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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-05-08 17:17:13 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-05-08 17:17:13 -0400 |
| commit | f322e262386d155c4b543f51c9939dca525a2948 (patch) | |
| tree | 9b4830ee578bc9058496ec4094392414cd5112f3 /kernel | |
| parent | d86561b4c7473ad43e365afdba2142b75907c9d2 (diff) | |
| parent | 8058bd0faad860e75547cc5cb5d4ade016247a79 (diff) | |
Merge tag 'trace-fixes-v3.15-rc4-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"This contains two fixes.
The first is a long standing bug that causes bogus data to show up in
the refcnt field of the module_refcnt tracepoint. It was introduced
by a merge conflict resolution back in 2.6.35-rc days.
The result should be 'refcnt = incs - decs', but instead it did
'refcnt = incs + decs'.
The second fix is to a bug that was introduced in this merge window
that allowed for a tracepoint funcs pointer to be used after it was
freed. Moving the location of where the probes are released solved
the problem"
* tag 'trace-fixes-v3.15-rc4-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracepoint: Fix use of tracepoint funcs after rcu free
trace: module: Maintain a valid user count
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/tracepoint.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index ac5b23cf7212..6620e5837ce2 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c | |||
| @@ -188,7 +188,6 @@ static int tracepoint_add_func(struct tracepoint *tp, | |||
| 188 | WARN_ON_ONCE(1); | 188 | WARN_ON_ONCE(1); |
| 189 | return PTR_ERR(old); | 189 | return PTR_ERR(old); |
| 190 | } | 190 | } |
| 191 | release_probes(old); | ||
| 192 | 191 | ||
| 193 | /* | 192 | /* |
| 194 | * rcu_assign_pointer has a smp_wmb() which makes sure that the new | 193 | * rcu_assign_pointer has a smp_wmb() which makes sure that the new |
| @@ -200,6 +199,7 @@ static int tracepoint_add_func(struct tracepoint *tp, | |||
| 200 | rcu_assign_pointer(tp->funcs, tp_funcs); | 199 | rcu_assign_pointer(tp->funcs, tp_funcs); |
| 201 | if (!static_key_enabled(&tp->key)) | 200 | if (!static_key_enabled(&tp->key)) |
| 202 | static_key_slow_inc(&tp->key); | 201 | static_key_slow_inc(&tp->key); |
| 202 | release_probes(old); | ||
| 203 | return 0; | 203 | return 0; |
| 204 | } | 204 | } |
| 205 | 205 | ||
| @@ -221,7 +221,6 @@ static int tracepoint_remove_func(struct tracepoint *tp, | |||
| 221 | WARN_ON_ONCE(1); | 221 | WARN_ON_ONCE(1); |
| 222 | return PTR_ERR(old); | 222 | return PTR_ERR(old); |
| 223 | } | 223 | } |
| 224 | release_probes(old); | ||
| 225 | 224 | ||
| 226 | if (!tp_funcs) { | 225 | if (!tp_funcs) { |
| 227 | /* Removed last function */ | 226 | /* Removed last function */ |
| @@ -232,6 +231,7 @@ static int tracepoint_remove_func(struct tracepoint *tp, | |||
| 232 | static_key_slow_dec(&tp->key); | 231 | static_key_slow_dec(&tp->key); |
| 233 | } | 232 | } |
| 234 | rcu_assign_pointer(tp->funcs, tp_funcs); | 233 | rcu_assign_pointer(tp->funcs, tp_funcs); |
| 234 | release_probes(old); | ||
| 235 | return 0; | 235 | return 0; |
| 236 | } | 236 | } |
| 237 | 237 | ||
