This brings in the mainline tree right after armsoc contents was merged
this release cycle, so that we can re-run savedefconfig, etc.
Signed-off-by: Olof Johansson <olof@lixom.net>
Pull ARM SoC defconfig updates from Olof Johansson:
"We keep this in a separate branch to avoid cross-branch conflicts, but
most of the material here is fairly boring -- some new drivers turned
on for hardware since they were merged, and some refreshed files due
to time having moved a lot of entries around"
* tag 'armsoc-defconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (36 commits)
ARM: config: multi_v5: ASPEED SDHCI, SGPIO
ARM: configs: multi_v7: ASPEED network, gpio, FSI
ARM: config: aspeed-g4: Add MMC, and cleanup
ARM: config: aspeed-g5: Add SGPIO and FSI drivers
ARM: config: aspeed-g5: Enable 8250_DW quirks
arm64: defconfig: Change CONFIG_AT803X_PHY from m to y
ARM: shmobile: defconfig: Refresh for v5.4-rc1
arm64: defconfig: Enable R8A77961 SoC
ARM: configs: sunxi: Enable MICREL_PHY
arm64: defconfig: add new Allwinner crypto options
ARM: configs: sunxi: add new Allwinner crypto options
ARM: tegra: Enable Tegra VDE driver in tegra_defconfig
ARM: imx_v6_v7_defconfig: Enable CONFIG_TOUCHSCREEN_DA9052
arm64: defconfig: Enable configs for S32V234
arm64: defconfig: Enable CONFIG_KEYBOARD_IMX_SC_KEY as module
arm64: defconfig: Enable SMMU v3 PMCG
arm64: defconfig: Enable HiSilicon ZIP controller
arm64: defconfig: enable Altera GPIO controller
ARM: multi_v7_defconfig: Enable audio support for stm32mp157
arm64: defconfig: enable rsu driver
...
Pull ARM SoC driver updates from Olof Johansson:
"Various driver updates for platforms:
- A larger set of work on Tegra 2/3 around memory controller and
regulator features, some fuse cleanups, etc..
- MMP platform drivers, in particular for USB PHY, and other smaller
additions.
- Samsung Exynos 5422 driver for DMC (dynamic memory configuration),
and ASV (adaptive voltage), allowing the platform to run at more
optimal operating points.
- Misc refactorings and support for RZ/G2N and R8A774B1 from Renesas
- Clock/reset control driver for TI/OMAP
- Meson-A1 reset controller support
- Qualcomm sdm845 and sda845 SoC IDs for socinfo"
* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (150 commits)
firmware: arm_scmi: Fix doorbell ring logic for !CONFIG_64BIT
soc: fsl: add RCPM driver
dt-bindings: fsl: rcpm: Add 'little-endian' and update Chassis definition
memory: tegra: Consolidate registers definition into common header
memory: tegra: Ensure timing control debug features are disabled
memory: tegra: Introduce Tegra30 EMC driver
memory: tegra: Do not handle error from wait_for_completion_timeout()
memory: tegra: Increase handshake timeout on Tegra20
memory: tegra: Print a brief info message about EMC timings
memory: tegra: Pre-configure debug register on Tegra20
memory: tegra: Include io.h instead of iopoll.h
memory: tegra: Adapt for Tegra20 clock driver changes
memory: tegra: Don't set EMC rate to maximum on probe for Tegra20
memory: tegra: Add gr2d and gr3d to DRM IOMMU group
memory: tegra: Set DMA mask based on supported address bits
soc: at91: Add Atmel SFR SN (Serial Number) support
memory: atmel-ebi: switch to SPDX license identifiers
memory: atmel-ebi: move NUM_CS definition inside EBI driver
soc: mediatek: Refactor bus protection control
soc: mediatek: Refactor sram control
...
