From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Sun, 14 Mar 2010 22:30:15 +0000 Subject: [PATCH 06/10] ARM: ftrace: add Thumb-2 support In-Reply-To: <1268462987-8271-7-git-send-email-rabin@rab.in> References: <1268462987-8271-1-git-send-email-rabin@rab.in> <1268462987-8271-7-git-send-email-rabin@rab.in> Message-ID: <1268605815.2168.6.camel@e102109-lin.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, 2010-03-13 at 06:49 +0000, Rabin Vincent wrote: > - The problem with the "mov lr, pc", is that it does not set the lsb when > storing the pc in lr. The called function returns with "bx lr", and the > mode changes to ARM. The blx is to avoid this. I'm not familiar with ftrace but why does the called function returns using "bx lr". Is this generated by the compiler? I had the impression that if we don't enable interworking, we wouldn't get this instruction (but haven't tried this yet). -- Catalin