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authorGeert Uytterhoeven <geert+renesas@glider.be>2015-02-23 18:37:24 +0300
committerEduardo Valentin <edubezval@gmail.com>2015-02-24 21:56:42 +0300
commit0b37a83a91e885250c68546ce7271ce722120c99 (patch)
tree30af05e3cf65ae0ca9ecca44f02a473c55a40e2a /drivers/thermal/rcar_thermal.c
parent12ca7188468ee29c4e717f73db4bf43c90954fc7 (diff)
downloadlinux-0b37a83a91e885250c68546ce7271ce722120c99.tar.xz
thermal: rcar: Fix race condition between init and interrupt
As soon as the interrupt has been enabled by devm_request_irq(), the interrupt routine may be called, depending on the current status of the hardware. However, at that point rcar_thermal_common hasn't been initialized complely yet. E.g. rcar_thermal_common.base is still NULL, causing a NULL pointer dereference: Unable to handle kernel NULL pointer dereference at virtual address 0000000c pgd = c0004000 [0000000c] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.19.0-rc7-ape6evm-04564-gb6e46cb7cbe82389 #30 Hardware name: Generic R8A73A4 (Flattened Device Tree) task: ee8953c0 ti: ee896000 task.ti: ee896000 PC is at rcar_thermal_irq+0x1c/0xf0 LR is at _raw_spin_lock_irqsave+0x48/0x54 Postpone the call to devm_request_irq() until all initialization has been done to fix this. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Diffstat (limited to 'drivers/thermal/rcar_thermal.c')
-rw-r--r--drivers/thermal/rcar_thermal.c22
1 files changed, 9 insertions, 13 deletions
diff --git a/drivers/thermal/rcar_thermal.c b/drivers/thermal/rcar_thermal.c
index 2580a4872f90..3c2c1720ba4a 100644
--- a/drivers/thermal/rcar_thermal.c
+++ b/drivers/thermal/rcar_thermal.c
@@ -387,21 +387,9 @@ static int rcar_thermal_probe(struct platform_device *pdev)
irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (irq) {
- int ret;
-
/*
* platform has IRQ support.
* Then, driver uses common registers
- */
-
- ret = devm_request_irq(dev, irq->start, rcar_thermal_irq, 0,
- dev_name(dev), common);
- if (ret) {
- dev_err(dev, "irq request failed\n ");
- return ret;
- }
-
- /*
* rcar_has_irq_support() will be enabled
*/
res = platform_get_resource(pdev, IORESOURCE_MEM, mres++);
@@ -456,8 +444,16 @@ static int rcar_thermal_probe(struct platform_device *pdev)
}
/* enable temperature comparation */
- if (irq)
+ if (irq) {
+ ret = devm_request_irq(dev, irq->start, rcar_thermal_irq, 0,
+ dev_name(dev), common);
+ if (ret) {
+ dev_err(dev, "irq request failed\n ");
+ goto error_unregister;
+ }
+
rcar_thermal_common_write(common, ENR, enr_bits);
+ }
platform_set_drvdata(pdev, common);