Imbus/xv6-riscv-kernel
1
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

fix corner cases in exec of ELF

Browse source 
put an invalid page below the stack
have fork() handle invalid pages
This commit is contained in:
Robert Morris 2010-08-06 11:12:18 -04:00
parent 1afc9d3fca
commit c4cc10da7e
8 changed files with 84 additions and 37 deletions
Download patch file Download diff file Expand all files Collapse all files

7
exec.c
View file

@ -43,13 +43,16 @@ exec(char *path, char **argv)
goto bad;
if (!allocuvm(pgdir, (char *)ph.va, ph.memsz))
goto bad;
sz += PGROUNDUP(ph.memsz);
if(ph.va + ph.memsz > sz)
sz = ph.va + ph.memsz;
if (!loaduvm(pgdir, (char *)ph.va, ip, ph.offset, ph.filesz))
goto bad;
}
iunlockput(ip);
// Allocate and initialize stack at sz
sz = PGROUNDUP(sz);
sz += PGSIZE; // leave an invalid page
if (!allocuvm(pgdir, (char *)sz, PGSIZE))
goto bad;
mem = uva2ka(pgdir, (char *)sz);
@ -95,7 +98,7 @@ exec(char *path, char **argv)
proc->tf->eip = elf.entry; // main
proc->tf->esp = sp;
loadvm(proc);
switchuvm(proc);
freevm(oldpgdir);