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b=VvaFYJk6gzu/SrmA09X4ZSzC66zDqCpQdKMerjfFF8ltzZcGubm1Fi6hqS8PSalnU /cJIQJUAUZKfTqzO2x6UAcOcfbBsNE5cUJzXeH15YV6aVonxi5xT3DBuu3ZGeXZb9g JJrJtkPMyBeinuZzO/aSs8L1QZXoYELYABRGGdYk= Date: Tue, 14 Oct 2025 19:09:16 -0700 From: Andrew Morton To: Yadong Qi Cc: urezki@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, ying.huang@linux.alibaba.com, dan.carpenter@linaro.org, kernel test robot , Huang Ying , Dev Jain , Uladzislau Rezki (Sony) Subject: Re: [PATCH] mm: vmalloc: fix uninitialized value issue Message-Id: <20251014190916.e9285e8ac6a8301cdacd9fe8@linux-foundation.org> In-Reply-To: <20251014102337.5453-1-yadong.qi@linux.alibaba.com> References: <20251014102337.5453-1-yadong.qi@linux.alibaba.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Queue-Id: 8C1BA1C000F X-Rspamd-Server: rspam02 X-Stat-Signature: utsaxdfneycpszud38g5zgeu5ooutqgs X-HE-Tag: 1760494158-761075 X-HE-Meta: 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 HHFTWO6r uTRmnh7E4BGb54npJSgrAezdxVQdpuyzPOWXrSi1dauAIA1qfwVymDRahB0SHlDUExCmhy1yNQiya4tKBlKe3hyCJ4dEPdFe1dLUOfRB22OmOus3L9aJw1Hi0Rb5j0mHOpAl2fUFlWU45/s3FWrpTPs7l95vK0n+VvNNWWes/K3WG8dN9pC+8BOCFgGlILsOseRv/3elaAreGmEgf9PlLCQlxTj5efjmrDbP9kGEVgUhWzxkr3DxNiLZxlMPk8EoVLnaDWENlhYctsKZuF7WmH2RnKPxIBVeacGDxhUfxV47Tbw+DJ8rs+fmcs1XTW7TiWTdzYk7RgtvUDCM7rw6V1BhCsYToHK78XWwX X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, 14 Oct 2025 18:23:37 +0800 Yadong Qi wrote: > Issues reported by LKP: > mm/vmalloc.c:191 vmap_pmd_range() error: uninitialized symbol 'err'. > mm/vmalloc.c:243 vmap_pud_range() error: uninitialized symbol 'err'. > mm/vmalloc.c:295 vmap_p4d_range() error: uninitialized symbol 'err'. > > Fix by initailizing err with 0. This fixes warnings which were introduced by mm.git's recent "mm: vmalloc: WARN_ON if mapping size is not PAGE_SIZE aligned". Please do point out such details. > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -170,7 +170,7 @@ static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, > { > pmd_t *pmd; > unsigned long next; > - int err; > + int err = 0; > > pmd = pmd_alloc_track(&init_mm, pud, addr, mask); > if (!pmd) So we get the below: : static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, : phys_addr_t phys_addr, pgprot_t prot, : unsigned int max_page_shift, pgtbl_mod_mask *mask) : { : pmd_t *pmd; : unsigned long next; : int err = 0; : : pmd = pmd_alloc_track(&init_mm, pud, addr, mask); : if (!pmd) : return -ENOMEM; : do { : next = pmd_addr_end(addr, end); : : if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot, : max_page_shift)) { : *mask |= PGTBL_PMD_MODIFIED; : continue; : } : : err = vmap_pte_range(pmd, addr, next, phys_addr, prot, max_page_shift, mask); : if (err) : break; : } while (pmd++, phys_addr += (next - addr), addr = next, addr != end); : return err; : } If every single pmd fails vmap_try_huge_pmd() then this function returns zero, indicating success. Is this behavior correct and desirable?