[PATCH] use ptrace_get_task_struct in various places
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 <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Родитель
6b34350f49
Коммит
6b9c7ed848
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@ -265,30 +265,16 @@ do_sys_ptrace(long request, long pid, long addr, long data,
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lock_kernel();
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DBG(DBG_MEM, ("request=%ld pid=%ld addr=0x%lx data=0x%lx\n",
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request, pid, addr, data));
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ret = -EPERM;
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if (request == PTRACE_TRACEME) {
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/* are we already being traced? */
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if (current->ptrace & PT_PTRACED)
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goto out_notsk;
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ret = security_ptrace(current->parent, current);
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if (ret)
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goto out_notsk;
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/* set the ptrace bit in the process ptrace flags. */
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current->ptrace |= PT_PTRACED;
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ret = 0;
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ret = ptrace_traceme();
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goto out_notsk;
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}
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if (pid == 1) /* you may not mess with init */
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goto out_notsk;
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ret = -ESRCH;
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read_lock(&tasklist_lock);
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child = find_task_by_pid(pid);
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if (child)
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get_task_struct(child);
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read_unlock(&tasklist_lock);
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if (!child)
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child = ptrace_get_task_struct(pid);
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if (IS_ERR(child)) {
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ret = PTR_ERR(child);
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goto out_notsk;
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}
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if (request == PTRACE_ATTACH) {
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ret = ptrace_attach(child);
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@ -1761,21 +1761,15 @@ sys32_ptrace (int request, pid_t pid, unsigned int addr, unsigned int data)
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lock_kernel();
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if (request == PTRACE_TRACEME) {
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ret = sys_ptrace(request, pid, addr, data);
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ret = ptrace_traceme();
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goto out;
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}
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ret = -ESRCH;
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read_lock(&tasklist_lock);
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child = find_task_by_pid(pid);
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if (child)
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get_task_struct(child);
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read_unlock(&tasklist_lock);
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if (!child)
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child = ptrace_get_task_struct(pid);
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if (IS_ERR(child)) {
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ret = PTR_ERR(child);
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goto out;
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ret = -EPERM;
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if (pid == 1) /* no messing around with init! */
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goto out_tsk;
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}
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if (request == PTRACE_ATTACH) {
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ret = sys_ptrace(request, pid, addr, data);
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@ -1422,14 +1422,7 @@ sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data)
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lock_kernel();
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ret = -EPERM;
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if (request == PTRACE_TRACEME) {
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/* are we already being traced? */
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if (current->ptrace & PT_PTRACED)
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goto out;
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ret = security_ptrace(current->parent, current);
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if (ret)
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goto out;
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current->ptrace |= PT_PTRACED;
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ret = 0;
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ret = ptrace_traceme();
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goto out;
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}
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@ -762,28 +762,16 @@ asmlinkage long sys_ptrace(long request, long pid, long addr, long data)
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int ret;
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lock_kernel();
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ret = -EPERM;
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if (request == PTRACE_TRACEME) {
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/* are we already being traced? */
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if (current->ptrace & PT_PTRACED)
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goto out;
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/* set the ptrace bit in the process flags. */
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current->ptrace |= PT_PTRACED;
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ret = 0;
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ret = ptrace_traceme();
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goto out;
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}
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ret = -ESRCH;
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read_lock(&tasklist_lock);
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child = find_task_by_pid(pid);
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if (child)
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get_task_struct(child);
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read_unlock(&tasklist_lock);
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if (!child)
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goto out;
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ret = -EPERM;
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if (pid == 1) /* you may not mess with init */
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child = ptrace_get_task_struct(pid);
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if (IS_ERR(child)) {
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ret = PTR_ERR(child);
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goto out;
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}
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if (request == PTRACE_ATTACH) {
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ret = ptrace_attach(child);
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@ -57,30 +57,16 @@ asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
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(unsigned long) data);
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#endif
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lock_kernel();
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ret = -EPERM;
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if (request == PTRACE_TRACEME) {
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/* are we already being traced? */
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if (current->ptrace & PT_PTRACED)
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goto out;
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if ((ret = security_ptrace(current->parent, current)))
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goto out;
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/* set the ptrace bit in the process flags. */
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current->ptrace |= PT_PTRACED;
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ret = 0;
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ret = ptrace_traceme();
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goto out;
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}
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ret = -ESRCH;
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read_lock(&tasklist_lock);
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child = find_task_by_pid(pid);
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if (child)
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get_task_struct(child);
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read_unlock(&tasklist_lock);
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if (!child)
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goto out;
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ret = -EPERM;
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if (pid == 1) /* you may not mess with init */
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goto out_tsk;
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child = ptrace_get_task_struct(pid);
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if (IS_ERR(child)) {
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ret = PTR_ERR(child);
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goto out;
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}
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if (request == PTRACE_ATTACH) {
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ret = ptrace_attach(child);
