On Wed, Dec 11 2013, Francis Moreau wrote: > On 12/11/2013 12:14 PM, Greg KH wrote: >> On Wed, Dec 11, 2013 at 10:13:29AM +0100, Francis Moreau wrote: >>> Hi Greg (KH), >>> >>> On 12/10/2013 11:44 AM, Francis Moreau wrote: >>>> Hi Greg, >>>> >>>> I'm wondering if the patch you already submitted for 3.10, 3.11 and 3.12 >>>> stable trees is also required by 3.4 stable one ? >>>> >>>> The patch I'm talking about is "ipc,shm: fix shm_file deletion races" >>> >>> Maybe you have an idea ? >> >> Let me turn it around the other way, why do you think it is needed for >> 3.4? Does it apply there? Do you have this problem with the 3.4 >> kernel? > > After a quick look at the patch, I *think* 3.4 is suffering the same > issue (maybe older kernels do too): it also does the "fput()" thing > after releasing the lock. > > But I'm really not sure. > > And no I haven't met this problem with 3.4. > > Thanks. I don't think that 3.4 suffers the same problem. So I don't see any reason to apply "fix shm_file deletion races" to 3.4.x. 3.4 is immune because it use exclusive locking (spinlock) for shm-id-to-shm-object conversions (shm_lock_check() in shmctl()). Newer kernels use rcu protected schemes so more races are possible. Furthermore, I ran some quick tests on v3.4.71 and did not find any crashes. So I don't think 3.4.x needs this patch. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html