The patch titled
x86: fix vector_lock deadlock in io_apic.c
has been removed from the -mm tree. Its filename is
x86_64-mm-serialize-assign_irq_vector-use-of-static-variables-fix.patch
This patch was probably dropped from -mm because
it has now been merged into a subsystem tree or
into Linus's tree, or because it was folded into
its parent patch in the -mm tree.
------------------------------------------------------
Subject: x86: fix vector_lock deadlock in io_apic.c
From: Ingo Molnar <mingo@xxxxxxx>
Fix a potential deadlock scenario introduced by io_apic.c's new vector_lock
on i386 and x86_64.
Found by the locking correctness validator. The patch was boot-tested on
x86. For details of the deadlock scenario, see the validator output:
======================================================
[ BUG: hard-safe -> hard-unsafe lock order detected! ]
------------------------------------------------------
idle/1 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
(msi_lock){....}, at: [<c04ff8d2>] startup_msi_irq_wo_maskbit+0x10/0x35
and this task is already holding:
(&irq_desc[i].lock){++..}, at: [<c015b924>] probe_irq_on+0x36/0x107
which would create a new lock dependency:
(&irq_desc[i].lock){++..} -> (msi_lock){....}
but this new dependency connects a hard-irq-safe lock:
(&irq_desc[i].lock){++..}
... which became hard-irq-safe at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10485e9>] _spin_lock+0x21/0x2f
[<c015aff5>] __do_IRQ+0x3d/0x113
[<c01062d3>] do_IRQ+0x8c/0xad
to a hard-irq-unsafe lock:
(vector_lock){--..}
... which became hard-irq-unsafe at:
... [<c01468c4>] lockdep_acquire+0x68/0x84
[<c10485e9>] _spin_lock+0x21/0x2f
[<c011b5e8>] assign_irq_vector+0x34/0xc8
[<c1aa82fa>] setup_IO_APIC+0x45a/0xcff
[<c1aa56e3>] smp_prepare_cpus+0x5ea/0x8aa
[<c010033f>] init+0x32/0x2cb
[<c0102005>] kernel_thread_helper+0x5/0xb
which could potentially lead to deadlocks!
other info that might help us debug this:
3 locks held by idle/1:
#0: (port_mutex){--..}, at: [<c067070d>] uart_add_one_port+0x61/0x289
#1: (&state->mutex){--..}, at: [<c067071f>] uart_add_one_port+0x73/0x289
#2: (&irq_desc[i].lock){++..}, at: [<c015b924>] probe_irq_on+0x36/0x107
the hard-irq-safe lock's dependencies:
-> (&irq_desc[i].lock){++..} ops: 9861 {
initial-use at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
[<c015b415>] setup_irq+0x9b/0x14d
[<c1aaa4c4>] time_init_hook+0xf/0x11
[<c1a9f320>] time_init+0x44/0x46
[<c1a9955f>] start_kernel+0x191/0x38f
[<c0100210>] 0xc0100210
in-hardirq-W at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10485e9>] _spin_lock+0x21/0x2f
[<c015aff5>] __do_IRQ+0x3d/0x113
[<c01062d3>] do_IRQ+0x8c/0xad
in-softirq-W at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10485e9>] _spin_lock+0x21/0x2f
[<c015aff5>] __do_IRQ+0x3d/0x113
[<c01062d3>] do_IRQ+0x8c/0xad
}
... key at: [<c1ea31e0>] irq_desc_lock_type+0x0/0x20
-> (i8259A_lock){++..} ops: 5149 {
initial-use at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
[<c0108090>] init_8259A+0x11/0x8f
[<c1aa0d22>] init_ISA_irqs+0x12/0x4d
[<c1aaa4f0>] pre_intr_init_hook+0x8/0xa
[<c1aa0cb9>] init_IRQ+0xe/0x65
[<c1a99546>] start_kernel+0x178/0x38f
[<c0100210>] 0xc0100210
in-hardirq-W at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
