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Groups > linux.kernel > #1269583
| From | Ben Hutchings <ben@decadent.org.uk> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3.2 12/60] genirq: Fix race in register_irq_proc() |
| Date | 2015-11-15 03:10 +0100 |
| Message-ID | <quUVt-3GF-47@gated-at.bofh.it> (permalink) |
| References | <quUVr-3GF-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
3.2.73-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Ben Hutchings <ben@decadent.org.uk>
commit 95c2b17534654829db428f11bcf4297c059a2a7e upstream.
Per-IRQ directories in procfs are created only when a handler is first
added to the irqdesc, not when the irqdesc is created. In the case of
a shared IRQ, multiple tasks can race to create a directory. This
race condition seems to have been present forever, but is easier to
hit with async probing.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Link: http://lkml.kernel.org/r/1443266636.2004.2.camel@decadent.org.uk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/irq/proc.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -12,6 +12,7 @@
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
+#include <linux/mutex.h>
#include "internals.h"
@@ -326,18 +327,29 @@ void register_handler_proc(unsigned int
void register_irq_proc(unsigned int irq, struct irq_desc *desc)
{
+ static DEFINE_MUTEX(register_lock);
char name [MAX_NAMELEN];
- if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip) || desc->dir)
+ if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip))
return;
+ /*
+ * irq directories are registered only when a handler is
+ * added, not when the descriptor is created, so multiple
+ * tasks might try to register at the same time.
+ */
+ mutex_lock(®ister_lock);
+
+ if (desc->dir)
+ goto out_unlock;
+
memset(name, 0, MAX_NAMELEN);
sprintf(name, "%d", irq);
/* create /proc/irq/1234 */
desc->dir = proc_mkdir(name, root_irq_dir);
if (!desc->dir)
- return;
+ goto out_unlock;
#ifdef CONFIG_SMP
/* create /proc/irq/<irq>/smp_affinity */
@@ -358,6 +370,9 @@ void register_irq_proc(unsigned int irq,
proc_create_data("spurious", 0444, desc->dir,
&irq_spurious_proc_fops, (void *)(long)irq);
+
+out_unlock:
+ mutex_unlock(®ister_lock);
}
void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)
--
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[PATCH 3.2 00/60] 3.2.73-rc1 review Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
[PATCH 3.2 43/60] dm btree remove: fix a bug when rebalancing nodes after removal Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
[PATCH 3.2 27/60] 3w-9xxx: don't unmap bounce buffered commands Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
[PATCH 3.2 12/60] genirq: Fix race in register_irq_proc() Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
[PATCH 3.2 31/60] iommu/vt-d: fix range computation when making room for large pages Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
[PATCH 3.2 28/60] xen-blkfront: check for null drvdata in blkback_changed (XenbusStateClosing) Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
[PATCH 3.2 32/60] xhci: don't finish a TD if we get a short transfer event mid TD Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
[PATCH 3.2 46/60] md/raid1: don't clear bitmap bit when bad-block-list write fails. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
[PATCH 3.2 24/60] iwlwifi: dvm: fix D3 firmware PN programming Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
[PATCH 3.2 04/60] regmap: debugfs: Don't bother actually printing when calculating max length Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:10 +0100
[PATCH 3.2 55/60] asix: Don't reset PHY on if_up for ASIX 88772 Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 08/60] UBI: Validate data_size Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 53/60] skbuff: Fix skb checksum partial check. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 38/60] IB/cm: Fix rb-tree duplicate free and use-after-free Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 20/60] usb: Add device quirk for Logitech PTZ cameras Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 33/60] xhci: handle no ping response error properly Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 19/60] USB: Add reset-resume quirk for two Plantronics usb headphones. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 44/60] dm btree: fix leak of bufio-backed block in btree_split_beneath error path Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 40/60] powerpc/rtas: Validate rtas.entry before calling enter_rtas() Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 34/60] xhci: Switch Intel Lynx Point LP ports to EHCI on shutdown. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 07/60] x86/xen: Do not clip xen_e820_map to xen_e820_map_entries when sanitizing map Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 03/60] regmap: debugfs: Ensure we don't underflow when printing access masks Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 51/60] net: add length argument to skb_copy_and_csum_datagram_iovec Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 05/60] ath9k: declare required extra tx headroom Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 39/60] drm/nouveau/gem: return only valid domain when there's only one Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 06/60] m68k: Define asmlinkage_protect Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 26/60] sched/core: Fix TASK_DEAD race in finish_task_switch() Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 45/60] md/raid1: ensure device failure recorded before write request returns. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 15/60] md/raid0: update queue parameter in a safer location. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 59/60] KEYS: Fix race between key destruction and finding a keyring by name Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 23/60] ppp: don't override sk->sk_state in pppoe_flush_dev() Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 49/60] mvsas: Fix NULL pointer dereference in mvs_slot_task_free Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 58/60] KVM: x86: work around infinite loop in microcode when #AC is delivered Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:20 +0100
[PATCH 3.2 42/60] ppp: fix pppoe_dev deletion condition in pppoe_release() Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
[PATCH 3.2 10/60] MIPS: dma-default: Fix 32-bit fall back to GFP_DMA Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
[PATCH 3.2 50/60] sched: declare pid_alive as inline Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
[PATCH 3.2 17/60] clocksource: Fix abs() usage w/ 64bit values Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
[PATCH 3.2 36/60] crypto: api - Only abort operations on fatal signal Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
[PATCH 3.2 16/60] md/raid0: apply base queue limits *before* disk_stack_limits Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
[PATCH 3.2 47/60] md/raid10: ensure device failure recorded before write request returns. Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
[PATCH 3.2 57/60] Failing to send a CLOSE if file is opened WRONLY and server reboots on a 4.x mount Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
[PATCH 3.2 14/60] [SMB3] Do not fall back to SMBWriteX in set_file_size error cases Ben Hutchings <ben@decadent.org.uk> - 2015-11-15 03:30 +0100
Re: [PATCH 3.2 00/60] 3.2.73-rc1 review Guenter Roeck <linux@roeck-us.net> - 2015-11-15 14:50 +0100
Re: [PATCH 3.2 00/60] 3.2.73-rc1 review Ben Hutchings <ben@decadent.org.uk> - 2015-11-16 12:20 +0100
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