__save_fpu() has this pattern:
if (unlikely(system_state == SYSTEM_BOOTING))
xsave_state_booting(&fpu->state.xsave);
else
xsave_state(&fpu->state.xsave);
... but it does not actually get called during system bootup.
So remove the complication and always call xsave_state().
To make sure this assumption is correct, add a WARN_ONCE()
debug check to xsave_state().
Reviewed-by: Borislav Petkov <b...@alien8.de>
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: Dave Hansen <dave.han...@linux.intel.com>
Cc: Fenghua Yu <fenghua...@intel.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Oleg Nesterov <o...@redhat.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
arch/x86/include/asm/fpu/xsave.h | 2 ++
arch/x86/kernel/fpu/core.c | 5 +----
2 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/fpu/xsave.h b/arch/x86/include/asm/fpu/xsave.h
index a10e66582c1b..2f2ed322263f 100644
--- a/arch/x86/include/asm/fpu/xsave.h
+++ b/arch/x86/include/asm/fpu/xsave.h
@@ -133,6 +133,8 @@ static inline int xsave_state(struct xsave_struct *fx)
u32 hmask = mask >> 32;
int err = 0;
+ WARN_ON(system_state == SYSTEM_BOOTING);
+
/*
* If xsaves is enabled, xsaves replaces xsaveopt because
* it supports compact format and supervisor states in addition to
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 43689660d71c..a0e2b65745da 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -172,10 +172,7 @@ EXPORT_SYMBOL_GPL(irq_ts_restore);
static void __save_fpu(struct fpu *fpu)
{
if (use_xsave()) {
- if (unlikely(system_state == SYSTEM_BOOTING))
- xsave_state_booting(&fpu->state.xsave);
- else
- xsave_state(&fpu->state.xsave);
+ xsave_state(&fpu->state.xsave);
} else {
fpu_fxsave(fpu);
}
--
2.1.0
--
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