Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'x86-core-2023-07-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fix from Thomas Gleixner:
"A single fix for the mechanism to park CPUs with an INIT IPI.
On shutdown or kexec, the kernel tries to park the non-boot CPUs with
an INIT IPI. But the same code path is also used by the crash utility.
If the CPU which panics is not the boot CPU then it sends an INIT IPI
to the boot CPU which resets the machine.
Prevent this by validating that the CPU which runs the stop mechanism
is the boot CPU. If not, leave the other CPUs in HLT"
* tag 'x86-core-2023-07-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/smp: Don't send INIT to boot CPU
+8
+8
arch/x86/kernel/smpboot.c
+8
arch/x86/kernel/smpboot.c
···
1348
1348
if (apic->wakeup_secondary_cpu_64 || apic->wakeup_secondary_cpu)
1349
1349
return false;
1350
1350
1351
+
/*
1352
+
* If this is a crash stop which does not execute on the boot CPU,
1353
+
* then this cannot use the INIT mechanism because INIT to the boot
1354
+
* CPU will reset the machine.
1355
+
*/
1356
+
if (this_cpu)
1357
+
return false;
1358
+
1351
1359
for_each_present_cpu(cpu) {
1352
1360
if (cpu == this_cpu)
1353
1361
continue;