[<c0107fb0>] mask_and_ack_8259A+0x1b/0xcc
[<c015b007>] __do_IRQ+0x4f/0x113
[<c01062d3>] do_IRQ+0x8c/0xad
in-softirq-W at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
[<c0107fb0>] mask_and_ack_8259A+0x1b/0xcc
[<c015b007>] __do_IRQ+0x4f/0x113
[<c01062d3>] do_IRQ+0x8c/0xad
}
... key at: [<c142f174>] i8259A_lock+0x14/0x40
... acquired at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
[<c0107eb2>] enable_8259A_irq+0x10/0x47
[<c0107f12>] startup_8259A_irq+0x8/0xc
[<c015b45e>] setup_irq+0xe4/0x14d
[<c1aaa4c4>] time_init_hook+0xf/0x11
[<c1a9f320>] time_init+0x44/0x46
[<c1a9955f>] start_kernel+0x191/0x38f
[<c0100210>] 0xc0100210
-> (ioapic_lock){+...} ops: 122 {
initial-use at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
[<c1aa71db>] io_apic_get_version+0x16/0x55
[<c1aa5c73>] mp_register_ioapic+0xc6/0x127
[<c1aa382e>] acpi_parse_ioapic+0x2d/0x39
[<c1abe031>] acpi_table_parse_madt_family+0xb4/0x100
[<c1abe093>] acpi_table_parse_madt+0x16/0x18
[<c1aa3c8a>] acpi_boot_init+0x132/0x251
[<c1aa08ea>] setup_arch+0xd36/0xe37
[<c1a99434>] start_kernel+0x66/0x38f
[<c0100210>] 0xc0100210
in-hardirq-W at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
[<c011bce1>] mask_IO_APIC_irq+0x11/0x31
[<c011c5cc>] ack_edge_ioapic_vector+0x31/0x41
[<c015b007>] __do_IRQ+0x4f/0x113
[<c01062d3>] do_IRQ+0x8c/0xad
}
... key at: [<c1432514>] ioapic_lock+0x14/0x3c
-> (i8259A_lock){++..} ops: 5149 {
initial-use at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
[<c0108090>] init_8259A+0x11/0x8f
[<c1aa0d22>] init_ISA_irqs+0x12/0x4d
[<c1aaa4f0>] pre_intr_init_hook+0x8/0xa
[<c1aa0cb9>] init_IRQ+0xe/0x65
[<c1a99546>] start_kernel+0x178/0x38f
[<c0100210>] 0xc0100210
in-hardirq-W at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
[<c0107fb0>] mask_and_ack_8259A+0x1b/0xcc
[<c015b007>] __do_IRQ+0x4f/0x113
[<c01062d3>] do_IRQ+0x8c/0xad
in-softirq-W at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
[<c0107fb0>] mask_and_ack_8259A+0x1b/0xcc
[<c015b007>] __do_IRQ+0x4f/0x113
[<c01062d3>] do_IRQ+0x8c/0xad
}
... key at: [<c142f174>] i8259A_lock+0x14/0x40
... acquired at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
[<c0107e6b>] disable_8259A_irq+0x10/0x47
[<c011bdbd>] startup_edge_ioapic_vector+0x31/0x58
[<c015b45e>] setup_irq+0xe4/0x14d
[<c015b5a1>] request_irq+0xda/0xf9
[<c1ac983a>] rtc_init+0x6a/0x1a7
[<c0100457>] init+0x14a/0x2cb
[<c0102005>] kernel_thread_helper+0x5/0xb
... acquired at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
[<c011bce1>] mask_IO_APIC_irq+0x11/0x31
[<c011c5cc>] ack_edge_ioapic_vector+0x31/0x41
[<c015b007>] __do_IRQ+0x4f/0x113
[<c01062d3>] do_IRQ+0x8c/0xad
the hard-irq-unsafe lock's dependencies:
-> (vector_lock){--..} ops: 31 {
initial-use at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10485e9>] _spin_lock+0x21/0x2f
[<c011b5e8>] assign_irq_vector+0x34/0xc8
[<c1aa82fa>] setup_IO_APIC+0x45a/0xcff
[<c1aa56e3>] smp_prepare_cpus+0x5ea/0x8aa
[<c010033f>] init+0x32/0x2cb
[<c0102005>] kernel_thread_helper+0x5/0xb
softirq-on-W at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10485e9>] _spin_lock+0x21/0x2f
[<c011b5e8>] assign_irq_vector+0x34/0xc8
[<c1aa82fa>] setup_IO_APIC+0x45a/0xcff
[<c1aa56e3>] smp_prepare_cpus+0x5ea/0x8aa
