Messages in this thread | | | Subject | Re: [Intel-wired-lan] [PATCH] igc: Do not use link uninitialized in igc_check_for_copper_link | From | "Neftin, Sasha" <> | Date | Sun, 19 Jul 2020 08:34:12 +0300 |
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On 7/17/2020 05:12, Nathan Chancellor wrote: > On Thu, Jul 16, 2020 at 07:29:03PM +0300, Neftin, Sasha wrote: >> On 7/16/2020 07:49, Nathan Chancellor wrote: >>> Clang warns: >>> >> Hello Nathan, >> Thanks for tracking our code.Please, look at https://patchwork.ozlabs.org/project/intel-wired-lan/patch/20200709073416.14126-1-sasha.neftin@intel.com/ >> - I hope this patch already address this Clang warns - please, let me know. > > I have not explicitly tested it but it seems obvious that it will. Let's > go with that. > Good Nathan, let's go with my https://patchwork.ozlabs.org/project/intel-wired-lan/patch/20200709073416.14126-1-sasha.neftin@intel.com/ and let me know if warning still generated. Thanks, Sasha > Cheers, > Nathan > >>> drivers/net/ethernet/intel/igc/igc_mac.c:374:6: warning: variable 'link' >>> is used uninitialized whenever 'if' condition is true >>> [-Wsometimes-uninitialized] >>> if (!mac->get_link_status) { >>> ^~~~~~~~~~~~~~~~~~~~~ >>> drivers/net/ethernet/intel/igc/igc_mac.c:424:33: note: uninitialized use >>> occurs here >>> ret_val = igc_set_ltr_i225(hw, link); >>> ^~~~ >>> drivers/net/ethernet/intel/igc/igc_mac.c:374:2: note: remove the 'if' if >>> its condition is always false >>> if (!mac->get_link_status) { >>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ >>> drivers/net/ethernet/intel/igc/igc_mac.c:367:11: note: initialize the >>> variable 'link' to silence this warning >>> bool link; >>> ^ >>> = 0 >>> 1 warning generated. >>> >>> It is not wrong, link is only uninitialized after this through >>> igc_phy_has_link. Presumably, if we skip the majority of this function >>> when get_link_status is false, we should skip calling igc_set_ltr_i225 >>> as well. Just directly return 0 in this case, rather than bothering with >>> adding another label or initializing link in the if statement. >>> >>> Fixes: 707abf069548 ("igc: Add initial LTR support") >>> Link: https://github.com/ClangBuiltLinux/linux/issues/1095 >>> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> >>> --- >>> drivers/net/ethernet/intel/igc/igc_mac.c | 6 ++---- >>> 1 file changed, 2 insertions(+), 4 deletions(-) >>> >>> diff --git a/drivers/net/ethernet/intel/igc/igc_mac.c b/drivers/net/ethernet/intel/igc/igc_mac.c >>> index b47e7b0a6398..26e3c56a4a8b 100644 >>> --- a/drivers/net/ethernet/intel/igc/igc_mac.c >>> +++ b/drivers/net/ethernet/intel/igc/igc_mac.c >>> @@ -371,10 +371,8 @@ s32 igc_check_for_copper_link(struct igc_hw *hw) >>> * get_link_status flag is set upon receiving a Link Status >>> * Change or Rx Sequence Error interrupt. >>> */ >>> - if (!mac->get_link_status) { >>> - ret_val = 0; >>> - goto out; >>> - } >>> + if (!mac->get_link_status) >>> + return 0; >>> /* First we want to see if the MII Status Register reports >>> * link. If so, then we want to get the current speed/duplex >>> >>> base-commit: ca0e494af5edb59002665bf12871e94b4163a257 >>> >> Thanks, >> Sasha
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