From: Tony Wu Date: Sun, 12 May 2013 15:04:29 +0000 (+0000) Subject: MIPS: Fix sibling call handling in get_frame_info X-Git-Tag: v3.10-rc2~10^2~2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e7438c4b893e87311d2fb0facb3e6a0df17abe01;p=pandora-kernel.git MIPS: Fix sibling call handling in get_frame_info Given a function, get_frame_info() analyzes its instructions to figure out frame size and return address. get_frame_info() works as follows: 1. analyze up to 128 instructions if the function size is unknown 2. search for 'addiu/daddiu sp,sp,-immed' for frame size 3. search for 'sw ra,offset(sp)' for return address 4. end search when it sees jr/jal/jalr This leads to an issue when the given function is a sibling call, example shown as follows. 801ca110 : 801ca110: 8f820000 lw v0,0(gp) 801ca114: 8c420000 lw v0,0(v0) 801ca118: 080726f0 j 801c9bc0 <__schedule> 801ca11c: 00000000 nop 801ca120 : 801ca120: 27bdffe8 addiu sp,sp,-24 801ca124: 3c028022 lui v0,0x8022 801ca128: afbf0014 sw ra,20(sp) In this case, get_frame_info() cannot properly detect schedule's frame info, and eventually returns io_schedule's instead. This patch adds 'j' to the end search condition to workaround sibling call cases. Signed-off-by: Tony Wu Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5236/ Signed-off-by: Ralf Baechle --- Reading git-diff-tree failed