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@ -45,33 +45,19 @@ long compat_sys_ptrace(int request, int pid, unsigned long addr,
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unsigned long data)
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{
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struct task_struct *child;
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int ret = -EPERM;
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int ret;
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lock_kernel();
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if (request == PTRACE_TRACEME) {
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/* are we already being traced? */
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if (current->ptrace & PT_PTRACED)
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goto out;
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ret = security_ptrace(current->parent, current);
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if (ret)
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goto out;
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/* set the ptrace bit in the process flags. */
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current->ptrace |= PT_PTRACED;
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ret = 0;
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ret = ptrace_traceme();
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goto out;
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}
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ret = -ESRCH;
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read_lock(&tasklist_lock);
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child = find_task_by_pid(pid);
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if (child)
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get_task_struct(child);
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read_unlock(&tasklist_lock);
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if (!child)
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goto out;
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ret = -EPERM;
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if (pid == 1) /* you may not mess with init */
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goto out_tsk;
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child = ptrace_get_task_struct(pid);
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if (IS_ERR(child)) {
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ret = PTR_ERR(child);
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goto out;
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}
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if (request == PTRACE_ATTACH) {
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ret = ptrace_attach(child);
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@ -712,35 +712,18 @@ sys_ptrace(long request, long pid, long addr, long data)
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int ret;
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lock_kernel();
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if (request == PTRACE_TRACEME) {
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/* are we already being traced? */
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ret = -EPERM;
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if (current->ptrace & PT_PTRACED)
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goto out;
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ret = security_ptrace(current->parent, current);
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if (ret)
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goto out;
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/* set the ptrace bit in the process flags. */
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current->ptrace |= PT_PTRACED;
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ret = ptrace_traceme();
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goto out;
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}
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ret = -EPERM;
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if (pid == 1) /* you may not mess with init */
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goto out;
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ret = -ESRCH;
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read_lock(&tasklist_lock);
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child = find_task_by_pid(pid);
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if (child)
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get_task_struct(child);
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read_unlock(&tasklist_lock);
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if (!child)
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child = ptrace_get_task_struct(pid);
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if (IS_ERR(child)) {
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ret = PTR_ERR(child);
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goto out;
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}
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ret = do_ptrace(child, request, addr, data);
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put_task_struct(child);
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out:
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unlock_kernel();
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@ -286,40 +286,17 @@ asmlinkage void do_ptrace(struct pt_regs *regs)
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s, (int) request, (int) pid, addr, data, addr2);
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}
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#endif
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if (request == PTRACE_TRACEME) {
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int my_ret;
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/* are we already being traced? */
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if (current->ptrace & PT_PTRACED) {
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pt_error_return(regs, EPERM);
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goto out;
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}
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my_ret = security_ptrace(current->parent, current);
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if (my_ret) {
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pt_error_return(regs, -my_ret);
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goto out;
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}
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/* set the ptrace bit in the process flags. */
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current->ptrace |= PT_PTRACED;
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ret = ptrace_traceme();
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pt_succ_return(regs, 0);
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goto out;
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}
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#ifndef ALLOW_INIT_TRACING
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if (pid == 1) {
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/* Can't dork with init. */
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pt_error_return(regs, EPERM);
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goto out;
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}
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#endif
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read_lock(&tasklist_lock);
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child = find_task_by_pid(pid);
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if (child)
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get_task_struct(child);
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read_unlock(&tasklist_lock);
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if (!child) {
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pt_error_return(regs, ESRCH);
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child = ptrace_get_task_struct(pid);
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if (IS_ERR(child)) {
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ret = PTR_ERR(child);
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pt_error_return(regs, -ret);
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goto out;
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}
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@ -198,39 +198,15 @@ asmlinkage void do_ptrace(struct pt_regs *regs)
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}
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#endif
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if (request == PTRACE_TRACEME) {
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int ret;
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/* are we already being traced? */
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if (current->ptrace & PT_PTRACED) {
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pt_error_return(regs, EPERM);
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goto out;
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}
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ret = security_ptrace(current->parent, current);
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if (ret) {
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pt_error_return(regs, -ret);
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goto out;
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}
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/* set the ptrace bit in the process flags. */
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current->ptrace |= PT_PTRACED;
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ret = ptrace_traceme();
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pt_succ_return(regs, 0);
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goto out;
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}
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#ifndef ALLOW_INIT_TRACING
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if (pid == 1) {
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/* Can't dork with init. */
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pt_error_return(regs, EPERM);
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goto out;
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}
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#endif
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read_lock(&tasklist_lock);
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child = find_task_by_pid(pid);
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if (child)
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get_task_struct(child);
