[PATCH] microblaze: uartlite: avoid NULL pointer exception
From: Stephan Linz
Date: Wed Aug 08 2012 - 14:44:48 EST
'prop' is an pointer and can only be unset (NULL) after
prop = of_get_property() when it goes wrong.
Kernel oops in ulite_probe():
[ 1.016645] uartlite 8fff0000.debug: failed to get alias id, errno -19
[ 1.024246] Oops: kernel access of bad area, sig: 11
[ 1.029733] Registers dump: mode=27827D60
[ 1.034362] r1=C79113E0, r2=00000000, r3=00000000, r4=00000000
[ 1.040918] r5=C02E1E49, r6=C02D5918, r7=00000070, r8=000014C9
[ 1.047475] r9=000014C8, r10=000014C9, r11=00000006, r12=FFFFFFFC
[ 1.054318] r13=00000000, r14=C79114A0, r15=C0293BDC, r16=00000000
[ 1.061261] r17=C0293BE4, r18=FFFFFFFE, r19=C788BDC8, r20=00000000
[ 1.068207] r21=00000000, r22=FFFFFFED, r23=C788BDC0, r24=C033E840
[ 1.075145] r25=C033EEA4, r26=00000000, r27=00000000, r28=00000000
[ 1.082086] r29=00000000, r30=00000000, r31=C7824AC0, rPC=C0293BE4
[ 1.089024] msr=000046A2, ear=00000000, esr=00000872, fsr=C7827E08
[ 1.096281] Kernel panic - not syncing: Attempted to kill init!
Now it is:
[ 1.014924] uartlite 8fff0000.debug: failed to get alias id, errno -19
[ 1.022543] uartlite 8fff0000.debug: failed to get port-number
Signed-off-by: Stephan Linz <linz@xxxxxxxxxx>
---
drivers/tty/serial/uartlite.c | 5 ++---
1 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index a276282..3cba732 100644
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -589,9 +589,8 @@ static int __devinit ulite_probe(struct platform_device *pdev)
dev_warn(&pdev->dev, "failed to get alias id, errno %d\n", id);
/* Fall back to old port-number property */
prop = of_get_property(pdev->dev.of_node, "port-number", NULL);
- if (prop < 0) {
- dev_warn(&pdev->dev,
- "failed to get port-number, errno %d\n", prop);
+ if (!prop) {
+ dev_warn(&pdev->dev, "failed to get port-number\n");
id = -1;
} else
id = be32_to_cpup(prop);
--
1.7.0.4
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