ARM: 8052/1: unwind: Fix handling of "Pop r4-r[4+nnn],r14" opcode
authorNikolay Borisov <Nikolay.Borisov@arm.com>
Thu, 8 May 2014 14:54:26 +0000 (15:54 +0100)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Sun, 25 May 2014 22:44:26 +0000 (23:44 +0100)
commit8203d5b628907ae6141e4eb52f9b48e0f1f46cd2
tree8b635436986e4036ace52cb30299eac7b7bfe70f
parent537094b64b229bf3ad146042f83e74cf6abe59df
ARM: 8052/1: unwind: Fix handling of "Pop r4-r[4+nnn],r14" opcode

The arm EABI states that unwind opcode 10100nnn means pop register r4-4[4+nnn],aditionally there is a similar unwind opcode: 10101nnn which means the same thing plus popping r14. Those two cases are handled by the unwind_exec_pop_r4_to_rN function which checks whether the 4th bit is set and does r14 popping.

However, up until now it has been checking whether the 8th bit was set (mask & 0x80) instead of the 4th (mask & 0x8), a simple to make typo but this meant that we were always popping r14 even if we had the former opcode.

This patch changes the mask so that the 2 unwind opcodes are being handled correctly.

Signed-off-by: Nikolay Borisov <Nikolay.Borisov@arm.com>
Reviewed-by: Anurag Aggarwal <anurag19aggarwal@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/kernel/unwind.c