Add support for the same output format as the bash script,
and use its implementation instead of the previous one.
I opted to do such patch in order to have a single script
responsible for parsing Documentation/features and
produce different outputs.
As someone may rely on the past format, which is easy
to parse it, get_feat.pl now gains a new command with
the same output format as the previous script.
As a side effect, the perl script is a lot faster, as it reads
each file only once, instead of parsing files several times
via a for command and grep commands inside it.
This patch also changes the features list order to be
case-insensitive, in order to better match the output of
the existing script.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/a97f49677805ad4e6b982d02c0db8c9dfbbd20a6.1606748711.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The Documentation/features contains a set of parseable files.
It is not worth converting them to ReST format, as they're
useful the way it is. It is, however, interesting to parse
them and produce output on different formats:
1) Output the contents of a feature in ReST format;
2) Output what features a given architecture supports;
3) Output a matrix with features x architectures.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/8b0c1ad06d689283a6d78c4ccd188a02c3acc0de.1606748711.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Sphinx 3.1 introduced namespaces for C cross-references. With this,
each C domain type/function declaration is put inside the namespace that
was active at the time of its declaration.
Add support for automatic cross-referencing inside C namespaces by
checking whether the corresponding source file had a C namespace Sphinx
directive, and if so, try cross-referencing inside of it before going to
the global scope.
This assumes there's only one namespace (if any) per rst file.
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@protonmail.com>
Link: https://lore.kernel.org/r/20201117021107.214704-1-nfraprado@protonmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently, we do not have any documentation on commit reverts regarding
the requirement of Signed-off-by tag for it. This may be misleading to
the users.
Evaluating MISSING_SIGN_OFF checkpatch warnings on v4.13..v5.8 showed
that 4 out of 11 cases missing a sign-off are revert commits.
Add documentation regarding the same to document the community
consensus and let readers know.
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20201110174749.32068-1-yashsri421@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Pull driver core documentation fixes from Greg KH:
"Some small Documentation fixes that were fallout from the larger
documentation update we did in 5.10-rc2.
Nothing major here at all, but all of these have been in linux-next
and resolve build warnings when building the documentation files"
* tag 'driver-core-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
Documentation: remove mic/index from misc-devices/index.rst
scripts: get_api.pl: Add sub-titles to ABI output
scripts: get_abi.pl: Don't let ABI files to create subtitles
docs: leds: index.rst: add a missing file
docs: ABI: sysfs-class-net: fix a typo
docs: ABI: sysfs-driver-dma-ioatdma: what starts with /sys
Pull tty/serial fixes from Greg KH:
"Here are a small number of small tty and serial fixes for some
reported problems for the tty core, vt code, and some serial drivers.
They include fixes for:
- a buggy and obsolete vt font ioctl removal
- 8250_mtk serial baudrate runtime warnings
- imx serial earlycon build configuration fix
- txx9 serial driver error path cleanup issues
- tty core fix in release_tty that can be triggered by trying to bind
an invalid serial port name to a speakup console device
Almost all of these have been in linux-next without any problems, the
only one that hasn't, just deletes code :)"
* tag 'tty-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
vt: Disable KD_FONT_OP_COPY
tty: fix crash in release_tty if tty->port is not set
serial: txx9: add missing platform_driver_unregister() on error in serial_txx9_init
tty: serial: imx: enable earlycon by default if IMX_SERIAL_CONSOLE is enabled
serial: 8250_mtk: Fix uart_get_baud_rate warning
Pull USB fixes from Greg KH:
"Here are some small USB fixes and new device ids:
- USB gadget fixes for some reported issues
- Fixes for the ever-troublesome apple fastcharge driver, hopefully
we finally have it right.
- More USB core quirks for odd devices
- USB serial driver fixes for some long-standing issues that were
recently found
- some new USB serial driver device ids
All have been in linux-next with no reported issues"
* tag 'usb-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
USB: apple-mfi-fastcharge: fix reference leak in apple_mfi_fc_set_property
usb: mtu3: fix panic in mtu3_gadget_stop()
USB: serial: option: add Telit FN980 composition 0x1055
USB: serial: option: add LE910Cx compositions 0x1203, 0x1230, 0x1231
USB: serial: cyberjack: fix write-URB completion race
USB: Add NO_LPM quirk for Kingston flash drive
USB: serial: option: add Quectel EC200T module support
usb: raw-gadget: fix memory leak in gadget_setup
usb: dwc2: Avoid leaving the error_debugfs label unused
usb: dwc3: ep0: Fix delay status handling
usb: gadget: fsl: fix null pointer checking
usb: gadget: goku_udc: fix potential crashes in probe
usb: dwc3: pci: add support for the Intel Alder Lake-S
current->group_leader->exit_signal may change during copy_process() if
current->real_parent exits.
