Commit 5861bbfc authored by Roland McGrath's avatar Roland McGrath

tracehook: fix CLONE_PTRACE

In the change in commit 09a05394, I
overlooked two nits in the logic and this broke using CLONE_PTRACE
when PTRACE_O_TRACE* are not being used.

A parent that is itself traced at all but not using PTRACE_O_TRACE*,
using CLONE_PTRACE would have its new child fail to be traced.

A parent that is not itself traced at all that uses CLONE_PTRACE
(which should be a no-op in this case) would confuse the bookkeeping
and lead to a crash at exit time.

This restores the missing checks and fixes both failure modes.
Reported-by: default avatarEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
parent 685d87f7
...@@ -172,7 +172,7 @@ static inline void ptrace_init_task(struct task_struct *child, bool ptrace) ...@@ -172,7 +172,7 @@ static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
child->ptrace = 0; child->ptrace = 0;
if (unlikely(ptrace)) { if (unlikely(ptrace)) {
child->ptrace = current->ptrace; child->ptrace = current->ptrace;
__ptrace_link(child, current->parent); ptrace_link(child, current->parent);
} }
} }
......
...@@ -280,7 +280,7 @@ static inline void tracehook_report_clone(int trace, struct pt_regs *regs, ...@@ -280,7 +280,7 @@ static inline void tracehook_report_clone(int trace, struct pt_regs *regs,
unsigned long clone_flags, unsigned long clone_flags,
pid_t pid, struct task_struct *child) pid_t pid, struct task_struct *child)
{ {
if (unlikely(trace)) { if (unlikely(trace) || unlikely(clone_flags & CLONE_PTRACE)) {
/* /*
* The child starts up with an immediate SIGSTOP. * The child starts up with an immediate SIGSTOP.
*/ */
......
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