A kernel which boots in 5-level paging mode crashes in a small percentage
of cases if KASLR is enabled.
This issue was tracked down to the case when the kernel image unpacks in a
way that it crosses an 1G boundary. The crash is caused by an overrun of
the PMD page table in __startup_64() and corruption of P4D page table
allocated next to it. This particular issue is not visible with 4-level
paging as P4D page tables are not used.
But the P4D and the PUD calculation have similar problems.
The PMD index calculation is wrong due to operator precedence, which fails
to confine the PMDs in the PMD array on wrap around.
The P4D calculation for 5-level paging and the PUD calculation calculate
the first index correctly, but then blindly increment it which causes the
same issue when a kernel image is located across a 512G and for 5-level
paging across a 46T boundary.
This wrap around mishandling was introduced when these parts moved from
assembly to C.
Restore it to the correct behaviour.
Fixes: c88d71508e ("x86/boot/64: Rewrite startup_64() in C")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190620112345.28833-1-kirill.shutemov@linux.intel.com
/proc/sys/net/ipv6/route/skip_notify_on_dev_down assumes given value to be
0 or 1. Use proc_dointvec_minmax instead of proc_dointvec.
Fixes: 7c6bb7d2fa ("net/ipv6: Add knob to skip DELROUTE message ondevice down")
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In commit 19e4e76806 ("ipv4: Fix raw socket lookup for local
traffic"), the dif argument to __raw_v4_lookup() is coming from the
returned value of inet_iif() but the change was done only for the first
lookup. Subsequent lookups in the while loop still use skb->dev->ifIndex.
Fixes: 19e4e76806 ("ipv4: Fix raw socket lookup for local traffic")
Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
DM verity should also use DMERR_LIMIT to limit repeat data block
corruption messages.
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
For the first call to realloc_argv() in dm_split_args(), old_argv is
NULL and size is zero. Then memcpy is called, with the NULL old_argv
as the source argument and a zero size argument. AFAIK, this is
undefined behavior and generates the following warning when compiled
with UBSAN on ppc64le:
In file included from ./arch/powerpc/include/asm/paca.h:19,
from ./arch/powerpc/include/asm/current.h:16,
from ./include/linux/sched.h:12,
from ./include/linux/kthread.h:6,
from drivers/md/dm-core.h:12,
from drivers/md/dm-table.c:8:
In function 'memcpy',
inlined from 'realloc_argv' at drivers/md/dm-table.c:565:3,
inlined from 'dm_split_args' at drivers/md/dm-table.c:588:9:
./include/linux/string.h:345:9: error: argument 2 null where non-null expected [-Werror=nonnull]
return __builtin_memcpy(p, q, size);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/md/dm-table.c: In function 'dm_split_args':
./include/linux/string.h:345:9: note: in a call to built-in function '__builtin_memcpy'
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Currently, although we submit super bios in order (and super.nr_entries
is incremented by each logged entry), submit_bio() is async so each
super sector may not be written to log device in order and then the
final nr_entries may be smaller than it should be.
This problem can be reproduced by the xfstests generic/455 with ext4:
QA output created by 455
-Silence is golden
+mark 'end' does not exist
Fix this by serializing submission of super sectors to make sure each
is written to the log disk in order.
Fixes: 0e9cebe724 ("dm: add log writes target")
Cc: stable@vger.kernel.org
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Suggested-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
These printing macros already add a trailing newline, so having another
one here just makes for blank lines when these prints are enabled.
Remove these needless newlines.
Fixes: 6bbc923dfc ("dm: add support to directly boot to a mapped device")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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: 7074f076ff ("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>
Currently arm64 uses the default implementation of panic_smp_self_stop()
where the CPU runs in a cpu_relax() loop unable to receive IPIs anymore.
As a result, when two CPUs panic() simultaneously we get "SMP: failed to
stop secondary CPUs" warnings and extra delays before a reset, because
smp_send_stop() still tries to stop the other paniced CPU.
Provide an implementation of panic_smp_self_stop() that is identical to
the IPI CPU stop handler, so that the online status of stopped CPUs gets
properly updated.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The current code puts the stopped cpus in an 'yield' instruction loop.
Using a busy loop here is unnecessary, we can use the cpu_park_loop()
function here to do a wfi/wfe.