Move the assignment inside tasklist_lock to avoid the race.
Signed-off-by: Eddy Wu <eddy_wu@trendmicro.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's buggy:
On Fri, Nov 06, 2020 at 10:30:08PM +0800, Minh Yuan wrote:
> We recently discovered a slab-out-of-bounds read in fbcon in the latest
> kernel ( v5.10-rc2 for now ). The root cause of this vulnerability is that
> "fbcon_do_set_font" did not handle "vc->vc_font.data" and
> "vc->vc_font.height" correctly, and the patch
> <https://lkml.org/lkml/2020/9/27/223> for VT_RESIZEX can't handle this
> issue.
>
> Specifically, we use KD_FONT_OP_SET to set a small font.data for tty6, and
> use KD_FONT_OP_SET again to set a large font.height for tty1. After that,
> we use KD_FONT_OP_COPY to assign tty6's vc_font.data to tty1's vc_font.data
> in "fbcon_do_set_font", while tty1 retains the original larger
> height. Obviously, this will cause an out-of-bounds read, because we can
> access a smaller vc_font.data with a larger vc_font.height.
Further there was only one user ever.
- Android's loadfont, busybox and console-tools only ever use OP_GET
and OP_SET
- fbset documentation only mentions the kernel cmdline font: option,
not anything else.
- systemd used OP_COPY before release 232 published in Nov 2016
Now unfortunately the crucial report seems to have gone down with
gmane, and the commit message doesn't say much. But the pull request
hints at OP_COPY being broken
https://github.com/systemd/systemd/pull/3651
So in other words, this never worked, and the only project which
foolishly every tried to use it, realized that rather quickly too.
Instead of trying to fix security issues here on dead code by adding
missing checks, fix the entire thing by removing the functionality.
Note that systemd code using the OP_COPY function ignored the return
value, so it doesn't matter what we're doing here really - just in
case a lone server somewhere happens to be extremely unlucky and
running an affected old version of systemd. The relevant code from
font_copy_to_all_vcs() in systemd was:
/* copy font from active VT, where the font was uploaded to */
cfo.op = KD_FONT_OP_COPY;
cfo.height = vcs.v_active-1; /* tty1 == index 0 */
(void) ioctl(vcfd, KDFONTOP, &cfo);
Note this just disables the ioctl, garbage collecting the now unused
callbacks is left for -next.
v2: Tetsuo found the old mail, which allowed me to find it on another
archive. Add the link too.
Acked-by: Peilin Ye <yepeilin.cs@gmail.com>
Reported-by: Minh Yuan <yuanmingbuaa@gmail.com>
References: https://lists.freedesktop.org/archives/systemd-devel/2016-June/036935.html
References: https://github.com/systemd/systemd/pull/3651
Cc: Greg KH <greg@kroah.com>
Cc: Peilin Ye <yepeilin.cs@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://lore.kernel.org/r/20201108153806.3140315-1-daniel.vetter@ffwll.ch
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull xfs fixes from Darrick Wong:
- Fix an uninitialized struct problem
- Fix an iomap problem zeroing unwritten EOF blocks
- Fix some clumsy error handling when writeback fails on filesystems
with blocksize < pagesize
- Fix a retry loop not resetting loop variables properly
- Fix scrub flagging rtinherit inodes on a non-rt fs, since the kernel
actually does permit that combination
- Fix excessive page cache flushing when unsharing part of a file
* tag 'xfs-5.10-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: only flush the unshared range in xfs_reflink_unshare
xfs: fix scrub flagging rtinherit even if there is no rt device
xfs: fix missing CoW blocks writeback conversion retry
iomap: clean up writeback state logic on writepage error
iomap: support partial page discard on writeback block mapping failure
xfs: flush new eof page on truncate to avoid post-eof corruption
xfs: set xefi_discard when creating a deferred agfl free log intent item
Merge procfs splice read fixes from Christoph Hellwig:
"Greg reported a problem due to the fact that Android tests use procfs
files to test splice, which stopped working with the changes for
set_fs() removal.
This series adds read_iter support for seq_file, and uses those for
various proc files using seq_file to restore splice read support"
[ Side note: Christoph initially had a scripted "move everything over"
patch, which looks fine, but I personally would prefer us to actively
discourage splice() on random files. So this does just the minimal
basic core set of proc file op conversions.
