
+}
+
+static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+ struct pt_regs *regs)
+{
+ unsigned long restorer;
+ struct rt_sigframe __user *frame;
+ int err = 0, sig = ksig->sig;
+
+ frame = get_sigframe(&ksig->ka, regs, sizeof(*frame));
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ goto err;
+
+ /* Always write at least the signal number for the stack backtracer. */
+ if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
+ /* At sigreturn time, restore the callee-save registers too. */
+ err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+ regs->flags |= PT_FLAGS_RESTORE_REGS;
+ } else {
+ err |= __put_user(ksig->info.si_signo, &frame->info.si_signo);
+ }
+
+ /* Create the ucontext. */
+ err |= __clear_user(&frame->save_area, sizeof(frame->save_area));
+ err |= __put_user(0, &frame->uc.uc_flags);
+ err |= __put_user(NULL, &frame->uc.uc_link);
+ err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
+ err |= setup_sigcontext(&frame->uc.uc_mcontext, regs);
+ err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+ if (err)
+ goto err;
+
+ restorer = VDSO_SYM(&__vdso_rt_sigreturn);
+ if (ksig->ka.sa.sa_flags & SA_RESTORER)
+ restorer = (unsigned long) ksig->ka.sa.sa_restorer;
+
+ /*
+ * Set up registers for signal handler.
+ * Registers that we don't modify keep the value they had from
+ * user-space at the time we took the signal.
+ * We always pass siginfo and mcontext, regardless of SA_SIGINFO,
+ * since some things rely on this (e.g. glibc's debug/segfault.c).
+ */
+ regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
+ regs->ex1 = PL_ICS_EX1(USER_PL, 1); /* set crit sec in handler */
+ regs->sp = (unsigned long) frame;
+ regs->lr = restorer;
+ regs->regs[0] = (unsigned long) sig;
+ regs->regs[1] = (unsigned long) &frame->info;
+ regs->regs[2] = (unsigned long) &frame->uc;
+ regs->flags |= PT_FLAGS_CALLER_SAVES;
+ return 0;
+
+err:
+ trace_unhandled_signal("bad sigreturn frame", regs,
+ (unsigned long)frame, SIGSEGV);
+ return -EFAULT;
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+
+static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+ sigset_t *oldset = sigmask_to_save();
+ int ret;
+
+ /* Are we from a system call? */
+ if (regs->faultnum == INT_SWINT_1) {
+ /* If so, check system call restarting.. */
+ switch (regs->regs[0]) {
+ case -ERESTART_RESTARTBLOCK:
+ case -ERESTARTNOHAND:
+ regs->regs[0] = -EINTR;
+ break;
+
+ case -ERESTARTSYS:
+ if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
+ regs->regs[0] = -EINTR;
+ break;
+ }
+ /* fallthrough */
+ case -ERESTARTNOINTR:
+ /* Reload caller-saves to restore r0..r5 and r10. */
+ regs->flags |= PT_FLAGS_CALLER_SAVES;
+ regs->regs[0] = regs->orig_r0;
+ regs->pc -= 8;
+ }
+ }
+
+ /* Set up the stack frame */
+#ifdef CONFIG_COMPAT
+ if (is_compat_task())
+ ret = compat_setup_rt_frame(ksig, oldset, regs);
+ else
+#endif
+ ret = setup_rt_frame(ksig, oldset, regs);
+
+ signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
+}
+
+/*
+ * 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.
+ */
+void do_signal(struct pt_regs *regs)
+{
+ struct ksignal ksig;
+
+ /*
+ * i386 will check if we're coming from kernel mode and bail out
+ * here. In my experience this just turns weird crashes into
+ * weird spin-hangs. But if we find a case where this seems
+ * helpful, we can reinstate the check on "!user_mode(regs)".
