Imbus/xv6-riscv-kernel
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Read curproc from cpu structure, but be careful because after a schedule event

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myproc() points to a different thread.

   myproc();
   sched();
   myproc();  // this proc maybe different than the one before sched

Thus, in a function that operates on one thread better to retrieve the
current process once at the start of the function.
This commit is contained in:
Frans Kaashoek 2017-01-31 20:21:14 -05:00
parent abf847a083
commit fbb4c09444
7 changed files with 97 additions and 62 deletions
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12
sysfile.c
View file

@ -41,10 +41,11 @@ static int
fdalloc(struct file *f)
{
int fd;
struct proc *curproc = myproc();
for(fd = 0; fd < NOFILE; fd++){
if(myproc()->ofile[fd] == 0){
myproc()->ofile[fd] = f;
if(curproc->ofile[fd] == 0){
curproc->ofile[fd] = f;
return fd;
}
}
@ -373,7 +374,8 @@ sys_chdir(void)
{
char *path;
struct inode *ip;
struct proc *curproc = myproc();
begin_op();
if(argstr(0, &path) < 0 || (ip = namei(path)) == 0){
end_op();
@ -386,9 +388,9 @@ sys_chdir(void)
return -1;
}
iunlock(ip);
iput(myproc()->cwd);
iput(curproc->cwd);
end_op();
myproc()->cwd = ip;
curproc->cwd = ip;
return 0;
}