For completeness, and in case people care, that script was
sed -i -e 's/\.proc_read\(\s*=\s*\)seq_read/\.proc_read_iter\1seq_read_iter/g'
but I'll wait and see if somebody has a strong argument for using
splice on random small /proc files before I'd run it on the whole
kernel. - Linus ]
* emailed patches from Christoph Hellwig <hch@lst.de>:
proc "seq files": switch to ->read_iter
proc "single files": switch to ->read_iter
proc/stat: switch to ->read_iter
proc/cpuinfo: switch to ->read_iter
proc: wire up generic_file_splice_read for iter ops
seq_file: add seq_read_iter
Pull x86 fixes from Thomas Gleixner:
"A set of x86 fixes:
- Use SYM_FUNC_START_WEAK in the mem* ASM functions instead of a
combination of .weak and SYM_FUNC_START_LOCAL which makes LLVMs
integrated assembler upset
- Correct the mitigation selection logic which prevented the related
prctl to work correctly
- Make the UV5 hubless system work correctly by fixing up the
malformed table entries and adding the missing ones"
* tag 'x86-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/platform/uv: Recognize UV5 hubless system identifier
x86/platform/uv: Remove spaces from OEM IDs
x86/platform/uv: Fix missing OEM_TABLE_ID
x86/speculation: Allow IBPB to be conditionally enabled on CPUs with always-on STIBP
x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S
Pull perf fix from Thomas Gleixner:
"A single fix for the perf core plugging a memory leak in the address
filter parser"
* tag 'perf-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix a memory leak in perf_event_parse_addr_filter()
Pull futex fix from Thomas Gleixner:
"A single fix for the futex code where an intermediate state in the
underlying RT mutex was not handled correctly and triggering a BUG()
instead of treating it as another variant of retry condition"
* tag 'locking-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Handle transient "ownerless" rtmutex state correctly
Pull irq fixes from Thomas Gleixner:
"A set of fixes for interrupt chip drivers:
- Fix the fallout of the IPI as interrupt conversion in Kconfig and
the BCM2836 interrupt chip driver
- Fixes for interrupt affinity setting and the handling of
hierarchical irq domains in the SiFive PLIC driver
- Make the unmapped event handling in the TI SCI driver work
correctly
- A few minor fixes and cleanups in various chip drivers and Kconfig"
* tag 'irq-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
dt-bindings: irqchip: ti, sci-inta: Fix diagram indentation for unmapped events
irqchip/ti-sci-inta: Add support for unmapped event handling
dt-bindings: irqchip: ti, sci-inta: Update for unmapped event handling
irqchip/renesas-intc-irqpin: Merge irlm_bit and needs_irlm
irqchip/sifive-plic: Fix chip_data access within a hierarchy
irqchip/sifive-plic: Fix broken irq_set_affinity() callback
irqchip/stm32-exti: Add all LP timer exti direct events support
irqchip/bcm2836: Fix missing __init annotation
irqchip/mips: Drop selection of IRQ_DOMAIN_HIERARCHY
irqchip/mst: Make mst_intc_of_init static
irqchip/mst: MST_IRQ should depend on ARCH_MEDIATEK or ARCH_MSTARV7
genirq: Let GENERIC_IRQ_IPI select IRQ_DOMAIN_HIERARCHY
Pull entry code fix from Thomas Gleixner:
"A single fix for the generic entry code to correct the wrong
assumption that the lockdep interrupt state needs not to be
established before calling the RCU check"
* tag 'core-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
entry: Fix the incorrect ordering of lockdep and RCU check
Pull powerpc fixes from Michael Ellerman:
- fix miscompilation with GCC 4.9 by using asm_goto_volatile for put_user()
- fix for an RCU splat at boot caused by a recent lockdep change
- fix for a possible deadlock in our EEH debugfs code
- several fixes for handling of _PAGE_ACCESSED on 32-bit platforms
- build fix when CONFIG_NUMA=n
Thanks to Andreas Schwab, Christophe Leroy, Oliver O'Halloran, Qian Cai,
and Scott Cheloha.