+ */
+
+ if (get_signal(&ksig)) {
+ /* Whee! Actually deliver the signal. */
+ handle_signal(&ksig, regs);
+ goto done;
+ }
+
+ /* Did we come from a system call? */
+ if (regs->faultnum == INT_SWINT_1) {
+ /* Restart the system call - no handlers present */
+ switch (regs->regs[0]) {
+ case -ERESTARTNOHAND:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ regs->flags |= PT_FLAGS_CALLER_SAVES;
+ regs->regs[0] = regs->orig_r0;
+ regs->pc -= 8;
+ break;
+
+ case -ERESTART_RESTARTBLOCK:
+ regs->flags |= PT_FLAGS_CALLER_SAVES;
+ regs->regs[TREG_SYSCALL_NR] = __NR_restart_syscall;
+ regs->pc -= 8;
+ break;
+ }
+ }
+
+ /* If there's no signal to deliver, just put the saved sigmask back. */
+ restore_saved_sigmask();
+
+done:
+ /* Avoid double syscall restart if there are nested signals. */
+ regs->faultnum = INT_SWINT_1_SIGRETURN;
+}
+
+int show_unhandled_signals = 1;
+
+static int __init crashinfo(char *str)
+{
+ const char *word;
+
+ if (*str == '\0')
+ show_unhandled_signals = 2;
+ else if (*str != '=' || kstrtoint(++str, 0, &show_unhandled_signals) != 0)
+ return 0;
+
+ switch (show_unhandled_signals) {
+ case 0:
+ word = "No";
+ break;
+ case 1:
+ word = "One-line";
+ break;
+ default:
+ word = "Detailed";
+ break;
+ }
+ pr_info("%s crash reports will be generated on the console\n", word);
+ return 1;
+}
+__setup("crashinfo", crashinfo);
+
+static void dump_mem(void __user *address)
+{
+ void __user *addr;
+ enum { region_size = 256, bytes_per_line = 16 };
+ int i, j, k;
+ int found_readable_mem = 0;
+
+ if (!access_ok(VERIFY_READ, address, 1)) {
+ pr_err("Not dumping at address 0x%lx (kernel address)\n",
+ (unsigned long)address);
+ return;
+ }
+
+ addr = (void __user *)
+ (((unsigned long)address & -bytes_per_line) - region_size/2);
+ if (addr > address)
+ addr = NULL;
+ for (i = 0; i < region_size;
+ addr += bytes_per_line, i += bytes_per_line) {
+ unsigned char buf[bytes_per_line];
+ char line[100];
+ if (copy_from_user(buf, addr, bytes_per_line))
+ continue;
+ if (!found_readable_mem) {
+ pr_err("Dumping memory around address 0x%lx:\n",
+ (unsigned long)address);
+ found_readable_mem = 1;
+ }
+ j = sprintf(line, REGFMT ":", (unsigned long)addr);
+ for (k = 0; k < bytes_per_line; ++k)
+ j += sprintf(&line[j], " %02x", buf[k]);
+ pr_err("%s\n", line);
+ }
+ if (!found_readable_mem)
+ pr_err("No readable memory around address 0x%lx\n",
+ (unsigned long)address);
+}
+
+void trace_unhandled_signal(const char *type, struct pt_regs *regs,
+ unsigned long address, int sig)
+{
+ struct task_struct *tsk = current;
+
+ if (show_unhandled_signals == 0)
+ return;
+
+ /* If the signal is handled, don't show it here. */
+ if (!is_global_init(tsk)) {
+ void __user *handler =
+ tsk->sighand->action[sig-1].sa.sa_handler;
+ if (handler != SIG_IGN && handler != SIG_DFL)
+ return;
+ }
+
+ /* Rate-limit the one-line output, not the detailed output. */
+ if (show_unhandled_signals <= 1 && !printk_ratelimit())
+ return;
+
+ printk("%s%s[%d]: %s at %lx pc "REGFMT" signal %d",
+ task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
+ tsk->comm, task_pid_nr(tsk), type, address, regs->pc, sig);
+
+ print_vma_addr(KERN_CONT " in ", regs->pc);
+
+ printk(KERN_CONT "\n");
+
+ if (show_unhandled_signals > 1) {
+ switch (sig) {
+ case SIGILL:
+ case SIGFPE:
+ case SIGSEGV:
+ case SIGBUS:
+ pr_err("User crash: signal %d, trap %ld, address 0x%lx\n",
+ sig, regs->faultnum, address);
+ show_regs(regs);
+ dump_mem((void __user *)address);
+ break;
+ default:
+ pr_err("User crash: signal %d, trap %ld\n",
+ sig, regs->faultnum);
+ break;
+ }
+ }
+}
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