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Finn Thain 427c5ce441 block/swim3: Fix regression on PowerBook G3
As of v4.20, the swim3 driver crashes when loaded on a PowerBook G3
(Wallstreet).

MacIO PCI driver attached to Gatwick chipset
MacIO PCI driver attached to Heathrow chipset
swim3 0.00015000:floppy: [fd0] SWIM3 floppy controller in media bay
0.00013020:ch-a: ttyS0 at MMIO 0xf3013020 (irq = 16, base_baud = 230400) is a Z85c30 ESCC - Serial port
0.00013000:ch-b: ttyS1 at MMIO 0xf3013000 (irq = 17, base_baud = 230400) is a Z85c30 ESCC - Infrared port
macio: fixed media-bay irq on gatwick
macio: fixed left floppy irqs
swim3 1.00015000:floppy: [fd1] Couldn't request interrupt
Unable to handle kernel paging request for data at address 0x00000024
Faulting instruction address: 0xc02652f8
Oops: Kernel access of bad area, sig: 11 [#1]
BE SMP NR_CPUS=2 PowerMac
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.20.0 #2
NIP:  c02652f8 LR: c026915c CTR: c0276d1c
REGS: df43ba10 TRAP: 0300   Not tainted  (4.20.0)
MSR:  00009032 <EE,ME,IR,DR,RI>  CR: 28228288  XER: 00000100
DAR: 00000024 DSISR: 40000000
GPR00: c026915c df43bac0 df439060 c0731524 df494700 00000000 c06e1c08 00000001
GPR08: 00000001 00000000 df5ff220 00001032 28228282 00000000 c0004ca4 00000000
GPR16: 00000000 00000000 00000000 c073144c dfffe064 c0731524 00000120 c0586108
GPR24: c073132c c073143c c073143c 00000000 c0731524 df67cd70 df494700 00000001
NIP [c02652f8] blk_mq_free_rqs+0x28/0xf8
LR [c026915c] blk_mq_sched_tags_teardown+0x58/0x84
Call Trace:
[df43bac0] [c0045f50] flush_workqueue_prep_pwqs+0x178/0x1c4 (unreliable)
[df43bae0] [c026915c] blk_mq_sched_tags_teardown+0x58/0x84
[df43bb00] [c02697f0] blk_mq_exit_sched+0x9c/0xb8
[df43bb20] [c0252794] elevator_exit+0x84/0xa4
[df43bb40] [c0256538] blk_exit_queue+0x30/0x50
[df43bb50] [c0256640] blk_cleanup_queue+0xe8/0x184
[df43bb70] [c034732c] swim3_attach+0x330/0x5f0
[df43bbb0] [c034fb24] macio_device_probe+0x58/0xec
[df43bbd0] [c032ba88] really_probe+0x1e4/0x2f4
[df43bc00] [c032bd28] driver_probe_device+0x64/0x204
[df43bc20] [c0329ac4] bus_for_each_drv+0x60/0xac
[df43bc50] [c032b824] __device_attach+0xe8/0x160
[df43bc80] [c032ab38] bus_probe_device+0xa0/0xbc
[df43bca0] [c0327338] device_add+0x3d8/0x630
[df43bcf0] [c0350848] macio_add_one_device+0x444/0x48c
[df43bd50] [c03509f8] macio_pci_add_devices+0x168/0x1bc
[df43bd90] [c03500ec] macio_pci_probe+0xc0/0x10c
[df43bda0] [c02ad884] pci_device_probe+0xd4/0x184
[df43bdd0] [c032ba88] really_probe+0x1e4/0x2f4
[df43be00] [c032bd28] driver_probe_device+0x64/0x204
[df43be20] [c032bfcc] __driver_attach+0x104/0x108
[df43be40] [c0329a00] bus_for_each_dev+0x64/0xb4
[df43be70] [c032add8] bus_add_driver+0x154/0x238
[df43be90] [c032ca24] driver_register+0x84/0x148
[df43bea0] [c0004aa0] do_one_initcall+0x40/0x188
[df43bf00] [c0690100] kernel_init_freeable+0x138/0x1d4
[df43bf30] [c0004cbc] kernel_init+0x18/0x10c
[df43bf40] [c00121e4] ret_from_kernel_thread+0x14/0x1c
Instruction dump:
5484d97e 4bfff4f4 9421ffe0 7c0802a6 bf410008 7c9e2378 90010024 8124005c
2f890000 419e0078 81230004 7c7c1b78 <81290024> 2f890000 419e0064 81440000
---[ end trace 12025ab921a9784c ]---

Reverting commit 8ccb8cb189 ("swim3: convert to blk-mq") resolves the
problem.

That commit added a struct blk_mq_tag_set to struct floppy_state and
initialized it with a blk_mq_init_sq_queue() call. Unfortunately, there
is a memset() in swim3_add_device() that subsequently clears the
floppy_state struct. That means fs->tag_set->ops is a NULL pointer, and
it gets dereferenced by blk_mq_free_rqs() which gets called in the
request_irq() error path. Move the memset() to fix this bug.

BTW, the request_irq() failure for the left mediabay floppy (fd1) is not
a regression. I don't know why it happens. The right media bay floppy
(fd0) works fine however.

Reported-and-tested-by: Stan Johnson <userm57@yahoo.com>
Fixes: 8ccb8cb189 ("swim3: convert to blk-mq")
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-31 10:19:19 -07:00
Documentation block: update sysfs documentation 2018-12-16 19:53:06 -07:00
LICENSES This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-09 15:12:33 -08:00
block bsg: deprecate BIDI support in bsg 2018-12-21 08:47:58 -07:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto crypto: user - Disable statistics interface 2018-12-07 13:56:08 +08:00
drivers block/swim3: Fix regression on PowerBook G3 2018-12-31 10:19:19 -07:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Linux 4.20-rc6 2018-12-09 17:45:40 -07:00
include blkcg: clean up blkg_tryget_closest() 2018-12-21 08:47:05 -07:00
init Linux 4.20-rc5 2018-12-04 09:38:05 -07:00
ipc ipc: IPCMNI limit check for semmni 2018-10-31 08:54:14 -07:00
kernel Linux 4.20-rc6 2018-12-09 17:45:40 -07:00
lib iov_iter: introduce hash_and_copy_to_iter helper 2018-12-13 09:58:54 +01:00
mm Linux 4.20-rc6 2018-12-09 17:45:40 -07:00
net datagram: introduce skb_copy_and_hash_datagram_iter helper 2018-12-13 09:58:55 +01:00
samples VFIO updates for v4.20 2018-10-31 11:01:38 -07:00
scripts Fixes for stackleak 2018-12-07 13:13:07 -08:00
security selinux/stable-4.20 PR 20181129 2018-11-29 10:15:06 -08:00
sound ALSA: hda/realtek: Fix mic issue on Acer AIO Veriton Z4860G/Z6860G 2018-12-05 16:39:59 +01:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-09 15:12:33 -08:00
usr initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
virt Revert "mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks" 2018-10-26 16:25:19 -07:00
.clang-format page cache: Convert find_get_pages_contig to XArray 2018-10-21 10:46:34 -04:00
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.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
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.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
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CREDITS MAINTAINERS: change Sparse's maintainer 2018-11-25 09:17:43 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-09 15:12:33 -08:00
Makefile Linux 4.20-rc6 2018-12-09 15:31:00 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.