Yu-cheng Yu dffba9a31c x86/fpu/xstate: Fix xcomp_bv in XSAVES header ... The compacted-format XSAVES area is determined at boot time and never changed after. The field xsave.header.xcomp_bv indicates which components are in the fixed XSAVES format. In fpstate_init() we did not set xcomp_bv to reflect the XSAVES format since at the time there is no valid data. However, after we do copy_init_fpstate_to_fpregs() in fpu__clear(), as in commit: b22cbe404a x86/fpu: Fix invalid FPU ptrace state after execve() and when __fpu_restore_sig() does fpu__restore() for a COMPAT-mode app, a #GP occurs. This can be easily triggered by doing valgrind on a COMPAT-mode "Hello World," as reported by Joakim Tjernlund and others: https://bugzilla.kernel.org/show_bug.cgi?id=190061 Fix it by setting xcomp_bv correctly. This patch also moves the xcomp_bv initialization to the proper place, which was in copyin_to_xsaves() as of: 4c833368f0 x86/fpu: Set the xcomp_bv when we fake up a XSAVES area which fixed the bug too, but it's more efficient and cleaner to initialize things once per boot, not for every signal handling operation. Reported-by: Kevin Hao <haokexin@gmail.com> Reported-by: Joakim Tjernlund <Joakim.Tjernlund@infinera.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: haokexin@gmail.com Link: http://lkml.kernel.org/r/1485212084-4418-1-git-send-email-yu-cheng.yu@intel.com [ Combined it with 4c833368f0. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>		2017-01-24 09:04:48 +01:00
..
bugs.c	x86/fpu: Stop saving and restoring CR0.TS in fpu__init_check_bugs()	2016-11-01 07:47:53 +01:00
core.c	x86/fpu/xstate: Fix xcomp_bv in XSAVES header	2017-01-24 09:04:48 +01:00
init.c	x86/fpu: Get rid of two redundant clts() calls	2016-11-01 07:47:53 +01:00
Makefile	x86/fpu: Factor out the FPU regset code into fpu/regset.c	2015-05-19 15:48:09 +02:00
regset.c	x86/fpu/xstate: Fix PTRACE frames for XSAVES	2016-07-10 17:12:10 +02:00
signal.c	x86/fpu: Remove use_eager_fpu()	2016-10-07 11:14:36 +02:00
xstate.c	x86/fpu/xstate: Fix xcomp_bv in XSAVES header	2017-01-24 09:04:48 +01:00