From: Martin Schwidefsky Date: Thu, 28 Feb 2013 15:28:41 +0000 (+0100) Subject: s390: critical section cleanup vs. machine checks X-Git-Tag: v3.9-rc4~33^2~8 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6551fbdfd8b85d1ab5822ac98abb4fb449bcfae0;p=pandora-kernel.git s390: critical section cleanup vs. machine checks The current machine check code uses the registers stored by the machine in the lowcore at __LC_GPREGS_SAVE_AREA as the registers of the interrupted context. The registers 0-7 of a user process can get clobbered if a machine checks interrupts the execution of a critical section in entry[64].S. The reason is that the critical section cleanup code may need to modify the PSW and the registers for the previous context to get to the end of a critical section. If registers 0-7 have to be replaced the relevant copy will be in the registers, which invalidates the copy in the lowcore. The machine check handler needs to explicitly store registers 0-7 to the stack. Cc: stable@vger.kernel.org Signed-off-by: Martin Schwidefsky --- Reading git-diff-tree failed