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authorJakub Kicinski <kuba@kernel.org>2020-09-04 21:18:58 -0700
committerJakub Kicinski <kuba@kernel.org>2020-09-04 21:28:59 -0700
commit44a8c4f33c0073ca614db79f22e023811bdd0f3c (patch)
tree2d29271961a485f621bd14294ec57e816290541e /arch/x86/kernel/smpboot.c
parent3ab1270bfa1e8ae7db0d46fee90c5db2935ac91b (diff)
parentc70672d8d316ebd46ea447effadfe57ab7a30a50 (diff)
downloadlinux-44a8c4f33c0073ca614db79f22e023811bdd0f3c.tar.bz2
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
We got slightly different patches removing a double word in a comment in net/ipv4/raw.c - picked the version from net. Simple conflict in drivers/net/ethernet/ibm/ibmvnic.c. Use cached values instead of VNIC login response buffer (following what commit 507ebe6444a4 ("ibmvnic: Fix use-after-free of VNIC login response buffer") did). Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'arch/x86/kernel/smpboot.c')
-rw-r--r--arch/x86/kernel/smpboot.c26
1 files changed, 20 insertions, 6 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 27aa04a95702..f5ef689dd62a 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1594,14 +1594,28 @@ int native_cpu_disable(void)
if (ret)
return ret;
- /*
- * Disable the local APIC. Otherwise IPI broadcasts will reach
- * it. It still responds normally to INIT, NMI, SMI, and SIPI
- * messages.
- */
- apic_soft_disable();
cpu_disable_common();
+ /*
+ * Disable the local APIC. Otherwise IPI broadcasts will reach
+ * it. It still responds normally to INIT, NMI, SMI, and SIPI
+ * messages.
+ *
+ * Disabling the APIC must happen after cpu_disable_common()
+ * which invokes fixup_irqs().
+ *
+ * Disabling the APIC preserves already set bits in IRR, but
+ * an interrupt arriving after disabling the local APIC does not
+ * set the corresponding IRR bit.
+ *
+ * fixup_irqs() scans IRR for set bits so it can raise a not
+ * yet handled interrupt on the new destination CPU via an IPI
+ * but obviously it can't do so for IRR bits which are not set.
+ * IOW, interrupts arriving after disabling the local APIC will
+ * be lost.
+ */
+ apic_soft_disable();
+
return 0;
}