linux-stable.git/drivers/block/brd.c, branch linux-5.4.y

brd: check and limit max_part par

2020-02-24T07:37:02+00:00

[ Upstream commit c8ab422553c81a0eb070329c63725df1cd1425bc ]

In brd_init func, rd_nr num of brd_device are firstly allocated
and add in brd_devices, then brd_devices are traversed to add each
brd_device by calling add_disk func. When allocating brd_device,
the disk->first_minor is set to i * max_part, if rd_nr * max_part
is larger than MINORMASK, two different brd_device may have the same
devt, then only one of them can be successfully added.
when rmmod brd.ko, it will cause oops when calling brd_exit.

Follow those steps:
  # modprobe brd rd_nr=3 rd_size=102400 max_part=1048576
  # rmmod brd
then, the oops will appear.

Oops log:
[  726.613722] Call trace:
[  726.614175]  kernfs_find_ns+0x24/0x130
[  726.614852]  kernfs_find_and_get_ns+0x44/0x68
[  726.615749]  sysfs_remove_group+0x38/0xb0
[  726.616520]  blk_trace_remove_sysfs+0x1c/0x28
[  726.617320]  blk_unregister_queue+0x98/0x100
[  726.618105]  del_gendisk+0x144/0x2b8
[  726.618759]  brd_exit+0x68/0x560 [brd]
[  726.619501]  __arm64_sys_delete_module+0x19c/0x2a0
[  726.620384]  el0_svc_common+0x78/0x130
[  726.621057]  el0_svc_handler+0x38/0x78
[  726.621738]  el0_svc+0x8/0xc
[  726.622259] Code: aa0203f6 aa0103f7 aa1e03e0 d503201f (7940e260)

Here, we add brd_check_and_reset_par func to check and limit max_part par.

--
V5->V6:
 - remove useless code

V4->V5:(suggested by Ming Lei)
 - make sure max_part is not larger than DISK_MAX_PARTS

V3->V4:(suggested by Ming Lei)
 - remove useless change
 - add one limit of max_part

V2->V3: (suggested by Ming Lei)
 - clear .minors when running out of consecutive minor space in brd_alloc
 - remove limit of rd_nr

V1->V2:
 - add more checks in brd_check_par_valid as suggested by Ming Lei.

Signed-off-by: Zhiqiang Liu 
Reviewed-by: Bob Liu 
Reviewed-by: Ming Lei 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

treewide: Add SPDX license identifier for more missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have MODULE_LICENCE("GPL*") inside which was used in the initial
   scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

brd: add cond_resched to brd_free_pages

2019-05-09T18:51:27+00:00

The loop that frees all the pages can take unbounded amount of time, so
add cond_resched() to it.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Jens Axboe

brd: re-enable __GFP_HIGHMEM in brd_insert_page()

2019-04-22T15:48:12+00:00

__GFP_HIGHMEM is disabled if dax is enabled on brd, however
dax support for brd has been removed since commit (7a862fbbdec6
"brd: remove dax support"), so restore __GFP_HIGHMEM in
brd_insert_page().

Also remove the no longer applicable comments about DAX and highmem.

Cc: stable@vger.kernel.org
Fixes: 7a862fbbdec6 ("brd: remove dax support")
Signed-off-by: Hou Tao 
Signed-off-by: Jens Axboe

block: brd: associate with queue until adding disk

2018-11-02T01:59:51+00:00

brd_free() may be called in failure path on one brd instance which
disk isn't added yet, so release handler of gendisk may free the
associated request_queue early and causes the following use-after-free[1].

This patch fixes this issue by associating gendisk with request_queue
just before adding disk.

