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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15
exec.c
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@ -17,6 +17,7 @@ exec(char *path, char **argv)
struct inode *ip;
struct proghdr ph;
pde_t *pgdir, *oldpgdir;
struct proc *curproc = myproc();
begin_op();
@ -90,15 +91,15 @@ exec(char *path, char **argv)
for(last=s=path; *s; s++)
if(*s == '/')
last = s+1;
safestrcpy(myproc()->name, last, sizeof(myproc()->name));
safestrcpy(curproc->name, last, sizeof(curproc->name));
// Commit to the user image.
oldpgdir = myproc()->pgdir;
myproc()->pgdir = pgdir;
myproc()->sz = sz;
myproc()->tf->eip = elf.entry; // main
myproc()->tf->esp = sp;
switchuvm(myproc());
oldpgdir = curproc->pgdir;
curproc->pgdir = pgdir;
curproc->sz = sz;
curproc->tf->eip = elf.entry; // main
curproc->tf->esp = sp;
switchuvm(curproc);
freevm(oldpgdir);
return 0;