1 files changed, 315 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/signal.c b/arch/microblaze/kernel/signal.c
new file mode 100644
index 000000000..c3aebec71
--- /dev/null
+++ b/arch/microblaze/kernel/signal.c
@@ -0,0 +1,315 @@
+/*
+ * 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 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/resume_user_mode.h>
+#include <asm/entry.h>
+#include <asm/ucontext.h>
+#include <linux/uaccess.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(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);
+	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;
+	pmd_t *pmdp;
+	pte_t *ptep;
+
+	frame = get_sigframe(ksig, regs, sizeof(*frame));
+
+	if (!access_ok(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);
+	pmdp = pmd_off(current->mm, 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();
+	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, read_thread_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) ||
+	    test_thread_flag(TIF_NOTIFY_SIGNAL))
+		do_signal(regs, in_syscall);
+
+	if (test_thread_flag(TIF_NOTIFY_RESUME))
+		resume_user_mode_work(regs);
+}