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| author | Yu-cheng Yu <yu-cheng.yu@intel.com> | 2016-05-20 10:47:08 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-06-18 10:10:19 +0200 |
| commit | 99aa22d0d8f70d9317727ab40c85b2ead740a6ca (patch) | |
| tree | 34a01084331465f07c9fb42715bdad32e0ec59ac /arch/x86/kernel/fpu/signal.c | |
| parent | 7d9370607d28afd454775c623d5447603473a3c3 (diff) | |
| download | linux-99aa22d0d8f70d9317727ab40c85b2ead740a6ca.tar.gz linux-99aa22d0d8f70d9317727ab40c85b2ead740a6ca.tar.bz2 linux-99aa22d0d8f70d9317727ab40c85b2ead740a6ca.zip | |
x86/fpu/xstate: Copy xstate registers directly to the signal frame when compacted format is in use
XSAVES is a kernel instruction and uses a compacted format. When working
with user space, the kernel should provide standard-format, non-supervisor
state data. We cannot do __copy_to_user() from a compacted-format kernel
xstate area to a signal frame.
Dave Hansen proposes this method to simplify copy xstate directly to user.
This patch is based on an earlier patch from Fenghua Yu <fenghua.yu@intel.com>
Originally-from: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/c36f419d525517d04209a28dd8e1e5af9000036e.1463760376.git.yu-cheng.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/fpu/signal.c')
| -rw-r--r-- | arch/x86/kernel/fpu/signal.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 06d80f62c03f..8aa96cbb5dfb 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -8,6 +8,7 @@ #include <asm/fpu/internal.h> #include <asm/fpu/signal.h> #include <asm/fpu/regset.h> +#include <asm/fpu/xstate.h> #include <asm/sigframe.h> #include <asm/trace/fpu.h> @@ -169,7 +170,7 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size) sizeof(struct user_i387_ia32_struct), NULL, (struct _fpstate_32 __user *) buf) ? -1 : 1; - if (fpregs_active()) { + if (fpregs_active() || using_compacted_format()) { /* Save the live register state to the user directly. */ if (copy_fpregs_to_sigframe(buf_fx)) return -1; |