diff options
| author | Yu-cheng Yu <yu-cheng.yu@intel.com> | 2020-05-12 07:54:37 -0700 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-05-13 10:31:07 +0200 |
| commit | 524bb73bc15c56f5587e33c817e103a259b019d2 (patch) | |
| tree | e539de40d35be74e8b43cb9daec3e80f773d70f3 /arch/x86/kernel/fpu/signal.c | |
| parent | 8ab22804efefea9ecf3c68aa00f1fa69c70fcfad (diff) | |
| download | linux-524bb73bc15c56f5587e33c817e103a259b019d2.tar.bz2 | |
x86/fpu/xstate: Separate user and supervisor xfeatures mask
Before the introduction of XSAVES supervisor states, 'xfeatures_mask' is
used at various places to determine XSAVE buffer components and XCR0 bits.
It contains only user xstates. To support supervisor xstates, it is
necessary to separate user and supervisor xstates:
- First, change 'xfeatures_mask' to 'xfeatures_mask_all', which represents
the full set of bits that should ever be set in a kernel XSAVE buffer.
- Introduce xfeatures_mask_supervisor() and xfeatures_mask_user() to
extract relevant xfeatures from xfeatures_mask_all.
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200512145444.15483-4-yu-cheng.yu@intel.com
Diffstat (limited to 'arch/x86/kernel/fpu/signal.c')
| -rw-r--r-- | arch/x86/kernel/fpu/signal.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 585e3651b98f..3df0cfae535f 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -252,13 +252,17 @@ sanitize_restored_xstate(union fpregs_state *state, */ static int copy_user_to_fpregs_zeroing(void __user *buf, u64 xbv, int fx_only) { + u64 init_bv; + if (use_xsave()) { if (fx_only) { - u64 init_bv = xfeatures_mask & ~XFEATURE_MASK_FPSSE; + init_bv = xfeatures_mask_user() & ~XFEATURE_MASK_FPSSE; + copy_kernel_to_xregs(&init_fpstate.xsave, init_bv); return copy_user_to_fxregs(buf); } else { - u64 init_bv = xfeatures_mask & ~xbv; + init_bv = xfeatures_mask_user() & ~xbv; + if (unlikely(init_bv)) copy_kernel_to_xregs(&init_fpstate.xsave, init_bv); return copy_user_to_xregs(buf, xbv); @@ -358,7 +362,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size) if (use_xsave() && !fx_only) { - u64 init_bv = xfeatures_mask & ~xfeatures; + u64 init_bv = xfeatures_mask_user() & ~xfeatures; if (using_compacted_format()) { ret = copy_user_to_xstate(&fpu->state.xsave, buf_fx); @@ -389,7 +393,9 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size) fpregs_lock(); if (use_xsave()) { - u64 init_bv = xfeatures_mask & ~XFEATURE_MASK_FPSSE; + u64 init_bv; + + init_bv = xfeatures_mask_user() & ~XFEATURE_MASK_FPSSE; copy_kernel_to_xregs(&init_fpstate.xsave, init_bv); } @@ -465,7 +471,7 @@ void fpu__init_prepare_fx_sw_frame(void) fx_sw_reserved.magic1 = FP_XSTATE_MAGIC1; fx_sw_reserved.extended_size = size; - fx_sw_reserved.xfeatures = xfeatures_mask; + fx_sw_reserved.xfeatures = xfeatures_mask_user(); fx_sw_reserved.xstate_size = fpu_user_xstate_size; if (IS_ENABLED(CONFIG_IA32_EMULATION) || |