On Tue, 2012-01-24 at 12:34 -0500, Mimi Zohar wrote: > The circular lockdep is caused by allocating the 'iint' for mmapped > files. Originally when an 'iint' was allocated for every inode > in inode_alloc_security(), before the inode was accessible, no > locking was necessary. Commits bc7d2a3e and 196f518 changed this > behavior and allocated the 'iint' on a per need basis, resulting in > the mmap_sem being taken before the i_mutex for mmapped files. > > Possible unsafe locking scenario: > CPU0 CPU1 > ---- ---- > lock(&mm->mmap_sem); > lock(&sb->s_type->i_mutex_key); > lock(&mm->mmap_sem); > lock(&sb->s_type->i_mutex_key); > > The existing security_file_mmap() hook is after the mmap_sem is taken. > This patch moves the ima_file_mmap() call from security_file_mmap() to > prior to the mmap_sem being taken. > > Changelog v1: > - Instead of just pre-allocating the iint in a new hook, do ALL of the > work in the new/moved ima_file_mmap() hook. (Based on Eric Paris' suggestion.) > - Removed do_mmap_with_sem() helper function. > - export ima_file_mmap() Why does it need to be exported? What module might call this? -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