[1] KASAN: use-after-free Read in del_timer_syncNon-volatile memory driver v1.3
Linux agpgart interface v0.103
[drm] Initialized vgem 1.0.0 20120112 for virtual device on minor 0
usbcore: registered new interface driver udl
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x36d9/0x4c20
kernel/locking/lockdep.c:3218
Read of size 8 at addr ffff8801d1b6b540 by task swapper/0/1

CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x244/0x39d lib/dump_stack.c:113
  print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
  __lock_acquire+0x36d9/0x4c20 kernel/locking/lockdep.c:3218
  lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844
  del_timer_sync+0xb7/0x270 kernel/time/timer.c:1283
  blk_cleanup_queue+0x413/0x710 block/blk-core.c:809
  brd_free+0x5d/0x71 drivers/block/brd.c:422
  brd_init+0x2eb/0x393 drivers/block/brd.c:518
  do_one_initcall+0x145/0x957 init/main.c:890
  do_initcall_level init/main.c:958 [inline]
  do_initcalls init/main.c:966 [inline]
  do_basic_setup init/main.c:984 [inline]
  kernel_init_freeable+0x5c6/0x6b9 init/main.c:1148
  kernel_init+0x11/0x1ae init/main.c:1068
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:350

Reported-by: syzbot+3701447012fe951dabb2@syzkaller.appspotmail.com
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe

block: make bdev_ops->rw_page() take a REQ_OP instead of bool

2018-07-18T14:44:14+00:00

c11f0c0b5bb9 ("block/mm: make bdev_ops->rw_page() take a bool for
read/write") replaced @op with boolean @is_write, which limited the
amount of information going into ->rw_page() and more importantly
page_endio(), which removed the need to expose block internals to mm.

Unfortunately, we want to track discards separately and @is_write
isn't enough information.  This patch updates bdev_ops->rw_page() to
take REQ_OP instead but leaves page_endio() to take bool @is_write.
This allows the block part of operations to have enough information
while not leaking it to mm.

Signed-off-by: Tejun Heo 
Cc: Mike Christie 
Cc: Minchan Kim 
Cc: Dan Williams 
Signed-off-by: Jens Axboe

block drivers/block: Use octal not symbolic permissions

2018-05-24T19:38:59+00:00

Convert the S_ symbolic permissions to their octal equivalents as
using octal and not symbolic permissions is preferred by many as more
readable.

see: https://lkml.org/lkml/2016/8/2/1945

Done with automated conversion via:
$ ./scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace 

Miscellanea:

o Wrapped modified multi-line calls to a single line where appropriate
o Realign modified multi-line calls to open parenthesis

Signed-off-by: Joe Perches 
Signed-off-by: Jens Axboe

brd: Mark as non-rotational

2018-05-09T14:43:57+00:00

This commit sets QUEUE_FLAG_NONROT and clears up QUEUE_FLAG_ADD_RANDOM
to mark the ramdisks as non-rotational device.

Signed-off-by: SeongJae Park 
Signed-off-by: Jens Axboe

block: Move SECTOR_SIZE and SECTOR_SHIFT definitions into

2018-03-17T20:45:23+00:00

It happens often while I'm preparing a patch for a block driver that
I'm wondering: is a definition of SECTOR_SIZE and/or SECTOR_SHIFT
available for this driver? Do I have to introduce definitions of these
constants before I can use these constants? To avoid this confusion,
move the existing definitions of SECTOR_SIZE and SECTOR_SHIFT into the
 header file such that these become available for all
block drivers. Make the SECTOR_SIZE definition in the uapi msdos_fs.h
header file conditional to avoid that including that header file after
 causes the compiler to complain about a SECTOR_SIZE
redefinition.

Note: the SECTOR_SIZE / SECTOR_SHIFT / SECTOR_BITS definitions have
not been removed from uapi header files nor from NAND drivers in
which these constants are used for another purpose than converting
block layer offsets and sizes into a number of sectors.

Cc: David S. Miller 
Cc: Mike Snitzer 
Cc: Dan Williams 
Cc: Minchan Kim 
Cc: Nitin Gupta 
Reviewed-by: Sergey Senozhatsky 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Martin K. Petersen 
Signed-off-by: Bart Van Assche 
Signed-off-by: Jens Axboe

genhd: Rename get_disk() to get_disk_and_module()

2018-02-26T16:48:42+00:00

Rename get_disk() to get_disk_and_module() to make sure what the
function does. It's not a great name but at least it is now clear that
put_disk() is not it's counterpart.

Signed-off-by: Jan Kara 
Signed-off-by: Jens Axboe