Clang warns that proto in rmnet_map_v5_checksum_uplink_packet() might be used uninitialized: drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c:283:14: warning: variable 'proto' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] } else if (skb->protocol == htons(ETH_P_IPV6)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c:295:36: note: uninitialized use occurs here check = rmnet_map_get_csum_field(proto, trans); ^~~~~ drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c:283:10: note: remove the 'if' if its condition is always true } else if (skb->protocol == htons(ETH_P_IPV6)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c:270:11: note: initialize the variable 'proto' to silence this warning u8 proto; ^ = '\0' 1 warning generated. This is technically a false positive because there is an if statement above this one that checks skb->protocol for not being either ETH_P_IP{,V6}. However, it is more obvious to sink that into the if statement as an else branch, which makes the code clearer and fixes the warning. At the same time, move the "IS_ENABLED(CONFIG_IPV6)" into the else if condition so that the else branch of the preprocessor conditional can be shared, since there is no build failure with CONFIG_IPV6 disabled. Fixes: b6e5d27e32ef ("net: ethernet: rmnet: Add support for MAPv5 egress packets") Link: https://github.com/ClangBuiltLinux/linux/issues/1390 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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