Pull MIPS updates from Ralf Baechle:
"Boston platform support:
- Document DT bindings
- Add CLK driver for board clocks
CM:
- Avoid per-core locking with CM3 & higher
- WARN on attempt to lock invalid VP, not BUG
CPS:
- Select CONFIG_SYS_SUPPORTS_SCHED_SMT for MIPSr6
- Prevent multi-core with dcache aliasing
- Handle cores not powering down more gracefully
- Handle spurious VP starts more gracefully
DSP:
- Add lwx & lhx missaligned access support
eBPF:
- Add MIPS support along with many supporting change to add the
required infrastructure
Generic arch code:
- Misc sysmips MIPS_ATOMIC_SET fixes
- Drop duplicate HAVE_SYSCALL_TRACEPOINTS
- Negate error syscall return in trace
- Correct forced syscall errors
- Traced negative syscalls should return -ENOSYS
- Allow samples/bpf/tracex5 to access syscall arguments for sane
traces
- Cleanup from old Kconfig options in defconfigs
- Fix PREF instruction usage by memcpy for MIPS R6
- Fix various special cases in the FPU eulation
- Fix some special cases in MIPS16e2 support
- Fix MIPS I ISA /proc/cpuinfo reporting
- Sort MIPS Kconfig alphabetically
- Fix minimum alignment requirement of IRQ stack as required by
ABI / GCC
- Fix special cases in the module loader
- Perform post-DMA cache flushes on systems with MAARs
- Probe the I6500 CPU
- Cleanup cmpxchg and add support for 1 and 2 byte operations
- Use queued read/write locks (qrwlock)
- Use queued spinlocks (qspinlock)
- Add CPU shared FTLB feature detection
- Handle tlbex-tlbp race condition
- Allow storing pgd in C0_CONTEXT for MIPSr6
- Use current_cpu_type() in m4kc_tlbp_war()
- Support Boston in the generic kernel
Generic platform:
- yamon-dt: Pull YAMON DT shim code out of SEAD-3 board
- yamon-dt: Support > 256MB of RAM
- yamon-dt: Use serial* rather than uart* aliases
- Abstract FDT fixup application
- Set RTC_ALWAYS_BCD to 0
- Add a MAINTAINERS entry
core kernel:
- qspinlock.c: include linux/prefetch.h
Loongson 3:
- Add support
Perf:
- Add I6500 support
SEAD-3:
- Remove GIC timer from DT
- Set interrupt-parent per-device, not at root node
- Fix GIC interrupt specifiers
SMP:
- Skip IPI setup if we only have a single CPU
VDSO:
- Make comment match reality
- Improvements to time code in VDSO"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (86 commits)
locking/qspinlock: Include linux/prefetch.h
MIPS: Fix MIPS I ISA /proc/cpuinfo reporting
MIPS: Fix minimum alignment requirement of IRQ stack
MIPS: generic: Support MIPS Boston development boards
MIPS: DTS: img: Don't attempt to build-in all .dtb files
clk: boston: Add a driver for MIPS Boston board clocks
dt-bindings: Document img,boston-clock binding
MIPS: Traced negative syscalls should return -ENOSYS
MIPS: Correct forced syscall errors
MIPS: Negate error syscall return in trace
MIPS: Drop duplicate HAVE_SYSCALL_TRACEPOINTS select
MIPS16e2: Provide feature overrides for non-MIPS16 systems
MIPS: MIPS16e2: Report ASE presence in /proc/cpuinfo
MIPS: MIPS16e2: Subdecode extended LWSP/SWSP instructions
MIPS: MIPS16e2: Identify ASE presence
MIPS: VDSO: Fix a mismatch between comment and preprocessor constant
MIPS: VDSO: Add implementation of gettimeofday() fallback
MIPS: VDSO: Add implementation of clock_gettime() fallback
MIPS: VDSO: Fix conversions in do_monotonic()/do_monotonic_coarse()
MIPS: Use current_cpu_type() in m4kc_tlbp_war()
...
