-@code{sigsetjmp}, and functions @code{_setjmp} and @code{_longjmp} are
-available that don't save or restore the signal mask. On System V platforms,
-and on glibc platforms by default, @code{setjmp} doesn't save the signal mask.
+@code{sigsetjmp(.,1)}, and functions @code{_setjmp} and @code{_longjmp} are
+available that don't save or restore the signal mask. On System V platforms
+(excluding HP-UX), and on glibc platforms by default, @code{setjmp} doesn't
+save the signal mask.