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authorFenghua Yu <fenghua.yu@intel.com>2016-05-20 17:47:05 (GMT)
committerIngo Molnar <mingo@kernel.org>2016-06-18 08:10:18 (GMT)
commita1141e0b5ca6ee3e5e35d5f1a310a5ecb9c96ce5 (patch)
tree3f6562ed55d70ddb83adcdcada133b57c3aa9cf7 /arch/x86/kernel/fpu/init.c
parentd1898b733619bd46194bd25aa6452d238ff2dc4e (diff)
downloadlinux-a1141e0b5ca6ee3e5e35d5f1a310a5ecb9c96ce5.tar.xz
x86/fpu/xstate: Define and use 'fpu_user_xstate_size'
The kernel xstate area can be in standard or compacted format; it is always in standard format for user mode. When XSAVES is enabled, the kernel uses the compacted format and it is necessary to use a separate fpu_user_xstate_size for signal/ptrace frames. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> [ Rebased the patch and cleaned up the naming. ] 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: 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/8756ec34dabddfc727cda5743195eb81e8caf91c.1463760376.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/fpu/init.c')
-rw-r--r--arch/x86/kernel/fpu/init.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index aacfd7a..5b1928c 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -195,7 +195,7 @@ static void __init fpu__init_task_struct_size(void)
}
/*
- * Set up the xstate_size based on the legacy FPU context size.
+ * Set up the user and kernel xstate_size based on the legacy FPU context size.
*
* We set this up first, and later it will be overwritten by
* fpu__init_system_xstate() if the CPU knows about xstates.
@@ -226,6 +226,9 @@ static void __init fpu__init_system_xstate_size_legacy(void)
else
xstate_size = sizeof(struct fregs_state);
}
+
+ fpu_user_xstate_size = xstate_size;
+
/*
* Quirk: we don't yet handle the XSAVES* instructions
* correctly, as we don't correctly convert between