Pull UML updates from Richard Weinberger:
"Mostly fixes for UML:
- First round of fixes for PTRACE_GETRESET/SETREGSET
- A printf vs printk cleanup
- Minor improvements"
* 'for-linus-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: Correctly check for PTRACE_GETRESET/SETREGSET
um: v2: Use generic NOTES macro
um: Add kerneldoc for userspace_tramp() and start_userspace()
um: Add kerneldoc for segv_handler
um: stub-data.h: remove superfluous include
um: userspace - be more verbose in ptrace set regs error
um: add dummy ioremap and iounmap functions
um: Allow building and running on older hosts
um: Avoid longjmp/setjmp symbol clashes with libpthread.a
um: console: Ignore console= option
um: Use os_warn to print out pre-boot warning/error messages
um: Add os_warn() for pre-boot warning/error messages
um: Use os_info for the messages on normal path
um: Add os_info() for pre-boot information messages
um: Use printk instead of printf in make_uml_dir
Pull UBIFS updates from Richard Weinberger:
- Updates and fixes for the file encryption mode
- Minor improvements
- Random fixes
* tag 'upstream-4.13-rc1' of git://git.infradead.org/linux-ubifs:
ubifs: Set double hash cookie also for RENAME_EXCHANGE
ubifs: Massage assert in ubifs_xattr_set() wrt. init_xattrs
ubifs: Don't leak kernel memory to the MTD
ubifs: Change gfp flags in page allocation for bulk read
ubifs: Fix oops when remounting with no_bulk_read.
ubifs: Fail commit if TNC is obviously inconsistent
ubifs: allow userspace to map mounts to volumes
ubifs: Wire-up statx() support
ubifs: Remove dead code from ubifs_get_link()
ubifs: Massage debug prints wrt. fscrypt
ubifs: Add assert to dent_key_init()
ubifs: Fix unlink code wrt. double hash lookups
ubifs: Fix data node size for truncating uncompressed nodes
ubifs: Don't encrypt special files on creation
ubifs: Fix memory leak in RENAME_WHITEOUT error path in do_rename
ubifs: Fix inode data budget in ubifs_mknod
ubifs: Correctly evict xattr inodes
ubifs: Unexport ubifs_inode_slab
ubifs: don't bother checking for encryption key in ->mmap()
ubifs: require key for truncate(2) of encrypted file
Pull more KVM updates from Radim Krčmář:
"Second batch of KVM updates for v4.13
Common:
- add uevents for VM creation/destruction
- annotate and properly access RCU-protected objects
s390:
- rename IOCTL added in the first v4.13 merge
x86:
- emulate VMLOAD VMSAVE feature in SVM
- support paravirtual asynchronous page fault while nested
- add Hyper-V userspace interfaces for better migration
- improve master clock corner cases
- extend internal error reporting after EPT misconfig
- correct single-stepping of emulated instructions in SVM
- handle MCE during VM entry
- fix nVMX VM entry checks and nVMX VMCS shadowing"
* tag 'kvm-4.13-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits)
kvm: x86: hyperv: make VP_INDEX managed by userspace
KVM: async_pf: Let guest support delivery of async_pf from guest mode
KVM: async_pf: Force a nested vmexit if the injected #PF is async_pf
KVM: async_pf: Add L1 guest async_pf #PF vmexit handler
KVM: x86: Simplify kvm_x86_ops->queue_exception parameter list
kvm: x86: hyperv: add KVM_CAP_HYPERV_SYNIC2
KVM: x86: make backwards_tsc_observed a per-VM variable
KVM: trigger uevents when creating or destroying a VM
KVM: SVM: Enable Virtual VMLOAD VMSAVE feature
KVM: SVM: Add Virtual VMLOAD VMSAVE feature definition
KVM: SVM: Rename lbr_ctl field in the vmcb control area
KVM: SVM: Prepare for new bit definition in lbr_ctl
KVM: SVM: handle singlestep exception when skipping emulated instructions
KVM: x86: take slots_lock in kvm_free_pit
KVM: s390: Fix KVM_S390_GET_CMMA_BITS ioctl definition
kvm: vmx: Properly handle machine check during VM-entry
KVM: x86: update master clock before computing kvmclock_offset
kvm: nVMX: Shadow "high" parts of shadowed 64-bit VMCS fields
kvm: nVMX: Fix nested_vmx_check_msr_bitmap_controls
kvm: nVMX: Validate the I/O bitmaps on nested VM-entry
...
Pull XFS fixes from Darrick Wong:
"Largely debugging and regression fixes.
