The following commit has been merged into the x86/fpu branch of tip:
Commit-ID: ff7ebff47c595e747aa1bb10d8a30b2acb7d425b
Gitweb: https://git.kernel.org/tip/ff7ebff47c595e747aa1bb10d8a30b2acb7d425b
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Wed, 23 Jun 2021 14:02:09 +02:00
Committer: Borislav Petkov <bp@xxxxxxx>
CommitterDate: Wed, 23 Jun 2021 19:09:53 +02:00
x86/pkru: Provide pkru_write_default()
Provide a simple and trivial helper which just writes the PKRU default
value without trying to fiddle with the task's xsave buffer.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Link: https://lkml.kernel.org/r/20210623121455.513729794@xxxxxxxxxxxxx
---
arch/x86/include/asm/pkru.h | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/x86/include/asm/pkru.h b/arch/x86/include/asm/pkru.h
index 19d3d7b..7e45509 100644
--- a/arch/x86/include/asm/pkru.h
+++ b/arch/x86/include/asm/pkru.h
@@ -60,4 +60,12 @@ static inline void write_pkru(u32 pkru)
fpregs_unlock();
}
+static inline void pkru_write_default(void)
+{
+ if (!cpu_feature_enabled(X86_FEATURE_OSPKE))
+ return;
+
+ wrpkru(pkru_get_init_value());
+}
+
#endif
|