diff options
| -rw-r--r-- | fs/proc/base.c | 20 | ||||
| -rw-r--r-- | fs/proc/internal.h | 2 | ||||
| -rw-r--r-- | fs/proc/task_mmu.c | 3 | ||||
| -rw-r--r-- | fs/proc/task_nommu.c | 4 | ||||
| -rw-r--r-- | include/linux/ptrace.h | 1 | ||||
| -rw-r--r-- | kernel/ptrace.c | 4 |
6 files changed, 27 insertions, 7 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 02a63ac0417..7411bfb0b7c 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -202,6 +202,26 @@ static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vf (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \ security_ptrace(current,task) == 0)) +struct mm_struct *mm_for_maps(struct task_struct *task) +{ + struct mm_struct *mm = get_task_mm(task); + if (!mm) + return NULL; + down_read(&mm->mmap_sem); + task_lock(task); + if (task->mm != mm) + goto out; + if (task->mm != current->mm && __ptrace_may_attach(task) < 0) + goto out; + task_unlock(task); + return mm; +out: + task_unlock(task); + up_read(&mm->mmap_sem); + mmput(mm); + return NULL; +} + static int proc_pid_cmdline(struct task_struct *task, char * buffer) { int res = 0; diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 1820eb2ef76..05b3e900626 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -27,6 +27,8 @@ struct vmalloc_info { unsigned long largest_chunk; }; +extern struct mm_struct *mm_for_maps(struct task_struct *); + #ifdef CONFIG_MMU #define VMALLOC_TOTAL (VMALLOC_END - VMALLOC_START) extern void get_vmalloc_info(struct vmalloc_info *vmi); diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index c24d81a5a04..8043a3eab52 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -397,12 +397,11 @@ static void *m_start(struct seq_file *m, loff_t *pos) if (!priv->task) return NULL; - mm = get_task_mm(priv->task); + mm = mm_for_maps(priv->task); if (!mm) return NULL; priv->tail_vma = tail_vma = get_gate_vma(priv->task); - down_read(&mm->mmap_sem); /* Start with last addr hint */ if (last_addr && (vma = find_vma(mm, last_addr))) { diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index d8b8c7183c2..1932c2ca345 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -165,15 +165,13 @@ static void *m_start(struct seq_file *m, loff_t *pos) if (!priv->task) return NULL; - mm = get_task_mm(priv->task); + mm = mm_for_maps(priv->task); if (!mm) { put_task_struct(priv->task); priv->task = NULL; return NULL; } - down_read(&mm->mmap_sem); - /* start from the Nth VMA */ for (vml = mm->context.vmlist; vml; vml = vml->next) if (n-- == 0) diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index ae8146abd74..3ea5750a0f7 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -97,6 +97,7 @@ extern void __ptrace_link(struct task_struct *child, extern void __ptrace_unlink(struct task_struct *child); extern void ptrace_untrace(struct task_struct *child); extern int ptrace_may_attach(struct task_struct *task); +extern int __ptrace_may_attach(struct task_struct *task); static inline void ptrace_link(struct task_struct *child, struct task_struct *new_parent) diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 7c76f2ffaea..0c65d306f41 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -120,7 +120,7 @@ int ptrace_check_attach(struct task_struct *child, int kill) return ret; } -static int may_attach(struct task_struct *task) +int __ptrace_may_attach(struct task_struct *task) { /* May we inspect the given task? * This check is used both for attaching with ptrace @@ -154,7 +154,7 @@ int ptrace_may_attach(struct task_struct *task) { int err; task_lock(task); - err = may_attach(task); + err = __ptrace_may_attach(task); task_unlock(task); return !err; } |