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authorOleg Nesterov <oleg@redhat.com>2013-07-08 16:00:54 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-09 10:33:26 -0700
commit7c8df28633bf0b7eb253f866029be0ac59ddb062 (patch)
treed8fba38a54a339d460026f79952cab16240e4e5a /kernel
parente8c073c4ff51207f5c1c37fb054360bbc0f38251 (diff)
downloadlinux-7c8df28633bf0b7eb253f866029be0ac59ddb062.tar.bz2
ptrace: revert "Prepare to fix racy accesses on task breakpoints"
This reverts commit bf26c018490c ("Prepare to fix racy accesses on task breakpoints"). The patch was fine but we can no longer race with SIGKILL after commit 9899d11f6544 ("ptrace: ensure arch_ptrace/ptrace_request can never race with SIGKILL"), the __TASK_TRACED tracee can't be woken up and ->ptrace_bps[] can't go away. Now that ptrace_get_breakpoints/ptrace_put_breakpoints have no callers, we can kill them and remove task->ptrace_bp_refcnt. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Michael Neuling <mikey@neuling.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/exit.c2
-rw-r--r--kernel/ptrace.c16
2 files changed, 1 insertions, 17 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index fafe75d9e6f6..a949819055d5 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -808,7 +808,7 @@ void do_exit(long code)
/*
* FIXME: do that only when needed, using sched_exit tracepoint
*/
- ptrace_put_breakpoints(tsk);
+ flush_ptrace_hw_breakpoint(tsk);
exit_notify(tsk, group_dead);
#ifdef CONFIG_NUMA
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index ba5e6cea181a..a146ee327f6a 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -1221,19 +1221,3 @@ asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
return ret;
}
#endif /* CONFIG_COMPAT */
-
-#ifdef CONFIG_HAVE_HW_BREAKPOINT
-int ptrace_get_breakpoints(struct task_struct *tsk)
-{
- if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt))
- return 0;
-
- return -1;
-}
-
-void ptrace_put_breakpoints(struct task_struct *tsk)
-{
- if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt))
- flush_ptrace_hw_breakpoint(tsk);
-}
-#endif /* CONFIG_HAVE_HW_BREAKPOINT */