diff options
| author | John Garry <john.garry@huawei.com> | 2019-10-16 13:19:52 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-10-31 22:18:54 +0300 |
| commit | 130f4caf145c3562108b245a576db30b916199d2 (patch) | |
| tree | f065c1f10250b236659c9ab6d7d75b468b13dd04 /Documentation/driver-api | |
| parent | e964a17d8c6356b86aab4cdc3ea7fdc2abd21352 (diff) | |
| download | linux-130f4caf145c3562108b245a576db30b916199d2.tar.xz | |
libata: Ensure ata_port probe has completed before detach
With CONFIG_DEBUG_TEST_DRIVER_REMOVE set, we may find the following WARN:
[ 23.452574] ------------[ cut here ]------------
[ 23.457190] WARNING: CPU: 59 PID: 1 at drivers/ata/libata-core.c:6676 ata_host_detach+0x15c/0x168
[ 23.466047] Modules linked in:
[ 23.469092] CPU: 59 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc1-00010-g5b83fd27752b-dirty #296
[ 23.477776] Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI RC0 - V1.16.01 03/15/2019
[ 23.486286] pstate: a0c00009 (NzCv daif +PAN +UAO)
[ 23.491065] pc : ata_host_detach+0x15c/0x168
[ 23.495322] lr : ata_host_detach+0x88/0x168
[ 23.499491] sp : ffff800011cabb50
[ 23.502792] x29: ffff800011cabb50 x28: 0000000000000007
[ 23.508091] x27: ffff80001137f068 x26: ffff8000112c0c28
[ 23.513390] x25: 0000000000003848 x24: ffff0023ea185300
[ 23.518689] x23: 0000000000000001 x22: 00000000000014c0
[ 23.523987] x21: 0000000000013740 x20: ffff0023bdc20000
[ 23.529286] x19: 0000000000000000 x18: 0000000000000004
[ 23.534584] x17: 0000000000000001 x16: 00000000000000f0
[ 23.539883] x15: ffff0023eac13790 x14: ffff0023eb76c408
[ 23.545181] x13: 0000000000000000 x12: ffff0023eac13790
[ 23.550480] x11: ffff0023eb76c228 x10: 0000000000000000
[ 23.555779] x9 : ffff0023eac13798 x8 : 0000000040000000
[ 23.561077] x7 : 0000000000000002 x6 : 0000000000000001
[ 23.566376] x5 : 0000000000000002 x4 : 0000000000000000
[ 23.571674] x3 : ffff0023bf08a0bc x2 : 0000000000000000
[ 23.576972] x1 : 3099674201f72700 x0 : 0000000000400284
[ 23.582272] Call trace:
[ 23.584706] ata_host_detach+0x15c/0x168
[ 23.588616] ata_pci_remove_one+0x10/0x18
[ 23.592615] ahci_remove_one+0x20/0x40
[ 23.596356] pci_device_remove+0x3c/0xe0
[ 23.600267] really_probe+0xdc/0x3e0
[ 23.603830] driver_probe_device+0x58/0x100
[ 23.608000] device_driver_attach+0x6c/0x90
[ 23.612169] __driver_attach+0x84/0xc8
[ 23.615908] bus_for_each_dev+0x74/0xc8
[ 23.619730] driver_attach+0x20/0x28
[ 23.623292] bus_add_driver+0x148/0x1f0
[ 23.627115] driver_register+0x60/0x110
[ 23.630938] __pci_register_driver+0x40/0x48
[ 23.635199] ahci_pci_driver_init+0x20/0x28
[ 23.639372] do_one_initcall+0x5c/0x1b0
[ 23.643199] kernel_init_freeable+0x1a4/0x24c
[ 23.647546] kernel_init+0x10/0x108
[ 23.651023] ret_from_fork+0x10/0x18
[ 23.654590] ---[ end trace 634a14b675b71c13 ]---
With KASAN also enabled, we may also get many use-after-free reports.
The issue is that when CONFIG_DEBUG_TEST_DRIVER_REMOVE is set, we may
attempt to detach the ata_port before it has been probed.
This is because the ata_ports are async probed, meaning that there is no
guarantee that the ata_port has probed prior to detach. When the ata_port
does probe in this scenario, we get all sorts of issues as the detach may
have already happened.
Fix by ensuring synchronisation with async_synchronize_full(). We could
alternatively use the cookie returned from the ata_port probe
async_schedule() call, but that means managing the cookie, so more
complicated.
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'Documentation/driver-api')
0 files changed, 0 insertions, 0 deletions