Hi Dan, > -----Original Message----- > From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > Sent: Monday, November 4, 2024 12:31 AM > To: oe-kbuild@xxxxxxxxxxxxxxx; Sridhar, Kanchana P > <kanchana.p.sridhar@xxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; linux- > mm@xxxxxxxxx; hannes@xxxxxxxxxxx; yosryahmed@xxxxxxxxxx; > nphamcs@xxxxxxxxx; chengming.zhou@xxxxxxxxx; > usamaarif642@xxxxxxxxx; ryan.roberts@xxxxxxx; Huang, Ying > <ying.huang@xxxxxxxxx>; 21cnbao@xxxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx; > linux-crypto@xxxxxxxxxxxxxxx; herbert@xxxxxxxxxxxxxxxxxxx; > davem@xxxxxxxxxxxxx; clabbe@xxxxxxxxxxxx; ardb@xxxxxxxxxx; > ebiggers@xxxxxxxxxx; surenb@xxxxxxxxxx; Accardi, Kristen C > <kristen.c.accardi@xxxxxxxxx>; zanussi@xxxxxxxxxx > Cc: lkp <lkp@xxxxxxxxx>; oe-kbuild-all@xxxxxxxxxxxxxxx; Feghali, Wajdi K > <wajdi.k.feghali@xxxxxxxxx>; Gopal, Vinodh <vinodh.gopal@xxxxxxxxx>; > Sridhar, Kanchana P <kanchana.p.sridhar@xxxxxxxxx> > Subject: Re: [PATCH v2 13/13] mm: zswap: Compress batching with Intel IAA > in zswap_store() of large folios. > > Hi Kanchana, > > kernel test robot noticed the following build warnings: > > url: https://github.com/intel-lab-lkp/linux/commits/Kanchana-P- > Sridhar/crypto-acomp-Define-two-new-interfaces-for-compress-decompress- > batching/20241103-112337 > base: 5c4cf96cd70230100b5d396d45a5c9a332539d19 > patch link: https://lore.kernel.org/r/20241103032111.333282-14- > kanchana.p.sridhar%40intel.com > patch subject: [PATCH v2 13/13] mm: zswap: Compress batching with Intel > IAA in zswap_store() of large folios. > config: x86_64-randconfig-161-20241104 (https://download.01.org/0day- > ci/archive/20241104/202411040859.2z0MfFkR-lkp@xxxxxxxxx/config) > compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > the same patch/commit), kindly add following tags > | Reported-by: kernel test robot <lkp@xxxxxxxxx> > | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > | Closes: https://lore.kernel.org/r/202411040859.2z0MfFkR-lkp@xxxxxxxxx/ > > smatch warnings: > mm/zswap.c:1788 zswap_store_propagate_errors() warn: variable > dereferenced before check 'sbp->entry' (see line 1785) > > vim +1788 mm/zswap.c > > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1771 static > __always_inline void zswap_store_propagate_errors( > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1772 struct > zswap_store_pipeline_state *zst, > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1773 u8 > error_batch_idx) > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1774 { > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1775 u8 i; > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1776 > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1777 if (zst- > >errors[error_batch_idx]) > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1778 > return; > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1779 > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1780 for (i = 0; i < > zst->nr_comp_pages; ++i) { > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1781 > struct zswap_store_sub_batch_page *sbp = &zst->sub_batch[i]; > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1782 > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1783 if > (sbp->batch_idx == error_batch_idx) { > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1784 > if (!sbp->error) { > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 @1785 > if (!IS_ERR_VALUE(sbp->entry->handle)) > ^^^^^^^^^^^^^^^^^^ > Dereferenced > > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1786 > zpool_free(zst->pool->zpool, sbp->entry->handle); > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1787 > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 @1788 > if (sbp->entry) { > ^^^^^^^^^^ > Checked too late Thanks for pointing this out. The implementation makes sure that all sbp->entry values are valid before it gets to zswap_store_propagate_errors(). That said, I agree, the sbp->entry check can be done earlier to make the code more correct/readable. I will fix this in v3. Thanks, Kanchana > > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1789 > zswap_entry_cache_free(sbp->entry); > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1790 > sbp->entry = NULL; > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1791 > } > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1792 > sbp->error = -EINVAL; > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1793 > } > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1794 } > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1795 } > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1796 > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1797 /* > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1798 * Set zswap > status for the folio to "error" > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1799 * for use in > swap_writepage. > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1800 */ > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1801 zst- > >errors[error_batch_idx] = -EINVAL; > c1252ac91d6a6a Kanchana P Sridhar 2024-11-02 1802 } > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests/wiki
