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-rw-r--r--arch/microblaze/kernel/signal.c325
1 files changed, 325 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/signal.c b/arch/microblaze/kernel/signal.c
new file mode 100644
index 000000000..97001524c
--- /dev/null
+++ b/arch/microblaze/kernel/signal.c
@@ -0,0 +1,325 @@
+/*
+ * Signal handling
+ *
+ * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2008-2009 PetaLogix
+ * Copyright (C) 2003,2004 John Williams <jwilliams@itee.uq.edu.au>
+ * Copyright (C) 2001 NEC Corporation
+ * Copyright (C) 2001 Miles Bader <miles@gnu.org>
+ * Copyright (C) 1999,2000 Niibe Yutaka & Kaz Kojima
+ * Copyright (C) 1991,1992 Linus Torvalds
+ *
+ * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
+ *
+ * This file was was derived from the sh version, arch/sh/kernel/signal.c
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file COPYING in the main directory of this
+ * archive 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/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/personality.h>
+#include <linux/percpu.h>
+#include <linux/linkage.h>
+#include <linux/tracehook.h>
+#include <asm/entry.h>
+#include <asm/ucontext.h>
+#include <linux/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <linux/syscalls.h>
+#include <asm/cacheflush.h>
+#include <asm/syscalls.h>
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+struct sigframe {
+ struct sigcontext sc;
+ unsigned long extramask[_NSIG_WORDS-1];
+ unsigned long tramp[2]; /* signal trampoline */
+};
+
+struct rt_sigframe {
+ struct siginfo info;
+ struct ucontext uc;
+ unsigned long tramp[2]; /* signal trampoline */
+};
+
+static int restore_sigcontext(struct pt_regs *regs,
+ struct sigcontext __user *sc, int *rval_p)
+{
+ unsigned int err = 0;
+
+#define COPY(x) {err |= __get_user(regs->x, &sc->regs.x); }
+ COPY(r0);
+ COPY(r1);
+ COPY(r2); COPY(r3); COPY(r4); COPY(r5);
+ COPY(r6); COPY(r7); COPY(r8); COPY(r9);
+ COPY(r10); COPY(r11); COPY(r12); COPY(r13);
+ COPY(r14); COPY(r15); COPY(r16); COPY(r17);
+ COPY(r18); COPY(r19); COPY(r20); COPY(r21);
+ COPY(r22); COPY(r23); COPY(r24); COPY(r25);
+ COPY(r26); COPY(r27); COPY(r28); COPY(r29);
+ COPY(r30); COPY(r31);
+ COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
+#undef COPY
+
+ *rval_p = regs->r3;
+
+ return err;
+}
+
+asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+{
+ struct rt_sigframe __user *frame =
+ (struct rt_sigframe __user *)(regs->r1);
+
+ sigset_t set;
+ int rval;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ 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, &rval))
+ goto badframe;
+
+ if (restore_altstack(&frame->uc.uc_stack))
+ goto badframe;
+
+ return rval;
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+static int
+setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
+ unsigned long mask)
+{
+ int err = 0;
+
+#define COPY(x) {err |= __put_user(regs->x, &sc->regs.x); }
+ COPY(r0);
+ COPY(r1);
+ COPY(r2); COPY(r3); COPY(r4); COPY(r5);
+ COPY(r6); COPY(r7); COPY(r8); COPY(r9);
+ COPY(r10); COPY(r11); COPY(r12); COPY(r13);
+ COPY(r14); COPY(r15); COPY(r16); COPY(r17);
+ COPY(r18); COPY(r19); COPY(r20); COPY(r21);
+ COPY(r22); COPY(r23); COPY(r24); COPY(r25);
+ COPY(r26); COPY(r27); COPY(r28); COPY(r29);
+ COPY(r30); COPY(r31);
+ COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
+#undef COPY
+
+ err |= __put_user(mask, &sc->oldmask);
+
+ return err;
+}
+
+/*
+ * Determine which stack to use..