Pull ARM SoC platform updates from Olof Johansson:
"Most of these are for MMP (seeing a bunch of cleanups and refactorings
for the first time in a while), and for OMAP (a bunch of cleanups and
added support for voltage controller on OMAP4430)"
* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (51 commits)
ARM: OMAP2+: Add missing put_device() call in omapdss_init_of()
OMAP2: fixup doc comments in omap_device
ARM: OMAP1: drop duplicated dependency on ARCH_OMAP1
ARM: ASPEED: update default ARCH_NR_GPIO for ARCH_ASPEED
ARM: imx: use generic function to exit coherency
ARM: tegra: Use WFE for power-gating on Tegra30
ARM: tegra: Fix FLOW_CTLR_HALT register clobbering by tegra_resume()
ARM: exynos: Enable exynos-asv driver for ARCH_EXYNOS
ARM: s3c: Rename s5p_usb_phy functions
ARM: s3c: Rename s3c64xx_spi_setname() function
ARM: imx: Add serial number support for i.MX6/7 SoCs
ARM: imx: Drop imx_anatop_usb_chrg_detect_disable()
arm64: Introduce config for S32
ARM: hisi: drop useless depend on ARCH_MULTI_V7
arm64: realtek: Select reset controller
ARM: shmobile: rcar-gen2: Drop legacy DT clock support
ARM: OMAP2+: Remove duplicated include from pmic-cpcap.c
ARM: OMAP1: ams-delta FIQ: Fix a typo ("Initiaize")
MAINTAINERS: Add logicpd-som-lv and logicpd-torpedo to OMAP TREE
ARM: OMAP2+: pdata-quirks: drop TI_ST/KIM support
...
Pull pwm updates from Thierry Reding:
"Various changes and minor fixes across a couple of drivers"
* tag 'pwm/for-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
pwm: stm32: Pass breakinput instead of its values
pwm: stm32: Remove clutter from ternary operator
pwm: stm32: Validate breakinput data from DT
pwm: Update comment on struct pwm_ops::apply
pwm: sun4i: Fix incorrect calculation of duty_cycle/period
pwm: stm32: Add power management support
pwm: stm32: Split breakinput apply routine to ease PM support
dt-bindings: pwm-stm32: Document pinctrl sleep state
pwm: sun4i: Drop redundant assignment to variable pval
dt-bindings: pwm: mediatek: Remove gratuitous compatible string for MT7629
Pull thermal management updates from Zhang Rui:
- Fix a deadlock regression in thermal core framework, which was
introduced in 5.3 (Wei Wang)
- Initialize thermal control framework earlier to enable thermal
mitigation during boot (Amit Kucheria)
- Convert the Intelligent Power Allocator (IPA) thermal governor to
follow the generic PM_EM instead of its own Energy Model (Quentin
Perret)
- Introduce a new Amlogic soc thermal driver (Guillaume La Roque)
- Add interrupt support for tsens thermal driver (Amit Kucheria)
- Add support for MSM8956/8976 in tsens thermal driver
(AngeloGioacchino Del Regno)
- Add support for r8a774b1 in rcar thermal driver (Biju Das)
- Add support for Thermal Monitor Unit v2 in qoriq thermal driver
(Yuantian Tang)
- Some other fixes/cleanups on thermal core framework and soc thermal
drivers (Colin Ian King, Daniel Lezcano, Hsin-Yi Wang, Tian Tao)
* 'thermal/next' of git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux: (32 commits)
thermal: Fix deadlock in thermal thermal_zone_device_check
thermal: cpu_cooling: Migrate to using the EM framework
thermal: cpu_cooling: Make the power-related code depend on IPA
PM / EM: Declare EM data types unconditionally
arm64: defconfig: Enable CONFIG_ENERGY_MODEL
drivers: thermal: tsens: fix potential integer overflow on multiply
thermal: cpu_cooling: Reorder the header file
thermal: cpu_cooling: Remove pointless dependency on CONFIG_OF
thermal: no need to set .owner when using module_platform_driver
thermal: qcom: tsens-v1: Fix kfree of a non-pointer value
cpufreq: qcom-hw: Move driver initialization earlier
clk: qcom: Initialize clock drivers earlier
cpufreq: Initialize cpufreq-dt driver earlier
cpufreq: Initialize the governors in core_initcall
thermal: Initialize thermal subsystem earlier
thermal: Remove netlink support
dt: thermal: tsens: Document compatible for MSM8976/56
thermal: qcom: tsens-v1: Add support for MSM8956 and MSM8976
MAINTAINERS: add entry for Amlogic Thermal driver
thermal: amlogic: Add thermal driver to support G12 SoCs
...
