diff options
| author | Yuntao Wang <yuntao.wang@linux.dev> | 2024-08-13 09:48:27 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-09-12 11:11:28 +0200 |
| commit | 73d20d08d39edd690fd7a88a52a07c3083ce2bca (patch) | |
| tree | cb24c813e3f8fa11579ecf177227bf5449503b87 /arch | |
| parent | 55c834bc9f822af0b799ced3deb4fa9944e77d31 (diff) | |
x86/apic: Make x2apic_disable() work correctly
commit 0ecc5be200c84e67114f3640064ba2bae3ba2f5a upstream.
x2apic_disable() clears x2apic_state and x2apic_mode unconditionally, even
when the state is X2APIC_ON_LOCKED, which prevents the kernel to disable
it thereby creating inconsistent state.
Due to the early state check for X2APIC_ON, the code path which warns about
a locked X2APIC cannot be reached.
Test for state < X2APIC_ON instead and move the clearing of the state and
mode variables to the place which actually disables X2APIC.
[ tglx: Massaged change log. Added Fixes tag. Moved clearing so it's at the
right place for back ports ]
Fixes: a57e456a7b28 ("x86/apic: Fix fallout from x2apic cleanup")
Signed-off-by: Yuntao Wang <yuntao.wang@linux.dev>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240813014827.895381-1-yuntao.wang@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/apic/apic.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 06d5a7eeee81..f2e605ee75d9 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1812,12 +1812,9 @@ static __init void apic_set_fixmap(bool read_apic); static __init void x2apic_disable(void) { - u32 x2apic_id, state = x2apic_state; + u32 x2apic_id; - x2apic_mode = 0; - x2apic_state = X2APIC_DISABLED; - - if (state != X2APIC_ON) + if (x2apic_state < X2APIC_ON) return; x2apic_id = read_apic_id(); @@ -1830,6 +1827,10 @@ static __init void x2apic_disable(void) } __x2apic_disable(); + + x2apic_mode = 0; + x2apic_state = X2APIC_DISABLED; + /* * Don't reread the APIC ID as it was already done from * check_x2apic() and the APIC driver still is a x2APIC variant, |