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.
code
Clone this repository
https://tangled.org/tjh.dev/kernel
git@gordian.tjh.dev:tjh.dev/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Pull block fix from Jens Axboe:
"Just a single fix for a patch from Greg KH, which reportedly break
block debugfs locations for certain setups. Trivial enough that I
think we should include it now, rather than wait and release 5.2 with
it, since it's a regression in this series"
* tag 'for-linus-20190706' of git://git.kernel.dk/linux-block:
blk-mq: fix up placement of debugfs directory of queue files
Pull MIPS fixes from Paul Burton:
"A few more MIPS fixes:
- Fix a silly typo in virt_addr_valid which led to completely bogus
behavior (that happened to stop tripping up hardened usercopy
despite being broken).
- Fix UART parity setup on AR933x systems.
- A build fix for non-Linux build machines.
- Have the 'all' make target build DTBs, primarily to fit in with the
behavior of scripts/package/builddeb.
- Handle an execution hazard in TLB exceptions that use KScratch
registers, which could inadvertently clobber the $1 register on
some generally higher-end out-of-order CPUs.
- A MAINTAINERS update to fix the path to the NAND driver for Ingenic
systems"
* tag 'mips_fixes_5.2_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
MAINTAINERS: Correct path to moved files
MIPS: Add missing EHB in mtc0 -> mfc0 sequence.
MIPS: have "plain" make calls build dtbs for selected platforms
MIPS: fix build on non-linux hosts
MIPS: ath79: fix ar933x uart parity mode
MIPS: Fix bounds check virt_addr_valid
When the blk-mq debugfs file creation logic was "cleaned up" it was
cleaned up too much, causing the queue file to not be created in the
correct location. Turns out the check for the directory being present
is needed as if that has not happened yet, the files should not be
created, and the function will be called later on in the initialization
code so that the files can be created in the correct location.
Fixes: 6cfc0081b046 ("blk-mq: no need to check return value of debugfs_create functions")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: linux-block@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull dmaengine fixes from Vinod Koul:
- bam_dma fix for completed descriptor count
- fix for imx-sdma remove BD_INTR for channel0 and use-after-free on
probe error path
- endian bug fix in jz4780 IRQ handler
* tag 'dmaengine-fix-5.2' of git://git.infradead.org/users/vkoul/slave-dma:
dmaengine: qcom: bam_dma: Fix completed descriptors count
dmaengine: imx-sdma: remove BD_INTR for channel0
dmaengine: imx-sdma: fix use-after-free on probe error path
dmaengine: jz4780: Fix an endian bug in IRQ handler
The driver was moved in commit 1838a7b31fcb ("mtd: rawnand: Move
drivers for Ingenic SoCs to subfolder").
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@vger.kernel.org
By mistake, there is a '&' instead of a '==' in the definition of the
macro BFQQ_TOTALLY_SEEKY. This commit replaces the wrong operator with
the correct one.
Fixes: 7074f076ff15 ("block, bfq: do not tag totally seeky queues as soft rt")
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull SCSI fixes from James Bottomley:
"Two iscsi fixes.
One for an oops in the client which can be triggered by the server
authentication protocol and the other in the target code which causes
data corruption"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: iscsi: set auth_protocol back to NULL if CHAP_A value is not supported
scsi: target/iblock: Fix overrun in WRITE SAME emulation
One space is left unused in circular FIFO to differentiate
'full' and 'empty' cases. So take that in to account while
counting for the descriptors completed.
Fixes the issue reported here,
https://lkml.org/lkml/2019/6/18/669
Cc: stable@vger.kernel.org
Reported-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add a missing EHB (Execution Hazard Barrier) in mtc0 -> mfc0 sequence.
Without this execution hazard barrier it's possible for the value read
back from the KScratch register to be the value from before the mtc0.
Reproducible on P5600 & P6600.
The hazard is documented in the MIPS Architecture Reference Manual Vol.
III: MIPS32/microMIPS32 Privileged Resource Architecture (MD00088), rev
6.03 table 8.1 which includes:
Producer | Consumer | Hazard
----------|----------|----------------------------
mtc0 | mfc0 | any coprocessor 0 register
Signed-off-by: Dmitry Korotin <dkorotin@wavecomp.com>
[paul.burton@mips.com:
- Commit message tweaks.
- Add Fixes tags.
- Mark for stable back to v3.15 where P5600 support was introduced.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: 3d8bfdd03072 ("MIPS: Use C0_KScratch (if present) to hold PGD pointer.")
Fixes: 829dcc0a956a ("MIPS: Add MIPS P5600 probe support")
Cc: linux-mips@vger.kernel.org
Cc: stable@vger.kernel.org # v3.15+
Stephen reports:
I hit the following General Protection Fault when testing io_uring via
the io_uring engine in fio. This was on a VM running 5.2-rc5 and the
latest version of fio. The issue occurs for both null_blk and fake NVMe
drives. I have not tested bare metal or real NVMe SSDs. The fio script
used is given below.