Signed-off-by: Jayachandran C <jnair@caviumnetworks.com>
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The actual layout for OCELOT_GPIO_ALT[01] when there are more than 32 pins
is interleaved, i.e. OCELOT_GPIO_ALT0[0], OCELOT_GPIO_ALT1[0],
OCELOT_GPIO_ALT0[1], OCELOT_GPIO_ALT1[1]. Introduce a new REG_ALT macro to
facilitate the register offset calculation and use it where necessary.
Fixes: da801ab56a pinctrl: ocelot: add MSCC Jaguar2 support
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The third argument passed to REG is not the correct one and
ocelot_gpio_set_direction is not working for pins after 31. Fix that by
passing the pin number instead of the modulo 32 value.
Fixes: da801ab56a pinctrl: ocelot: add MSCC Jaguar2 support
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
ARMv8.5 introduces the FRINT series of instructions for rounding floating
point numbers to integers. Provide a capability to userspace in order to
allow applications to determine if the system supports these instructions.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
ARMv8.5 adds new instructions XAFLAG and AXFLAG to translate the
representation of the results of floating point comparisons between the
native ARM format and an alternative format used by some software. Add
a hwcap allowing userspace to determine if they are present, since we
referred to earlier CondM extensions as FLAGM call these extensions
FLAGM2.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Currently probing of the mcp23s08 results in an error message
"detected irqchip that is shared with multiple gpiochips:
please fix the driver"
This is due to the following:
Call to mcp23s08_irqchip_setup() with call hierarchy:
mcp23s08_irqchip_setup()
gpiochip_irqchip_add_nested()
gpiochip_irqchip_add_key()
gpiochip_set_irq_hooks()
Call to devm_gpiochip_add_data() with call hierarchy:
devm_gpiochip_add_data()
gpiochip_add_data_with_key()
gpiochip_add_irqchip()
gpiochip_set_irq_hooks()
The gpiochip_add_irqchip() returns immediately if there isn't a irqchip
but we added a irqchip due to the previous mcp23s08_irqchip_setup()
call. So it calls gpiochip_set_irq_hooks() a second time.
Fix this by moving the call to devm_gpiochip_add_data before
the call to mcp23s08_irqchip_setup
Fixes: 02e389e63e ("pinctrl: mcp23s08: fix irq setup order")
Suggested-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This adds 4 SND_PCI_QUIRK(...) lines for several barebone models of the ODM
Clevo. The model names are written in regex syntax to describe/match all clevo
models that are similar enough and use the same PCI SSID that this fixup works
for them.
Additionally the lines regarding SSID 0x96e1 and 0x97e1 didn't fix audio for the
all our Clevo notebooks using these SSIDs (models Clevo P960* and P970*) since
ALC1220_FIXP_CLEVO_PB51ED_PINS swapped pins that are not necesarry to be
swapped. This patch initiates ALC1220_FIXUP_CLEVO_P950 instead for these model
and fixes the audio.
Fixes: 80690a276f ("ALSA: hda/realtek - Add quirk for Tuxedo XC 1509")
Signed-off-by: Richard Sailer <rs@tuxedocomputers.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
i.MX fixes for 5.2, round 3:
- A recent testing by Sébastien discovers that the PWM interrupts of
i.MX6UL were wrongly coded in device tree. It's a fix for it.
* tag 'imx-fixes-5.2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux:
ARM: dts: imx6ul: fix PWM[1-4] interrupts
Signed-off-by: Olof Johansson <olof@lixom.net>
ARM: dts: Amlogic fixes for v5.2-rc
- fix GPU interrupts and operating voltage
* tag 'amlogic-fixes' of https://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-amlogic:
ARM: dts: meson8b: fix the operating voltage of the Mali GPU
ARM: dts: meson8b: drop undocumented property from the Mali GPU node
ARM: dts: meson8: fix GPU interrupts and drop an undocumented property
Signed-off-by: Olof Johansson <olof@lixom.net>
The early machine check runs in real mode, so locking is unnecessary.
Worse, the windup does not restore AMR, so this can result in a false
KUAP fault after a recoverable machine check hits inside a user copy
operation.
Fix this similarly to HMI by just avoiding the kuap lock in the
early machine check handler (it will be set by the late handler that
runs in virtual mode if that runs). If the virtual mode handler is
reached, it will lock and restore the AMR.
