Michal Hocko edce5e6f33 uio: fix false positive __might_sleep warning splat ... Andy has reported a __might_sleep warning [ 5174.883617] WARNING: CPU: 0 PID: 1532 at /home/agrover/git/kernel/kernel/sched/core.c:7389 __might_sleep+0x7d/0x90() [ 5174.884407] do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffffa02a5821>] uio_read+0x91/0x170 [uio] [ 5174.885198] Modules linked in: tcm_loop target_core_user uio target_core_pscsi target_core_file target_core_iblock iscsi_target_mod target_core_mod uinput fuse nfsv3 nfs_acl nfs lockd grace fscache sunrpc microcode i2c_piix4 virtio_balloon i2c_core xfs libcrc32c crc32c_intel virtio_net virtio_blk [ 5174.887351] CPU: 0 PID: 1532 Comm: tcmu-runner Not tainted 4.2.0-rc7+ [ 5174.887853] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 [ 5174.888633] ffffffff81a3b870 ffff880045393ca8 ffffffff817afaae 0000000000000000 [ 5174.889224] ffff880045393cf8 ffff880045393ce8 ffffffff8109a846 ffff880045393cd8 [ 5174.889793] ffffffffa02a7150 00000000000002dc 0000000000000000 ffff880045008000 [ 5174.890375] Call Trace: [ 5174.890562] [<ffffffff817afaae>] dump_stack+0x4c/0x65 [ 5174.890938] [<ffffffff8109a846>] warn_slowpath_common+0x86/0xc0 [ 5174.891388] [<ffffffff8109a8c6>] warn_slowpath_fmt+0x46/0x50 [ 5174.891808] [<ffffffffa02a5821>] ? uio_read+0x91/0x170 [uio] [ 5174.892237] [<ffffffffa02a5821>] ? uio_read+0x91/0x170 [uio] [ 5174.892653] [<ffffffff810c584d>] __might_sleep+0x7d/0x90 [ 5174.893055] [<ffffffff811ea023>] __might_fault+0x43/0xa0 [ 5174.893448] [<ffffffff817b31ce>] ? schedule+0x3e/0x90 [ 5174.893820] [<ffffffffa02a58c2>] uio_read+0x132/0x170 [uio] [ 5174.894240] [<ffffffff810cbb80>] ? wake_up_q+0x70/0x70 [ 5174.894620] [<ffffffff81236168>] __vfs_read+0x28/0xe0 [ 5174.894993] [<ffffffff81353233>] ? security_file_permission+0xa3/0xc0 [ 5174.895541] [<ffffffff8123678f>] ? rw_verify_area+0x4f/0xf0 [ 5174.896006] [<ffffffff812368ba>] vfs_read+0x8a/0x140 [ 5174.896391] [<ffffffff817b28f5>] ? __schedule+0x425/0xcc0 [ 5174.896788] [<ffffffff812375d9>] SyS_read+0x49/0xb0 The warning is a false positive because uio_read doesn't depent on TASK_INTERRUPTIBLE after copy_to_user so it is safe to silence the warning by an explicit setting the state to TASK_RUNNING in the path which might call into TASK_RUNNING. Reported-by: Andy Grover <agrover@redhat.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2015-10-04 12:32:25 +01:00
..
Kconfig	uio: UIO_PRUSS should depend on HAS_DMA	2015-08-05 13:25:59 -07:00
Makefile
uio.c	uio: fix false positive __might_sleep warning splat	2015-10-04 12:32:25 +01:00
uio_aec.c
uio_cif.c
uio_dmem_genirq.c
uio_fsl_elbc_gpcm.c	uio: uio_fsl_elbc_gpcm: Fix module autoload for OF platform driver	2015-10-04 12:32:25 +01:00
uio_mf624.c
uio_netx.c
uio_pci_generic.c
uio_pdrv_genirq.c
uio_pruss.c
uio_sercos3.c