diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2021-10-15 01:09:37 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-10-22 11:04:46 +0200 |
| commit | daddee24731938781b7876d20335ea3754d23484 (patch) | |
| tree | 813540fbc6ce16fe4cc8ffce5e6fa326c2b12afa /arch/x86/kernel/fpu/core.c | |
| parent | 1c253ff2287fe31307a67938c4487936db967ff5 (diff) | |
x86/fpu: Mop up xfeatures_mask_uabi()
Use the new fpu_user_cfg to retrieve the information instead of
xfeatures_mask_uabi() which will be no longer correct when dynamically
enabled features become available.
Using fpu_user_cfg is appropriate when setting XCOMP_BV in the
init_fpstate since it has space allocated for "max_features". But,
normal fpstates might only have space for default xfeatures. Since
XRSTOR* derives the format of the XSAVE buffer from XCOMP_BV, this can
lead to XRSTOR reading out of bounds.
So when copying actively used fpstate, simply read the XCOMP_BV features
bits directly out of the fpstate instead.
This correction courtesy of Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211014230739.408879849@linutronix.de
Diffstat (limited to 'arch/x86/kernel/fpu/core.c')
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 501e21c341f1..5acc077cb9f1 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -237,7 +237,7 @@ int fpu_copy_kvm_uabi_to_fpstate(struct fpu *fpu, const void *buf, u64 xcr0, } /* Ensure that XCOMP_BV is set up for XSAVES */ - xstate_init_xcomp_bv(&kstate->regs.xsave, xfeatures_mask_uabi()); + xstate_init_xcomp_bv(&kstate->regs.xsave, kstate->xfeatures); return 0; } EXPORT_SYMBOL_GPL(fpu_copy_kvm_uabi_to_fpstate); @@ -333,7 +333,7 @@ void fpstate_init_user(struct fpstate *fpstate) return; } - xstate_init_xcomp_bv(&fpstate->regs.xsave, xfeatures_mask_uabi()); + xstate_init_xcomp_bv(&fpstate->regs.xsave, fpstate->xfeatures); if (cpu_feature_enabled(X86_FEATURE_FXSR)) fpstate_init_fxstate(fpstate); |