tree 33b5aa5b63268b8f4d1428d74547fd351bb37113
parent 5e21ccb136047e556acf0fdf227cab5db05c1c25
author Miklos Szeredi <[EMAIL PROTECTED]> Wed, 07 Sep 2005 05:18:24 -0700
committer Linus Torvalds <[EMAIL PROTECTED]> Thu, 08 Sep 2005 06:57:43 -0700
[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 <[EMAIL PROTECTED]>
Cc: <[EMAIL PROTECTED]>
Cc: Christoph Hellwig <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
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
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -346,33 +346,6 @@ 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;
@@ -382,7 +355,7 @@ 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);
}
@@ -685,7 +658,7 @@ 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;
@@ -711,7 +684,7 @@ 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;
@@ -749,7 +722,7 @@ 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);
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -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)
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -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;
-
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