From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f70.google.com (mail-pj1-f70.google.com [209.85.216.70]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8772D50390F for ; Fri, 18 Sep 2026 15:33:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789745615; cv=none; b=F3LElOsJR4O7JbcsCfvnchYQmvhEUl4lHB4TRGkMSc2Pviev8r0tSWarTaTuPrJ99kT4m5tD8souyrutgIxpDYBrExaNgeFBMJfgKxzahguNrkzgFNmez9zyWma8IJOq60D7SO5Hzr12bFefPMdQLjkGQJJN90pwwGDFjoieHj4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789745615; c=relaxed/simple; bh=oZ/fvi1k3DBUjyI5jwjRUhQencv56NnJtg/3XEZIHys=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=YWAOx5hzBRI6aOYiSJV29TxyEN3iaQTGnkxUskLtVkHZu+uqzW3gWGkhFIh0/UERuB82BQ+qMXI/47OUsL+2dhyu3ikGvggDFl6VmHl0vhvzu4nuygvGbcLTehkkXTC+hYNecZhquz4az9/vlMMkyyxCs1PvEe5/D5BqmL0BCag= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--surenb.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=n9i36t6K; arc=none smtp.client-ip=209.85.216.70 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--surenb.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="n9i36t6K" Received: by mail-pj1-f70.google.com with SMTP id 98e67ed59e1d1-39deda201bcso88437a91.2 for ; Fri, 18 Sep 2026 08:33:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1789745611; x=1790350411; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=lv14f2Ly5jvNlP8xqLAumR3AMqosSrAJIJiLUsY0qSI=; b=n9i36t6KbS4CJ5stYwzw0HkXIZXHjaA0Hh6ILrDQEiEejy7c3Xqs4QtWyPFtTgvRlk zhsgc/xy/hRSiedZKRgJ0wMW1xsQqXRWruHnvNcqboawv93danlDRXGjpUNEwbcDdrgX u9LjewKBF5OTu3fD28sRMUkNht2k+Y0R663hIvz8WbpyrkF72t4LH+MriGEidFOe+5Yf jRhm6DaSMjESHyqp1li6ZJLPKf5yPMIwAHqHXJjUwvXb9UBkXmX265GzOG/2RKJN8K9v JASbdVMjdCoiC7FpR4jqFxX+l6iYxiTPqyep37wB6w23hNxyvtDui/fKeGJy++r5amaO EIxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789745611; x=1790350411; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=lv14f2Ly5jvNlP8xqLAumR3AMqosSrAJIJiLUsY0qSI=; b=XxwbNzSsdrXvG5DbPxlwnGml+RR5YO7UpJP4iNQOeSm5gw1zJDNAWYDWXikFBLFhoQ O/BKQwA8ZVkviRl/PPumTwRsvgFbAorQauqH4Rua/QxYqnOqPIQZuHWHfCuE18T48r6X 3/Kctxu63pcmkM1x/GR4zlWGtT9hx+DQk3VTKhSDqOjvJ2qJJHr7NvYq4qhZaqtXZRzS wNjt2Q0hxyRuyWH/PnXJNbcAx0VCS3izY7FshGYSBjtb+tsNcww/ils2qIXXZ3+p+hpp VqRgA2UroRVMAxKUNFTZ68Zi/8GNFi2u06ix2ouBdsuCQSOXSfEZtNCT02AQSnrcWXTl QsWg== X-Forwarded-Encrypted: i=1; AKwUvBw/SkMWPC2lSprQupJ7vS9QY1X2Cu9RXVSUHOPw0+VaQosqJurMDr0Y8VsXk9qLFa7xUkHuVVAX+8WKw0E=@vger.kernel.org X-Gm-Message-State: AFuF++moCASPZSWvKrL29h0huCx6cJDitn40TUnknDP3tgi75Sw00s/K ow4TTYOnOUPjACNVPckWcL/mFFbiahicloJILJ9Bdk7Qh0+FqkVhZEyDCNkXF/jivUWoNWKBMWT 23CuRwQ== X-Received: from dlbcy8.prod.google.com ([2002:a05:7022:b88:b0:143:7b76:ee9c]) (user=surenb job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90a:d410:b0:39d:f024:c7e2 with SMTP id 98e67ed59e1d1-39e54cb099bmr6569591a91.4.1789745611342; Fri, 18 Sep 2026 08:33:31 -0700 (PDT) Date: Fri, 18 Sep 2026 08:33:16 -0700 In-Reply-To: <20260918153318.758387-1-surenb@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260918153318.758387-1-surenb@google.com> X-Mailer: git-send-email 2.55.0.1082.g2b9226bbc0-goog Message-ID: <20260918153318.758387-6-surenb@google.com> Subject: [PATCH v5 5/7] proc/task_mmu: change proc_get_vma() to stop returning gate VMA at the end From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: liam@infradead.org, ljs@kernel.org, vbabka@kernel.org, david@kernel.org, willy@infradead.org, jannh@google.com, paulmck@kernel.org, pfalcato@suse.de, xueyuan.chen21@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, surenb@google.com Content-Type: text/plain; charset="UTF-8" proc_get_vma() returning gate VMA at the end is desirable for the its current m_start/m_next callers, as they need to report a gate VMA at the end of the address space. This behavior is very specific to these callers and makes proc_get_vma() hard to use for other purposes. Move this usage-specific behavior into the callers themselves so that proc_get_vma() returns either a valid VMA, an error or a NULL when no more VMAs are available. This makes it more generic, simpler and usable in the later patches. Signed-off-by: Suren Baghdasaryan Reviewed-by: Lorenzo Stoakes (ARM) Acked-by: David Hildenbrand (Arm) --- fs/proc/task_mmu.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 8f2f302d4563..2c90b91d271b 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -240,9 +240,6 @@ static struct vm_area_struct *proc_get_vma(struct seq_file *m, loff_t *ppos) * found the extended vma with the same vm_start. */ *ppos = vma->vm_end; - } else { - *ppos = SENTINEL_VMA_GATE; - vma = get_gate_vma(priv->lock_ctx.mm); } return vma; @@ -252,6 +249,7 @@ static void *m_start(struct seq_file *m, loff_t *ppos) { struct proc_maps_private *priv = m->private; struct proc_maps_locking_ctx *lock_ctx; + struct vm_area_struct *vma; loff_t last_addr = *ppos; struct mm_struct *mm; @@ -281,19 +279,39 @@ static void *m_start(struct seq_file *m, loff_t *ppos) *ppos = last_addr = priv->last_pos; vma_iter_init(&priv->iter, mm, (unsigned long)last_addr); hold_task_mempolicy(priv); + /* + * If seq_file had to flush its collected data right after m_next() set + * position to SENTINEL_VMA_GATE, m_start() will get that sentinel and + * should return gate_vma without calling proc_get_vma(). + */ if (last_addr == SENTINEL_VMA_GATE) return get_gate_vma(mm); - return proc_get_vma(m, ppos); + vma = proc_get_vma(m, ppos); + if (vma) + return vma; + + /* Return gate VMA at the end */ + *ppos = SENTINEL_VMA_GATE; + return get_gate_vma(mm); } static void *m_next(struct seq_file *m, void *v, loff_t *ppos) { + struct proc_maps_private *priv = m->private; + struct vm_area_struct *vma; + if (*ppos == SENTINEL_VMA_GATE) { *ppos = SENTINEL_VMA_END; return NULL; } - return proc_get_vma(m, ppos); + vma = proc_get_vma(m, ppos); + if (vma) + return vma; + + /* Return gate VMA at the end */ + *ppos = SENTINEL_VMA_GATE; + return get_gate_vma(priv->lock_ctx.mm); } static void m_stop(struct seq_file *m, void *v) -- 2.55.0.1082.g2b9226bbc0-goog