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authorThomas Gleixner <tglx@linutronix.de>2017-10-16 16:16:19 +0200
committerThomas Gleixner <tglx@linutronix.de>2017-10-17 16:45:09 +0200
commit0696d059f23c05f2dbc3b19ef50e5bdd175b782b (patch)
treee06b5344da043b2a7d1f5a0af687c83317a4d769
parentx86/apic/vector: Ignore set_affinity call for inactive interrupts (diff)
downloadlinux-0696d059f23c05f2dbc3b19ef50e5bdd175b782b.tar.xz
linux-0696d059f23c05f2dbc3b19ef50e5bdd175b782b.zip
x86/vector: Use correct per cpu variable in free_moved_vector()
free_moved_vector() accesses the per cpu vector array with this_cpu_write() to clear the vector. The function has two call sites: 1) The vector cleanup IPI 2) The force_complete_move() code path For #1 this_cpu_write() is correct as it runs on the CPU on which the vector needs to be freed. For #2 this_cpu_write() is wrong because the function is called from an outgoing CPU which is not necessarily the CPU on which the previous vector needs to be freed. As a result it sets the vector on the outgoing CPU to NULL, which is pointless as that CPU does not handle interrupts anymore. What's worse is that it leaves the vector on the previous target CPU in place which later on triggers the BUG_ON(vector) in the vector allocation code when the vector gets reused. That's possible because the bitmap allocator entry of that CPU is freed correctly. Always use the CPU to which the vector was associated and clear the vector entry on that CPU. Fixup the tracepoint as well so it tracks on which CPU the vector gets removed. Fixes: 69cde0004a4b ("x86/vector: Use matrix allocator for vector assignment") Reported-by: Petri Latvala <petri.latvala@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Juergen Gross <jgross@suse.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Len Brown <lenb@kernel.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rui Zhang <rui.zhang@intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Alok Kataria <akataria@vmware.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Yu Chen <yu.c.chen@intel.com> Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1710161614430.1973@nanos
-rw-r--r--arch/x86/include/asm/trace/irq_vectors.h12
-rw-r--r--arch/x86/kernel/apic/vector.c4
2 files changed, 10 insertions, 6 deletions
diff --git a/arch/x86/include/asm/trace/irq_vectors.h b/arch/x86/include/asm/trace/irq_vectors.h
index bc09c5cf6390..bfd480b827f5 100644
--- a/arch/x86/include/asm/trace/irq_vectors.h
+++ b/arch/x86/include/asm/trace/irq_vectors.h
@@ -360,24 +360,28 @@ TRACE_EVENT(vector_setup,
TRACE_EVENT(vector_free_moved,
- TP_PROTO(unsigned int irq, unsigned int vector, bool is_managed),
+ TP_PROTO(unsigned int irq, unsigned int cpu, unsigned int vector,
+ bool is_managed),
- TP_ARGS(irq, vector, is_managed),
+ TP_ARGS(irq, cpu, vector, is_managed),
TP_STRUCT__entry(
__field( unsigned int, irq )
+ __field( unsigned int, cpu )
__field( unsigned int, vector )
__field( bool, is_managed )
),
TP_fast_assign(
__entry->irq = irq;
+ __entry->cpu = cpu;
__entry->vector = vector;
__entry->is_managed = is_managed;
),
- TP_printk("irq=%u vector=%u is_managed=%d",
- __entry->irq, __entry->vector, __entry->is_managed)
+ TP_printk("irq=%u cpu=%u vector=%u is_managed=%d",
+ __entry->irq, __entry->cpu, __entry->vector,
+ __entry->is_managed)
);
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index 573538e0981e..05c85e693a5d 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -797,9 +797,9 @@ static void free_moved_vector(struct apic_chip_data *apicd)
*/
WARN_ON_ONCE(managed);
- trace_vector_free_moved(apicd->irq, vector, managed);
+ trace_vector_free_moved(apicd->irq, cpu, vector, managed);
irq_matrix_free(vector_matrix, cpu, vector, managed);
- __this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
+ per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED;
hlist_del_init(&apicd->clist);
apicd->prev_vector = 0;
apicd->move_in_progress = 0;