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| author | Thomas Gleixner <tglx@linutronix.de> | 2021-06-23 15:02:07 +0300 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-06-23 19:59:44 +0300 |
| commit | 8a1dc55a3f3ef0a723c3c117a567e7b5dd2c1793 (patch) | |
| tree | 81c47aabaa457f59348e7d168325ecf9d803340c /arch/x86/include/asm/pkeys.h | |
| parent | b2681e791dbcee6acb1dca7a5076a0285109ac4c (diff) | |
| download | linux-8a1dc55a3f3ef0a723c3c117a567e7b5dd2c1793.tar.xz | |
x86/cpu: Sanitize X86_FEATURE_OSPKE
X86_FEATURE_OSPKE is enabled first on the boot CPU and the feature flag is
set. Secondary CPUs have to enable CR4.PKE as well and set their per CPU
feature flag. That's ineffective because all call sites have checks for
boot_cpu_data.
Make it smarter and force the feature flag when PKU is enabled on the boot
cpu which allows then to use cpu_feature_enabled(X86_FEATURE_OSPKE) all
over the place. That either compiles the code out when PKEY support is
disabled in Kconfig or uses a static_cpu_has() for the feature check which
makes a significant difference in hotpaths, e.g. context switch.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210623121455.305113644@linutronix.de
Diffstat (limited to 'arch/x86/include/asm/pkeys.h')
| -rw-r--r-- | arch/x86/include/asm/pkeys.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/include/asm/pkeys.h b/arch/x86/include/asm/pkeys.h index 2ff9b98812b7..4128f647c755 100644 --- a/arch/x86/include/asm/pkeys.h +++ b/arch/x86/include/asm/pkeys.h @@ -9,14 +9,14 @@ * will be necessary to ensure that the types that store key * numbers and masks have sufficient capacity. */ -#define arch_max_pkey() (boot_cpu_has(X86_FEATURE_OSPKE) ? 16 : 1) +#define arch_max_pkey() (cpu_feature_enabled(X86_FEATURE_OSPKE) ? 16 : 1) extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, unsigned long init_val); static inline bool arch_pkeys_enabled(void) { - return boot_cpu_has(X86_FEATURE_OSPKE); + return cpu_feature_enabled(X86_FEATURE_OSPKE); } /* @@ -26,7 +26,7 @@ static inline bool arch_pkeys_enabled(void) extern int __execute_only_pkey(struct mm_struct *mm); static inline int execute_only_pkey(struct mm_struct *mm) { - if (!boot_cpu_has(X86_FEATURE_OSPKE)) + if (!cpu_feature_enabled(X86_FEATURE_OSPKE)) return ARCH_DEFAULT_PKEY; return __execute_only_pkey(mm); @@ -37,7 +37,7 @@ extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma, static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot, int pkey) { - if (!boot_cpu_has(X86_FEATURE_OSPKE)) + if (!cpu_feature_enabled(X86_FEATURE_OSPKE)) return 0; return __arch_override_mprotect_pkey(vma, prot, pkey); |