sigaltstack
int sigaltstack(const stack_t * __restrict, stack_t * __restrict);
typedef int (__sys_sigaltstack_t)(const struct sigaltstack *, struct sigaltstack *);
int __sys_sigaltstack(const struct sigaltstack * ss, struct sigaltstack * oss);
struct sigaltstack;
struct sigaltstack ss, oss, *ssp;
LINUX_CTR2(sigaltstack, "%p, %p", uap->uss, uap->uoss);
#define __stack_t sigaltstack
char ss_l_[PADL_(const struct sigaltstack *)]; const struct sigaltstack * ss; char ss_r_[PADR_(const struct sigaltstack *)];
char oss_l_[PADL_(struct sigaltstack *)]; struct sigaltstack * oss; char oss_r_[PADR_(struct sigaltstack *)];
ATF_REQUIRE(sigaltstack(&ss, NULL) == 0);
EXPECT_OK(sigaltstack(NULL, &ss));
ATF_REQUIRE(sigaltstack(&ss, &oss) == 0);
if (sigaltstack(&ssa, NULL) == -1)