From: Martin Schwidefsky Date: Fri, 24 Jul 2009 10:39:52 +0000 (+0200) Subject: [S390] vdso: clock_gettime of CLOCK_THREAD_CPUTIME_ID with noexec=on X-Git-Tag: v2.6.31-rc5~90^2~1 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1277580fe5dfb5aef84854bdb7983657df00b920;p=pandora-kernel.git [S390] vdso: clock_gettime of CLOCK_THREAD_CPUTIME_ID with noexec=on The combination of noexec=on and a clock_gettime call with clock id CLOCK_THREAD_CPUTIME_ID is broken. The vdso code switches to the access register mode to get access to the per-cpu data structure to execute the magic ectg instruction. After the ectg instruction the code always switches back to the primary mode but for noexec=on the correct mode is the secondary mode. The effect of the bug is that the user space program looses the access to all mappings without PROT_EXEC, e.g. the stack. The problem is fixed by restoring the mode that has been active before the switch to the access register mode. Signed-off-by: Martin Schwidefsky --- Reading git-diff-tree failed