ARM SCMI fix for v5.5
Yet another single fix to avoid double freeing in scmi_device_create
error path
* tag 'scmi-fix-5.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
firmware: arm_scmi: Avoid double free in error flow
firmware: arm_scmi: Fix doorbell ring logic for !CONFIG_64BIT
Link: https://lore.kernel.org/r/20191202114559.GB20965@bogus
Signed-off-by: Olof Johansson <olof@lixom.net>
ARMv8 Juno fixes for v5.5
Couple of fixes:
1. Fix for UART clock frequency on all Juno variants that exist since
the platform was added. This is mainly due to incorrect Juno SoC
TRM that was referred during initial development days
2. Drop "dma-ranges" property for now as they are triggering loads of
warning on boot
* tag 'juno-fixes-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
Revert "arm64: dts: juno: add dma-ranges property"
arm64: dts: juno: Fix UART frequency
arm64: dts: juno: add GPU subsystem
Link: https://lore.kernel.org/r/20191202114338.GA20965@bogus
Signed-off-by: Olof Johansson <olof@lixom.net>
This pull request contains MAINTAINERS file updates for Broadcom SoCs,
please pull the following:
- Stefan and Eric step down from doing BCM283x maintenance and Nicolas
replaces them both moving forward
* tag 'arm-soc/for-5.5/maintainers-part2' of https://github.com/Broadcom/stblinux:
MAINTAINERS: Make Nicolas Saenz Julienne the new bcm2835 maintainer
Link: https://lore.kernel.org/r/20191127191932.9711-1-f.fainelli@gmail.com
Signed-off-by: Olof Johansson <olof@lixom.net>
snoop_file_poll() is defined as returning 'unsigned int' but the
.poll method is declared as returning '__poll_t', a bitwise type.
Fix this by using the proper return type and using the EPOLL
constants instead of the POLL ones, as required for __poll_t.
Link: https://lore.kernel.org/r/20191121051851.268726-1-joel@jms.id.au
Fixes: 3772e5da44 ("drivers/misc: Aspeed LPC snoop output using misc chardev")
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Olof Johansson <olof@lixom.net>
Merge more updates from Andrew Morton:
"Most of the rest of MM and various other things. Some Kconfig rework
still awaits merges of dependent trees from linux-next.
Subsystems affected by this patch series: mm/hotfixes, mm/memcg,
mm/vmstat, mm/thp, procfs, sysctl, misc, notifiers, core-kernel,
bitops, lib, checkpatch, epoll, binfmt, init, rapidio, uaccess, kcov,
ubsan, ipc, bitmap, mm/pagemap"
* akpm: (86 commits)
mm: remove __ARCH_HAS_4LEVEL_HACK and include/asm-generic/4level-fixup.h
um: add support for folded p4d page tables
um: remove unused pxx_offset_proc() and addr_pte() functions
sparc32: use pgtable-nopud instead of 4level-fixup
parisc/hugetlb: use pgtable-nopXd instead of 4level-fixup
parisc: use pgtable-nopXd instead of 4level-fixup
nds32: use pgtable-nopmd instead of 4level-fixup
microblaze: use pgtable-nopmd instead of 4level-fixup
m68k: mm: use pgtable-nopXd instead of 4level-fixup
m68k: nommu: use pgtable-nopud instead of 4level-fixup
c6x: use pgtable-nopud instead of 4level-fixup
arm: nommu: use pgtable-nopud instead of 4level-fixup
alpha: use pgtable-nopud instead of 4level-fixup
gpio: pca953x: tighten up indentation
gpio: pca953x: convert to use bitmap API
gpio: pca953x: use input from regs structure in pca953x_irq_pending()
gpio: pca953x: remove redundant variable and check in IRQ handler
lib/bitmap: introduce bitmap_replace() helper
lib/test_bitmap: fix comment about this file
lib/test_bitmap: move exp1 and exp2 upper for others to use
...
