From 95c2b17534654829db428f11bcf4297c059a2a7e Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Sat, 26 Sep 2015 12:23:56 +0100 Subject: genirq: Fix race in register_irq_proc() 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 Link: http://lkml.kernel.org/r/1443266636.2004.2.camel@decadent.org.uk Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org --- kernel/irq/proc.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'kernel/irq') diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index e3a8c9577ba6..a50ddc9417ff 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -12,6 +12,7 @@ #include #include #include +#include #include "internals.h" @@ -323,18 +324,29 @@ void register_handler_proc(unsigned int irq, struct irqaction *action) 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//smp_affinity */ @@ -355,6 +367,9 @@ void register_irq_proc(unsigned int irq, struct irq_desc *desc) 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) -- cgit v1.2.3 From 9d67dc5da59d63f746aad8f6ec4fbb86d6486f76 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 6 Oct 2015 22:24:50 +0200 Subject: genirq: Export handle_bad_irq A cleanup of the omap gpio driver introduced a use of the handle_bad_irq() function in a device driver that can be a loadable module. This broke the ARM allmodconfig build: ERROR: "handle_bad_irq" [drivers/gpio/gpio-omap.ko] undefined! This patch exports the handle_bad_irq symbol in order to allow the use in modules. Signed-off-by: Arnd Bergmann Cc: Grygorii Strashko Cc: Santosh Shilimkar Cc: Linus Walleij Cc: Austin Schuh Cc: Tony Lindgren Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/5847725.4IBopItaOr@wuerfel Signed-off-by: Thomas Gleixner --- kernel/irq/handle.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/irq') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index de41a68fc038..77983fc9aa63 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -35,6 +35,7 @@ void handle_bad_irq(struct irq_desc *desc) kstat_incr_irqs_this_cpu(desc); ack_bad_irq(irq); } +EXPORT_SYMBOL_GPL(handle_bad_irq); /* * Special, empty irq handler: -- cgit v1.2.3 From e3096c9c7c645279808a6bf7ac2031b1895ddffb Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 6 Oct 2015 22:59:40 +0200 Subject: genirq: Fix handle_bad_irq kerneldoc comment A recent cleanup removed the 'irq' parameter from many functions, but left the documentation for this in place for at least one function. This removes it. Fixes: bd0b9ac405e1 ("genirq: Remove irq argument from irq flow handlers") Reported-by: kbuild test robot Signed-off-by: Arnd Bergmann Cc: Grygorii Strashko Cc: Tony Lindgren Cc: Linus Walleij Cc: kbuild-all@01.org Cc: Austin Schuh Cc: Santosh Shilimkar Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/5400000.cD19rmgWjV@wuerfel Signed-off-by: Thomas Gleixner --- kernel/irq/handle.c | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel/irq') diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 77983fc9aa63..e25a83b67cce 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -22,7 +22,6 @@ /** * handle_bad_irq - handle spurious and unhandled irqs - * @irq: the interrupt number * @desc: description of the interrupt * * Handles spurious and unhandled IRQ's. It also prints a debugmessage. -- cgit v1.2.3