x86/apic: Make x2apic_disable() work correctly

Browse source

commit 0ecc5be200 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: a57e456a7b ("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>

...

This commit is contained in:

Yuntao Wang 2024-08-13 09:48:27 +08:00 • committed by Greg Kroah-Hartman

parent 55c834bc9f

commit 73d20d08d3

1 changed files with 6 additions and 5 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

11

arch/x86/kernel/apic/apic.c

View file