vaddr              28 elf.h            uint vaddr;
vaddr              50 exec.c             if(ph.vaddr + ph.memsz < ph.vaddr)
vaddr              52 exec.c             if((sz = allocuvm(pgdir, sz, ph.vaddr + ph.memsz)) == 0)
vaddr              54 exec.c             if(ph.vaddr % PGSIZE != 0)
vaddr              56 exec.c             if(loaduvm(pgdir, (char*)ph.vaddr, ip, ph.off, ph.filesz) < 0)