[<c010033f>] init+0x32/0x2cb
[<c0102005>] kernel_thread_helper+0x5/0xb
hardirq-on-W at:
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10485e9>] _spin_lock+0x21/0x2f
[<c011b5e8>] assign_irq_vector+0x34/0xc8
[<c1aa82fa>] setup_IO_APIC+0x45a/0xcff
[<c1aa56e3>] smp_prepare_cpus+0x5ea/0x8aa
[<c010033f>] init+0x32/0x2cb
[<c0102005>] kernel_thread_helper+0x5/0xb
}
... key at: [<c1432574>] vector_lock+0x14/0x3c
stack backtrace:
[<c0104f36>] show_trace+0xd/0xf
[<c010543e>] dump_stack+0x17/0x19
[<c0144e34>] check_usage+0x1f6/0x203
[<c0146395>] __lockdep_acquire+0x8c2/0xaa5
[<c01468c4>] lockdep_acquire+0x68/0x84
[<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
[<c04ff8d2>] startup_msi_irq_wo_maskbit+0x10/0x35
[<c015b932>] probe_irq_on+0x44/0x107
[<c0673d58>] serial8250_config_port+0x84b/0x986
[<c06707b1>] uart_add_one_port+0x105/0x289
[<c1ace54b>] serial8250_init+0xc3/0x10a
[<c0100457>] init+0x14a/0x2cb
[<c0102005>] kernel_thread_helper+0x5/0xb
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
arch/i386/kernel/io_apic.c | 9 +++++----
arch/x86_64/kernel/io_apic.c | 7 ++++---
2 files changed, 9 insertions(+), 7 deletions(-)
diff -puN arch/i386/kernel/io_apic.c~x86_64-mm-serialize-assign_irq_vector-use-of-static-variables-fix arch/i386/kernel/io_apic.c
--- devel/arch/i386/kernel/io_apic.c~x86_64-mm-serialize-assign_irq_vector-use-of-static-variables-fix 2006-05-11 15:18:25.000000000 -0700
+++ devel-akpm/arch/i386/kernel/io_apic.c 2006-05-11 15:18:25.000000000 -0700
@@ -1155,14 +1155,15 @@ u8 irq_vector[NR_IRQ_VECTORS] __read_mos
int assign_irq_vector(int irq)
{
static int current_vector = FIRST_DEVICE_VECTOR, offset = 0;
+ unsigned long flags;
int vector;
BUG_ON(irq != AUTO_ASSIGN && (unsigned)irq >= NR_IRQ_VECTORS);
- spin_lock(&vector_lock);
+ spin_lock_irqsave(&vector_lock, flags);
if (irq != AUTO_ASSIGN && IO_APIC_VECTOR(irq) > 0) {
- spin_unlock(&vector_lock);
+ spin_unlock_irqrestore(&vector_lock, flags);
return IO_APIC_VECTOR(irq);
}
next:
@@ -1173,7 +1174,7 @@ next:
if (current_vector >= FIRST_SYSTEM_VECTOR) {
offset++;
if (!(offset%8)) {
- spin_unlock(&vector_lock);
+ spin_unlock_irqrestore(&vector_lock, flags);
return -ENOSPC;
}
current_vector = FIRST_DEVICE_VECTOR + offset;
@@ -1184,7 +1185,7 @@ next:
if (irq != AUTO_ASSIGN)
IO_APIC_VECTOR(irq) = vector;
- spin_unlock(&vector_lock);
+ spin_unlock_irqrestore(&vector_lock, flags);
return vector;
}
diff -puN arch/x86_64/kernel/io_apic.c~x86_64-mm-serialize-assign_irq_vector-use-of-static-variables-fix arch/x86_64/kernel/io_apic.c
--- devel/arch/x86_64/kernel/io_apic.c~x86_64-mm-serialize-assign_irq_vector-use-of-static-variables-fix 2006-05-11 15:18:25.000000000 -0700
+++ devel-akpm/arch/x86_64/kernel/io_apic.c 2006-05-11 15:18:25.000000000 -0700
@@ -816,14 +816,15 @@ u8 irq_vector[NR_IRQ_VECTORS] __read_mos
int assign_irq_vector(int irq)
{
static int current_vector = FIRST_DEVICE_VECTOR, offset = 0;
+ unsigned long flags;
int vector;
BUG_ON(irq != AUTO_ASSIGN && (unsigned)irq >= NR_IRQ_VECTORS);
- spin_lock(&vector_lock);
+ spin_lock_irqsave(&vector_lock, flags);
if (irq != AUTO_ASSIGN && IO_APIC_VECTOR(irq) > 0) {
- spin_unlock(&vector_lock);
+ spin_unlock_irqrestore(&vector_lock, flags);
return IO_APIC_VECTOR(irq);
}
next:
