This is a note to let you know that I've just added the patch titled
iwlwifi: mvm: avoid harmless -Wmaybe-uninialized warning
to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iwlwifi-mvm-avoid-harmless-wmaybe-uninialized-warning.patch
and it can be found in the queue-4.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 5a7d87da8d9b9f04ecdbebe7e5710a1391f85fa8 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@xxxxxxxx>
Date: Fri, 27 May 2016 15:07:03 +0200
Subject: iwlwifi: mvm: avoid harmless -Wmaybe-uninialized warning
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From: Arnd Bergmann <arnd@xxxxxxxx>
commit 5a7d87da8d9b9f04ecdbebe7e5710a1391f85fa8 upstream.
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@xxxxxxxx>
Fixes: 6fa52430f0b3 ("iwlwifi: mvm: change mcc update API")
Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/wireless/intel/iwlwifi/mvm/nvm.c | 41 +++++++++++++--------------
1 file changed, 21 insertions(+), 20 deletions(-)
--- 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,
.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,
/* 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);
Patches currently in stable-queue which might be from arnd@xxxxxxxx are
queue-4.7/iwlwifi-mvm-avoid-harmless-wmaybe-uninialized-warning.patch
queue-4.7/arm-8617-1-dma-fix-dma_max_pfn.patch
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