In musl, as far as I can tell, `_NSIG` is always defined as either 65, or 128 (for all three MIPS architectures) at the bottom of `${arch}/bits/signal.h`. Meanwhile, in `src/signal/block.c`, there is a test `#if ULONG_MAX == 0xffffffff && _NSIG == 129`, which will never succeed since _NSIG will be 128 instead of 129. This seems likely to be left over from Commit: fix _NSIG and SIGRTMAX on mips.

I have not demonstrated the bug, I found it by inspection of the source. My guess is that this bug causes __block_all_sigs to fail to block high real time signals on MIPS. At best, however, this test seems to be dead code.

(I am not subscribed to the mailing list; please cc me directly on any responses I need to see.)

My apologies if I have misunderstood the situation.

Sincerely,

- Jasper Hugunin