Messages in this thread Patch in this message | | | Subject | [PATCH 5/8] remove duplicated code from proc and ptrace | From | Miklos Szeredi <> | Date | Tue, 23 Aug 2005 22:36:17 +0200 |
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Extract common code used by ptrace_attach() and may_ptrace_attach() into a separate function.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Index: linux/kernel/ptrace.c =================================================================== --- linux.orig/kernel/ptrace.c 2005-08-19 14:47:20.000000000 +0200 +++ linux/kernel/ptrace.c 2005-08-19 14:47:36.000000000 +0200 @@ -118,6 +118,33 @@ int ptrace_check_attach(struct task_stru 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 *ta 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; Index: linux/include/linux/ptrace.h =================================================================== --- linux.orig/include/linux/ptrace.h 2005-08-19 14:47:20.000000000 +0200 +++ linux/include/linux/ptrace.h 2005-08-19 14:47:36.000000000 +0200 @@ -90,6 +90,7 @@ extern void __ptrace_link(struct task_st 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) Index: linux/fs/proc/base.c =================================================================== --- linux.orig/fs/proc/base.c 2005-08-19 14:47:36.000000000 +0200 +++ linux/fs/proc/base.c 2005-08-19 14:47:36.000000000 +0200 @@ -347,33 +347,6 @@ static int proc_root_link(struct inode * (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; @@ -383,7 +356,7 @@ static int proc_pid_environ(struct task_ 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); } @@ -686,7 +659,7 @@ static ssize_t mem_read(struct file * fi 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; @@ -712,7 +685,7 @@ static ssize_t mem_read(struct file * fi 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; @@ -750,7 +723,7 @@ static ssize_t mem_write(struct file * f 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); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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