@@ -842,7 +843,7 @@ next:
if (irq != AUTO_ASSIGN)
IO_APIC_VECTOR(irq) = vector;
- spin_unlock(&vector_lock);
+ spin_unlock_irqrestore(&vector_lock, flags);
return vector;
}
_
Patches currently in -mm which might be from mingo@xxxxxxx are
git-acpi.patch
fix-drivers-mfd-ucb1x00-corec-irq-probing-bug.patch
git-dvb.patch
git-netdev-all.patch
fix-for-serial-uart-lockup.patch
qla2xxx-lock-ordering-fix.patch
qla2xxx-lock-ordering-fix-warning-fix.patch
swapless-pm-add-r-w-migration-entries-fix.patch
i386-break-out-of-recursion-in-stackframe-walk.patch
move-vsyscall-page-out-of-fixmap-into-normal-vma-as-per-mmap.patch
move-vsyscall-page-out-of-fixmap-into-normal-vma-as-per-mmap-tidy.patch
move-vsyscall-page-out-of-fixmap-into-normal-vma-as-per-mmap-fix.patch
work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs.patch
kernel-kernel-cpuc-to-mutexes.patch
cond-resched-might-sleep-fix.patch
define-__raw_get_cpu_var-and-use-it.patch
ide-cd-end-of-media-error-fix.patch
time-clocksource-infrastructure.patch
sched-comment-bitmap-size-accounting.patch
sched-fix-interactive-ceiling-code.patch
sched-implement-smpnice.patch
sched-protect-calculation-of-max_pull-from-integer-wrap.patch
sched-store-weighted-load-on-up.patch
sched-add-discrete-weighted-cpu-load-function.patch
sched-prevent-high-load-weight-tasks-suppressing-balancing.patch
sched-improve-stability-of-smpnice-load-balancing.patch
sched-improve-smpnice-load-balancing-when-load-per-task.patch
smpnice-dont-consider-sched-groups-which-are-lightly-loaded-for-balancing.patch
smpnice-dont-consider-sched-groups-which-are-lightly-loaded-for-balancing-fix.patch
sched-modify-move_tasks-to-improve-load-balancing-outcomes.patch
sched-avoid-unnecessarily-moving-highest-priority-task-move_tasks.patch
sched-avoid-unnecessarily-moving-highest-priority-task-move_tasks-fix-2.patch
sched_domain-handle-kmalloc-failure.patch
sched_domain-handle-kmalloc-failure-fix.patch
sched_domain-dont-use-gfp_atomic.patch
sched_domain-use-kmalloc_node.patch
sched_domain-allocate-sched_group-structures-dynamically.patch
sched-add-above-background-load-function.patch
mm-implement-swap-prefetching-fix.patch
pi-futex-futex-code-cleanups.patch
pi-futex-futex-code-cleanups-fix.patch
pi-futex-introduce-debug_check_no_locks_freed.patch
pi-futex-add-plist-implementation.patch
pi-futex-scheduler-support-for-pi.patch
pi-futex-rt-mutex-core.patch
pi-futex-rt-mutex-core-fix-timeout-race.patch
pi-futex-rt-mutex-docs.patch
pi-futex-rt-mutex-debug.patch
pi-futex-rt-mutex-tester.patch
pi-futex-rt-mutex-futex-api.patch
pi-futex-futex_lock_pi-futex_unlock_pi-support.patch
pi-futex-v2.patch
pi-futex-v3.patch
pi-futex-patchset-v4.patch
pi-futex-patchset-v4-update.patch
pi-futex-patchset-v4-fix.patch
rtmutex-remove-buggy-bug_on-in-pi-boosting-code.patch
futex-pi-enforce-waiter-bit-when-owner-died-is-detected.patch
rtmutex-debug-printk-correct-task-information.patch
futex-pi-make-use-of-restart_block-when-interrupted.patch
document-futex-pi-design.patch
futex_requeue-optimization.patch
reiser4.patch
detect-atomic-counter-underflows.patch
debug-shared-irqs.patch
make-frame_pointer-default=y.patch
mutex-subsystem-synchro-test-module.patch
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