[io_uring]
time_based=1
runtime=60
filename=/dev/nvme2n1 (note /dev/nullb0 also fails)
ioengine=io_uring
bs=4k
rw=readwrite
direct=1
fixedbufs=1
sqthread_poll=1
sqthread_poll_cpu=0
general protection fault: 0000 [#1] SMP PTI
CPU: 0 PID: 872 Comm: io_uring-sq Not tainted 5.2.0-rc5-cpacket-io-uring #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
RIP: 0010:fput_many+0x7/0x90
Code: 01 48 85 ff 74 17 55 48 89 e5 53 48 8b 1f e8 a0 f9 ff ff 48 85 db 48 89 df 75 f0 5b 5d f3 c3 0f 1f 40 00 0f 1f 44 00 00 89 f6 <f0> 48 29 77 38 74 01 c3 55 48 89 e5 53 48 89 fb 65 48 \
RSP: 0018:ffffadeb817ebc50 EFLAGS: 00010246
RAX: 0000000000000004 RBX: ffff8f46ad477480 RCX: 0000000000001805
RDX: 0000000000000000 RSI: 0000000000000001 RDI: f18b51b9a39552b5
RBP: ffffadeb817ebc58 R08: ffff8f46b7a318c0 R09: 000000000000015d
R10: ffffadeb817ebce8 R11: 0000000000000020 R12: ffff8f46ad4cd000
R13: 00000000fffffff7 R14: ffffadeb817ebe30 R15: 0000000000000004
FS: 0000000000000000(0000) GS:ffff8f46b7a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055828f0bbbf0 CR3: 0000000232176004 CR4: 00000000003606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
? fput+0x13/0x20
io_free_req+0x20/0x40
io_put_req+0x1b/0x20
io_submit_sqe+0x40a/0x680
? __switch_to_asm+0x34/0x70
? __switch_to_asm+0x40/0x70
io_submit_sqes+0xb9/0x160
? io_submit_sqes+0xb9/0x160
? __switch_to_asm+0x40/0x70
? __switch_to_asm+0x34/0x70
? __schedule+0x3f2/0x6a0
? __switch_to_asm+0x34/0x70
io_sq_thread+0x1af/0x470
? __switch_to_asm+0x34/0x70
? wait_woken+0x80/0x80
? __switch_to+0x85/0x410
? __switch_to_asm+0x40/0x70
? __switch_to_asm+0x34/0x70
? __schedule+0x3f2/0x6a0
kthread+0x105/0x140
? io_submit_sqes+0x160/0x160
? kthread+0x105/0x140
? io_submit_sqes+0x160/0x160
? kthread_destroy_worker+0x50/0x50
ret_from_fork+0x35/0x40
which occurs because using a kernel side submission thread isn't valid
without using fixed files (registered through io_uring_register()). This
causes io_uring to put the request after logging an error, but before
the file field is set in the request. If it happens to be non-zero, we
attempt to fput() garbage.
Fix this by ensuring that req->file is initialized when the request is
allocated.
Cc: stable@vger.kernel.org # 5.1+
Reported-by: Stephen Bates <sbates@raithlin.com>
Tested-by: Stephen Bates <sbates@raithlin.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull vfs fixlet from Al Viro:
"Fix bogus default y in Kconfig (VALIDATE_FS_PARSER)
That thing should not be turned on by default, especially since it's
not quiet in case it finds no problems. Geert has sent the obvious fix
quite a few times, but it fell through the cracks"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: VALIDATE_FS_PARSER should default to n
If the CHAP_A value is not supported, the chap_server_open() function
should free the auth_protocol pointer and set it to NULL, or we will leave
a dangling pointer around.
[ 66.010905] Unsupported CHAP_A value
[ 66.011660] Security negotiation failed.
[ 66.012443] iSCSI Login negotiation failed.
[ 68.413924] general protection fault: 0000 [#1] SMP PTI
[ 68.414962] CPU: 0 PID: 1562 Comm: targetcli Kdump: loaded Not tainted 4.18.0-80.el8.x86_64 #1
[ 68.416589] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[ 68.417677] RIP: 0010:__kmalloc_track_caller+0xc2/0x210
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
It is possible for an irq triggered by channel0 to be received later
after clks are disabled once firmware loaded during sdma probe. If
that happens then clearing them by writing to SDMA_H_INTR won't work
and the kernel will hang processing infinite interrupts. Actually,
don't need interrupt triggered on channel0 since it's pollling
SDMA_H_STATSTOP to know channel0 done rather than interrupt in
current code, just clear BD_INTR to disable channel0 interrupt to
avoid the above case.
This issue was brought by commit 1d069bfa3c78 ("dmaengine: imx-sdma:
ack channel 0 IRQ in the interrupt handler") which didn't take care
the above case.
Fixes: 1d069bfa3c78 ("dmaengine: imx-sdma: ack channel 0 IRQ in the interrupt handler")
Cc: stable@vger.kernel.org #5.0+
Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Reported-by: Sven Van Asbroeck <thesven73@gmail.com>
Tested-by: Sven Van Asbroeck <thesven73@gmail.com>
Reviewed-by: Michael Olbrich <m.olbrich@pengutronix.de>
Signed-off-by: Vinod Koul <vkoul@kernel.org>