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AJvYcCXO5KhquGqBPgPcms2zwQdj91pemiTrGVMWwekB4YnqMh2dgCT8IWH9SoUlJvnN3xIxWtApjPj4tA==@kvack.org X-Gm-Message-State: AOJu0Yzr0BlhmG10CEI0jQqsoBafhjFIBeJ6P8T8QxvhfcTWKxti0p/S Z+tHKpaheAuhbx65Y/vbFdD2keFXT+xd5VLe0iH6IBMIPH5Z9BxnsKWy+iVdch3zKGReR2C7so5 kSRFNZA== X-Google-Smtp-Source: AGHT+IEe6D0EDOa4VLSLQnNt443QGZdBsTsucswGzk0sXMtaRnOh2OfcwLIsh8g7TBhjLjlnLUKia1iuw4c= X-Received: from plbka16.prod.google.com ([2002:a17:903:3350:b0:240:9ca:fc49]) (user=surenb job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:fc50:b0:234:ef42:5d65 with SMTP id d9443c01a7336-24096c0dcf7mr124221755ad.52.1753999231880; Thu, 31 Jul 2025 15:00:31 -0700 (PDT) Date: Thu, 31 Jul 2025 15:00:23 -0700 In-Reply-To: <20250731220024.702621-1-surenb@google.com> Mime-Version: 1.0 References: <20250731220024.702621-1-surenb@google.com> X-Mailer: git-send-email 2.50.1.565.gc32cd1483b-goog Message-ID: <20250731220024.702621-3-surenb@google.com> Subject: [PATCH 2/3] fs/proc/task_mmu: factor out proc_maps_private fields used by PROCMAP_QUERY From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: Liam.Howlett@oracle.com, lorenzo.stoakes@oracle.com, david@redhat.com, vbabka@suse.cz, peterx@redhat.com, jannh@google.com, hannes@cmpxchg.org, mhocko@kernel.org, paulmck@kernel.org, shuah@kernel.org, adobriyan@gmail.com, brauner@kernel.org, josef@toxicpanda.com, yebin10@huawei.com, linux@weissschuh.net, willy@infradead.org, osalvador@suse.de, andrii@kernel.org, ryan.roberts@arm.com, christophe.leroy@csgroup.eu, tjmercier@google.com, kaleshsingh@google.com, aha310510@gmail.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, surenb@google.com Content-Type: text/plain; charset="UTF-8" X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 0E149C0008 X-Stat-Signature: roewcdygbudecuwh49b9gri6grpiqa1b X-HE-Tag: 1753999232-193743 X-HE-Meta: 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 m2oi+c4R 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 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: List-Subscribe: List-Unsubscribe: Refactor struct proc_maps_private so that the fields used by PROCMAP_QUERY ioctl are moved into a separate structure. In the next patch this allows ioctl to reuse some of the functions used for reading /proc/pid/maps without using file->private_data. This prevents concurrent modification of file->private_data members by ioctl and /proc/pid/maps readers. The change is pure code refactoring and has no functional changes. Signed-off-by: Suren Baghdasaryan --- fs/proc/internal.h | 15 ++++++---- fs/proc/task_mmu.c | 70 +++++++++++++++++++++++----------------------- 2 files changed, 45 insertions(+), 40 deletions(-) diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 7c235451c5ea..e2447b22592e 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -379,16 +379,21 @@ extern void proc_self_init(void); * task_[no]mmu.c */ struct mem_size_stats; -struct proc_maps_private { - struct inode *inode; - struct task_struct *task; + +struct proc_maps_query_data { struct mm_struct *mm; - struct vma_iterator iter; - loff_t last_pos; #ifdef CONFIG_PER_VMA_LOCK bool mmap_locked; struct vm_area_struct *locked_vma; #endif +}; + +struct proc_maps_private { + struct inode *inode; + struct task_struct *task; + struct vma_iterator iter; + loff_t last_pos; + struct proc_maps_query_data query; #ifdef CONFIG_NUMA struct mempolicy *task_mempolicy; #endif diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 3d6d8a9f13fc..509fa162760a 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -132,11 +132,11 @@ static void release_task_mempolicy(struct proc_maps_private *priv) #ifdef CONFIG_PER_VMA_LOCK -static void unlock_vma(struct proc_maps_private *priv) +static void unlock_vma(struct proc_maps_query_data *query) { - if (priv->locked_vma) { - vma_end_read(priv->locked_vma); - priv->locked_vma = NULL; + if (query->locked_vma) { + vma_end_read(query->locked_vma); + query->locked_vma = NULL; } } @@ -151,14 +151,14 @@ static inline bool lock_vma_range(struct seq_file *m, * walking the vma tree under rcu read protection. */ if (m->op != &proc_pid_maps_op) { - if (mmap_read_lock_killable(priv->mm)) + if (mmap_read_lock_killable(priv->query.mm)) return false; - priv->mmap_locked = true; + priv->query.mmap_locked = true; } else { rcu_read_lock(); - priv->locked_vma = NULL; - priv->mmap_locked = false; + priv->query.locked_vma = NULL; + priv->query.mmap_locked = false; } return true; @@ -166,10 +166,10 @@ static inline bool lock_vma_range(struct seq_file *m, static inline void unlock_vma_range(struct proc_maps_private *priv) { - if (priv->mmap_locked) { - mmap_read_unlock(priv->mm); + if (priv->query.mmap_locked) { + mmap_read_unlock(priv->query.mm); } else { - unlock_vma(priv); + unlock_vma(&priv->query); rcu_read_unlock(); } } @@ -179,13 +179,13 @@ static struct vm_area_struct *get_next_vma(struct proc_maps_private *priv, { struct vm_area_struct *vma; - if (priv->mmap_locked) + if (priv->query.mmap_locked) return vma_next(&priv->iter); - unlock_vma(priv); - vma = lock_next_vma(priv->mm, &priv->iter, last_pos); + unlock_vma(&priv->query); + vma = lock_next_vma(priv->query.mm, &priv->iter, last_pos); if (!IS_ERR_OR_NULL(vma)) - priv->locked_vma = vma; + priv->query.locked_vma = vma; return vma; } @@ -193,14 +193,14 @@ static struct vm_area_struct *get_next_vma(struct proc_maps_private *priv, static inline bool fallback_to_mmap_lock(struct proc_maps_private *priv, loff_t pos) { - if (priv->mmap_locked) + if (priv->query.mmap_locked) return false; rcu_read_unlock(); - mmap_read_lock(priv->mm); + mmap_read_lock(priv->query.mm); /* Reinitialize the iterator after taking mmap_lock */ vma_iter_set(&priv->iter, pos); - priv->mmap_locked = true; + priv->query.mmap_locked = true; return true; } @@ -210,12 +210,12 @@ static inline bool fallback_to_mmap_lock(struct proc_maps_private *priv, static inline bool lock_vma_range(struct seq_file *m, struct proc_maps_private *priv) { - return mmap_read_lock_killable(priv->mm) == 0; + return mmap_read_lock_killable(priv->query.mm) == 0; } static inline void unlock_vma_range(struct proc_maps_private *priv) { - mmap_read_unlock(priv->mm); + mmap_read_unlock(priv->query.mm); } static struct vm_area_struct *get_next_vma(struct proc_maps_private *priv, @@ -258,7 +258,7 @@ static struct vm_area_struct *proc_get_vma(struct seq_file *m, loff_t *ppos) *ppos = vma->vm_end; } else { *ppos = SENTINEL_VMA_GATE; - vma = get_gate_vma(priv->mm); + vma = get_gate_vma(priv->query.mm); } return vma; @@ -278,7 +278,7 @@ static void *m_start(struct seq_file *m, loff_t *ppos) if (!priv->task) return ERR_PTR(-ESRCH); - mm = priv->mm; + mm = priv->query.mm; if (!mm || !mmget_not_zero(mm)) { put_task_struct(priv->task); priv->task = NULL; @@ -318,7 +318,7 @@ static void *m_next(struct seq_file *m, void *v, loff_t *ppos) static void m_stop(struct seq_file *m, void *v) { struct proc_maps_private *priv = m->private; - struct mm_struct *mm = priv->mm; + struct mm_struct *mm = priv->query.mm; if (!priv->task) return; @@ -339,9 +339,9 @@ static int proc_maps_open(struct inode *inode, struct file *file, return -ENOMEM; priv->inode = inode; - priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); - if (IS_ERR_OR_NULL(priv->mm)) { - int err = priv->mm ? PTR_ERR(priv->mm) : -ESRCH; + priv->query.mm = proc_mem_open(inode, PTRACE_MODE_READ); + if (IS_ERR_OR_NULL(priv->query.mm)) { + int err = priv->query.mm ? PTR_ERR(priv->query.mm) : -ESRCH; seq_release_private(inode, file); return err; @@ -355,8 +355,8 @@ static int proc_map_release(struct inode *inode, struct file *file) struct seq_file *seq = file->private_data; struct proc_maps_private *priv = seq->private; - if (priv->mm) - mmdrop(priv->mm); + if (priv->query.mm) + mmdrop(priv->query.mm); return seq_release_private(inode, file); } @@ -610,7 +610,7 @@ static int do_procmap_query(struct proc_maps_private *priv, void __user *uarg) if (!!karg.build_id_size != !!karg.build_id_addr) return -EINVAL; - mm = priv->mm; + mm = priv->query.mm; if (!mm || !mmget_not_zero(mm)) return -ESRCH; @@ -1307,7 +1307,7 @@ static int show_smaps_rollup(struct seq_file *m, void *v) { struct proc_maps_private *priv = m->private; struct mem_size_stats mss = {}; - struct mm_struct *mm = priv->mm; + struct mm_struct *mm = priv->query.mm; struct vm_area_struct *vma; unsigned long vma_start = 0, last_vma_end = 0; int ret = 0; @@ -1452,9 +1452,9 @@ static int smaps_rollup_open(struct inode *inode, struct file *file) goto out_free; priv->inode = inode; - priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); - if (IS_ERR_OR_NULL(priv->mm)) { - ret = priv->mm ? PTR_ERR(priv->mm) : -ESRCH; + priv->query.mm = proc_mem_open(inode, PTRACE_MODE_READ); + if (IS_ERR_OR_NULL(priv->query.mm)) { + ret = priv->query.mm ? PTR_ERR(priv->query.mm) : -ESRCH; single_release(inode, file); goto out_free; @@ -1472,8 +1472,8 @@ static int smaps_rollup_release(struct inode *inode, struct file *file) struct seq_file *seq = file->private_data; struct proc_maps_private *priv = seq->private; - if (priv->mm) - mmdrop(priv->mm); + if (priv->query.mm) + mmdrop(priv->query.mm); kfree(priv); return single_release(inode, file); -- 2.50.1.565.gc32cd1483b-goog