shell nits

fix Regehr complaint
This commit is contained in:
Robert Morris 2016-08-08 13:06:38 -04:00
parent 50edfe1412
commit 0a4a4230a3
2 changed files with 8 additions and 4 deletions

5
sh.c
View file

@ -147,7 +147,7 @@ main(void)
static char buf[100];
int fd;
// Assumes three file descriptors open.
// Ensure that three file descriptors are open.
while((fd = open("console", O_RDWR)) >= 0){
if(fd >= 3){
close(fd);
@ -158,8 +158,7 @@ main(void)
// Read and run input commands.
while(getcmd(buf, sizeof(buf)) >= 0){
if(buf[0] == 'c' && buf[1] == 'd' && buf[2] == ' '){
// Clumsy but will have to do for now.
// Chdir has no effect on the parent if run in the child.
// Chdir must be called by the parent, not the child.
buf[strlen(buf)-1] = 0; // chop \n
if(chdir(buf+3) < 0)
printf(2, "cannot cd %s\n", buf+3);

7
vm.c
View file

@ -237,7 +237,12 @@ allocuvm(pde_t *pgdir, uint oldsz, uint newsz)
return 0;
}
memset(mem, 0, PGSIZE);
mappages(pgdir, (char*)a, PGSIZE, v2p(mem), PTE_W|PTE_U);
if(mappages(pgdir, (char*)a, PGSIZE, v2p(mem), PTE_W|PTE_U) < 0){
cprintf("allocuvm out of memory (2)\n");
deallocuvm(pgdir, newsz, oldsz);
kfree(mem);
return 0;
}
}
return newsz;
}