1 files changed, 248 insertions, 0 deletions
diff --git a/arch/tile/kernel/compat_signal.c b/arch/tile/kernel/compat_signal.c
new file mode 100644
index 000000000..e8c2c0414
--- /dev/null
+++ b/arch/tile/kernel/compat_signal.c
@@ -0,0 +1,248 @@
+/*
+ * 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>
+
+struct compat_ucontext {
+	compat_ulong_t	  uc_flags;
+	compat_uptr_t     uc_link;
+	struct compat_sigaltstack	  uc_stack;
+	struct sigcontext uc_mcontext;
+	sigset_t	  uc_sigmask;	/* mask last for extensibility */
+};
+
+struct compat_rt_sigframe {
+	unsigned char save_area[C_ABI_SAVE_AREA_SIZE]; /* caller save area */
+	struct compat_siginfo info;
+	struct compat_ucontext uc;
+};
+
+int copy_siginfo_to_user32(struct compat_siginfo __user *to, const siginfo_t *from)
+{
+	int err;
+
+	if (!access_ok(VERIFY_WRITE, to, sizeof(struct compat_siginfo)))
+		return -EFAULT;
+
+	/* If you change siginfo_t structure, please make sure that
+	   this code is fixed accordingly.
+	   It should never copy any pad contained in the structure
+	   to avoid security leaks, but must copy the generic
+	   3 ints plus the relevant union member.  */
+	err = __put_user(from->si_signo, &to->si_signo);
+	err |= __put_user(from->si_errno, &to->si_errno);
+	err |= __put_user((short)from->si_code, &to->si_code);
+
+	if (from->si_code < 0) {
+		err |= __put_user(from->si_pid, &to->si_pid);
+		err |= __put_user(from->si_uid, &to->si_uid);
+		err |= __put_user(from->si_int, &to->si_int);
+	} else {
+		/*
+		 * First 32bits of unions are always present:
+		 * si_pid === si_band === si_tid === si_addr(LS half)
+		 */
+		err |= __put_user(from->_sifields._pad[0],
+				  &to->_sifields._pad[0]);
+		switch (from->si_code >> 16) {
+		case __SI_FAULT >> 16:
+			break;
+		case __SI_CHLD >> 16:
+			err |= __put_user(from->si_utime, &to->si_utime);
+			err |= __put_user(from->si_stime, &to->si_stime);
+			err |= __put_user(from->si_status, &to->si_status);
+			/* FALL THROUGH */
+		default:
+		case __SI_KILL >> 16:
+			err |= __put_user(from->si_uid, &to->si_uid);
+			break;
+		case __SI_POLL >> 16:
+			err |= __put_user(from->si_fd, &to->si_fd);
+			break;
+		case __SI_TIMER >> 16:
+			err |= __put_user(from->si_overrun, &to->si_overrun);
+			err |= __put_user(from->si_int, &to->si_int);
+			break;
+			 /* This is not generated by the kernel as of now.  */
+		case __SI_RT >> 16:
+		case __SI_MESGQ >> 16:
+			err |= __put_user(from->si_uid, &to->si_uid);
+			err |= __put_user(from->si_int, &to->si_int);
+			break;
+		}
+	}
+	return err;
+}
+
+int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
+{
+	int err;
+
+	if (!access_ok(VERIFY_READ, from, sizeof(struct compat_siginfo)))
+		return -EFAULT;
+
+	memset(to, 0, sizeof(*to));
+
+	err = __get_user(to->si_signo, &from->si_signo);
+	err |= __get_user(to->si_errno, &from->si_errno);
+	err |= __get_user(to->si_code, &from->si_code);
+
+	err |= __get_user(to->si_pid, &from->si_pid);
+	err |= __get_user(to->si_uid, &from->si_uid);
+	err |= __get_user(to->si_int, &from->si_int);
+
+	return err;
+}
+
+/* The assembly shim for this function arranges to ignore the return value. */
+long compat_sys_rt_sigreturn(void)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct compat_rt_sigframe __user *frame =
+		(struct compat_rt_sigframe __user *) compat_ptr(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 (compat_restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return 0;
+
+badframe:
+	signal_fault("bad sigreturn frame", regs, frame, 0);
+	return 0;
+}
+
+/*
+ * Determine which stack to use..
+ */
+static inline void __user *compat_get_sigframe(struct k_sigaction *ka,
+					       struct pt_regs *regs,
+					       size_t frame_size)
+{
+	unsigned long sp;
+
+	/* Default to using normal stack */
+	sp = (unsigned long)compat_ptr(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;
+}
+
+int compat_setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+			  struct pt_regs *regs)
+{
+	unsigned long restorer;
+	struct compat_rt_sigframe __user *frame;
+	int err = 0, sig = ksig->sig;
+
+	frame = compat_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_user32(&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(0, &frame->uc.uc_link);
+	err |= __compat_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 = ptr_to_compat_reg(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 = ptr_to_compat_reg(ksig->ka.sa.sa_handler);
+	regs->ex1 = PL_ICS_EX1(USER_PL, 1); /* set crit sec in handler */
+	regs->sp = ptr_to_compat_reg(frame);
+	regs->lr = restorer;
+	regs->regs[0] = (unsigned long) sig;
+	regs->regs[1] = ptr_to_compat_reg(&frame->info);
+	regs->regs[2] = ptr_to_compat_reg(&frame->uc);
+	regs->flags |= PT_FLAGS_CALLER_SAVES;
+	return 0;
+
+err:
+	trace_unhandled_signal("bad sigreturn frame", regs,
+			      (unsigned long)frame, SIGSEGV);
+	return -EFAULT;
+}