sbrk
extern void *sbrk(int increment);
brk_end = PAGE_ALIGN((unsigned long) sbrk(0));
brk_start = (unsigned long) sbrk(0);
CASE_TEST(sbrk_0); EXPECT_PTRNE(has_brk, sbrk(0), (void *)-1); break;
CASE_TEST(sbrk); if ((p1 = p2 = sbrk(4096)) != (void *)-1) p2 = sbrk(-4096); EXPECT_SYSZR(has_brk, (p2 == (void *)-1) || p2 == p1); break;
CASE_TEST(brk); EXPECT_SYSZR(has_brk, brk(sbrk(0))); break;
char *brk = sbrk(0) != (void *)-1 ? sbrk(0) : &end;
void *addr = sbrk(0);