Thread (1 message) 1 message, 1 author, 2019-09-24
STALE2503d REVIEWED: 6 (5M)

2 review trailers (1 from subsystem maintainers).

[PATCH AUTOSEL 5.2 17/70] PCI: rpaphp: Avoid a sometimes-uninitialized warning

From: Sasha Levin <sashal@kernel.org>
Date: 2019-09-24 16:46:36
Also in: linux-pci, lkml, stable
Subsystem: ibm power pci hotplug driver for rpa-compliant ppc64 platform, linux for powerpc (32-bit and 64-bit), pci subsystem, the rest · Maintainers: Tyrel Datwyler, Madhavan Srinivasan, Bjorn Helgaas, Linus Torvalds

From: Nathan Chancellor <redacted>

[ Upstream commit 0df3e42167caaf9f8c7b64de3da40a459979afe8 ]

When building with -Wsometimes-uninitialized, clang warns:

drivers/pci/hotplug/rpaphp_core.c:243:14: warning: variable 'fndit' is
used uninitialized whenever 'for' loop exits because its condition is
false [-Wsometimes-uninitialized]
        for (j = 0; j < entries; j++) {
                    ^~~~~~~~~~~
drivers/pci/hotplug/rpaphp_core.c:256:6: note: uninitialized use occurs
here
        if (fndit)
            ^~~~~
drivers/pci/hotplug/rpaphp_core.c:243:14: note: remove the condition if
it is always true
        for (j = 0; j < entries; j++) {
                    ^~~~~~~~~~~
drivers/pci/hotplug/rpaphp_core.c:233:14: note: initialize the variable
'fndit' to silence this warning
        int j, fndit;
                    ^
                     = 0

fndit is only used to gate a sprintf call, which can be moved into the
loop to simplify the code and eliminate the local variable, which will
fix this warning.

Fixes: 2fcf3ae508c2 ("hotplug/drc-info: Add code to search ibm,drc-info property")
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <redacted>
Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Acked-by: Joel Savitz <redacted>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/504
Link: https://lore.kernel.org/r/20190603221157.58502-1-natechancellor@gmail.com (local)
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/hotplug/rpaphp_core.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)
diff --git a/drivers/pci/hotplug/rpaphp_core.c b/drivers/pci/hotplug/rpaphp_core.c
index bcd5d357ca238..c3899ee1db995 100644
--- a/drivers/pci/hotplug/rpaphp_core.c
+++ b/drivers/pci/hotplug/rpaphp_core.c
@@ -230,7 +230,7 @@ static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
 	struct of_drc_info drc;
 	const __be32 *value;
 	char cell_drc_name[MAX_DRC_NAME_LEN];
-	int j, fndit;
+	int j;
 
 	info = of_find_property(dn->parent, "ibm,drc-info", NULL);
 	if (info == NULL)
@@ -245,17 +245,13 @@ static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
 
 		/* Should now know end of current entry */
 
-		if (my_index > drc.last_drc_index)
-			continue;
-
-		fndit = 1;
-		break;
+		/* Found it */
+		if (my_index <= drc.last_drc_index) {
+			sprintf(cell_drc_name, "%s%d", drc.drc_name_prefix,
+				my_index);
+			break;
+		}
 	}
-	/* Found it */
-
-	if (fndit)
-		sprintf(cell_drc_name, "%s%d", drc.drc_name_prefix, 
-			my_index);
 
 	if (((drc_name == NULL) ||
 	     (drc_name && !strcmp(drc_name, cell_drc_name))) &&
-- 
2.20.1
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