- Add some locking assertions for the _ilock helpers.
- Revert the XFS_QMOPT_NOLOCK patch; after discussion with hch the
online fsck patch that would have needed it has been redesigned and
no longer needs it.
- Fix behavioral regression of SEEK_HOLE/DATA with negative offsets
to match 4.12-era XFS behavior"
* tag 'xfs-4.13-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
vfs: in iomap seek_{hole,data}, return -ENXIO for negative offsets
Revert "xfs: grab dquots without taking the ilock"
xfs: assert locking precondition in xfs_readlink_bmap_ilocked
xfs: assert locking precondіtion in xfs_attr_list_int_ilocked
xfs: fixup xfs_attr_get_ilocked
Pull btrfs fixes from David Sterba:
"We've identified and fixed a silent corruption (introduced by code in
the first pull), a fixup after the blk_status_t merge and two fixes to
incremental send that Filipe has been hunting for some time"
* 'for-4.13-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Btrfs: fix unexpected return value of bio_readpage_error
btrfs: btrfs_create_repair_bio never fails, skip error handling
btrfs: cloned bios must not be iterated by bio_for_each_segment_all
Btrfs: fix write corruption due to bio cloning on raid5/6
Btrfs: incremental send, fix invalid memory access
Btrfs: incremental send, fix invalid path for link commands
Pull a few more input updates from Dmitry Torokhov:
- multi-touch handling for Xen
- fix for long-standing bug causing crashes in i8042 on boot
- change to gpio_keys to better handle key presses during system state
transition
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: i8042 - fix crash at boot time
Input: gpio_keys - handle the missing key press event in resume phase
Input: xen-kbdfront - add multi-touch support
Pull crypto fixes from Herbert Xu:
- fix new compiler warnings in cavium
- set post-op IV properly in caam (this fixes chaining)
- fix potential use-after-free in atmel in case of EBUSY
- fix sleeping in softirq path in chcr
- disable buggy sha1-avx2 driver (may overread and page fault)
- fix use-after-free on signals in caam
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: cavium - make several functions static
crypto: chcr - Avoid algo allocation in softirq.
crypto: caam - properly set IV after {en,de}crypt
crypto: atmel - only treat EBUSY as transient if backlog
crypto: af_alg - Avoid sock_graft call warning
crypto: caam - fix signals handling
crypto: sha1-ssse3 - Disable avx2
Pull device properties framework fix from Rafael Wysocki:
"This fixes a problem with bool properties that could be seen as "true"
when the property was not present at all by adding a special helper
for bool properties with checks for all of the requisute conditions
(Sakari Ailus)"
* tag 'devprop-fix-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
device property: Introduce fwnode_call_bool_op() for ops that return bool
Pull ACPI fixes from Rafael Wysocki:
"These fix the return value of an IRQ mapping routine in the ACPI core,
fix an EC driver issue causing abnormal fan behavior after system
resume on some systems and add quirks for ACPI device objects that
need to be treated as "always present" to work around bogus
implementations of the _STA control method.
Specifics:
- Fix the return value of acpi_gsi_to_irq() to make the GSI to IRQ
mapping work on the Mustang (ARM64) platform (Mark Salter).
- Fix an EC driver issue that causes fans to behave abnormally after
system resume on some systems which turns out to be related to
switching over the EC into the polling mode during the noirq stages
of system suspend and resume (Lv Zheng).
- Add quirks for ACPI device objects that need to be treated as
"always present", because their _STA methods are designed to work
around Windows driver bugs and return garbage from our perspective
(Hans de Goede)"
* tag 'acpi-fixes-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / x86: Add KIOX000A accelerometer on GPD win to always_present_ids array
ACPI / x86: Add Dell Venue 11 Pro 7130 touchscreen to always_present_ids
ACPI / x86: Allow matching always_present_id array entries by DMI
Revert "ACPI / EC: Enable event freeze mode..." to fix a regression
ACPI / EC: Drop EC noirq hooks to fix a regression
ACPI / irq: Fix return code of acpi_gsi_to_irq()
Pull power management fixes from Rafael Wysocki:
"These fix a recently exposed issue in the PCI device wakeup code and
one older problem related to PCI device wakeup that has been reported
recently, modify one more piece of computations in intel_pstate to get
rid of a rounding error, fix a possible race in the schedutil cpufreq
governor, fix the device PM QoS sysfs interface to correctly handle
invalid user input, fix return values of two probe routines in devfreq
drivers and constify an attribute_group structure in devfreq.
