Clone of the upstream issue https://code.google.com/p/conman/issues/detail?id=15


> Reported by markkawi..., Nov 27, 2012
> 
> What steps will reproduce the problem?
> 
> Create a conman.conf file with 4,096 or more "console" entries, all using IPMI SOL, and try to run conmand. It will crash.
> 
> What is the expected output? What do you see instead?
> 
> 
> What version of the software are you using? On what operating system?
> 
> ConMan 0.2.7, CentOS 5.5 (kernel 2.6.18)
> 
> Please provide any additional information below.
> 
> The relevant defines:
> 
> #define IPMI_ENGINE_CONSOLES_PER_THREAD 128
> #define IPMICONSOLE_THREAD_COUNT_MAX 32
> 
> When there are 4,096 or more consoles using IPMI SOL, the following line is run:
> 
> num_threads = ((num_consoles - 1) / IPMI_ENGINE_CONSOLES_PER_THREAD) + 1;
> 
> (this is on line 96 of the file server-ipmi.c. The math works out to: ((4096 - 1) / 128) + 1. That goes to 33 when num_consoles is >= 4096. But 33 is greater than IPMICONSOLE_THREAD_COUNT_MAX, and libipmiconsole refuses to initialize the engine.
> 
> The workaround is to make sure that num_threads never exceeds IPMICONSOLE_THREAD_COUNT_MAX:
> 
> Mark-Pettits-Twitter-Laptop:~/conman/conman$ git diff
> diff --git a/server-ipmi.c b/server-ipmi.c
> index ba2ec65..2b7775a 100644
> --- a/server-ipmi.c
> +++ b/server-ipmi.c
> @@ -93,6 +93,7 @@ void ipmi_init(int num_consoles)
> return;
> }
> num_threads = ((num_consoles - 1) / IPMI_ENGINE_CONSOLES_PER_THREAD) + 1;
> +    num_threads = MIN(num_threads, IPMICONSOLE_THREAD_COUNT_MAX);
> 
> if (ipmiconsole_engine_init(num_threads, 0) < 0) {
> log_err(0, "Unable to start IPMI SOL engine");