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-rw-r--r--arch/c6x/kernel/signal.c326
1 files changed, 326 insertions, 0 deletions
diff --git a/arch/c6x/kernel/signal.c b/arch/c6x/kernel/signal.c
new file mode 100644
index 000000000..3c4bb5a5c
--- /dev/null
+++ b/arch/c6x/kernel/signal.c
@@ -0,0 +1,326 @@
+/*
+ * Port on Texas Instruments TMS320C6x architecture
+ *
+ * Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
+ * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
+ *
+ * Updated for 2.6.34: Mark Salter <msalter@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/uaccess.h>
+#include <linux/syscalls.h>
+#include <linux/tracehook.h>
+
+#include <asm/ucontext.h>
+#include <asm/cacheflush.h>
+
+
+/*
+ * Do a signal return, undo the signal stack.
+ */
+
+#define RETCODE_SIZE (9 << 2) /* 9 instructions = 36 bytes */
+
+struct rt_sigframe {
+ struct siginfo __user *pinfo;
+ void __user *puc;
+ struct siginfo info;
+ struct ucontext uc;
+ unsigned long retcode[RETCODE_SIZE >> 2];
+};
+
+static int restore_sigcontext(struct pt_regs *regs,
+ struct sigcontext __user *sc)
+{
+ int err = 0;
+
+ /* The access_ok check was done by caller, so use __get_user here */
+#define COPY(x) (err |= __get_user(regs->x, &sc->sc_##x))
+
+ COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8);
+ COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9);
+ COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9);
+
+ COPY(a16); COPY(a17); COPY(a18); COPY(a19);
+ COPY(a20); COPY(a21); COPY(a22); COPY(a23);
+ COPY(a24); COPY(a25); COPY(a26); COPY(a27);
+ COPY(a28); COPY(a29); COPY(a30); COPY(a31);
+ COPY(b16); COPY(b17); COPY(b18); COPY(b19);
+ COPY(b20); COPY(b21); COPY(b22); COPY(b23);
+ COPY(b24); COPY(b25); COPY(b26); COPY(b27);
+ COPY(b28); COPY(b29); COPY(b30); COPY(b31);
+
+ COPY(csr); COPY(pc);
+
+#undef COPY
+
+ return err;
+}
+
+asmlinkage int do_rt_sigreturn(struct pt_regs *regs)
+{
+ struct rt_sigframe __user *frame;
+ sigset_t set;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ /*
+ * Since we stacked the signal on a dword boundary,
+ * 'sp' should be dword aligned here. If it's
+ * not, then the user is trying to mess with us.
+ */
+ if (regs->sp & 7)
+ goto badframe;
+
+ frame = (struct rt_sigframe __user *) ((unsigned long) regs->sp + 8);
+
+ 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;
+
+ return regs->a4;
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
+ unsigned long mask)
+{
+ int err = 0;
+
+ err |= __put_user(mask, &sc->sc_mask);
+
+ /* The access_ok check was done by caller, so use __put_user here */
+#define COPY(x) (err |= __put_user(regs->x, &sc->sc_##x))
+
+ COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8);
+ COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9);
+ COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9);
+
+ COPY(a16); COPY(a17); COPY(a18); COPY(a19);
+ COPY(a20); COPY(a21); COPY(a22); COPY(a23);
+ COPY(a24); COPY(a25); COPY(a26); COPY(a27);
+ COPY(a28); COPY(a29); COPY(a30); COPY(a31);
+ COPY(b16); COPY(b17); COPY(b18); COPY(b19);
+ COPY(b20); COPY(b21); COPY(b22); COPY(b23);
+ COPY(b24); COPY(b25); COPY(b26); COPY(b27);
+ COPY(b28); COPY(b29); COPY(b30); COPY(b31);
+
+ COPY(csr); COPY(pc);
+
+#undef COPY
+
+ return err;
+}
+
+static inline void __user *get_sigframe(struct ksignal *ksig,
+ struct pt_regs *regs,
+ unsigned long framesize)
+{
+ unsigned long sp = sigsp(regs->sp, ksig);
+
+ /*
+ * No matter what happens, 'sp' must be dword
+ * aligned. Otherwise, nasty things will happen
+ */
+ return (void __user *)((sp - framesize) & ~7);
+}
+
+static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+ struct pt_regs *regs)
+{
+ struct rt_sigframe __user *frame;
+ unsigned long __user *retcode;
+ int err = 0;
+
+ frame = get_sigframe(ksig, regs, sizeof(*frame));
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ return -EFAULT;
+
+ err |= __put_user(&frame->info, &frame->pinfo);
+ err |= __put_user(&frame->uc, &frame->puc);
