Messages in this thread | | | Subject | Re: Avoiding OOM on overcommit...? | From | James Antill <> | Date | 24 Mar 2000 16:01:53 -0500 |
| |
Alan Cox <alan@lxorguk.ukuu.org.uk> writes:
> o There is an implicit unchecked memory allocation in normal C - stack > pages. So a stack page OOM will kill you anyway (forget calling a > function to report it, you have nothing to report it on)
Although everything else you said was right, you can do some damage control in the above situation.
Basically...
#ifdef HAVE_SIGALTSTACK do { struct sigaltstack alt_stack; static char buffer[SIGSTKSZ]; alt_stack.ss_size = SIGSTKSZ; alt_stack.ss_sp = buffer; alt_stack.ss_flags = 0;
if (sigaltstack(&alt_stack, NULL) == -1) { /* this should be impossible */ /* **** log error **** */ break; }
sa.sa_flags |= SA_ONSTACK; } while (FALSE); #endif sa.sa_handler = internal_signal_crash;
if (sigaction(SIGSEGV, &sa, NULL) == -1) /* **** log error **** */ ;
...etc. for SIGBUS etc.
Again as alan said your _system_ still needs to recover from someone pulling the power (just fitting a UPS doesn't count as they fail too), but you should still do stuff like the above and check error codes on read()/close()/malloc()[1]. All in my opinion.
[1] Some people may think the above is in priority order, you can think that if you wish but I'll still do all of them.
-- James Antill -- james@and.org "If we can't keep this sort of thing out of the kernel, we might as well pack it up and go run Solaris." -- Larry McVoy.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |