[PATCH] cxl/core: Avoid using dev uninitialized in devm_cxl_add_decoder()

From: Nathan Chancellor
Date: Wed Aug 25 2021 - 13:33:44 EST


Clang warns:

drivers/cxl/core/bus.c:527:6: warning: variable 'dev' is used
uninitialized whenever 'if' condition is true
[-Wsometimes-uninitialized]
if (rc)
^~
drivers/cxl/core/bus.c:541:13: note: uninitialized use occurs here
put_device(dev);
^~~
drivers/cxl/core/bus.c:527:2: note: remove the 'if' if its condition is
always false
if (rc)
^~~~~~~
drivers/cxl/core/bus.c:507:6: warning: variable 'dev' is used
uninitialized whenever 'if' condition is true
[-Wsometimes-uninitialized]
if (cxld->interleave_ways < 1) {
^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/cxl/core/bus.c:541:13: note: uninitialized use occurs here
put_device(dev);
^~~
drivers/cxl/core/bus.c:507:2: note: remove the 'if' if its condition is
always false
if (cxld->interleave_ways < 1) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/cxl/core/bus.c:498:20: note: initialize the variable 'dev' to
silence this warning
struct device *dev;
^
= NULL
2 warnings generated.

Return the error code directly rather than attempting to call
device_put() with an uninitialized pointer.

Fixes: b7ca54b62551 ("cxl/core: Split decoder setup into alloc + add")
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
---
drivers/cxl/core/bus.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/cxl/core/bus.c b/drivers/cxl/core/bus.c
index 1320a996220a..f4d5319e29e3 100644
--- a/drivers/cxl/core/bus.c
+++ b/drivers/cxl/core/bus.c
@@ -504,10 +504,8 @@ int devm_cxl_add_decoder(struct device *host, struct cxl_decoder *cxld,
if (IS_ERR(cxld))
return PTR_ERR(cxld);

- if (cxld->interleave_ways < 1) {
- rc = -EINVAL;
- goto err;
- }
+ if (cxld->interleave_ways < 1)
+ return -EINVAL;

device_lock(&port->dev);
if (list_empty(&port->dports))
@@ -525,7 +523,7 @@ int devm_cxl_add_decoder(struct device *host, struct cxl_decoder *cxld,
}
device_unlock(&port->dev);
if (rc)
- goto err;
+ return rc;

dev = &cxld->dev;
rc = dev_set_name(dev, "decoder%d.%d", port->id, cxld->id);

base-commit: 036a16a39e2fab9bf7279201d04cf7e90993521f
--
2.33.0