Commit bb6e6470 authored by Haavard Skinnemoen's avatar 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: default avatarHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
parent fbe0b8d5
...@@ -75,8 +75,17 @@ void _exception(long signr, struct pt_regs *regs, int code, ...@@ -75,8 +75,17 @@ void _exception(long signr, struct pt_regs *regs, int code,
{ {
siginfo_t info; 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); die("Unhandled exception in kernel mode", regs, signr);
}
memset(&info, 0, sizeof(info)); memset(&info, 0, sizeof(info));
info.si_signo = signr; info.si_signo = signr;
......
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