Dmitry Torokhov <dmitry.torok...@gmail.com> writes: > We do not ever intend to unregister "user" sysctl table, unfortunately > it leads kmemleak to believe that we are leaking memory:
Sounds like an issue with kmemleak because we do retain references. So no we don't intend to unregister the table. As for the patch. Nacked-by: "Eric W. Biederman" <ebied...@xmission.com> I can't see the using kmemleak_not_leak is possibly good form. I would much rather have suggestions about constructs that won't confuse kmemleak and won't need ugly annotations that serve no purpose but to appease a tool. Perhaps the user_header variable needs to be moved out of user_namespace_sysctl_init. Eric > unreferenced object 0xffff8807383bfd48 (size 96): > comm "swapper/0", pid 1, jiffies 4294894636 (age 278.320s) > hex dump (first 32 bytes): > a0 b4 b0 ba ff ff ff ff 00 00 00 00 01 00 00 00 ................ > 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<ffffffffb7de59e8>] kmemleak_alloc+0x28/0x50 > [<ffffffffb676e2f6>] __kmalloc+0x206/0x5a0 > [<ffffffffb69be2d3>] __register_sysctl_table+0xb3/0x1130 > [<ffffffffb69bf36b>] register_sysctl+0x1b/0x20 > [<ffffffffba840de1>] user_namespace_sysctl_init+0x17/0x4c > [<ffffffffb60022b7>] do_one_initcall+0xb7/0x2a0 > [<ffffffffba7eb102>] kernel_init_freeable+0x597/0x636 > [<ffffffffb7de0433>] kernel_init+0x13/0x140 > [<ffffffffb7dfb36a>] ret_from_fork+0x2a/0x40t show > [<ffffffffffffffff>] 0xffffffffffffffff > > Let's annotate the pointer as kmemleak_not_leak() to suppress the > kmemleak false positive. > > Reported-by: Jakub Kicinski <kubak...@wp.pl> > Signed-off-by: Dmitry Torokhov <dmitry.torok...@gmail.com> > --- > > This was only compiled; Jakub, could you give it a spin? > > kernel/ucount.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/ucount.c b/kernel/ucount.c > index 9d20d5d..07d69b2 100644 > --- a/kernel/ucount.c > +++ b/kernel/ucount.c > @@ -5,6 +5,7 @@ > * License. > */ > > +#include <linux/kmemleak.h> > #include <linux/stat.h> > #include <linux/sysctl.h> > #include <linux/slab.h> > @@ -226,6 +227,7 @@ static __init int user_namespace_sysctl_init(void) > */ > user_header = register_sysctl("user", empty); > BUG_ON(!user_header); > + kmemleak_not_leak(user_header); > BUG_ON(!setup_userns_sysctls(&init_user_ns)); > #endif > return 0; > -- > 2.8.0.rc3.226.g39d4020