Messages in this thread | | | Date | Sun, 26 Jun 2011 22:04:42 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH] ptrace: make former thread ID available via PTRACE_GETEVENTMSG after PTRACE_EVENT_EXEC stop (v.2) |
| |
On 06/26, Denys Vlasenko wrote: > > @@ -1366,13 +1366,22 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) > for (try=0; try<2; try++) { > read_lock(&binfmt_lock); > list_for_each_entry(fmt, &formats, lh) { > - int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; > - if (!fn) > + int (*load_binary)(struct linux_binprm *, struct pt_regs *); > + pid_t old_pid = old_pid; /* for compiler */
we have uninitialized_var() for this,
pid_t uninitialized_var(old_pid);
> + > + load_binary = fmt->load_binary; > + if (!load_binary) > continue; > if (!try_module_get(fmt->module)) > continue; > read_unlock(&binfmt_lock); > - retval = fn(bprm, regs); > + if (task_ptrace(current) & PT_PTRACED) {
May be PT_TRACE_EXEC makes more sense. Note that ptrace_event_enabled() was recently added.
> + /* Need to fetch pid before load_binary changes it */ > + rcu_read_lock(); > + old_pid = task_pid_nr_ns(current, task_active_pid_ns(current->parent));
OK, this looks correct. But imho this code looks strange inside the for (;;) loop. Perhaps it would be more clean to record the old pid before.
Also, this line is too long. Personally I do not care, but I told you we have the coding style police. Please use ./scripts/checkpatch.pl
> @@ -1381,7 +1390,7 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) > bprm->recursion_depth = depth; > if (retval >= 0) { > if (depth == 0) > - tracehook_report_exec(fmt, bprm, regs); > + tracehook_report_exec(fmt, bprm, regs, old_pid);
Heh, you are out of luck ;) This hook was already killed. Please redo against git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc.git ptrace
Also, please update the changelog. It should clearly explain why do we need this feature and what this patch does. The output from a test program doesn't make too much sense unless you show the source code.
Oleg.
| |