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[5.45.199.163]) by mx.google.com with ESMTP id v7si1003096lje.199.2019.05.15.01.41.13 for ; Wed, 15 May 2019 01:41:13 -0700 (PDT) Received-SPF: pass (google.com: domain of khlebnikov@yandex-team.ru designates 5.45.199.163 as permitted sender) client-ip=5.45.199.163; Authentication-Results: mx.google.com; dkim=pass header.i=@yandex-team.ru header.s=default header.b=bJzcjZX6; spf=pass (google.com: domain of khlebnikov@yandex-team.ru designates 5.45.199.163 as permitted sender) smtp.mailfrom=khlebnikov@yandex-team.ru; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=yandex-team.ru Received: from mxbackcorp1o.mail.yandex.net (mxbackcorp1o.mail.yandex.net [IPv6:2a02:6b8:0:1a2d::301]) by forwardcorp1j.mail.yandex.net (Yandex) with ESMTP id 917962E14C0; Wed, 15 May 2019 11:41:13 +0300 (MSK) Received: from smtpcorp1j.mail.yandex.net (smtpcorp1j.mail.yandex.net [2a02:6b8:0:1619::137]) by mxbackcorp1o.mail.yandex.net (nwsmtp/Yandex) with ESMTP id 7l8bZ6vz9S-fD0GwFgT; Wed, 15 May 2019 11:41:13 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1557909673; bh=on37xMtDHf4i5spIW0sgEiVZh+kGUSg0VAm5Sv46Das=; h=Message-ID:Date:To:From:Subject:Cc; b=bJzcjZX6IIAUCNZqdyJas7Z7fGK9P92gcfgKNFGVYrbxnXDJ17C82J8LRWdyyAtHl EqAUj/W8BAy4Hpaw7JwRetWb/oFU2VFVtGgph3dPKN16Nxj069xSvJi4qjWeh07zl9 r+h/pSCIwWSvsMqVdHCAPlw4g0drkv+mbzc+HnWY= Authentication-Results: mxbackcorp1o.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Received: from dynamic-red.dhcp.yndx.net (dynamic-red.dhcp.yndx.net [2a02:6b8:0:40c:ed19:3833:7ce1:2324]) by smtpcorp1j.mail.yandex.net (nwsmtp/Yandex) with ESMTPSA id dM2CepgjQa-fC8SnGfC; Wed, 15 May 2019 11:41:12 +0300 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client certificate not present) Subject: [PATCH 1/5] proc: use down_read_killable for /proc/pid/maps From: Konstantin Khlebnikov To: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org Cc: Cyrill Gorcunov , Kirill Tkhai , Al Viro Date: Wed, 15 May 2019 11:41:12 +0300 Message-ID: <155790967258.1319.11531787078240675602.stgit@buzz> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Do not stuck forever if something wrong. This function also used for /proc/pid/smaps. Signed-off-by: Konstantin Khlebnikov --- fs/proc/task_mmu.c | 6 +++++- fs/proc/task_nommu.c | 6 +++++- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 01d4eb0e6bd1..2bf210229daf 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -166,7 +166,11 @@ static void *m_start(struct seq_file *m, loff_t *ppos) if (!mm || !mmget_not_zero(mm)) return NULL; - down_read(&mm->mmap_sem); + if (down_read_killable(&mm->mmap_sem)) { + mmput(mm); + return ERR_PTR(-EINTR); + } + hold_task_mempolicy(priv); priv->tail_vma = get_gate_vma(mm); diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index 36bf0f2e102e..7907e6419e57 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -211,7 +211,11 @@ static void *m_start(struct seq_file *m, loff_t *pos) if (!mm || !mmget_not_zero(mm)) return NULL; - down_read(&mm->mmap_sem); + if (down_read_killable(&mm->mmap_sem)) { + mmput(mm); + return ERR_PTR(-EINTR); + } + /* start from the Nth VMA */ for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) if (n-- == 0)