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 A6C2A18CC1E for ; Tue, 30 Jul 2024 22:57:02 +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=1722380222; cv=none; b=QZ/G4RTTjctpNGsZ2VzfngmTgeBqM6faRaQ/jlC0VBpC1rL+FY8vAhok3qZnpg3t/A6Z/74PDloLKBCQKSlow4k05nJrv7m8pi8dSkbpwsoVJSsag8B4d10iEWl8Ga4hIu0xZpoPnw/zPGjf75IluAKjlyHnuG2q9BaqgA1czb4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722380222; c=relaxed/simple; bh=Dl7zAsvNqfjJTiME69Or/o9dgYhie0D4NQHvgtr4nnI=; h=Date:To:From:Subject:Message-Id; b=nmWLwOcLene2pkJ53U0sSed6kYjoQ29u0Q32H+uXFcH804iBhN8tDvAU4XMimAIozXVjChfD1w5jushgy8i0VwvV5Bat4+tNtLVY62XuICU2JmL9kPCQ8LYuNWv0j/dVpbLkvFYXjh2rR5x9g45S2ia2Bt1y/dWj38aIzunC/w0= 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=tKEdCxWl; 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="tKEdCxWl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3DED8C32782; Tue, 30 Jul 2024 22:57:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1722380222; bh=Dl7zAsvNqfjJTiME69Or/o9dgYhie0D4NQHvgtr4nnI=; h=Date:To:From:Subject:From; b=tKEdCxWlgmtaQT3NWiNx9If3HyQAMOvbp2NHPJzSZaJrdZ7leGD91pj4H4zgTTV0O 2QX2m8QNQKrmlyurR5A/d+0zSwT6SNFevXiSZzSS9HzNt4554bI9AyXiwc5rww7iiL DObkzrmH3KWhikOHUAx8Kuh+u1RUhCgC5iY6ylOw= Date: Tue, 30 Jul 2024 15:57:01 -0700 To: mm-commits@vger.kernel.org,dakr@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-kvmalloc-align-kvrealloc-with-krealloc-fix-3.patch added to mm-unstable branch Message-Id: <20240730225702.3DED8C32782@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: kvrealloc: properly document __GFP_ZERO behavior has been added to the -mm mm-unstable branch. Its filename is mm-kvmalloc-align-kvrealloc-with-krealloc-fix-3.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-kvmalloc-align-kvrealloc-with-krealloc-fix-3.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Danilo Krummrich Subject: mm: kvrealloc: properly document __GFP_ZERO behavior Date: Tue, 30 Jul 2024 20:49:44 +0200 Properly document that if __GFP_ZERO logic is requested, callers must ensure that, starting with the initial memory allocation, every subsequent call to this API for the same memory allocation is flagged with __GFP_ZERO. Otherwise, it is possible that __GFP_ZERO is not fully honored by this API. Link: https://lkml.kernel.org/r/20240730185049.6244-5-dakr@kernel.org Signed-off-by: Danilo Krummrich Signed-off-by: Andrew Morton --- mm/util.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/mm/util.c~mm-kvmalloc-align-kvrealloc-with-krealloc-fix-3 +++ a/mm/util.c @@ -726,12 +726,17 @@ EXPORT_SYMBOL(kvfree_sensitive); * @size: the size to reallocate * @flags: the flags for the page level allocator * - * The contents of the object pointed to are preserved up to the lesser of the - * new and old size (__GFP_ZERO flag is effectively ignored). - * * If @p is %NULL, kvrealloc() behaves exactly like kvmalloc(). If @size is 0 * and @p is not a %NULL pointer, the object pointed to is freed. * + * If __GFP_ZERO logic is requested, callers must ensure that, starting with the + * initial memory allocation, every subsequent call to this API for the same + * memory allocation is flagged with __GFP_ZERO. Otherwise, it is possible that + * __GFP_ZERO is not fully honored by this API. + * + * In any case, the contents of the object pointed to are preserved up to the + * lesser of the new and old sizes. + * * This function must not be called concurrently with itself or kvfree() for the * same memory allocation. * _ Patches currently in -mm which might be from dakr@kernel.org are mm-vmalloc-implement-vrealloc.patch mm-vmalloc-implement-vrealloc-fix.patch mm-vmalloc-implement-vrealloc-fix-2.patch mm-vmalloc-implement-vrealloc-fix-3.patch mm-vmalloc-implement-vrealloc-fix-4.patch mm-kvmalloc-align-kvrealloc-with-krealloc.patch mm-kvmalloc-align-kvrealloc-with-krealloc-fix.patch mm-kvmalloc-align-kvrealloc-with-krealloc-fix-2.patch mm-kvmalloc-align-kvrealloc-with-krealloc-fix-3.patch