| Message ID | 20190924090937.13001-1-Jason@zx2c4.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | net: print proper warning on dst underflow | expand |
From: "Jason A. Donenfeld" <Jason@zx2c4.com> Date: Tue, 24 Sep 2019 11:09:37 +0200 > Proper warnings with stack traces make it much easier to figure out > what's doing the double free and create more meaningful bug reports from > users. > > Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Applied, thanks.
On Tue, Sep 24, 2019 at 11:09:37AM +0200, Jason A. Donenfeld wrote: > Proper warnings with stack traces make it much easier to figure out > what's doing the double free and create more meaningful bug reports from > users. > > Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> > --- > net/core/dst.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/core/dst.c b/net/core/dst.c > index 1325316d9eab..193af526e908 100644 > --- a/net/core/dst.c > +++ b/net/core/dst.c > @@ -172,7 +172,7 @@ void dst_release(struct dst_entry *dst) > int newrefcnt; > > newrefcnt = atomic_dec_return(&dst->__refcnt); > - if (unlikely(newrefcnt < 0)) > + if (WARN_ONCE(newrefcnt < 0, "dst_release underflow")) > net_warn_ratelimited("%s: dst:%p refcnt:%d\n", > __func__, dst, newrefcnt); Should __refcnt be a refcount_t to gain saturation protection? It seems like going negative is bad... -Kees > if (!newrefcnt) > @@ -187,7 +187,7 @@ void dst_release_immediate(struct dst_entry *dst) > int newrefcnt; > > newrefcnt = atomic_dec_return(&dst->__refcnt); > - if (unlikely(newrefcnt < 0)) > + if (WARN_ONCE(newrefcnt < 0, "dst_release_immediate underflow")) > net_warn_ratelimited("%s: dst:%p refcnt:%d\n", > __func__, dst, newrefcnt); > if (!newrefcnt) > -- > 2.21.0 >
diff --git a/net/core/dst.c b/net/core/dst.c index 1325316d9eab..193af526e908 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -172,7 +172,7 @@ void dst_release(struct dst_entry *dst) int newrefcnt; newrefcnt = atomic_dec_return(&dst->__refcnt); - if (unlikely(newrefcnt < 0)) + if (WARN_ONCE(newrefcnt < 0, "dst_release underflow")) net_warn_ratelimited("%s: dst:%p refcnt:%d\n", __func__, dst, newrefcnt); if (!newrefcnt) @@ -187,7 +187,7 @@ void dst_release_immediate(struct dst_entry *dst) int newrefcnt; newrefcnt = atomic_dec_return(&dst->__refcnt); - if (unlikely(newrefcnt < 0)) + if (WARN_ONCE(newrefcnt < 0, "dst_release_immediate underflow")) net_warn_ratelimited("%s: dst:%p refcnt:%d\n", __func__, dst, newrefcnt); if (!newrefcnt)
Proper warnings with stack traces make it much easier to figure out what's doing the double free and create more meaningful bug reports from users. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> --- net/core/dst.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)