> -----Original Message-----
> From: [email protected] [mailto:owner-openssl-
> [email protected]] On Behalf Of Dr. Stephen Henson
> Sent: Wednesday, January 15, 2014 1:56 AM
> To: [email protected]
> Subject: Re: Deadlock in openssl1.0.1e.
>
> On Tue, Jan 14, 2014, Tayade, Nilesh wrote:
>
> > Hi,
> >
> > I am not able to understand what???s going wrong, below is the latest
> stack trace I got. Thread 19 is killed by a watchdog, and it was waiting on a
> lock.
> > Other threads do not show any lock being held.
> >
> >
>
> I'd suggest you modify your locking callback to store the location (file, line
> number) for the lock in question (18 which is CRYPTO_LOCK_RAND) when a
> lock is acquired successfully and clear it when the lock is released. Then
> when
> you get a deadlock you can see the last instance that held (but did not
> release) the lock.
>
> You could try compiling with LOCK_DEBUG but that will create a *lot* of
> output.
Thanks for your suggestions. I did try capturing the debug information and
below is how the state of the locks is. The array per lock stores information
of the owner, file and lock_present i.e. lock is held or not.
I see that the lock # 18 is held but when thread 19 was waiting, it was trying
for lock # 19. Not sure what's going on.
(gdb) p ssl_locks[18]
$22 = {
thread_id = 140003803043584,
file_name = "md_rand.c", '\000' <repeats 30 times>,
file_name_len = 9,
line = 384,
lock_present = 1
}
(gdb) p ssl_locks[19]
$23 = {
thread_id = 140003803043584,
file_name = "md_rand.c", '\000' <repeats 30 times>,
file_name_len = 9,
line = 389,
lock_present = 0
}
The mutex buffer looks like this. I am unable to interpret all the fields, any
pointers on these?
(gdb) p mutex_buf[19]
$15 = {
__data = {
__lock = -1770245546,
__count = 161970406,
__owner = -794915378,
__nusers = 890065223,
__kind = 634752049,
__spins = 239812167,
__list = {
__prev = 0x3cab28a258ddf6a1,
__next = 0x1b78c957a2cf4cef
}
},
__size =
"V2|\226\346x\247\t\316\215\236\320GQ\r51\214\325%G>K\016\241\366\335X\242(\253<\357LϢW\311x\033",
__align = 695657599214563926
}
>
> Steve.
> --
> Dr Stephen N. Henson. OpenSSL project core developer.
> Commercial tech support now available see: http://www.openssl.org
--
Thanks,
Nilesh
