From: Arnd Bergmann <arnd@arndb.de>
To: Emmanuel Grumbach <emmanuel.grumbach@intel.com>,
Matti Gottlieb <matti.gottlieb@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Arnd Bergmann <arnd@arndb.de>,
Johannes Berg <johannes.berg@intel.com>,
Luca Coelho <luciano.coelho@intel.com>,
Intel Linux Wireless <linuxwifi@intel.com>,
Kalle Valo <kvalo@codeaurora.org>,
Moshe Harel <moshe.harel@intel.com>,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] iwlwifi: mvm: avoid harmless -Wmaybe-uninialized warning
Date: Fri, 27 May 2016 15:07:03 +0200 [thread overview]
Message-ID: <1464354462-1940949-1-git-send-email-arnd@arndb.de> (raw)
gcc is apparently unablel to track the state of the local 'resp_v2'
variable across the kzalloc() function, and warns about the response
variable being used without an initialization:
drivers/net/wireless/intel/iwlwifi/mvm/nvm.c: In function ‘iwl_mvm_update_mcc’:
drivers/net/wireless/intel/iwlwifi/mvm/nvm.c:727:36: warning: ‘mcc_resp_v1’ may be used uninitialized in this function [-Wmaybe-uninitialized]
resp_cp->n_channels = mcc_resp_v1->n_channels;
drivers/net/wireless/intel/iwlwifi/mvm/nvm.c:721:3: warning: ‘mcc_resp’ may be used uninitialized in this function [-Wmaybe-uninitialized]
memcpy(resp_cp, mcc_resp, resp_len);
The warning showed up in x86 allmodconfig after my patch to
unhide -Wmaybe-uninitialized warnings by default was merged,
though it always existed in randconfig builds. I did not
catch the warning earlier because I was testing on ARM, which
never produced the warning.
This rearranges the code in a way that improves readability for
both humans and the compiler, and that avoids the warning.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 6fa52430f0b3 ("iwlwifi: mvm: change mcc update API")
---
drivers/net/wireless/intel/iwlwifi/mvm/nvm.c | 41 ++++++++++++++--------------
1 file changed, 21 insertions(+), 20 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/nvm.c b/drivers/net/wireless/intel/iwlwifi/mvm/nvm.c
index 25a98401a64f..0551a4bb163c 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/nvm.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/nvm.c
@@ -667,8 +667,7 @@ iwl_mvm_update_mcc(struct iwl_mvm *mvm, const char *alpha2,
.mcc = cpu_to_le16(alpha2[0] << 8 | alpha2[1]),
.source_id = (u8)src_id,
};
- struct iwl_mcc_update_resp *mcc_resp, *resp_cp = NULL;
- struct iwl_mcc_update_resp_v1 *mcc_resp_v1 = NULL;
+ struct iwl_mcc_update_resp *resp_cp;
struct iwl_rx_packet *pkt;
struct iwl_host_cmd cmd = {
.id = MCC_UPDATE_CMD,
@@ -701,34 +700,36 @@ iwl_mvm_update_mcc(struct iwl_mvm *mvm, const char *alpha2,
/* Extract MCC response */
if (resp_v2) {
- mcc_resp = (void *)pkt->data;
+ struct iwl_mcc_update_resp *mcc_resp = (void *)pkt->data;
+
n_channels = __le32_to_cpu(mcc_resp->n_channels);
+ resp_len = sizeof(struct iwl_mcc_update_resp) +
+ n_channels * sizeof(__le32);
+ resp_cp = kmemdup(mcc_resp, resp_len, GFP_KERNEL);
} else {
- mcc_resp_v1 = (void *)pkt->data;
+ struct iwl_mcc_update_resp_v1 *mcc_resp_v1 = (void *)pkt->data;
+
n_channels = __le32_to_cpu(mcc_resp_v1->n_channels);
+ resp_len = sizeof(struct iwl_mcc_update_resp) +
+ n_channels * sizeof(__le32);
+ resp_cp = kzalloc(resp_len, GFP_KERNEL);
+
+ if (resp_cp) {
+ resp_cp->status = mcc_resp_v1->status;
+ resp_cp->mcc = mcc_resp_v1->mcc;
+ resp_cp->cap = mcc_resp_v1->cap;
+ resp_cp->source_id = mcc_resp_v1->source_id;
+ resp_cp->n_channels = mcc_resp_v1->n_channels;
+ memcpy(resp_cp->channels, mcc_resp_v1->channels,
+ n_channels * sizeof(__le32));
+ }
}
- resp_len = sizeof(struct iwl_mcc_update_resp) + n_channels *
- sizeof(__le32);
-
- resp_cp = kzalloc(resp_len, GFP_KERNEL);
if (!resp_cp) {
ret = -ENOMEM;
goto exit;
}
- if (resp_v2) {
- memcpy(resp_cp, mcc_resp, resp_len);
- } else {
- resp_cp->status = mcc_resp_v1->status;
- resp_cp->mcc = mcc_resp_v1->mcc;
- resp_cp->cap = mcc_resp_v1->cap;
- resp_cp->source_id = mcc_resp_v1->source_id;
- resp_cp->n_channels = mcc_resp_v1->n_channels;
- memcpy(resp_cp->channels, mcc_resp_v1->channels,
- n_channels * sizeof(__le32));
- }
-
status = le32_to_cpu(resp_cp->status);
mcc = le16_to_cpu(resp_cp->mcc);
--
2.7.0
next reply other threads:[~2016-05-27 13:08 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-27 13:07 Arnd Bergmann [this message]
2016-05-30 20:37 ` [PATCH] iwlwifi: mvm: avoid harmless -Wmaybe-uninialized warning Coelho, Luciano
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1464354462-1940949-1-git-send-email-arnd@arndb.de \
--to=arnd@arndb.de \
--cc=emmanuel.grumbach@intel.com \
--cc=johannes.berg@intel.com \
--cc=kvalo@codeaurora.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-wireless@vger.kernel.org \
--cc=linuxwifi@intel.com \
--cc=luciano.coelho@intel.com \
--cc=matti.gottlieb@intel.com \
--cc=moshe.harel@intel.com \
--cc=netdev@vger.kernel.org \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).