Specifics:
- Avoid clearing the PCI PME Enable bit for devices as a result of
config space restoration which confuses AML executed afterward and
causes wakeup events to be lost on some systems (Rafael Wysocki).
- Fix the native PCIe PME interrupts handling in the cases when the
PME IRQ is set up as a system wakeup one so that runtime PM remote
wakeup works as expected after system resume on systems where that
happens (Rafael Wysocki).
- Fix the device PM QoS sysfs interface to handle invalid user input
correctly instead of using an unititialized variable value as the
latency tolerance for the device at hand (Dan Carpenter).
- Get rid of one more rounding error from intel_pstate computations
(Srinivas Pandruvada).
- Fix the schedutil cpufreq governor to prevent it from possibly
accessing unititialized data structures from governor callbacks in
some cases on systems when multiple CPUs share a single cpufreq
policy object (Vikram Mulukutla).
- Fix the return values of probe routines in two devfreq drivers
(Gustavo Silva).
- Constify an attribute_group structure in devfreq (Arvind Yadav)"
* tag 'pm-fixes-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PCI / PM: Fix native PME handling during system suspend/resume
PCI / PM: Restore PME Enable after config space restoration
cpufreq: schedutil: Fix sugov_start() versus sugov_update_shared() race
PM / QoS: return -EINVAL for bogus strings
cpufreq: intel_pstate: Fix ratio setting for min_perf_pct
PM / devfreq: constify attribute_group structures.
PM / devfreq: tegra: fix error return code in tegra_devfreq_probe()
PM / devfreq: rk3399_dmc: fix error return code in rk3399_dmcfreq_probe()
Merge even more updates from Andrew Morton:
- a few leftovers
- fault-injector rework
- add a module loader test driver
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
kmod: throttle kmod thread limit
kmod: add test driver to stress test the module loader
MAINTAINERS: give kmod some maintainer love
xtensa: use generic fb.h
fault-inject: add /proc/<pid>/fail-nth
fault-inject: simplify access check for fail-nth
fault-inject: make fail-nth read/write interface symmetric
fault-inject: parse as natural 1-based value for fail-nth write interface
fault-inject: automatically detect the number base for fail-nth write interface
kernel/watchdog.c: use better pr_fmt prefix
MAINTAINERS: move the befs tree to kernel.org
lib/atomic64_test.c: add a test that atomic64_inc_not_zero() returns an int
mm: fix overflow check in expand_upwards()
Using strscpy was wrong because FORTIFY_SOURCE is passing the maximum
possible size of the outermost object, but strscpy defines the count
parameter as the exact buffer size, so this could copy past the end of
the source. This would still be wrong with the planned usage of
__builtin_object_size(p, 1) for intra-object overflow checks since it's
the maximum possible size of the specified object with no guarantee of
it being that large.
Reuse of the fortified functions like this currently makes the runtime
error reporting less precise but that can be improved later on.
Noticed by Dave Jones and KASAN.
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull arch/tile updates from Chris Metcalf:
"This adds support for an <arch/intreg.h> to help with removing
__need_xxx #defines from glibc, and removes some dead code in
arch/tile/mm/init.c"
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
mm, tile: drop arch_{add,remove}_memory
tile: prefer <arch/intreg.h> to __need_int_reg_t
Pull powerpc fixes from Michael Ellerman:
"Nothing that really stands out, just a bunch of fixes that have come
in in the last couple of weeks.
None of these are actually fixes for code that is new in 4.13. It's
roughly half older bugs, with fixes going to stable, and half
fixes/updates for Power9.