* tag 'powerpc-5.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/numa: Fix build when CONFIG_NUMA=n
powerpc/8xx: Manage _PAGE_ACCESSED through APG bits in L1 entry
powerpc/8xx: Always fault when _PAGE_ACCESSED is not set
powerpc/40x: Always fault when _PAGE_ACCESSED is not set
powerpc/603: Always fault when _PAGE_ACCESSED is not set
powerpc: Use asm_goto_volatile for put_user()
powerpc/smp: Call rcu_cpu_starting() earlier
powerpc/eeh_cache: Fix a possible debugfs deadlock
Pull block fixes from Jens Axboe:
- NVMe pull request from Christoph:
- revert a nvme_queue size optimization (Keith Bush)
- fabrics timeout races fixes (Chao Leng and Sagi Grimberg)"
- null_blk zone locking fix (Damien)
* tag 'block-5.10-2020-11-07' of git://git.kernel.dk/linux-block:
null_blk: Fix scheduling in atomic with zoned mode
nvme-tcp: avoid repeated request completion
nvme-rdma: avoid repeated request completion
nvme-tcp: avoid race between time out and tear down
nvme-rdma: avoid race between time out and tear down
nvme: introduce nvme_sync_io_queues
Revert "nvme-pci: remove last_sq_tail"
Pull io_uring fixes from Jens Axboe:
"A set of fixes for io_uring:
- SQPOLL cancelation fixes
- Two fixes for the io_identity COW
- Cancelation overflow fix (Pavel)
- Drain request cancelation fix (Pavel)
- Link timeout race fix (Pavel)"
* tag 'io_uring-5.10-2020-11-07' of git://git.kernel.dk/linux-block:
io_uring: fix link lookup racing with link timeout
io_uring: use correct pointer for io_uring_show_cred()
io_uring: don't forget to task-cancel drained reqs
io_uring: fix overflowed cancel w/ linked ->files
io_uring: drop req/tctx io_identity separately
io_uring: ensure consistent view of original task ->mm from SQPOLL
io_uring: properly handle SQPOLL request cancelations
io-wq: cancel request if it's asking for files and we don't have them
Gratian managed to trigger the BUG_ON(!newowner) in fixup_pi_state_owner().
This is one possible chain of events leading to this:
Task Prio Operation
T1 120 lock(F)
T2 120 lock(F) -> blocks (top waiter)
T3 50 (RT) lock(F) -> boosts T1 and blocks (new top waiter)
XX timeout/ -> wakes T2
signal
T1 50 unlock(F) -> wakes T3 (rtmutex->owner == NULL, waiter bit is set)
T2 120 cleanup -> try_to_take_mutex() fails because T3 is the top waiter
and the lower priority T2 cannot steal the lock.
-> fixup_pi_state_owner() sees newowner == NULL -> BUG_ON()
The comment states that this is invalid and rt_mutex_real_owner() must
return a non NULL owner when the trylock failed, but in case of a queued
and woken up waiter rt_mutex_real_owner() == NULL is a valid transient
state. The higher priority waiter has simply not yet managed to take over
the rtmutex.
The BUG_ON() is therefore wrong and this is just another retry condition in
fixup_pi_state_owner().
Drop the locks, so that T3 can make progress, and then try the fixup again.
Gratian provided a great analysis, traces and a reproducer. The analysis is
to the point, but it confused the hell out of that tglx dude who had to
page in all the futex horrors again. Condensed version is above.
[ tglx: Wrote comment and changelog ]
Fixes: c1e2f0eaf0 ("futex: Avoid violating the 10th rule of futex")
Reported-by: Gratian Crisan <gratian.crisan@ni.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87a6w6x7bb.fsf@ni.com
Link: https://lore.kernel.org/r/87sg9pkvf7.fsf@nanos.tec.linutronix.de
Pull i2c fixes from Wolfram Sang:
"Driver bugfixes for I2C.
