* Alejandro Colomar: > Hi all, > > On 1/31/22 10:29, Ivan Zuboff wrote: >> Hello! >> >> Man page says: >> SA_ONSTACK >> Call the signal handler on an alternate signal stack >> provided by sigaltstack(2). *If an alternate stack is not >> available, the default stack will be used.* This flag is >> meaningful only when establishing a signal handler. >> https://man7.org/linux/man-pages/man2/sigaction.2.html >> >> glibc reference manual says: >> Macro: int SA_ONSTACK >> If this flag is set for a particular signal number, the system uses >> the signal stack when delivering that kind of signal. See Signal >> Stack. *If a signal with this flag arrives and you have not set a >> signal stack, the system terminates the program with SIGILL.* >> https://www.gnu.org/software/libc/manual/html_node/Flags-for-Sigaction.html >> >> As far as I understand, statements in *stars* are in conflict. glibc >> documentation says that "While the glibc manual remains the canonical >> source for API descriptions, the man-pages are an excellent >> reference.", so I decided to mail you supposing that man page is >> incorrect in this regard. >> https://www.gnu.org/software/libc/documentation.html >> >> Please correct me if I'm wrong. Also, sorry for my bad English, this >> is not my native language. >> >> Best regards, >> Ivan > > I received this bug report on linux-man@. The report is about a text > that predates git in the man-pages. Could you please confirm the bug, > and check if anything else needs to be fixed too? It's a bug in the glibc documentation. POSIX says: | SA_ONSTACK | [XSI] [Option Start] If set and an alternate signal stack has been | declared with sigaltstack(), the signal shall be delivered to the | calling process on that stack. Otherwise, the signal shall be | delivered on the current stack. [Option End] And that's also the Linux behavior. Thanks, Florian
