From 18d83fc611a8eb4a5ef157108cb0fd06a4d21678 Mon Sep 17 00:00:00 2001

From: Jackie Liu <liuyun01@kylinos.cn>

Date: Wed, 1 Sep 2021 20:35:57 +0800

Subject: [PATCH] ARM: s3c: irq-s3c24xx: Fix return value check for s3c24xx_init_intc()

Git-commit: 2aa717473ce96c93ae43a5dc8c23cedc8ce7dd9f

Patch-mainline: v5.16-rc1

References: stable-5.14.19

[ Upstream commit 2aa717473ce96c93ae43a5dc8c23cedc8ce7dd9f ]

The s3c24xx_init_intc() returns an error pointer upon failure, not NULL.

let's add an error pointer check in s3c24xx_handle_irq.

s3c_intc[0] is not NULL or ERR, we can simplify the code.

Fixes: 1f629b7a3ced ("ARM: S3C24XX: transform irq handling into a declarative form")

Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>

Link: https://lore.kernel.org/r/20210901123557.1043953-1-liu.yun@linux.dev

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

Signed-off-by: Sasha Levin <sashal@kernel.org>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 arch/arm/mach-s3c/irq-s3c24xx.c | 22 ++++++++++++++++++----

 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/arch/arm/mach-s3c/irq-s3c24xx.c b/arch/arm/mach-s3c/irq-s3c24xx.c

index 0c631c14a817..53081505e397 100644

--- a/arch/arm/mach-s3c/irq-s3c24xx.c

+++ b/arch/arm/mach-s3c/irq-s3c24xx.c

@@ -362,11 +362,25 @@ static inline int s3c24xx_handle_intc(struct s3c_irq_intc *intc,

 static asmlinkage void __exception_irq_entry s3c24xx_handle_irq(struct pt_regs *regs)

 {

 	do {

-		if (likely(s3c_intc[0]))

-			if (s3c24xx_handle_intc(s3c_intc[0], regs, 0))

-				continue;

+		/*

+		 * For platform based machines, neither ERR nor NULL can happen here.

+		 * The s3c24xx_handle_irq() will be set as IRQ handler iff this succeeds:

+		 *

+		 *    s3c_intc[0] = s3c24xx_init_intc()

+		 *

+		 * If this fails, the next calls to s3c24xx_init_intc() won't be executed.

+		 *

+		 * For DT machine, s3c_init_intc_of() could set the IRQ handler without

+		 * setting s3c_intc[0] only if it was called with num_ctrl=0. There is no

+		 * such code path, so again the s3c_intc[0] will have a valid pointer if

+		 * set_handle_irq() is called.

+		 *

+		 * Therefore in s3c24xx_handle_irq(), the s3c_intc[0] is always something.

+		 */

+		if (s3c24xx_handle_intc(s3c_intc[0], regs, 0))

+			continue;

-		if (s3c_intc[2])

+		if (!IS_ERR_OR_NULL(s3c_intc[2]))

 			if (s3c24xx_handle_intc(s3c_intc[2], regs, 64))

 				continue;

-- 

2.26.2