+ */
+static inline void __user *
+get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size)
+{
+ /* Default to using normal stack */
+ unsigned long sp = sigsp(regs->r1, ksig);
+
+ return (void __user *)((sp - frame_size) & -8UL);
+}
+
+static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+ struct pt_regs *regs)
+{
+ struct rt_sigframe __user *frame;
+ int err = 0, sig = ksig->sig;
+ unsigned long address = 0;
+#ifdef CONFIG_MMU
+ pmd_t *pmdp;
+ pte_t *ptep;
+#endif
+
+ frame = get_sigframe(ksig, regs, sizeof(*frame));
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ return -EFAULT;
+
+ if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+ err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+
+ /* Create the ucontext. */
+ err |= __put_user(0, &frame->uc.uc_flags);
+ err |= __put_user(NULL, &frame->uc.uc_link);
+ err |= __save_altstack(&frame->uc.uc_stack, regs->r1);
+ err |= setup_sigcontext(&frame->uc.uc_mcontext,
+ regs, set->sig[0]);
+ 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. */
+ /* minus 8 is offset to cater for "rtsd r15,8" */
+ /* addi r12, r0, __NR_sigreturn */
+ err |= __put_user(0x31800000 | __NR_rt_sigreturn ,
+ frame->tramp + 0);
+ /* brki r14, 0x8 */
+ err |= __put_user(0xb9cc0008, frame->tramp + 1);
+
+ /* Return from sighandler will jump to the tramp.
+ Negative 8 offset because return is rtsd r15, 8 */
+ regs->r15 = ((unsigned long)frame->tramp)-8;
+
+ address = ((unsigned long)frame->tramp);
+#ifdef CONFIG_MMU
+ pmdp = pmd_offset(pud_offset(
+ pgd_offset(current->mm, address),
+ address), address);
+
+ preempt_disable();
+ ptep = pte_offset_map(pmdp, address);
+ if (pte_present(*ptep)) {
+ address = (unsigned long) page_address(pte_page(*ptep));
+ /* MS: I need add offset in page */
+ address += ((unsigned long)frame->tramp) & ~PAGE_MASK;
+ /* MS address is virtual */
+ address = __virt_to_phys(address);
+ invalidate_icache_range(address, address + 8);
+ flush_dcache_range(address, address + 8);
+ }
+ pte_unmap(ptep);
+ preempt_enable();
+#else
+ flush_icache_range(address, address + 8);
+ flush_dcache_range(address, address + 8);
+#endif
+ if (err)
+ return -EFAULT;
+
+ /* Set up registers for signal handler */
+ regs->r1 = (unsigned long) frame;
+
+ /* Signal handler args: */
+ regs->r5 = sig; /* arg 0: signum */
+ regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */
+ regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */
+ /* Offset to handle microblaze rtid r14, 0 */
+ regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
+
+#ifdef DEBUG_SIG
+ pr_info("SIG deliver (%s:%d): sp=%p pc=%08lx\n",
+ current->comm, current->pid, frame, regs->pc);
+#endif
+
+ return 0;
+}
+
+/* Handle restarting system calls */
+static inline void
+handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
+{
+ switch (regs->r3) {
+ case -ERESTART_RESTARTBLOCK:
+ case -ERESTARTNOHAND:
+ if (!has_handler)
+ goto do_restart;
+ regs->r3 = -EINTR;
+ break;
+ case -ERESTARTSYS:
+ if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
+ regs->r3 = -EINTR;
+ break;
+ }
+ /* fallthrough */
+ case -ERESTARTNOINTR:
+do_restart:
+ /* offset of 4 bytes to re-execute trap (brki) instruction */
+ regs->pc -= 4;
+ break;
+ }
+}
+
+/*
+ * 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;
+
+ /* Set up the stack frame */
+ 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.
+ *
+ * Note that we go through the signals twice: once to check the signals that
+ * the kernel can handle, and then we build all the user-level signal handling
+ * stack-frames in one go after that.
+ */
+static void do_signal(struct pt_regs *regs, int in_syscall)
+{
+ struct ksignal ksig;
+
+#ifdef DEBUG_SIG
+ pr_info("do signal: %p %d\n", regs, in_syscall);
+ pr_info("do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
+ regs->r12, current_thread_info()->flags);
+#endif
+
+ if (get_signal(&ksig)) {
+ /* Whee! Actually deliver the signal. */
+ if (in_syscall)
+ handle_restart(regs, &ksig.ka, 1);
+ handle_signal(&ksig, regs);
+ return;
+ }
+
+ if (in_syscall)
+ handle_restart(regs, NULL, 0);
+
+ /*
+ * If there's no signal to deliver, we just put the saved sigmask
+ * back.
+ */
+ restore_saved_sigmask();
+}
+
+asmlinkage void do_notify_resume(struct pt_regs *regs, int in_syscall)
+{
+ if (test_thread_flag(TIF_SIGPENDING))
+ do_signal(regs, in_syscall);
+
+ if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
+ tracehook_notify_resume(regs);
+}