From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792594267; b=CI8XQgfZiDjhC6tfGkzioGEVK+hqjx5ijKdmpn/s1/XHivXnsc27ksLcAw7Nw4tRCDRO g758Rr/fAanx7ar3BUFdWKuyRyekyot0g4CHWYgyw+AizcvxvFfgNlBXMZKONLW0MNwSh lwDQabBkvkVWWstjUhszsw2ZXsUjrHUt41jaKJ3ai5/+pedA5gbvXG279OTBN7omD6Q94 48oI60dRZ8Utp4+LWKloXG8U1G9ejEdGGAnJ4ME4nMNqLW3jd9ZGTlmamd9QhB8RIGl0+ jyHmQbqXHyLof5RX/niO5M36AB7J+bhyYQH2FJJ3G7VqMyTTVhBRywhdHPL00yxZhLw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792594267; h=Received:DKIM-Signature:Subject:To:Cc:From:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=Tf2truVF0HJWt5aQe6XENxvc3Zf7LhrdjDkpDzoeZ2c=; b=ofVOZ/whw29WewAGoNvfE2HOh6WMjabbl6ZdHnpLKq8Sh4TaS++YP5hT27ay4AEXwrF2 BtLqzd44C0TtTpTa1kNXfJ9W4x5w3HJSpl4nuu6ThJLonEwUFfWYLKjnW3Fum8K9PwJeZ YQQTI8k31/JucDVHzIHzjT7nkiNFENftDdnm5159jQwEr1K8QyBKOp7T+nCiXom45qfQi s6G6cguSz6U/9IDvscRfhsDuQtyQbjzckF8TMq401/+Flk1JW0UhB/jsG/NXEqWmShCvd gx1dJuotWkxkRS+DZmIawH1AUuoI7pwiC6S6mzyFOBEjF73FxKjzhn76uw7Mt9bgXTA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=QmCIJP73; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 55490606A320 for ; Wed, 21 Oct 2026 14:51:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=QmCIJP73 Received: by smtp.kernel.org (Postfix) with ESMTPSA id A76E61F000C1; Wed, 21 Oct 2026 14:51:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792594267; bh=Tf2truVF0HJWt5aQe6XENxvc3Zf7LhrdjDkpDzoeZ2c=; h=Subject:To:Cc:From:Date; b=QmCIJP733+dcXGHyBfE95p5A8DL2Lkm3o7/5prKwIPIwouRgdM226hLbNGnff5+6A nfprRlUB+WLcPdZcqCYAD85hnXdBvGiq4A9YvplyUHqKliMQO2LtyKXj3n59UDeBfe M6flwtOUa6rDpwEYTgcf9VlTBBDl9KGXNtZunNGg= Subject: FAILED: patch "[PATCH] perf: Track the perf mlock gift separately" failed to apply to 6.6-stable tree To: ljs@kernel.org,ameer.hamza@truenas.com,peterz@infradead.org Cc: From: Date: Wed, 21 Oct 2026 16:43:18 +0200 Message-ID: <2026102118-chip-silicon-40c5@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 78436f3882fb8d848c823bf8cf754988202c5ca5 # git commit -s git send-email --to '' --in-reply-to '2026102118-chip-silicon-40c5@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 78436f3882fb8d848c823bf8cf754988202c5ca5 Mon Sep 17 00:00:00 2001 From: "Lorenzo Stoakes (ARM)" Date: Sat, 3 Oct 2026 17:29:07 +0100 Subject: [PATCH] perf: Track the perf mlock gift separately The locked_vm field in struct user_struct was originally introduced by commit 789f90fcf6b0 ("perf_counter: per user mlock gift") to provide an mlock-like budget for perf measured against mm->pinned_vm (since 2011). perf grants each user a 'gift' of perf_event_mlock_kb * online CPUs of buffer pages which is charged to user->locked_vm without any RLIMIT_MEMLOCK check. Only pages beyond the gift are checked against RLIMIT_MEMLOCK, per-mm, via mm->pinned_vm, which makes it different from the standard mlock() check, which is per-mm and made against RLIMIT_MEMLOCK. However, since this was introduced, a number of other components have utilised this field where a shared resource needed to be limited against RLIMIT_MEMLOCK. The other users are currently MSG_ZEROCOPY, io_uring, AF_XDP, iommufd, s390 KVM zPCI and most recently, secretmem in commit 97d34aa65c29 ("mm/secretmem: properly account locked pages"). This field is shared between all of these, but because the gift is not checked against RLIMIT_MEMLOCK, user->locked_vm alone can exceed it - 16 CPUs * 516 KiB is already more than the default 8 MiB - after which every other user of the field fails unconditionally. This was reported by a user who saw secretmem failing while running a simultaneous perf record. Resolve the issue by simply giving perf its own field separate from