From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 11/35] mm/mmap.c: initialize align_offset explicitly for vm_unmapped_area Date: Fri, 10 Apr 2020 14:32:48 -0700 Message-ID: <20200410213248.qLjye2jR5%akpm@linux-foundation.org> References: <20200410143047.bf34a933ce1affdc042c7c80@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:46670 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726582AbgDJVct (ORCPT ); Fri, 10 Apr 2020 17:32:49 -0400 In-Reply-To: <20200410143047.bf34a933ce1affdc042c7c80@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: akpm@linux-foundation.org, bp@suse.de, jaewon31.kim@samsung.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, walken@google.com, willy@infradead.org From: Jaewon Kim Subject: mm/mmap.c: initialize align_offset explicitly for vm_unmapped_area On passing requirement to vm_unmapped_area, arch_get_unmapped_area and arch_get_unmapped_area_topdown did not set align_offset. Internally on both unmapped_area and unmapped_area_topdown, if info->align_mask is 0, then info->align_offset was meaningless. But commit df529cabb7a2 ("mm: mmap: add trace point of vm_unmapped_area") always prints info->align_offset even though it is uninitialized. Fix this uninitialized value issue by setting it to 0 explicitly. Before 92.291104: vm_unmapped_area: addr=0x755b155000 err=0 total_vm=0x15aaf0 flags=0x1 len=0x109000 lo=0x8000 hi=0x75eed48000 mask=0x0 ofs=0x4022 After 68.584210: vm_unmapped_area: addr=0x74a4ca1000 err=0 total_vm=0x168ab1 flags=0x1 len=0x9000 lo=0x8000 hi=0x753d94b000 mask=0x0 ofs=0x0 Link: http://lkml.kernel.org/r/20200409094035.19457-1-jaewon31.kim@samsung.com Signed-off-by: Jaewon Kim Reviewed-by: Andrew Morton Cc: Matthew Wilcox (Oracle) Cc: Michel Lespinasse Cc: Borislav Petkov Signed-off-by: Andrew Morton --- mm/mmap.c | 2 ++ 1 file changed, 2 insertions(+) --- a/mm/mmap.c~mm-mmap-initialize-align_offset-explicitly-for-vm_unmapped_area +++ a/mm/mmap.c @@ -2123,6 +2123,7 @@ arch_get_unmapped_area(struct file *filp info.low_limit = mm->mmap_base; info.high_limit = mmap_end; info.align_mask = 0; + info.align_offset = 0; return vm_unmapped_area(&info); } #endif @@ -2164,6 +2165,7 @@ arch_get_unmapped_area_topdown(struct fi info.low_limit = max(PAGE_SIZE, mmap_min_addr); info.high_limit = arch_get_mmap_base(addr, mm->mmap_base); info.align_mask = 0; + info.align_offset = 0; addr = vm_unmapped_area(&info); /* _