diff options
| author |   Chang S. Bae <chang.seok.bae@intel.com> | 2021-10-21 15:55:18 -0700 |
|---|---|---|
| committer |   Borislav Petkov <bp@suse.de> | 2021-10-26 10:18:09 +0200 |
| commit | 8bf26758ca9659866b844dd51037314b4c0fa6bd (patch) | |
| tree | 4c702e253c9112ab848855451484aef3a9148ad0 | |
| parent | x86/msr-index: Add MSRs for XFD (diff) | |
| download | linux-dev-8bf26758ca9659866b844dd51037314b4c0fa6bd.tar.xz linux-dev-8bf26758ca9659866b844dd51037314b4c0fa6bd.zip | |
x86/fpu: Add XFD state to fpstate
Add storage for XFD register state to struct fpstate. This will be used to
store the XFD MSR state. This will be used for switching the XFD MSR when
FPU content is restored.
Add a per-CPU variable to cache the current MSR value so the MSR has only
to be written when the values are different.
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211021225527.10184-15-chang.seok.bae@intel.com
| -rw-r--r-- | arch/x86/include/asm/fpu/types.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.h | 4 |
3 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 595122fcaf51..b1897638d68d 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -322,6 +322,9 @@ struct fpstate { /* @user_xfeatures: xfeatures valid in UABI buffers */ u64 user_xfeatures; + /* @xfd: xfeatures disabled to trap userspace use. */ + u64 xfd; + /* @is_valloc: Indicator for dynamically allocated state */ unsigned int is_valloc : 1; diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 3349068cef7d..3b72cddf990d 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -27,6 +27,7 @@ #ifdef CONFIG_X86_64 DEFINE_STATIC_KEY_FALSE(__fpu_state_size_dynamic); +DEFINE_PER_CPU(u64, xfd_state); #endif /* The FPU state configuration data for kernel and user space */ @@ -409,6 +410,7 @@ static void __fpstate_reset(struct fpstate *fpstate) fpstate->user_size = fpu_user_cfg.default_size; fpstate->xfeatures = fpu_kernel_cfg.default_features; fpstate->user_xfeatures = fpu_user_cfg.default_features; + fpstate->xfd = init_fpstate.xfd; } void fpstate_reset(struct fpu *fpu) diff --git a/arch/x86/kernel/fpu/xstate.h b/arch/x86/kernel/fpu/xstate.h index 4ce1dc030f38..32a4dee4de3b 100644 --- a/arch/x86/kernel/fpu/xstate.h +++ b/arch/x86/kernel/fpu/xstate.h @@ -5,6 +5,10 @@ #include <asm/cpufeature.h> #include <asm/fpu/xstate.h> +#ifdef CONFIG_X86_64 +DECLARE_PER_CPU(u64, xfd_state); +#endif + static inline void xstate_init_xcomp_bv(struct xregs_state *xsave, u64 mask) { /* |