From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CE3927FBAC for ; Fri, 26 Apr 2024 04:01:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714104090; cv=none; b=NG0yMBF3/Hf4A8Eaob9afAJIzMwJ1BpfI4t0gShBofrJoorYzXx8hH0+aawPfnJyVkZfenjQ4VdPJAU8ntrcbCL3b4GpNx7h93pLBRliQ8zK/FKHrVixtnBAuJV85XBrLgJa4fAglz7uEf9OLiV86YIEuBJlKnhYVY1Nt28f9UI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714104090; c=relaxed/simple; bh=SXj1bcHR7bbEKRI4HdNR+U0P74kRveXncUiLixFMXEQ=; h=Date:To:From:Subject:Message-Id; b=kicnDvRneTThM929paHwxOZqG0uouuW9a/XTo4FgtXUyVgDS1WWV4XsXs1YEjLSsquYnR8Oh0OdLB3xA1GPDgiVmEWQgGyuNtl55xPiDS53eLl9T+Wobh/65V7UsdPw4cGoIVk77+Ncwcah8k98ACmFlDyFVpgWHPUDVHwbWHik= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=o0aDf/AK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="o0aDf/AK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3E91C113CD; Fri, 26 Apr 2024 04:01:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1714104090; bh=SXj1bcHR7bbEKRI4HdNR+U0P74kRveXncUiLixFMXEQ=; h=Date:To:From:Subject:From; b=o0aDf/AKBhWXpv0j/bEIrJwO5s74LE4EQb5tVWPryesPWBV+pO8B39fU+njzOKHBb YWis6lv8MlbSntiIINYgKC0zEsvM58/TDT78f7p+tsVtrt9IlQB9Mv1zD6A8WXnenK KM04egAuVmGT44i1p8uM90ko8fs6C8AFQHK+jI6w= Date: Thu, 25 Apr 2024 21:01:30 -0700 To: mm-commits@vger.kernel.org,tglx@linutronix.de,peterz@infradead.org,npiggin@gmail.com,naveen.n.rao@linux.ibm.com,mpe@ellerman.id.au,mingo@redhat.com,luto@kernel.org,Liam.Howlett@oracle.com,kirill.shutemov@linux.intel.com,keescook@chromium.org,James.Bottomley@HansenPartnership.com,hpa@zytor.com,guoren@kernel.org,deller@gmx.de,debug@rivosinc.com,dave.hansen@linux.intel.com,dan.j.williams@intel.com,christophe.leroy@csgroup.eu,broonie@kernel.org,bp@alien8.de,ast@kernel.org,aneesh.kumar@kernel.org,rick.p.edgecombe@intel.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] powerpc-use-initializer-for-struct-vm_unmapped_area_info.patch removed from -mm tree Message-Id: <20240426040130.A3E91C113CD@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: powerpc: use initializer for struct vm_unmapped_area_info has been removed from the -mm tree. Its filename was powerpc-use-initializer-for-struct-vm_unmapped_area_info.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Rick Edgecombe Subject: powerpc: use initializer for struct vm_unmapped_area_info Date: Mon, 25 Mar 2024 19:16:51 -0700 Future changes will need to add a new member to struct vm_unmapped_area_info. This would cause trouble for any call site that doesn't initialize the struct. Currently every caller sets each member manually, so if new members are added they will be uninitialized and the core code parsing the struct will see garbage in the new member. It could be possible to initialize the new member manually to 0 at each call site. This and a couple other options were discussed, and a working consensus (see links) was that in general the best way to accomplish this would be via static initialization with designated member initiators. Having some struct vm_unmapped_area_info instances not zero initialized will put those sites at risk of feeding garbage into vm_unmapped_area() if the convention is to zero initialize the struct and any new member addition misses a call site that initializes each member manually. It could be possible to leave the code mostly untouched, and just change the line: struct vm_unmapped_area_info info to: struct vm_unmapped_area_info info = {}; However, that would leave cleanup for the members that are manually set to zero, as it would no longer be required. So to be reduce the chance of bugs via uninitialized members, instead simply continue the process to initialize the struct this way tree wide. This will zero any unspecified members. Move the member initializers to the struct declaration when they are known at that time. Leave the members out that were manually initialized to zero, as this would be redundant for designated initializers. Link: https://lkml.kernel.org/r/20240326021656.202649-10-rick.p.edgecombe@intel.com Link: https://lore.kernel.org/lkml/202402280912.33AEE7A9CF@keescook/#t Link: https://lore.kernel.org/lkml/j7bfvig3gew3qruouxrh7z7ehjjafrgkbcmg6tcghhfh3rhmzi@wzlcoecgy5rs/ Signed-off-by: Rick Edgecombe Acked-by: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Aneesh Kumar K.V Cc: Naveen N. Rao Cc: Alexei Starovoitov Cc: Andy Lutomirski Cc: Borislav Petkov (AMD) Cc: Dan Williams Cc: Dave Hansen Cc: Deepak Gupta Cc: Guo Ren Cc: Helge Deller Cc: H. Peter Anvin (Intel) Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Kees Cook Cc: Kirill A. Shutemov Cc: Liam R. Howlett Cc: Mark Brown Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- arch/powerpc/mm/book3s64/slice.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) --- a/arch/powerpc/mm/book3s64/slice.c~powerpc-use-initializer-for-struct-vm_unmapped_area_info +++ a/arch/powerpc/mm/book3s64/slice.c @@ -282,12 +282,10 @@ static unsigned long slice_find_area_bot { int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); unsigned long found, next_end; - struct vm_unmapped_area_info info; - - info.flags = 0; - info.length = len; - info.align_mask = PAGE_MASK & ((1ul << pshift) - 1); - info.align_offset = 0; + struct vm_unmapped_area_info info = { + .length = len, + .align_mask = PAGE_MASK & ((1ul << pshift) - 1), + }; /* * Check till the allow max value for this mmap request */ @@ -326,13 +324,13 @@ static unsigned long slice_find_area_top { int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); unsigned long found, prev; - struct vm_unmapped_area_info info; + struct vm_unmapped_area_info info = { + .flags = VM_UNMAPPED_AREA_TOPDOWN, + .length = len, + .align_mask = PAGE_MASK & ((1ul << pshift) - 1), + }; unsigned long min_addr = max(PAGE_SIZE, mmap_min_addr); - info.flags = VM_UNMAPPED_AREA_TOPDOWN; - info.length = len; - info.align_mask = PAGE_MASK & ((1ul << pshift) - 1); - info.align_offset = 0; /* * If we are trying to allocate above DEFAULT_MAP_WINDOW * Add the different to the mmap_base. _ Patches currently in -mm which might be from rick.p.edgecombe@intel.com are