Thanks to: Aneesh Kumar K.V, Anton Blanchard, Balbir Singh, Benjamin
Herrenschmidt, Madhavan Srinivasan, Michael Neuling, Nicholas Piggin,
Oliver O'Halloran"
* tag 'powerpc-4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/64: Fix atomic64_inc_not_zero() to return an int
powerpc: Fix emulation of mfocrf in emulate_step()
powerpc: Fix emulation of mcrf in emulate_step()
powerpc/perf: Add POWER9 alternate PM_RUN_CYC and PM_RUN_INST_CMPL events
powerpc/perf: Fix SDAR_MODE value for continous sampling on Power9
powerpc/asm: Mark cr0 as clobbered in mftb()
powerpc/powernv: Fix local TLB flush for boot and MCE on POWER9
powerpc/mm/radix: Synchronize updates to the process table
powerpc/mm/radix: Properly clear process table entry
powerpc/powernv: Tell OPAL about our MMU mode on POWER9
powerpc/kexec: Fix radix to hash kexec due to IAMR/AMOR
If we reach the limit of modprobe_limit threads running the next
request_module() call will fail. The original reason for adding a kill
was to do away with possible issues with in old circumstances which would
create a recursive series of request_module() calls.
We can do better than just be super aggressive and reject calls once we've
reached the limit by simply making pending callers wait until the
threshold has been reduced, and then throttling them in, one by one.
This throttling enables requests over the kmod concurrent limit to be
processed once a pending request completes. Only the first item queued up
to wait is woken up. The assumption here is once a task is woken it will
have no other option to also kick the queue to check if there are more
pending tasks -- regardless of whether or not it was successful.
By throttling and processing only max kmod concurrent tasks we ensure we
avoid unexpected fatal request_module() calls, and we keep memory
consumption on module loading to a minimum.
With x86_64 qemu, with 4 cores, 4 GiB of RAM it takes the following run
time to run both tests:
time ./kmod.sh -t 0008
real 0m16.366s
user 0m0.883s
sys 0m8.916s
time ./kmod.sh -t 0009
real 0m50.803s
user 0m0.791s
sys 0m9.852s
Link: http://lkml.kernel.org/r/20170628223155.26472-4-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michal Marek <mmarek@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds a new stress test driver for kmod: the kernel module loader.
The new stress test driver, test_kmod, is only enabled as a module right
now. It should be possible to load this as built-in and load tests
early (refer to the force_init_test module parameter), however since a
lot of test can get a system out of memory fast we leave this disabled
for now.
Using a system with 1024 MiB of RAM can *easily* get your kernel OOM
fast with this test driver.
The test_kmod driver exposes API knobs for us to fine tune simple
request_module() and get_fs_type() calls. Since these API calls only
allow each one parameter a test driver for these is rather simple.
Other factors that can help out test driver though are the number of
calls we issue and knowing current limitations of each. This exposes
configuration as much as possible through userspace to be able to build
tests directly from userspace.
Since it allows multiple misc devices its will eventually (once we add a
knob to let us create new devices at will) also be possible to perform
more tests in parallel, provided you have enough memory.
We only enable tests we know work as of right now.
Demo screenshots:
# tools/testing/selftests/kmod/kmod.sh
kmod_test_0001_driver: OK! - loading kmod test
kmod_test_0001_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND
kmod_test_0001_fs: OK! - loading kmod test
kmod_test_0001_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL
kmod_test_0002_driver: OK! - loading kmod test
kmod_test_0002_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND
kmod_test_0002_fs: OK! - loading kmod test
kmod_test_0002_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL
kmod_test_0003: OK! - loading kmod test
kmod_test_0003: OK! - Return value: 0 (SUCCESS), expected SUCCESS
kmod_test_0004: OK! - loading kmod test
kmod_test_0004: OK! - Return value: 0 (SUCCESS), expected SUCCESS
kmod_test_0005: OK! - loading kmod test
kmod_test_0005: OK! - Return value: 0 (SUCCESS), expected SUCCESS
kmod_test_0006: OK! - loading kmod test
kmod_test_0006: OK! - Return value: 0 (SUCCESS), expected SUCCESS
kmod_test_0005: OK! - loading kmod test
kmod_test_0005: OK! - Return value: 0 (SUCCESS), expected SUCCESS
kmod_test_0006: OK! - loading kmod test
kmod_test_0006: OK! - Return value: 0 (SUCCESS), expected SUCCESS
XXX: add test restult for 0007
Test completed
You can also request for specific tests:
# tools/testing/selftests/kmod/kmod.sh -t 0001
kmod_test_0001_driver: OK! - loading kmod test
kmod_test_0001_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND
