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b=naYCHlv2BL4Vo5IMZ+rucI1IUcm2W+5FvAdPLeFy/8TMfofkrUngKY0lHlo/vG6F4 Lrr+4uVz6/cfuXZg0bnFRsvN2neMPceWNnPfBHNLESE+J5QuKgZ1YioVZSyBz5oJtJ ze2up/U4UFtMocCPZjFKPedCx8NGK25mUxbyfXm7gzZOOz/U5J95ePcwWQiSnduZia ZyS0JORzuiIOFYHqZDSK6REAX4/Td3RhawVi2D5joirUlDtFDsZ6vA1RSYiIc4ixK9 4TddXhyhT4jfAdrJmhVXMLJFQ1qORwSvUj8wIbVzE81kkbXNMgjtbTKzuymVgH9sGl Wlt66JKBy459Q== Date: Sun, 26 Jul 2026 11:24:19 +0300 From: Leon Romanovsky To: Andrew Morton Cc: Gou Hao , maddy@linux.ibm.com, mpe@ellerman.id.au, npiggin@gmail.com, chleroy@kernel.org, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch, bharat@chelsio.com, jgg@ziepe.ca, namcao@linutronix.de, ynorov@nvidia.com, sshegde@linux.ibm.com, nilay@linux.ibm.com, clg@kaod.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-mm@kvack.org, gouhaojake@163.com, kernel@uniontech.com Subject: Re: [PATCH v2 0/6] remove dead NULL checks after GFP_NOFAIL allocations and fix xive use-after-free Message-ID: <20260726082419.GF12003@unreal> References: <20260724022851.466017-1-gouhao@uniontech.com> <20260725202632.dcb325658896a470df91cf57@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260725202632.dcb325658896a470df91cf57@linux-foundation.org> X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 7D76F140003 X-Rspam-User: X-Stat-Signature: tuuijpzqbuhxa9mkz5si6bg6e3bsw4cq X-HE-Tag: 1785054263-942318 X-HE-Meta: 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 TyIQZtRt 2OthKiYH92/MH5Qv1MKNzseq2Khyvy2jTnIfgAGnfGZxVh9oZUpszp+tg6VPecQ+e6JEbcHMgEywEQMY6/XL3uj6+bK1vJFYKgyT2KVi5LuxapLkIOGuHkovJHXJyg0fXEEZ7QCTWp3EBDd0GS0G+9QTPByfDrIpqA0WWlkmB4FvWrwI1UjGtyZPc7oXmEt26zJLkE6JJVtixa3rqIt0ZsJA8y68DoSRyPTjIwiT2mkdzpAt6KCghaYfjHclmqX63eiPrqJGIg+b0Hdmk6l1Mpum85IUDWNYJHcoHdxNpaKyGeoxl9taRnzlelo1J8Oeuvlb1ySrkQpPCR2Uyld5qbnOkCmPzvabJs/a8RHcQ1JYNfCNTB1YgrNxWknSyC2T0UfctdTs5rZl5u7/3dgMNjSU6nUrTbIs57hmVy3Vbk1uPRXY= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sat, Jul 25, 2026 at 08:26:32PM -0700, Andrew Morton wrote: > On Fri, 24 Jul 2026 10:28:45 +0800 Gou Hao wrote: > > > This is a code cleanup series that removes unreachable > > NULL checks (and associated error handling) that follow allocations > > using __GFP_NOFAIL, which guarantees non-NULL return. > > Sigh. > > Back when Linux ran on an abacus, I added __GFP_NOFAIL because four or > five sites (file systems) were infinitely looping on alloc_pages until > it succeeded. I figured we should move this operation into the page > allocator so we could easily find those sites and fix them to Not Do > That. > > I made it very clear (changelog and code comments) that no new code > should use __GFP_NOFAIL. How did that work out? > > hp2:/usr/src/linux-7.2-rc4> grep -r __GFP_NOFAIL | wc -l > 241 > > So much lameness! My immediate reaction to your patchset is "No. Fix > the damn code instead". But I've resoundingly lost that fight. > > > Thanks, I'll scoop up the entire series. If individual patches pop up > in linux-next then I'll drop the mm.git copies. > > > > AI review has a shower of possible pre-existing issues. I'm seeing > use-after-free, double-free, leak, system hang, NULL pointer > dereference, usual stuff :( > > They're in powerpc and cxgb4, if maintainers are interested. > > https://sashiko.dev/#/patchset/20260724022851.466017-1-gouhao@uniontech.com Regarding cxgb4, yes, I'm looking into it. Thanks