the rest. BPF used user->locked_vm up until commit 80ee81e0403c ("bpf: Eliminate rlimit-based memory accounting infra for bpf maps") which landed in 5.11. Thus also eliminate the now-defunct ifdef for CONFIG_BPF_SYSCALL for user->locked_vm. This issue exists between all of the components which use user->locked_vm and perf, however secretmem is the first user who has caused a report over many years and has been backported, so target the fix at that. Fixes: 97d34aa65c29 ("mm/secretmem: properly account locked pages") Closes: https://lore.kernel.org/20261002175651.811343-1-ameer.hamza@truenas.com Reported-by: Ameer Hamza Signed-off-by: Lorenzo Stoakes (ARM) Signed-off-by: Peter Zijlstra (Intel) Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20261003-perf-locked-vm-fix-v1-1-d214dcaf0d76@kernel.org diff --git a/include/linux/sched/user.h b/include/linux/sched/user.h index 8d7e5521f7cd..ec262b605437 100644 --- a/include/linux/sched/user.h +++ b/include/linux/sched/user.h @@ -23,11 +23,13 @@ struct user_struct { struct hlist_node uidhash_node; kuid_t uid; -#if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL) || \ - defined(CONFIG_NET) || defined(CONFIG_IO_URING) || \ +#if defined(CONFIG_NET) || defined(CONFIG_IO_URING) || \ defined(CONFIG_VFIO_PCI_ZDEV_KVM) || IS_ENABLED(CONFIG_IOMMUFD) || \ defined(CONFIG_SECRETMEM) - atomic_long_t locked_vm; + atomic_long_t locked_vm; /* pinned pages charged to RLIMIT_MEMLOCK */ +#endif +#ifdef CONFIG_PERF_EVENTS + atomic_long_t perf_mlock; /* perf buffer pages within perf_event_mlock_kb */ #endif #ifdef CONFIG_WATCH_QUEUE atomic_t nr_watches; /* The number of watches this user currently has */ diff --git a/kernel/events/core.c b/kernel/events/core.c index 7846d70be57f..8b69d50fcbcb 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7059,7 +7059,7 @@ static void perf_mmap_close(struct vm_area_struct *vma) perf_pmu_output_stop(event); /* now it's safe to free the pages */ - atomic_long_sub(rb->aux_nr_pages - rb->aux_mmap_locked, &mmap_user->locked_vm); + atomic_long_sub(rb->aux_nr_pages - rb->aux_mmap_locked, &mmap_user->perf_mlock); atomic64_sub(rb->aux_mmap_locked, &vma->vm_mm->pinned_vm); /* this has to be the last one */ @@ -7242,11 +7242,11 @@ static bool perf_mmap_calc_limits(struct vm_area_struct *vma, long *user_extra, /* Increase the limit linearly with more CPUs */ user_lock_limit *= num_online_cpus(); - user_locked = atomic_long_read(&user->locked_vm); + user_locked = atomic_long_read(&user->perf_mlock); /* * sysctl_perf_event_mlock may have changed, so that - * user->locked_vm > user_lock_limit + * user->perf_mlock > user_lock_limit */ if (user_locked > user_lock_limit) user_locked = user_lock_limit; @@ -7254,7 +7254,7 @@ static bool perf_mmap_calc_limits(struct vm_area_struct *vma, long *user_extra, if (user_locked > user_lock_limit) { /* - * charge locked_vm until it hits user_lock_limit; + * charge perf_mlock until it hits user_lock_limit; * charge the rest from pinned_vm */ *extra = user_locked - user_lock_limit; @@ -7272,7 +7272,7 @@ static void perf_mmap_account(struct vm_area_struct *vma, long user_extra, long { struct user_struct *user = current_user(); - atomic_long_add(user_extra, &user->locked_vm); + atomic_long_add(user_extra, &user->perf_mlock); atomic64_add(extra, &vma->vm_mm->pinned_vm); } @@ -7281,7 +7281,7 @@ static void perf_mmap_unaccount(struct vm_area_struct *vma, struct perf_buffer * struct user_struct *user = rb->mmap_user; atomic_long_sub((perf_data_size(rb) >> PAGE_SHIFT) + 1 - rb->mmap_locked, - &user->locked_vm); + &user->perf_mlock); atomic64_sub(rb->mmap_locked, &vma->vm_mm->pinned_vm); }