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 738171C695 for ; Mon, 10 Nov 2025 19:11:48 +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=1762801908; cv=none; b=CS2CI3HhsSaKvXi3aD9kGOV6a8LcLwJbj/NFOXTSpLtLbQ3sWkf/cV6/GAi27gLgGS4wAB5V2nEVDZpbq0cjV34qO12ucmtN1w7G242A4C8XGT2145z1odPZX31LdgpF61Tn8DcgwXCog9pJnu5bJ389Dus9CnFIW16Xtec0xAY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762801908; c=relaxed/simple; bh=wF/H4HNs3fjIyDUN9zPt7XrbBggcgQ0gwi/tQUj5w9s=; h=Date:To:From:Subject:Message-Id; b=CbYnM7HVIuzVK5/lodzWVvU2kMUKd99FVuYin3yGnqQfwSerkqgWtuo1XRnFckEBWfdKnfWUhmF8dZQhDUMM9pABcEePD4AahIcXhh0ca56BJriR1olWtD1rLNq2NTdJMfc9KbQLvLEjAT5MnVQkYqkLfKifq+sP2IYaUihTw08= 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=VSwIiWfZ; 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="VSwIiWfZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2813DC2BC86; Mon, 10 Nov 2025 19:11:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1762801908; bh=wF/H4HNs3fjIyDUN9zPt7XrbBggcgQ0gwi/tQUj5w9s=; h=Date:To:From:Subject:From; b=VSwIiWfZpM2vguHmur+g9FWukAhvM9TiU+KovBekUalrXpmOtgkmbG6U3gReMlAUP wMvj8HER0imMRferYEv+spRoSWiY6aY1Rl+0NbHqtpvdstUfg5r7YomkZAB//zIvHR dgqc1eCINb8RpK79Cj8Qwkj7AQkCUX10trZAXf7E= Date: Mon, 10 Nov 2025 11:11:47 -0800 To: mm-commits@vger.kernel.org,urezki@gmail.com,hch@lst.de,hch@infradead.org,vishal.moola@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-vmalloc-warn-on-invalid-vmalloc-gfp-flags.patch added to mm-new branch Message-Id: <20251110191148.2813DC2BC86@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/vmalloc: warn on invalid vmalloc gfp flags has been added to the -mm mm-new branch. Its filename is mm-vmalloc-warn-on-invalid-vmalloc-gfp-flags.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmalloc-warn-on-invalid-vmalloc-gfp-flags.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. 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: "Vishal Moola (Oracle)" Subject: mm/vmalloc: warn on invalid vmalloc gfp flags Date: Mon, 10 Nov 2025 08:04:54 -0800 Patch series "make vmalloc gfp flags usage more apparent". We should do a better job at enforcing gfp flags for vmalloc. Right now, we have a kernel-doc for __vmalloc_node_range(), and hope callers pass in supported flags. If a caller were to pass in an unsupported flag, we may BUG, silently clear it, or completely ignore it. If we are more proactive about enforcing gfp flags, we can making sure callers know when they may be asking for unsupported behavior. This patchset lets vmalloc control the incoming gfp flags, and cleans up some hard to read gfp code. This patch (of 4): Vmalloc explicitly supports a list of flags, but we never enforce them. vmalloc has been trying to handle unsupported flags by clearing and setting flags wherever necessary. This is messy and makes the code harder to understand, when we could simply check for a supported input immediately instead. Define a helper mask and function telling callers they have passed in invalid flags, and clear those unsupported vmalloc flags. Link: https://lkml.kernel.org/r/20251110160457.61791-1-vishal.moola@gmail.com Link: https://lkml.kernel.org/r/20251110160457.61791-2-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) Suggested-by: Christoph Hellwig Reviewed-by: Christoph Hellwig Cc: "Uladzislau Rezki (Sony)" Signed-off-by: Andrew Morton --- mm/vmalloc.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) --- a/mm/vmalloc.c~mm-vmalloc-warn-on-invalid-vmalloc-gfp-flags +++ a/mm/vmalloc.c @@ -3911,6 +3911,24 @@ fail: return NULL; } +/* + * See __vmalloc_node_range() for a clear list of supported vmalloc flags. + * This gfp lists all flags currently passed through vmalloc. Currently, + * __GFP_ZERO is used by BFP and __GFP_NORETRY is used by percpu. + */ +#define GFP_VMALLOC_SUPPORTED (GFP_KERNEL | GFP_ATOMIC | GFP_NOWAIT |\ + __GFP_NOFAIL | __GFP_ZERO | __GFP_NORETRY) + +static gfp_t vmalloc_fix_flags(gfp_t flags) +{ + gfp_t invalid_mask = flags & ~GFP_VMALLOC_SUPPORTED; + + flags &= GFP_VMALLOC_SUPPORTED; + WARN(1, "Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n", + invalid_mask, &invalid_mask, flags, &flags); + return flags; +} + /** * __vmalloc_node_range - allocate virtually contiguous memory * @size: allocation size @@ -4092,6 +4110,8 @@ EXPORT_SYMBOL_GPL(__vmalloc_node_noprof) void *__vmalloc_noprof(unsigned long size, gfp_t gfp_mask) { + if (unlikely(gfp_mask & ~GFP_VMALLOC_SUPPORTED)) + gfp_mask = vmalloc_fix_flags(gfp_mask); return __vmalloc_node_noprof(size, 1, gfp_mask, NUMA_NO_NODE, __builtin_return_address(0)); } @@ -4131,6 +4151,8 @@ EXPORT_SYMBOL(vmalloc_noprof); */ void *vmalloc_huge_node_noprof(unsigned long size, gfp_t gfp_mask, int node) { + if (unlikely(gfp_mask & ~GFP_VMALLOC_SUPPORTED)) + gfp_mask = vmalloc_fix_flags(gfp_mask); return __vmalloc_node_range_noprof(size, 1, VMALLOC_START, VMALLOC_END, gfp_mask, PAGE_KERNEL, VM_ALLOW_HUGE_VMAP, node, __builtin_return_address(0)); _ Patches currently in -mm which might be from vishal.moola@gmail.com are mm-vmalloc-request-large-order-pages-from-buddy-allocator.patch mm-vmalloc-warn-on-invalid-vmalloc-gfp-flags.patch mm-vmalloc-add-a-helper-to-optimize-vmalloc-allocation-gfps.patch mm-vmalloc-cleanup-large_gfp-in-vm_area_alloc_pages.patch mm-vmalloc-cleanup-gfp-flag-use-in-new_vmap_block.patch