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| author | Yu-cheng Yu <yu-cheng.yu@intel.com> | 2020-05-12 07:54:42 -0700 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-05-16 11:24:14 +0200 |
| commit | eeedf1533687b8e81865fdbde79eddf7c4b76c9a (patch) | |
| tree | d09915825c3f70bdae5d9b2e9b1f421801105f00 /arch/x86/include/asm | |
| parent | c95473e175dd1234b7440daa6eb2670ebf529653 (diff) | |
| download | linux-eeedf1533687b8e81865fdbde79eddf7c4b76c9a.tar.bz2 | |
x86/fpu: Introduce copy_supervisor_to_kernel()
The XSAVES instruction takes a mask and saves only the features specified
in that mask. The kernel normally specifies that all features be saved.
XSAVES also unconditionally uses the "compacted format" which means that
all specified features are saved next to each other in memory. If a
feature is removed from the mask, all the features after it will "move
up" into earlier locations in the buffer.
Introduce copy_supervisor_to_kernel(), which saves only supervisor states
and then moves those states into the standard location where they are
normally found.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200512145444.15483-9-yu-cheng.yu@intel.com
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/fpu/xstate.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index 92104b298d77..422d8369012a 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -75,6 +75,7 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int of int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int offset, unsigned int size); int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf); int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf); +void copy_supervisor_to_kernel(struct xregs_state *xsave); /* Validate an xstate header supplied by userspace (ptrace or sigreturn) */ int validate_user_xstate_header(const struct xstate_header *hdr); |