Fixes: 890274c2dc ("powerpc/64s: Implement KUAP for Radix MMU")
Cc: Russell Currey <ruscur@russell.cc>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Otherwise, selecting it without MODULES leads to build failures.
Fixes: 58557e486f ("arm64: Allow user selection of ARM64_MODULE_PLTS")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Pull parisc fix from Helge Deller:
"Add missing PCREL64 relocation in module loader to fix module load
errors when the static branch and JUMP_LABEL feature is enabled on
a 64-bit kernel"
* 'parisc-5.2-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Fix module loading error with JUMP_LABEL feature
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: 3d8bfdd030 ("MIPS: Use C0_KScratch (if present) to hold PGD pointer.")
Fixes: 829dcc0a95 ("MIPS: Add MIPS P5600 probe support")
Cc: linux-mips@vger.kernel.org
Cc: stable@vger.kernel.org # v3.15+
Pull mfd bugfix from Lee Jones.
Fix stmfx type confusion between regmap_read() (which takes an "u32")
and the bitmap operations (which take an "unsigned long" array).
* tag 'mfd-fixes-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd:
mfd: stmfx: Fix an endian bug in stmfx_irq_handler()
mfd: stmfx: Uninitialized variable in stmfx_irq_handler()
The BPF code now takes care of mapping the code pages executable
after mapping them read-only, to ensure that no RWX mapped regions
are needed, even transiently. This means we can drop the executable
permissions from the mapping at allocation time.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In order to avoid transient inconsistencies where freed code pages
are remapped writable while stale TLB entries still exist on other
cores, mark the kprobes text pages with the VM_FLUSH_RESET_PERMS
attribute. This instructs the core vmalloc code not to defer the
TLB flush when this region is unmapped and returned to the page
allocator.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Wire up the special helper functions to manipulate aliases of vmalloc
regions in the linear map.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Now that the core code manages the executable permissions of code
regions of modules explicitly, it is no longer necessary to create
the module vmalloc regions with RWX permissions, and we can create
them with RW- permissions instead, which is preferred from a
security perspective.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Make ARM64_MODULE_PLTS a selectable Kconfig symbol, since some people
might have very big modules spilling out of the dedicated module area
into vmalloc. Help text is copied from the ARM 32-bit counterpart and
modified to a mention of KASLR and specific ARM errata workaround(s).
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Some Qualcomm Snapdragon based laptops built to run Microsoft Windows
are clearly ACPI 5.1 based, given that that is the first ACPI revision
that supports ARM, and introduced the FADT 'arm_boot_flags' field,
which has a non-zero field on those systems.
So in these cases, infer from the ARM boot flags that the FADT must be
5.1 or later, and treat it as 5.1.
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Graeme Gregory <graeme.gregory@linaro.org>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The syzbot reported
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xca/0x13e lib/dump_stack.c:113
print_address_description+0x67/0x231 mm/kasan/report.c:188
__kasan_report.cold+0x1a/0x32 mm/kasan/report.c:317
kasan_report+0xe/0x20 mm/kasan/common.c:614
qmi_wwan_probe+0x342/0x360 drivers/net/usb/qmi_wwan.c:1417
usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
really_probe+0x281/0x660 drivers/base/dd.c:509
driver_probe_device+0x104/0x210 drivers/base/dd.c:670
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:777
bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
Caused by too many confusing indirections and casts.
id->driver_info is a pointer stored in a long. We want the
pointer here, not the address of it.
Thanks-to: Hillf Danton <hdanton@sina.com>
Reported-by: syzbot+b68605d7fadd21510de1@syzkaller.appspotmail.com
Cc: Kristian Evensen <kristian.evensen@gmail.com>
Fixes: e4bf63482c ("qmi_wwan: Add quirk for Quectel dynamic config")
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is to fix an uninit-value issue, reported by syzbot:
BUG: KMSAN: uninit-value in memchr+0xce/0x110 lib/string.c:981
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x191/0x1f0 lib/dump_stack.c:113
kmsan_report+0x130/0x2a0 mm/kmsan/kmsan.c:622
__msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:310
memchr+0xce/0x110 lib/string.c:981
string_is_valid net/tipc/netlink_compat.c:176 [inline]
tipc_nl_compat_bearer_disable+0x2a1/0x480 net/tipc/netlink_compat.c:449
__tipc_nl_compat_doit net/tipc/netlink_compat.c:327 [inline]
tipc_nl_compat_doit+0x3ac/0xb00 net/tipc/netlink_compat.c:360
tipc_nl_compat_handle net/tipc/netlink_compat.c:1178 [inline]
tipc_nl_compat_recv+0x1b1b/0x27b0 net/tipc/netlink_compat.c:1281
TLV_GET_DATA_LEN() may return a negtive int value, which will be
used as size_t (becoming a big unsigned long) passed into memchr,
cause this issue.
