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| author | David Kaplan <david.kaplan@amd.com> | 2024-04-21 22:17:28 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-05-02 17:29:27 +0300 |
| commit | 6a190e7ca4e503635b9399e3c448e93c7ca1f75b (patch) | |
| tree | 230e463fbc772af93f87f566a3da8fc9948b9b92 | |
| parent | 0c42f7e039aba3de6d7dbf92da708e2b2ecba557 (diff) | |
| download | linux-6a190e7ca4e503635b9399e3c448e93c7ca1f75b.tar.xz | |
x86/cpu: Fix check for RDPKRU in __show_regs()
commit b53c6bd5d271d023857174b8fd3e32f98ae51372 upstream.
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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 7f94dbbc397b..a0d3059bee3d 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -137,7 +137,7 @@ 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()); } |