From: Maneesh Soni Date: Tue, 8 Nov 2011 11:38:26 +0000 (+0530) Subject: MIPS Kprobes: Support branch instructions probing X-Git-Tag: v3.3-rc1~65^2^8 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6457a396bbc20656009eaf950ca165912a943520;p=pandora-kernel.git MIPS Kprobes: Support branch instructions probing This patch provides support for kprobes on branch instructions. The branch instruction at the probed address is actually emulated and not executed out-of-line like other normal instructions. Instead the delay-slot instruction is copied and single stepped out of line. At the time of probe hit, the original branch instruction is evaluated and the target cp0_epc is computed similar to compute_retrun_epc(). It is also checked if the delay slot instruction can be skipped, which is true if there is a NOP in delay slot or branch is taken in case of branch likely instructions. Once the delay slot instruction is single stepped the normal execution resume with the cp0_epc updated the earlier computed cp0_epc as per the branch instructions. Signed-off-by: Maneesh Soni Signed-off-by: Victor Kamensky Cc: David Daney Cc: ananth@in.ibm.com Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/2914/ Signed-off-by: Ralf Baechle --- Reading git-diff-tree failed