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Vladimir Oltean b9da72cb70 spi: spi-fsl-dspi: Replace interruptible wait queue with a simple completion [ Upstream commit `4f5ee75ea1` ] Currently the driver puts the process in interruptible sleep waiting for the interrupt train to finish transfer to/from the tx_buf and rx_buf. But exiting the process with ctrl-c may make the kernel panic: the wait_event_interruptible call will return -ERESTARTSYS, which a proper driver implementation is perhaps supposed to handle, but nonetheless this one doesn't, and aborts the transfer altogether. Actually when the task is interrupted, there is still a high chance that the dspi_interrupt is still triggering. And if dspi_transfer_one_message returns execution all the way to the spi_device driver, that can free the spi_message and spi_transfer structures, leaving the interrupts to access a freed tx_buf and rx_buf. hexdump -C /dev/mtd0 00000000 00 75 68 75 0a ff ff ff ff ff ff ff ff ff ff ff \|.uhu............\| 00000010 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff \|................\| * ^C[ 38.495955] fsl-dspi 2120000.spi: Waiting for transfer to complete failed! [ 38.503097] spi_master spi2: failed to transfer one message from queue [ 38.509729] Unable to handle kernel paging request at virtual address ffff800095ab3377 [ 38.517676] Mem abort info: [ 38.520474] ESR = 0x96000045 [ 38.523533] EC = 0x25: DABT (current EL), IL = 32 bits [ 38.528861] SET = 0, FnV = 0 [ 38.531921] EA = 0, S1PTW = 0 [ 38.535067] Data abort info: [ 38.537952] ISV = 0, ISS = 0x00000045 [ 38.541797] CM = 0, WnR = 1 [ 38.544771] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000082621000 [ 38.551494] [ffff800095ab3377] pgd=00000020fffff003, p4d=00000020fffff003, pud=0000000000000000 [ 38.560229] Internal error: Oops: 96000045 [#1] PREEMPT SMP [ 38.565819] Modules linked in: [ 38.568882] CPU: 0 PID: 2729 Comm: hexdump Not tainted 5.6.0-rc4-next-20200306-00052-gd8730cdc8a0b-dirty #193 [ 38.578834] Hardware name: Kontron SMARC-sAL28 (Single PHY) on SMARC Eval 2.0 carrier (DT) [ 38.587129] pstate: 20000085 (nzCv daIf -PAN -UAO) [ 38.591941] pc : ktime_get_real_ts64+0x3c/0x110 [ 38.596487] lr : spi_take_timestamp_pre+0x40/0x90 [ 38.601203] sp : ffff800010003d90 [ 38.604525] x29: ffff800010003d90 x28: ffff80001200e000 [ 38.609854] x27: ffff800011da9000 x26: ffff002079c40400 [ 38.615184] x25: ffff8000117fe018 x24: ffff800011daa1a0 [ 38.620513] x23: ffff800015ab3860 x22: ffff800095ab3377 [ 38.625841] x21: 000000000000146e x20: ffff8000120c3000 [ 38.631170] x19: ffff0020795f6e80 x18: ffff800011da9948 [ 38.636498] x17: 0000000000000000 x16: 0000000000000000 [ 38.641826] x15: ffff800095ab3377 x14: 0720072007200720 [ 38.647155] x13: 0720072007200765 x12: 0775076507750771 [ 38.652483] x11: 0720076d076f0772 x10: 0000000000000040 [ 38.657812] x9 : ffff8000108e2100 x8 : ffff800011dcabe8 [ 38.663139] x7 : 0000000000000000 x6 : ffff800015ab3a60 [ 38.668468] x5 : 0000000007200720 x4 : ffff800095ab3377 [ 38.673796] x3 : 0000000000000000 x2 : 0000000000000ab0 [ 38.679125] x1 : ffff800011daa000 x0 : 0000000000000026 [ 38.684454] Call trace: [ 38.686905] ktime_get_real_ts64+0x3c/0x110 [ 38.691100] spi_take_timestamp_pre+0x40/0x90 [ 38.695470] dspi_fifo_write+0x58/0x2c0 [ 38.699315] dspi_interrupt+0xbc/0xd0 [ 38.702987] __handle_irq_event_percpu+0x78/0x2c0 [ 38.707706] handle_irq_event_percpu+0x3c/0x90 [ 38.712161] handle_irq_event+0x4c/0xd0 [ 38.716008] handle_fasteoi_irq+0xbc/0x170 [ 38.720115] generic_handle_irq+0x2c/0x40 [ 38.724135] __handle_domain_irq+0x68/0xc0 [ 38.728243] gic_handle_irq+0xc8/0x160 [ 38.732000] el1_irq+0xb8/0x180 [ 38.735149] spi_nor_spimem_read_data+0xe0/0x140 [ 38.739779] spi_nor_read+0xc4/0x120 [ 38.743364] mtd_read_oob+0xa8/0xc0 [ 38.746860] mtd_read+0x4c/0x80 [ 38.750007] mtdchar_read+0x108/0x2a0 [ 38.753679] __vfs_read+0x20/0x50 [ 38.757002] vfs_read+0xa4/0x190 [ 38.760237] ksys_read+0x6c/0xf0 [ 38.763471] __arm64_sys_read+0x20/0x30 [ 38.767319] el0_svc_common.constprop.3+0x90/0x160 [ 38.772125] do_el0_svc+0x28/0x90 [ 38.775449] el0_sync_handler+0x118/0x190 [ 38.779468] el0_sync+0x140/0x180 [ 38.782793] Code: 91000294 1400000f d50339bf f9405e80 (f90002c0) [ 38.788910] ---[ end trace 55da560db4d6bef7 ]--- [ 38.793540] Kernel panic - not syncing: Fatal exception in interrupt [ 38.799914] SMP: stopping secondary CPUs [ 38.803849] Kernel Offset: disabled [ 38.807344] CPU features: 0x10002,20006008 [ 38.811451] Memory Limit: none [ 38.814513] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- So it is clear that the "interruptible" part isn't handled correctly. When the process receives a signal, one could either attempt a clean abort (which appears to be difficult with this hardware) or just keep restarting the sleep until the wait queue really completes. But checking in a loop for -ERESTARTSYS is a bit too complicated for this driver, so just make the sleep uninterruptible, to avoid all that nonsense. The wait queue was actually restructured as a completion, after polling other drivers for the most "popular" approach. Fixes: `349ad66c0a` ("spi:Add Freescale DSPI driver for Vybrid VF610 platform") Reported-by: Michael Walle <michael@walle.cc> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/r/20200318001603.9650-7-olteanv@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2020-04-17 10:50:05 +02:00
arch	x86/boot: Use unsigned comparison for addresses	2020-04-17 10:50:03 +02:00
block	block: Fix use-after-free issue accessing struct io_cq	2020-04-17 10:50:04 +02:00
certs	PKCS#7: Refactor verify_pkcs7_signature()	2019-08-05 18:40:18 -04:00
crypto	crypto: rename sm3-256 to sm3 in hash_algo_name	2020-02-28 17:22:26 +01:00
Documentation	dt-bindings: net: FMan erratum A050385	2020-04-01 11:01:52 +02:00
drivers	spi: spi-fsl-dspi: Replace interruptible wait queue with a simple completion	2020-04-17 10:50:05 +02:00
fs	gfs2: Don't demote a glock until its revokes are written	2020-04-17 10:50:03 +02:00
include	block: Fix use-after-free issue accessing struct io_cq	2020-04-17 10:50:04 +02:00
init	kbuild: remove header compile test	2020-03-05 16:43:47 +01:00
ipc	Revert "ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()"	2020-02-28 17:22:20 +01:00
kernel	genirq/irqdomain: Check pointer in irq_domain_alloc_irqs_hierarchy()	2020-04-17 10:50:04 +02:00
lib	uapi: rename ext2_swab() to swab() and share globally in swab.h	2020-04-13 10:48:07 +02:00
LICENSES	LICENSES: Rename other to deprecated	2019-05-03 06:34:32 -06:00
mm	slub: improve bit diffusion for freelist ptr obfuscation	2020-04-13 10:48:07 +02:00
net	cfg80211: Do not warn on same channel at the end of CSA	2020-04-17 10:49:59 +02:00
samples	samples/bpf: Set -fno-stack-protector when building BPF programs	2020-02-24 08:36:36 +01:00
scripts	kconfig: introduce m32-flag and m64-flag	2020-04-08 09:08:37 +02:00
security	efi: Only print errors about failing to get certs if EFI vars are found	2020-03-12 13:00:14 +01:00
sound	ASoC: jz4740-i2s: Fix divider written at incorrect offset in register	2020-04-13 10:48:09 +02:00
tools	selftests/x86/ptrace_syscall_32: Fix no-vDSO segfault	2020-04-17 10:50:02 +02:00
usr	initramfs: restore default compression behavior	2020-04-08 09:08:38 +02:00
virt	KVM: Check for a bad hva before dropping into the ghc slow path	2020-03-05 16:43:48 +01:00
.clang-format	clang-format: Update with the latest for_each macro list	2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore	Opt out of scripts/get_maintainer.pl	2019-05-16 10:53:40 -07:00
.gitattributes	.gitattributes: set git diff driver for C source code files	2016-10-07 18:46:30 -07:00
.gitignore	Modules updates for v5.4	2019-09-22 10:34:46 -07:00
.mailmap	ARM: SoC fixes	2019-11-10 13:41:59 -08:00
COPYING	COPYING: use the new text with points to the license files	2018-03-23 12:41:45 -06:00
CREDITS	MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer	2019-10-10 08:12:51 -07:00
Kbuild	kbuild: do not descend to ./Kbuild when cleaning	2019-08-21 21:03:58 +09:00
Kconfig	docs: kbuild: convert docs to ReST and rename to *.rst	2019-06-14 14:21:21 -06:00
MAINTAINERS	MAINTAINERS: Update drm/i915 bug filing URL	2020-02-28 17:22:19 +01:00
Makefile	Linux 5.4.32	2020-04-13 10:48:18 +02:00
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.