kmod_test_0001_fs: OK! - loading kmod test
kmod_test_0001_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL
Test completed
Lastly, the current available number of tests:
# tools/testing/selftests/kmod/kmod.sh --help
Usage: tools/testing/selftests/kmod/kmod.sh [ -t <4-number-digit> ]
Valid tests: 0001-0009
0001 - Simple test - 1 thread for empty string
0002 - Simple test - 1 thread for modules/filesystems that do not exist
0003 - Simple test - 1 thread for get_fs_type() only
0004 - Simple test - 2 threads for get_fs_type() only
0005 - multithreaded tests with default setup - request_module() only
0006 - multithreaded tests with default setup - get_fs_type() only
0007 - multithreaded tests with default setup test request_module() and get_fs_type()
0008 - multithreaded - push kmod_concurrent over max_modprobes for request_module()
0009 - multithreaded - push kmod_concurrent over max_modprobes for get_fs_type()
The following test cases currently fail, as such they are not currently
enabled by default:
# tools/testing/selftests/kmod/kmod.sh -t 0008
# tools/testing/selftests/kmod/kmod.sh -t 0009
To be sure to run them as intended please unload both of the modules:
o test_module
o xfs
And ensure they are not loaded on your system prior to testing them. If
you use these paritions for your rootfs you can change the default test
driver used for get_fs_type() by exporting it into your environment. For
example of other test defaults you can override refer to kmod.sh
allow_user_defaults().
Behind the scenes this is how we fine tune at a test case prior to
hitting a trigger to run it:
cat /sys/devices/virtual/misc/test_kmod0/config
echo -n "2" > /sys/devices/virtual/misc/test_kmod0/config_test_case
echo -n "ext4" > /sys/devices/virtual/misc/test_kmod0/config_test_fs
echo -n "80" > /sys/devices/virtual/misc/test_kmod0/config_num_threads
cat /sys/devices/virtual/misc/test_kmod0/config
echo -n "1" > /sys/devices/virtual/misc/test_kmod0/config_num_threads
Finally to trigger:
echo -n "1" > /sys/devices/virtual/misc/test_kmod0/trigger_config
The kmod.sh script uses the above constructs to build different test cases.
A bit of interpretation of the current failures follows, first two
premises:
a) When request_module() is used userspace figures out an optimized
version of module order for us. Once it finds the modules it needs, as
per depmod symbol dep map, it will finit_module() the respective
modules which are needed for the original request_module() request.
b) We have an optimization in place whereby if a kernel uses
request_module() on a module already loaded we never bother userspace
as the module already is loaded. This is all handled by kernel/kmod.c.
A few things to consider to help identify root causes of issues:
0) kmod 19 has a broken heuristic for modules being assumed to be
built-in to your kernel and will return 0 even though request_module()
failed. Upgrade to a newer version of kmod.
1) A get_fs_type() call for "xfs" will request_module() for "fs-xfs",
not for "xfs". The optimization in kernel described in b) fails to
catch if we have a lot of consecutive get_fs_type() calls. The reason
is the optimization in place does not look for aliases. This means two
consecutive get_fs_type() calls will bump kmod_concurrent, whereas
request_module() will not.
This one explanation why test case 0009 fails at least once for
get_fs_type().
2) If a module fails to load --- for whatever reason (kmod_concurrent
limit reached, file not yet present due to rootfs switch, out of
memory) we have a period of time during which module request for the
same name either with request_module() or get_fs_type() will *also*
fail to load even if the file for the module is ready.
This explains why *multiple* NULLs are possible on test 0009.
3) finit_module() consumes quite a bit of memory.
4) Filesystems typically also have more dependent modules than other
modules, its important to note though that even though a get_fs_type()
call does not incur additional kmod_concurrent bumps, since userspace
loads dependencies it finds it needs via finit_module_fd(), it *will*
take much more memory to load a module with a lot of dependencies.
Because of 3) and 4) we will easily run into out of memory failures with
certain tests. For instance test 0006 fails on qemu with 1024 MiB of RAM.
It panics a box after reaping all userspace processes and still not
having enough memory to reap.
[arnd@arndb.de: add dependencies for test module]
Link: http://lkml.kernel.org/r/20170630154834.3689272-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20170628223155.26472-3-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michal Marek <mmarek@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds
Daniel Micay
Luis R. Rodriguez
Tobias Klauser
Akinobu Mita
Kefeng Wang