Userspace cannot compile <asm/sembuf.h> due to some missing type
definitions. For example, building it for x86 fails as follows:
CC usr/include/asm/sembuf.h.s
In file included from <command-line>:32:0:
usr/include/asm/sembuf.h:17:20: error: field `sem_perm' has incomplete type
struct ipc64_perm sem_perm; /* permissions .. see ipc.h */
^~~~~~~~
usr/include/asm/sembuf.h:24:2: error: unknown type name `__kernel_time_t'
__kernel_time_t sem_otime; /* last semop time */
^~~~~~~~~~~~~~~
usr/include/asm/sembuf.h:25:2: error: unknown type name `__kernel_ulong_t'
__kernel_ulong_t __unused1;
^~~~~~~~~~~~~~~~
usr/include/asm/sembuf.h:26:2: error: unknown type name `__kernel_time_t'
__kernel_time_t sem_ctime; /* last change time */
^~~~~~~~~~~~~~~
usr/include/asm/sembuf.h:27:2: error: unknown type name `__kernel_ulong_t'
__kernel_ulong_t __unused2;
^~~~~~~~~~~~~~~~
usr/include/asm/sembuf.h:29:2: error: unknown type name `__kernel_ulong_t'
__kernel_ulong_t sem_nsems; /* no. of semaphores in array */
^~~~~~~~~~~~~~~~
usr/include/asm/sembuf.h:30:2: error: unknown type name `__kernel_ulong_t'
__kernel_ulong_t __unused3;
^~~~~~~~~~~~~~~~
usr/include/asm/sembuf.h:31:2: error: unknown type name `__kernel_ulong_t'
__kernel_ulong_t __unused4;
^~~~~~~~~~~~~~~~
It is just a matter of missing include directive.
Include <asm/ipcbuf.h> to make it self-contained, and add it to
the compile-test coverage.
Link: http://lkml.kernel.org/r/20191030063855.9989-3-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Userspace cannot compile <asm/msgbuf.h> due to some missing type
definitions. For example, building it for x86 fails as follows:
CC usr/include/asm/msgbuf.h.s
In file included from usr/include/asm/msgbuf.h:6:0,
from <command-line>:32:
usr/include/asm-generic/msgbuf.h:25:20: error: field `msg_perm' has incomplete type
struct ipc64_perm msg_perm;
^~~~~~~~
usr/include/asm-generic/msgbuf.h:27:2: error: unknown type name `__kernel_time_t'
__kernel_time_t msg_stime; /* last msgsnd time */
^~~~~~~~~~~~~~~
usr/include/asm-generic/msgbuf.h:28:2: error: unknown type name `__kernel_time_t'
__kernel_time_t msg_rtime; /* last msgrcv time */
^~~~~~~~~~~~~~~
usr/include/asm-generic/msgbuf.h:29:2: error: unknown type name `__kernel_time_t'
__kernel_time_t msg_ctime; /* last change time */
^~~~~~~~~~~~~~~
usr/include/asm-generic/msgbuf.h:41:2: error: unknown type name `__kernel_pid_t'
__kernel_pid_t msg_lspid; /* pid of last msgsnd */
^~~~~~~~~~~~~~
usr/include/asm-generic/msgbuf.h:42:2: error: unknown type name `__kernel_pid_t'
__kernel_pid_t msg_lrpid; /* last receive pid */
^~~~~~~~~~~~~~
It is just a matter of missing include directive.
Include <asm/ipcbuf.h> to make it self-contained, and add it to
the compile-test coverage.
