A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-30 03:27:44 -04:00
Code Issues Projects Releases Packages Wiki Activity

[PATCH] use ptrace_get_task_struct in various places

Browse source 
The ptrace_get_task_struct() helper that I added as part of the ptrace
consolidation is useful in variety of places that currently opencode it.
Switch them to the common helpers.

Add a ptrace_traceme() helper that needs to be explicitly called, and simplify
the ptrace_get_task_struct() interface.  We don't need the request argument
now, and we return the task_struct directly, using ERR_PTR() for error
returns.  It's a bit more code in the callers, but we have two sane routines
that do one thing well now.

Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Christoph Hellwig 2006-01-08 01:02:33 -08:00 • committed by Linus Torvalds
commit 6b9c7ed848
12 changed files with 105 additions and 241 deletions
Download patch file Download diff file Expand all files Collapse all files

77
kernel/ptrace.c
View file

@ -408,54 +408,62 @@ int ptrace_request(struct task_struct *child, long request,
return ret;
}
#ifndef __ARCH_SYS_PTRACE
static int ptrace_get_task_struct(long request, long pid,
struct task_struct **childp)
/**
* ptrace_traceme -- helper for PTRACE_TRACEME
*
* Performs checks and sets PT_PTRACED.
* Should be used by all ptrace implementations for PTRACE_TRACEME.
*/
int ptrace_traceme(void)
{
struct task_struct *child;
int ret;
/*
* Callers use child == NULL as an indication to exit early even
* when the return value is 0, so make sure it is non-NULL here.
* Are we already being traced?
*/
*childp = NULL;
if (current->ptrace & PT_PTRACED)
return -EPERM;
ret = security_ptrace(current->parent, current);
if (ret)
return -EPERM;
/*
* Set the ptrace bit in the process ptrace flags.
*/
current->ptrace |= PT_PTRACED;
return 0;
}
if (request == PTRACE_TRACEME) {
/*
* Are we already being traced?
*/
if (current->ptrace & PT_PTRACED)
return -EPERM;
ret = security_ptrace(current->parent, current);
if (ret)
return -EPERM;
/*
* Set the ptrace bit in the process ptrace flags.
*/
current->ptrace |= PT_PTRACED;
return 0;
}
/**
* ptrace_get_task_struct -- grab a task struct reference for ptrace
* @pid: process id to grab a task_struct reference of
*
* This function is a helper for ptrace implementations. It checks
* permissions and then grabs a task struct for use of the actual
* ptrace implementation.
*
* Returns the task_struct for @pid or an ERR_PTR() on failure.
*/
struct task_struct *ptrace_get_task_struct(pid_t pid)
{
struct task_struct *child;
/*
* You may not mess with init
* Tracing init is not allowed.
*/
if (pid == 1)
return -EPERM;
return ERR_PTR(-EPERM);
ret = -ESRCH;
read_lock(&tasklist_lock);
child = find_task_by_pid(pid);
if (child)
get_task_struct(child);
read_unlock(&tasklist_lock);
if (!child)
return -ESRCH;
*childp = child;
return 0;
return ERR_PTR(-ESRCH);
return child;
}
#ifndef __ARCH_SYS_PTRACE
asmlinkage long sys_ptrace(long request, long pid, long addr, long data)
{
struct task_struct *child;
@ -465,9 +473,16 @@ asmlinkage long sys_ptrace(long request, long pid, long addr, long data)
* This lock_kernel fixes a subtle race with suid exec
*/
lock_kernel();
ret = ptrace_get_task_struct(request, pid, &child);
if (!child)
if (request == PTRACE_TRACEME) {
ret = ptrace_traceme();
goto out;
}
child = ptrace_get_task_struct(pid);
if (IS_ERR(child)) {
ret = PTR_ERR(child);
goto out;
}
if (request == PTRACE_ATTACH) {
ret = ptrace_attach(child);