From 2da958760f798224065508431787e3a83b7fe2ae Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 28 Jun 2013 21:59:54 +0200 Subject: [PATCH-0.9.33] MIPS: set _NSIG to 128, not 129. This matches glibc. Prompted by lkml discussion of a MIPS bug where sending signal 128 was found to be able to crash the machine :/ Signed-off-by: Denys Vlasenko --- libc/sysdeps/linux/mips/bits/signum.h | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/libc/sysdeps/linux/mips/bits/signum.h b/libc/sysdeps/linux/mips/bits/signum.h index cf9b834..e83250e 100644 --- a/libc/sysdeps/linux/mips/bits/signum.h +++ b/libc/sysdeps/linux/mips/bits/signum.h @@ -53,7 +53,20 @@ #define SIGXCPU 30 /* CPU limit exceeded (4.2 BSD). */ #define SIGXFSZ 31 /* File size limit exceeded (4.2 BSD). */ -/* Biggest signal number + 1 (including real-time signals). */ -#define _NSIG 129 +/* MIPS is special by having 128 signals. + * All (?) other architectures have at most 64 signals. + * Having 128 signals is problematic because signal nos are 1-based + * and last signal number is then 128. + * This plays havoc with WIFSIGNALED and WCOREDUMP in waitpid status word, + * when process dies from signal 128. + * Linux kernel 3.9 accepts signal 128, with awful results :/ + * It is being fixed. + * + * glibc (accidentally?) papers over this issue by declaring _NSIG to be 128, + * not 129 (despite claiming that _NSIG is "biggest signal number + 1" + * in the comment above that definition). We follow suit. + * Note that this results in __SIGRTMAX == 127. It is intended. + */ +#define _NSIG 128 #endif /* included. */ -- 1.8.1.2