Link: http://lkml.kernel.org/r/20191030063855.9989-2-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Userspace cannot compile <asm/ipcbuf.h> due to some missing type
definitions. For example, building it for x86 fails as follows:
CC usr/include/asm/ipcbuf.h.s
In file included from usr/include/asm/ipcbuf.h:1:0,
from <command-line>:32:
usr/include/asm-generic/ipcbuf.h:21:2: error: unknown type name `__kernel_key_t'
__kernel_key_t key;
^~~~~~~~~~~~~~
usr/include/asm-generic/ipcbuf.h:22:2: error: unknown type name `__kernel_uid32_t'
__kernel_uid32_t uid;
^~~~~~~~~~~~~~~~
usr/include/asm-generic/ipcbuf.h:23:2: error: unknown type name `__kernel_gid32_t'
__kernel_gid32_t gid;
^~~~~~~~~~~~~~~~
usr/include/asm-generic/ipcbuf.h:24:2: error: unknown type name `__kernel_uid32_t'
__kernel_uid32_t cuid;
^~~~~~~~~~~~~~~~
usr/include/asm-generic/ipcbuf.h:25:2: error: unknown type name `__kernel_gid32_t'
__kernel_gid32_t cgid;
^~~~~~~~~~~~~~~~
usr/include/asm-generic/ipcbuf.h:26:2: error: unknown type name `__kernel_mode_t'
__kernel_mode_t mode;
^~~~~~~~~~~~~~~
usr/include/asm-generic/ipcbuf.h:28:35: error: `__kernel_mode_t' undeclared here (not in a function)
unsigned char __pad1[4 - sizeof(__kernel_mode_t)];
^~~~~~~~~~~~~~~
usr/include/asm-generic/ipcbuf.h:31:2: error: unknown type name `__kernel_ulong_t'
__kernel_ulong_t __unused1;
^~~~~~~~~~~~~~~~
usr/include/asm-generic/ipcbuf.h:32:2: error: unknown type name `__kernel_ulong_t'
__kernel_ulong_t __unused2;
^~~~~~~~~~~~~~~~
It is just a matter of missing include directive.
Include <linux/posix_types.h> to make it self-contained, and add it to
the compile-test coverage.
Link: http://lkml.kernel.org/r/20191030063855.9989-1-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
At the moment, UBSAN report will be serialized using a spin_lock(). On
RT-systems, spinlocks are turned to rt_spin_lock and may sleep. This
will result to the following splat if the undefined behavior is in a
context that can sleep:
BUG: sleeping function called from invalid context at /src/linux/kernel/locking/rtmutex.c:968
in_atomic(): 1, irqs_disabled(): 128, pid: 3447, name: make
1 lock held by make/3447:
#0: 000000009a966332 (&mm->mmap_sem){++++}, at: do_page_fault+0x140/0x4f8
irq event stamp: 6284
hardirqs last enabled at (6283): [<ffff000011326520>] _raw_spin_unlock_irqrestore+0x90/0xa0
hardirqs last disabled at (6284): [<ffff0000113262b0>] _raw_spin_lock_irqsave+0x30/0x78
softirqs last enabled at (2430): [<ffff000010088ef8>] fpsimd_restore_current_state+0x60/0xe8
softirqs last disabled at (2427): [<ffff000010088ec0>] fpsimd_restore_current_state+0x28/0xe8
Preemption disabled at:
[<ffff000011324a4c>] rt_mutex_futex_unlock+0x4c/0xb0
CPU: 3 PID: 3447 Comm: make Tainted: G W 5.2.14-rt7-01890-ge6e057589653 #911
Call trace:
dump_backtrace+0x0/0x148
show_stack+0x14/0x20
dump_stack+0xbc/0x104
___might_sleep+0x154/0x210
rt_spin_lock+0x68/0xa0
ubsan_prologue+0x30/0x68
handle_overflow+0x64/0xe0
__ubsan_handle_add_overflow+0x10/0x18
__lock_acquire+0x1c28/0x2a28
lock_acquire+0xf0/0x370
_raw_spin_lock_irqsave+0x58/0x78
rt_mutex_futex_unlock+0x4c/0xb0
rt_spin_unlock+0x28/0x70
get_page_from_freelist+0x428/0x2b60
__alloc_pages_nodemask+0x174/0x1708
alloc_pages_vma+0x1ac/0x238
__handle_mm_fault+0x4ac/0x10b0
handle_mm_fault+0x1d8/0x3b0
do_page_fault+0x1c8/0x4f8
do_translation_fault+0xb8/0xe0
do_mem_abort+0x3c/0x98
el0_da+0x20/0x24
The spin_lock() will protect against multiple CPUs to output a report
together, I guess to prevent them from being interleaved. However, they
can still interleave with other messages (and even splat from
__might_sleep).
So the lock usefulness seems pretty limited. Rather than trying to
accomodate RT-system by switching to a raw_spin_lock(), the lock is now
completely dropped.
