sbrk 171 user/lib/libc/stdlib/malloc.c x = sbrk(0); sbrk 189 user/lib/libc/stdlib/malloc.c x = sbrk(adjust); sbrk 267 user/lib/libc/stdlib/malloc.c x = sbrk(size); sbrk 51 user/testbin/badcall/bad_sbrk.c rv = sbrk(val); sbrk 112 user/testbin/zero/zero.c base = sbrk(SBRK_SIZE);