tree d3546c0fe44e49d283ed3d0ced3b92873f28df34
parent fc14f9c1272f62c3e8d01300f52467c0d9af50f9
author Andy Lutomirski <luto@amacapital.net> 1416708031 -0800
committer Linus Torvalds <torvalds@linux-foundation.org> 1416779778 -0800

x86_64, traps: Fix the espfix64 #DF fixup and rewrite it in C

There's nothing special enough about the espfix64 double fault fixup to
justify writing it in assembly.  Move it to C.

This also fixes a bug: if the double fault came from an IST stack, the
old asm code would return to a partially uninitialized stack frame.

Fixes: 3891a04aafd668686239349ea58f3314ea2af86b
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>