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read_unlock(&tasklist_lock);
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if (!child) {
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pt_error_return(regs, ESRCH);
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child = ptrace_get_task_struct(pid);
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if (IS_ERR(child)) {
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ret = PTR_ERR(child);
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pt_error_return(regs, -ret);
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goto out;
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}
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@ -196,36 +196,6 @@ static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
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#undef R32
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static struct task_struct *find_target(int request, int pid, int *err)
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{
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struct task_struct *child;
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*err = -EPERM;
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if (pid == 1)
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return NULL;
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*err = -ESRCH;
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read_lock(&tasklist_lock);
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child = find_task_by_pid(pid);
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if (child)
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get_task_struct(child);
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read_unlock(&tasklist_lock);
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if (child) {
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*err = -EPERM;
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if (child->pid == 1)
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goto out;
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*err = ptrace_check_attach(child, request == PTRACE_KILL);
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if (*err < 0)
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goto out;
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return child;
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}
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out:
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if (child)
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put_task_struct(child);
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return NULL;
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}
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asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
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{
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struct task_struct *child;
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@ -254,9 +224,16 @@ asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
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break;
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}
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child = find_target(request, pid, &ret);
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if (!child)
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return ret;
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if (request == PTRACE_TRACEME)
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return ptrace_traceme();
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child = ptrace_get_task_struct(pid);
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if (IS_ERR(child))
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return PTR_ERR(child);
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ret = ptrace_check_attach(child, request == PTRACE_KILL);
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if (ret < 0)
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goto out;
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childregs = (struct pt_regs *)(child->thread.rsp0 - sizeof(struct pt_regs));
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|
@ -373,6 +350,7 @@ asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
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break;
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}
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out:
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put_task_struct(child);
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return ret;
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}
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@ -80,6 +80,8 @@
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extern long arch_ptrace(struct task_struct *child, long request, long addr, long data);
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extern struct task_struct *ptrace_get_task_struct(pid_t pid);
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extern int ptrace_traceme(void);
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extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
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extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
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extern int ptrace_attach(struct task_struct *tsk);
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|
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@ -408,20 +408,16 @@ int ptrace_request(struct task_struct *child, long request,
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return ret;
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}
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#ifndef __ARCH_SYS_PTRACE
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static int ptrace_get_task_struct(long request, long pid,
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struct task_struct **childp)
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/**
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* ptrace_traceme -- helper for PTRACE_TRACEME
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*
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* Performs checks and sets PT_PTRACED.
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* Should be used by all ptrace implementations for PTRACE_TRACEME.
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*/
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int ptrace_traceme(void)
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{
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struct task_struct *child;
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int ret;
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|
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/*
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* Callers use child == NULL as an indication to exit early even
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* when the return value is 0, so make sure it is non-NULL here.
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*/
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*childp = NULL;
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|
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if (request == PTRACE_TRACEME) {
|
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/*
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* Are we already being traced?
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*/
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|
@ -435,27 +431,39 @@ static int ptrace_get_task_struct(long request, long pid,
|
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*/
|
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current->ptrace |= PT_PTRACED;
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return 0;
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}
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}
|
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|
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/**
|
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* ptrace_get_task_struct -- grab a task struct reference for ptrace
|
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* @pid: process id to grab a task_struct reference of
|
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*
|
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* This function is a helper for ptrace implementations. It checks
|
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* permissions and then grabs a task struct for use of the actual
|
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* ptrace implementation.
|
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*
|
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* Returns the task_struct for @pid or an ERR_PTR() on failure.
|
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*/
|
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struct task_struct *ptrace_get_task_struct(pid_t pid)
|
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{
|
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struct task_struct *child;
|
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|
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/*
|
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* You may not mess with init
|
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* Tracing init is not allowed.
|
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*/
|
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if (pid == 1)
|
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return -EPERM;
|
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return ERR_PTR(-EPERM);
|
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|
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ret = -ESRCH;
|
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read_lock(&tasklist_lock);
|
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child = find_task_by_pid(pid);
|
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if (child)
|
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get_task_struct(child);
|
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read_unlock(&tasklist_lock);
|
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if (!child)
|
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return -ESRCH;
|
||||
|
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*childp = child;
|
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return 0;
|
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return ERR_PTR(-ESRCH);
|
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return child;
|
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}
|
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|
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#ifndef __ARCH_SYS_PTRACE
|
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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);
|
||||
|
|
Загрузка…
Ссылка в новой задаче