Re: [tip:irq/urgent] pinctrl/st: Fix race in installing chained IRQ handler

From: Maxime Coquelin
Date: Sat Jun 27 2015 - 02:53:32 EST


Hello Thomas,

On 06/26/2015 09:45 PM, tip-bot for Thomas Gleixner wrote:
Commit-ID: 1b11b0cb799e5f82ca6391a23eaa8f41c7466cc0
Gitweb: http://git.kernel.org/tip/1b11b0cb799e5f82ca6391a23eaa8f41c7466cc0
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Sun, 21 Jun 2015 20:16:15 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Thu, 25 Jun 2015 11:57:09 +0200

pinctrl/st: Fix race in installing chained IRQ handler

Fix a race where a pending interrupt could be received and the handler
called before the handler's data has been setup, by converting to
irq_set_chained_handler_and_data().

Search and conversion was done with coccinelle:

@@
expression E1, E2, E3;
@@
(
-if (irq_set_chained_handler(E1, E3) != 0)
- BUG();
|
-irq_set_chained_handler(E1, E3);
)
-irq_set_handler_data(E1, E2);
+irq_set_chained_handler_and_data(E1, E3, E2);

@@
expression E1, E2, E3;
@@
(
-if (irq_set_chained_handler(E1, E3) != 0)
- BUG();
...
|
-irq_set_chained_handler(E1, E3);
...
)
-irq_set_handler_data(E1, E2);
+irq_set_chained_handler_and_data(E1, E3, E2);

Reported-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Julia Lawall <Julia.Lawall@xxxxxxx>
Cc: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxx>
Cc: Maxime Coquelin <maxime.coquelin@xxxxxx>
Cc: Patrice Chotard <patrice.chotard@xxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: kernel@xxxxxxxxxxx
Cc: linux-gpio@xxxxxxxxxxxxxxx
---
drivers/pinctrl/pinctrl-st.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
index 65bf73b..10e9c4e8 100644
--- a/drivers/pinctrl/pinctrl-st.c
+++ b/drivers/pinctrl/pinctrl-st.c
@@ -1661,8 +1661,8 @@ static int st_pctl_probe_dt(struct platform_device *pdev,
if (IS_ERR(info->irqmux_base))
return PTR_ERR(info->irqmux_base);
- irq_set_chained_handler(irq, st_gpio_irqmux_handler);
- irq_set_handler_data(irq, info);
+ irq_set_chained_handler_and_data(irq, st_gpio_irqmux_handler,
+ info);
}

I cannot test the patch before Monday, but it looks good to me:
Acked-by: Maxime Coquelin <maxime.coquelin@xxxxxx>

Thanks!
Maxime
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