Commit bb6e6470 authored Jun 03, 2009 by Haavard Skinnemoen

avr32: Fix oops on unaligned user access

The unaligned address exception handler (and others) does not scan the
fixup tables before oopsing. This is bad because it means passing a
badly aligned pointer from user space might crash the kernel.

Fix this by scanning the fixup tables in _exception(). This should
resolve the issue for unaligned addresses as well as other less common
exceptions that might be happening during a userspace access. The page
fault handler already does fixup processing.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

parent fbe0b8d5

arch/avr32/kernel/traps.c

+10 −1

Original line number	Diff line number	Diff line
		@@ -75,8 +75,17 @@ void _exception(long signr, struct pt_regs *regs, int code,
		{
		siginfo_t info;

		if (!user_mode(regs))
		if (!user_mode(regs)) {
		const struct exception_table_entry *fixup;

		/* Are we prepared to handle this kernel fault? */
		fixup = search_exception_tables(regs->pc);
		if (fixup) {
		regs->pc = fixup->fixup;
		return;
		}
		die("Unhandled exception in kernel mode", regs, signr);
		}

		memset(&info, 0, sizeof(info));
		info.si_signo = signr;