From ab8d11beb46f0bd0617e04205c01f5c1fe845b61 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 6 Sep 2005 15:18:24 -0700 Subject: [PATCH] [PATCH] remove duplicated code from proc and ptrace Extract common code used by ptrace_attach() and may_ptrace_attach() into a separate function. Signed-off-by: Miklos Szeredi Cc: Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/base.c | 35 ++++------------------------------- include/linux/ptrace.h | 1 + kernel/ptrace.c | 41 ++++++++++++++++++++++++++++------------- 3 files changed, 33 insertions(+), 44 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 24eed139e54e..84751f3f52d5 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -346,33 +346,6 @@ 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)) -static int may_ptrace_attach(struct task_struct *task) -{ - int retval = 0; - - task_lock(task); - - if (!task->mm) - goto out; - if (((current->uid != task->euid) || - (current->uid != task->suid) || - (current->uid != task->uid) || - (current->gid != task->egid) || - (current->gid != task->sgid) || - (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE)) - goto out; - rmb(); - if (task->mm->dumpable != 1 && !capable(CAP_SYS_PTRACE)) - goto out; - if (security_ptrace(current, task)) - goto out; - - retval = 1; -out: - task_unlock(task); - return retval; -} - static int proc_pid_environ(struct task_struct *task, char * buffer) { int res = 0; @@ -382,7 +355,7 @@ static int proc_pid_environ(struct task_struct *task, char * buffer) if (len > PAGE_SIZE) len = PAGE_SIZE; res = access_process_vm(task, mm->env_start, buffer, len, 0); - if (!may_ptrace_attach(task)) + if (!ptrace_may_attach(task)) res = -ESRCH; mmput(mm); } @@ -685,7 +658,7 @@ static ssize_t mem_read(struct file * file, char __user * buf, int ret = -ESRCH; struct mm_struct *mm; - if (!MAY_PTRACE(task) || !may_ptrace_attach(task)) + if (!MAY_PTRACE(task) || !ptrace_may_attach(task)) goto out; ret = -ENOMEM; @@ -711,7 +684,7 @@ static ssize_t mem_read(struct file * file, char __user * buf, this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count; retval = access_process_vm(task, src, page, this_len, 0); - if (!retval || !MAY_PTRACE(task) || !may_ptrace_attach(task)) { + if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) { if (!ret) ret = -EIO; break; @@ -749,7 +722,7 @@ static ssize_t mem_write(struct file * file, const char * buf, struct task_struct *task = proc_task(file->f_dentry->d_inode); unsigned long dst = *ppos; - if (!MAY_PTRACE(task) || !may_ptrace_attach(task)) + if (!MAY_PTRACE(task) || !ptrace_may_attach(task)) return -ESRCH; page = (char *)__get_free_page(GFP_USER); diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 2afdafb62123..dc6f3647bfbc 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -90,6 +90,7 @@ extern void __ptrace_link(struct task_struct *child, struct task_struct *new_parent); 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); 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 8dcb8f6288bc..019e04ec065a 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -118,6 +118,33 @@ int ptrace_check_attach(struct task_struct *child, int kill) return ret; } +static int may_attach(struct task_struct *task) +{ + if (!task->mm) + return -EPERM; + if (((current->uid != task->euid) || + (current->uid != task->suid) || + (current->uid != task->uid) || + (current->gid != task->egid) || + (current->gid != task->sgid) || + (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE)) + return -EPERM; + smp_rmb(); + if (!task->mm->dumpable && !capable(CAP_SYS_PTRACE)) + return -EPERM; + + return security_ptrace(current, task); +} + +int ptrace_may_attach(struct task_struct *task) +{ + int err; + task_lock(task); + err = may_attach(task); + task_unlock(task); + return !err; +} + int ptrace_attach(struct task_struct *task) { int retval; @@ -127,22 +154,10 @@ int ptrace_attach(struct task_struct *task) goto bad; if (task == current) goto bad; - if (!task->mm) - goto bad; - if(((current->uid != task->euid) || - (current->uid != task->suid) || - (current->uid != task->uid) || - (current->gid != task->egid) || - (current->gid != task->sgid) || - (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE)) - goto bad; - smp_rmb(); - if (!task->mm->dumpable && !capable(CAP_SYS_PTRACE)) - goto bad; /* the same process cannot be attached many times */ if (task->ptrace & PT_PTRACED) goto bad; - retval = security_ptrace(current, task); + retval = may_attach(task); if (retval) goto bad; -- 2.34.1