diff options
Diffstat (limited to 'kernel/acct.c')
| -rw-r--r-- | kernel/acct.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/kernel/acct.c b/kernel/acct.c index cef9aca85..eeab054d0 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -37,6 +37,10 @@ * one race (and leak) in BSD implementation. * OK, that's better. ANOTHER race and leak in BSD variant. There always * is one more bug... 10/11/98, AV. + * + * Oh, fsck... Oopsable SMP race in do_process_acct() - we must hold + * ->mmap_sem to walk the vma list of current->mm. Nasty, since it leaks + * a struct file opened for write. Fixed. 2/6/2000, AV. */ #include <linux/config.h> @@ -66,7 +70,6 @@ int acct_parm[3] = {4, 2, 30}; /* * External references and all of the globals. */ -void acct_timeout(unsigned long); static volatile int acct_active; static volatile int acct_needcheck; @@ -77,7 +80,7 @@ static int do_acct_process(long, struct file *); /* * Called whenever the timer says to check the free space. */ -void acct_timeout(unsigned long unused) +static void acct_timeout(unsigned long unused) { acct_needcheck = 1; } @@ -303,11 +306,14 @@ static int do_acct_process(long exitcode, struct file *file) vsize = 0; if (current->mm) { - struct vm_area_struct *vma = current->mm->mmap; + struct vm_area_struct *vma; + down(¤t->mm->mmap_sem); + vma = current->mm->mmap; while (vma) { vsize += vma->vm_end - vma->vm_start; vma = vma->vm_next; } + up(¤t->mm->mmap_sem); } vsize = vsize / 1024; ac.ac_mem = encode_comp_t(vsize); |