Imbus/xv6-riscv-kernel
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PDF at http://am.lcs.mit.edu/~rsc/xv6.pdf

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Various changes made while offline.

 + bwrite sector argument is redundant; use b->sector.
 + reformatting of files for nicer PDF page breaks
 + distinguish between locked, unlocked inodes in type signatures
 + change FD_FILE to FD_INODE
 + move userinit (nee proc0init) to proc.c
 + move ROOTDEV to param.h
 + always parenthesize sizeof argument
This commit is contained in:
rsc 2007-08-22 06:01:32 +00:00
parent 3dcf889c1b
commit eaea18cb9c
25 changed files with 637 additions and 669 deletions
Download patch file Download diff file Expand all files Collapse all files

22
exec.c
View file

@ -19,7 +19,7 @@ int
exec(char *path, char **argv)
{
uint sz, sp, p1, p2;
int i, nargs, argbytes, len;
int i, nargs, argbytes, len, off;
struct inode *ip;
struct elfhdr elf;
struct proghdr ph;
@ -29,7 +29,7 @@ exec(char *path, char **argv)
sz = 0;
mem = 0;
if((ip = namei(path)) == 0)
if((ip = ilock(namei(path))) == 0)
return -1;
if(readi(ip, (char*)&elf, 0, sizeof(elf)) < sizeof(elf))
@ -38,9 +38,8 @@ exec(char *path, char **argv)
if(elf.magic != ELF_MAGIC)
goto bad;
for(i = 0; i < elf.phnum; i++){
if(readi(ip, (char*)&ph, elf.phoff + i * sizeof(ph),
sizeof(ph)) != sizeof(ph))
for(i=0, off=elf.phoff; i<elf.phnum; i++, off+=sizeof(ph)){
if(readi(ip, (char*)&ph, off, sizeof(ph)) != sizeof(ph))
goto bad;
if(ph.type != ELF_PROG_LOAD)
continue;
@ -94,7 +93,7 @@ exec(char *path, char **argv)
for(last=s=path; *s; s++)
if(*s == '/')
last = s+1;
safestrcpy(cp->name, last, sizeof cp->name);
safestrcpy(cp->name, last, sizeof(cp->name));
// commit to the new image.
kfree(cp->mem, cp->sz);
@ -102,9 +101,8 @@ exec(char *path, char **argv)
cp->mem = mem;
mem = 0;
for(i = 0; i < elf.phnum; i++){
if(readi(ip, (char*)&ph, elf.phoff + i * sizeof(ph),
sizeof(ph)) != sizeof(ph))
for(i=0, off=elf.phoff; i<elf.phnum; i++, off+=sizeof(ph)){
if(readi(ip, (char*)&ph, off, sizeof(ph)) != sizeof(ph))
goto bad2;
if(ph.type != ELF_PROG_LOAD)
continue;
@ -115,7 +113,7 @@ exec(char *path, char **argv)
memset(cp->mem + ph.va + ph.filesz, 0, ph.memsz - ph.filesz);
}
iput(ip);
iput(iunlock(ip));
cp->tf->eip = elf.entry;
cp->tf->esp = sp;
@ -126,11 +124,11 @@ exec(char *path, char **argv)
bad:
if(mem)
kfree(mem, sz);
iput(ip);
iput(iunlock(ip));
return -1;
bad2:
iput(ip);
iput(iunlock(ip));
proc_exit();
return 0;
}