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| author | David Kaplan <david.kaplan@amd.com> | 2024-04-21 21:17:28 +0200 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-04-24 14:30:21 +0200 |
| commit | b53c6bd5d271d023857174b8fd3e32f98ae51372 (patch) | |
| tree | eeafd7ae6d4e509710ad73bca78776bc62c7fb47 | |
| parent | 2718a7fdf292b2dcb49c856fa8a6a955ebbbc45f (diff) | |
| download | linux-b53c6bd5d271d023857174b8fd3e32f98ae51372.tar.gz | |
x86/cpu: Fix check for RDPKRU in __show_regs()
cpu_feature_enabled(X86_FEATURE_OSPKE) does not necessarily reflect
whether CR4.PKE is set on the CPU. In particular, they may differ on
non-BSP CPUs before setup_pku() is executed. In this scenario, RDPKRU
will #UD causing the system to hang.
Fix by checking CR4 for PKE enablement which is always correct for the
current CPU.
The scenario happens by inserting a WARN* before setup_pku() in
identiy_cpu() or some other diagnostic which would lead to calling
__show_regs().
[ bp: Massage commit message. ]
Signed-off-by: David Kaplan <david.kaplan@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240421191728.32239-1-bp@kernel.org
| -rw-r--r-- | arch/x86/kernel/process_64.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 7062b84dd467d6..6d3d20e3e43a9b 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -139,7 +139,7 @@ void __show_regs(struct pt_regs *regs, enum show_regs_mode mode, log_lvl, d3, d6, d7); } - if (cpu_feature_enabled(X86_FEATURE_OSPKE)) + if (cr4 & X86_CR4_PKE) printk("%sPKRU: %08x\n", log_lvl, read_pkru()); } |