Link: http://lkml.kernel.org/r/20190920100835.14999-1-julien.grall@arm.com
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reported-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series " kcov: collect coverage from usb and vhost", v3.
This patchset extends kcov to allow collecting coverage from backgound
kernel threads. This extension requires custom annotations for each of
the places where coverage collection is desired. This patchset
implements this for hub events in the USB subsystem and for vhost
workers. See the first patch description for details about the kcov
extension. The other two patches apply this kcov extension to USB and
vhost.
Examples of other subsystems that might potentially benefit from this
when custom annotations are added (the list is based on
process_one_work() callers for bugs recently reported by syzbot):
1. fs: writeback wb_workfn() worker,
2. net: addrconf_dad_work()/addrconf_verify_work() workers,
3. net: neigh_periodic_work() worker,
4. net/p9: p9_write_work()/p9_read_work() workers,
5. block: blk_mq_run_work_fn() worker.
These patches have been used to enable coverage-guided USB fuzzing with
syzkaller for the last few years, see the details here:
https://github.com/google/syzkaller/blob/master/docs/linux/external_fuzzing_usb.md
This patchset has been pushed to the public Linux kernel Gerrit
instance:
https://linux-review.googlesource.com/c/linux/kernel/git/torvalds/linux/+/1524
This patch (of 3):
Add background thread coverage collection ability to kcov.
With KCOV_ENABLE coverage is collected only for syscalls that are issued
from the current process. With KCOV_REMOTE_ENABLE it's possible to
collect coverage for arbitrary parts of the kernel code, provided that
those parts are annotated with kcov_remote_start()/kcov_remote_stop().
This allows to collect coverage from two types of kernel background
threads: the global ones, that are spawned during kernel boot in a
limited number of instances (e.g. one USB hub_event() worker thread is
spawned per USB HCD); and the local ones, that are spawned when a user
interacts with some kernel interface (e.g. vhost workers).
To enable collecting coverage from a global background thread, a unique
global handle must be assigned and passed to the corresponding
kcov_remote_start() call. Then a userspace process can pass a list of
such handles to the KCOV_REMOTE_ENABLE ioctl in the handles array field
of the kcov_remote_arg struct. This will attach the used kcov device to
the code sections, that are referenced by those handles.
Since there might be many local background threads spawned from
different userspace processes, we can't use a single global handle per
annotation. Instead, the userspace process passes a non-zero handle
through the common_handle field of the kcov_remote_arg struct. This
common handle gets saved to the kcov_handle field in the current
task_struct and needs to be passed to the newly spawned threads via
custom annotations. Those threads should in turn be annotated with
kcov_remote_start()/kcov_remote_stop().
Internally kcov stores handles as u64 integers. The top byte of a
handle is used to denote the id of a subsystem that this handle belongs
to, and the lower 4 bytes are used to denote the id of a thread instance
within that subsystem. A reserved value 0 is used as a subsystem id for
common handles as they don't belong to a particular subsystem. The
bytes 4-7 are currently reserved and must be zero. In the future the
number of bytes used for the subsystem or handle ids might be increased.
When a particular userspace process collects coverage by via a common
handle, kcov will collect coverage for each code section that is
annotated to use the common handle obtained as kcov_handle from the
current task_struct. However non common handles allow to collect
coverage selectively from different subsystems.
Link: http://lkml.kernel.org/r/e90e315426a384207edbec1d6aa89e43008e4caf.1572366574.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: David Windsor <dwindsor@gmail.com>
Cc: Elena Reshetova <elena.reshetova@intel.com>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