Most of them are for the new mlxbf driver which got more exposure
after rc1. The sh_mobile patch should already have reached you during
the merge window, but I accidently dropped it. However, since it fixes
a problem with rebooting, it is still fine for rc3"
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: designware: slave should do WRITE_REQUESTED before WRITE_RECEIVED
i2c: designware: call i2c_dw_read_clear_intrbits_slave() once
i2c: mlxbf: I2C_MLXBF should depend on MELLANOX_PLATFORM
i2c: mlxbf: Update author and maintainer email info
i2c: mlxbf: Update reference clock frequency
i2c: mlxbf: Remove unecessary wrapper functions
i2c: mlxbf: Fix resrticted cast warning of sparse
i2c: mlxbf: Add CONFIG_ACPI to guard ACPI function call
i2c: sh_mobile: implement atomic transfers
i2c: mediatek: move dma reset before i2c reset
Pull RISC-V fixes from Palmer Dabbelt:
- SPDX comment style fix
- ignore memory that is unusable
- avoid setting a kernel text offset for the !MMU kernels, where
skipping the first page of memory is both unnecessary and costly
- avoid passing the flag bits in satp to pfn_to_virt()
- fix __put_kernel_nofault, where we had the arguments to
__put_user_nocheck reversed
- workaround for a bug in the FU540 to avoid triggering PMP issues
during early boot
- change to how we pull symbols out of the vDSO. The old mechanism was
removed from binutils-2.35 (and has been backported to Debian's 2.34)
* tag 'riscv-for-linus-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
RISC-V: Fix the VDSO symbol generaton for binutils-2.35+
RISC-V: Use non-PGD mappings for early DTB access
riscv: uaccess: fix __put_kernel_nofault()
riscv: fix pfn_to_virt err in do_page_fault().
riscv: Set text_offset correctly for M-Mode
RISC-V: Remove any memblock representing unusable memory area
risc-v: kernel: ftrace: Fixes improper SPDX comment style
Johan writes:
USB-serial fixes for 5.10-rc3
Here's a fix for a long-standing issue with the cyberjack driver and
some new device ids.
All have been in linux-next with no reported issues.
* tag 'usb-serial-5.10-rc3' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial:
USB: serial: option: add Telit FN980 composition 0x1055
USB: serial: option: add LE910Cx compositions 0x1203, 0x1230, 0x1231
USB: serial: cyberjack: fix write-URB completion race
USB: serial: option: add Quectel EC200T module support
As shown through runtime testing, the "filename" allocation is not
always freed in perf_event_parse_addr_filter().
There are three possible ways that this could happen:
- It could be allocated twice on subsequent iterations through the loop,
- or leaked on the success path,
- or on the failure path.
Clean up the code flow to make it obvious that 'filename' is always
freed in the reallocation path and in the two return paths as well.
We rely on the fact that kfree(NULL) is NOP and filename is initialized
with NULL.
This fixes the leak. No other side effects expected.
[ Dan Carpenter: cleaned up the code flow & added a changelog. ]
[ Ingo Molnar: updated the changelog some more. ]
Fixes: 375637bc52 ("perf/core: Introduce address range filtering")
Signed-off-by: "kiyin(尹亮)" <kiyin@tencent.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "Srivatsa S. Bhat" <srivatsa@csail.mit.edu>
Cc: Anthony Liguori <aliguori@amazon.com>
--
kernel/events/core.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
Testing shows that trailing spaces caused problems with the OEM_ID and
the OEM_TABLE_ID. One being that the OEM_ID would not string compare
correctly. Another the OEM_ID and OEM_TABLE_ID would be concatenated
in the printout. Remove any trailing spaces.
Fixes: 1e61f5a95f ("Add and decode Arch Type in UVsystab")
Signed-off-by: Mike Travis <mike.travis@hpe.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201105222741.157029-3-mike.travis@hpe.com
Pull ceph fix from Ilya Dryomov:
"A fix for a potential stall on umount caused by the MDS dropping our
REQUEST_CLOSE message. The code that handled this case was
inadvertently disabled in 5.9, this patch removes it entirely and
fixes the problem in a way that is consistent with ceph-fuse"
* tag 'ceph-for-5.10-rc3' of git://github.com/ceph/ceph-client:
ceph: check session state after bumping session->s_seq
Pull Kselftest fixes from Shuah Khan:
"Fixes to the ftrace test and several fixes from Tommi Rantala for
various other tests"
* tag 'linux-kselftest-fixes-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests: binderfs: use SKIP instead of XFAIL
selftests: clone3: use SKIP instead of XFAIL
selftests: core: use SKIP instead of XFAIL in close_range_test.c
selftests: proc: fix warning: _GNU_SOURCE redefined
selftests: pidfd: drop needless linux/kcmp.h inclusion in pidfd_setns_test.c
selftests: pidfd: add CONFIG_CHECKPOINT_RESTORE=y to config
selftests: pidfd: skip test on kcmp() ENOSYS
selftests: pidfd: use ksft_test_result_skip() when skipping test
selftests/harness: prettify SKIP message whitespace again
selftests: pidfd: fix compilation errors due to wait.h
selftests: filter kselftest headers from command in lib.mk
selftests/ftrace: check for do_sys_openat2 in user-memory test
selftests/ftrace: Use $FUNCTION_FORK to reference kernel fork function
