critical impact:

sigaction, sigset_t - incompatible data types (CrCh112)

Problem description

The sigaction structure and sigset_t type on Tru64 UNIX are incompatible with the ones on HP-UX. Applications that use them in nonstandard ways might need to make code changes.

The sa_mask field of the sigaction structure is a sigset_t. The standard way to clear a signal set is with sigemptyset. On Tru64 UNIX, some programmers take a shortcut and set it to 0 (zero) directly. That is not portable, and will not compile on HP-UX because HP-UX implements sigset_t differently.

The Tru64 UNIX sigaction structure also has a nonstandard sa_signo field that does not exist on HP-UX. Tru64 UNIX applications do not need to set it because the kernel always overwrites whatever they set it to.

Identifiers

sigaction

sigset_t

Old behavior

struct sigaction sa;
sa.sa_handler = handler;
sa.sa_mask  = 0;
sa.sa_flags = 0;
sa.sa_signo = SIGINT;

See also

• Background information on signal specific issues impacts
• sigaction(2)
• sigemptyset(3)

Solution description

Review the applicable manpages and code to determine if you are using these data types in nonstandard ways.

New behavior

struct sigaction sa;
sa.sa_handler = handler;
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;

See also

• sigaction(2)
• sigemptyset(3C)

Problem summary