Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'gpio-fixes-for-v5.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio fix from Bartosz Golaszewski:
- fix a race condition with consumers accessing the fields of GPIO IRQ
chips before they're fully initialized
* tag 'gpio-fixes-for-v5.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
gpio: Restrict usage of GPIO chip irq members before initialization
+28
+19
drivers/gpio/gpiolib.c
+19
drivers/gpio/gpiolib.c
···
1404
1404
{
1405
1405
struct irq_domain *domain = gc->irq.domain;
1406
1406
1407
+
#ifdef CONFIG_GPIOLIB_IRQCHIP
1408
+
/*
1409
+
* Avoid race condition with other code, which tries to lookup
1410
+
* an IRQ before the irqchip has been properly registered,
1411
+
* i.e. while gpiochip is still being brought up.
1412
+
*/
1413
+
if (!gc->irq.initialized)
1414
+
return -EPROBE_DEFER;
1415
+
#endif
1416
+
1407
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if (!gpiochip_irqchip_irq_valid(gc, offset))
1408
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return -ENXIO;
1409
1419
···
1602
1592
gpiochip_set_irq_hooks(gc);
1603
1593
1604
1594
acpi_gpiochip_request_interrupts(gc);
1595
+
1596
+
/*
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+
* Using barrier() here to prevent compiler from reordering
1598
+
* gc->irq.initialized before initialization of above
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+
* GPIO chip irq members.
1600
+
*/
1601
+
barrier();
1602
+
1603
+
gc->irq.initialized = true;
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1606
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return 0;
1607
1606
}
+9
include/linux/gpio/driver.h
+9
include/linux/gpio/driver.h
···
222
222
bool per_parent_data;
223
223
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/**
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+
* @initialized:
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+
*
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+
* Flag to track GPIO chip irq member's initialization.
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+
* This flag will make sure GPIO chip irq members are not used
229
+
* before they are initialized.
230
+
*/
231
+
bool initialized;
232
+
233
+
/**
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* @init_hw: optional routine to initialize hardware before
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* an IRQ chip will be added. This is quite useful when
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* a particular driver wants to clear IRQ related registers