+ err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+
+ /* Clear all the bits of the ucontext we don't use. */
+ err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
+
+ 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 */
+ retcode = (unsigned long __user *) &frame->retcode;
+
+ /* The access_ok check was done above, so use __put_user here */
+#define COPY(x) (err |= __put_user(x, retcode++))
+
+ COPY(0x0000002AUL | (__NR_rt_sigreturn << 7));
+ /* MVK __NR_rt_sigreturn,B0 */
+ COPY(0x10000000UL); /* SWE */
+ COPY(0x00006000UL); /* NOP 4 */
+ COPY(0x00006000UL); /* NOP 4 */
+ COPY(0x00006000UL); /* NOP 4 */
+ COPY(0x00006000UL); /* NOP 4 */
+ COPY(0x00006000UL); /* NOP 4 */
+ COPY(0x00006000UL); /* NOP 4 */
+ COPY(0x00006000UL); /* NOP 4 */
+
+#undef COPY
+
+ if (err)
+ return -EFAULT;
+
+ flush_icache_range((unsigned long) &frame->retcode,
+ (unsigned long) &frame->retcode + RETCODE_SIZE);
+
+ retcode = (unsigned long __user *) &frame->retcode;
+
+ /* Change user context to branch to signal handler */
+ regs->sp = (unsigned long) frame - 8;
+ regs->b3 = (unsigned long) retcode;
+ regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
+
+ /* Give the signal number to the handler */
+ regs->a4 = ksig->sig;
+
+ /*
+ * For realtime signals we must also set the second and third
+ * arguments for the signal handler.
+ * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
+ */
+ regs->b4 = (unsigned long)&frame->info;
+ regs->a6 = (unsigned long)&frame->uc;
+
+ return 0;
+}
+
+static inline void
+handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
+{
+ switch (regs->a4) {
+ case -ERESTARTNOHAND:
+ if (!has_handler)
+ goto do_restart;
+ regs->a4 = -EINTR;
+ break;
+
+ case -ERESTARTSYS:
+ if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
+ regs->a4 = -EINTR;
+ break;
+ }
+ /* fallthrough */
+ case -ERESTARTNOINTR:
+do_restart:
+ regs->a4 = regs->orig_a4;
+ regs->pc -= 4;
+ break;
+ }
+}
+
+/*
+ * handle the actual delivery of a signal to userspace
+ */
+static void handle_signal(struct ksignal *ksig, struct pt_regs *regs,
+ int syscall)
+{
+ int ret;
+
+ /* Are we from a system call? */
+ if (syscall) {
+ /* If so, check system call restarting.. */
+ switch (regs->a4) {
+ case -ERESTART_RESTARTBLOCK:
+ case -ERESTARTNOHAND:
+ regs->a4 = -EINTR;
+ break;
+
+ case -ERESTARTSYS:
+ if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
+ regs->a4 = -EINTR;
+ break;
+ }
+
+ /* fallthrough */
+ case -ERESTARTNOINTR:
+ regs->a4 = regs->orig_a4;
+ regs->pc -= 4;
+ }
+ }
+
+ /* Set up the stack frame */
+ ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
+ signal_setup_done(ret, ksig, 0);
+}
+
+/*
+ * handle a potential signal
+ */
+static void do_signal(struct pt_regs *regs, int syscall)
+{
+ struct ksignal ksig;
+
+ /* we want the common case to go fast, which is why we may in certain
+ * cases get here from kernel mode */
+ if (!user_mode(regs))
+ return;
+
+ if (get_signal(&ksig)) {
+ handle_signal(&ksig, regs, syscall);
+ return;
+ }
+
+ /* did we come from a system call? */
+ if (syscall) {
+ /* restart the system call - no handlers present */
+ switch (regs->a4) {
+ case -ERESTARTNOHAND:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ regs->a4 = regs->orig_a4;
+ regs->pc -= 4;
+ break;
+
+ case -ERESTART_RESTARTBLOCK:
+ regs->a4 = regs->orig_a4;
+ regs->b0 = __NR_restart_syscall;
+ regs->pc -= 4;
+ break;
+ }
+ }
+
+ /* if there's no signal to deliver, we just put the saved sigmask
+ * back */
+ restore_saved_sigmask();
+}
+
+/*
+ * notification of userspace execution resumption
+ * - triggered by current->work.notify_resume
+ */
+asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags,
+ int syscall)
+{
+ /* deal with pending signal delivery */
+ if (thread_info_flags & (1 << TIF_SIGPENDING))
+ do_signal(regs, syscall);
+
+ if (thread_info_flags & (1 << TIF_NOTIFY_RESUME)) {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
+ }
+}