Similar to what it does in tipc_nl_compat_bearer_enable(), this
fix is to return -EINVAL when TLV_GET_DATA_LEN() is negtive in
tipc_nl_compat_bearer_disable(), as well as in
tipc_nl_compat_link_stat_dump() and tipc_nl_compat_link_reset_stats().
v1->v2:
- add the missing Fixes tags per Eric's request.
Fixes: 0762216c0a ("tipc: fix uninit-value in tipc_nl_compat_bearer_enable")
Fixes: 8b66fee7f8 ("tipc: fix uninit-value in tipc_nl_compat_link_reset_stats")
Reported-by: syzbot+30eaa8bf392f7fafffaf@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes the MAC address setup in the probe. The MAC address
retrieved using of_get_mac_address was checked for not containing an
error, but it may also be NULL which wasn't tested. Fix it by replacing
IS_ERR with IS_ERR_OR_NULL.
Fixes: 541ddc66d6 ("net: macb: support of_get_mac_address new ERR_PTR error")
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Refactoring of the vfio-ccw cp handling, simplifying the
code and avoiding unneeded allocating/copying.
* tag 'vfio-ccw-20190621' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw:
vfio-ccw: Remove copy_ccw_from_iova()
vfio-ccw: Factor out the ccw0-to-ccw1 transition
vfio-ccw: Copy CCW data outside length calculation
vfio-ccw: Skip second copy of guest cp to host
vfio-ccw: Move guest_cp storage into common struct
s390/cio: Combine direct and indirect CCW paths
vfio-ccw: Rearrange IDAL allocation in direct CCW
vfio-ccw: Remove pfn_array_table
vfio-ccw: Adjust the first IDAW outside of the nested loops
vfio-ccw: Rearrange pfn_array and pfn_array_table arrays
s390/cio: Use generalized CCW handler in cp_init()
s390/cio: Generalize the TIC handler
s390/cio: Refactor the routine that handles TIC CCWs
s390/cio: Squash cp_free() and cp_unpin_free()
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
It's not okay to cast a "u32 *" to "unsigned long *" when you are
doing a for_each_set_bit() loop because that will break on big
endian systems.
Fixes: 386145601b82 ("mfd: stmfx: Uninitialized variable in stmfx_irq_handler()")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Tested-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Initialize pidfd to an invalid descriptor, to fail gracefully on
those kernels that do not implement CLONE_PIDFD and leave pidfd
unchanged.
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Christian Brauner <christian@brauner.io>
Give userspace a cheap and reliable way to tell whether CLONE_PIDFD is
supported by the kernel or not. The easiest way is to pass an invalid
file descriptor value in parent_tidptr, perform the syscall and verify
that parent_tidptr has been changed to a valid file descriptor value.
CLONE_PIDFD uses parent_tidptr to return pidfds. CLONE_PARENT_SETTID
will use parent_tidptr to return the tid of the parent. The two flags
cannot be used together. Old kernels that only support
CLONE_PARENT_SETTID will not verify the value pointed to by
parent_tidptr. This behavior is unchanged even with the introduction of
CLONE_PIDFD.
However, if CLONE_PIDFD is specified the kernel will currently check the
value pointed to by parent_tidptr before placing the pidfd in the memory
pointed to. EINVAL will be returned if the value in parent_tidptr is not
0.
If CLONE_PIDFD is supported and fd 0 is closed, then the returned pidfd
can and likely will be 0 and parent_tidptr will be unchanged. This means
userspace must either check CLONE_PIDFD support beforehand or check that
fd 0 is not closed when invoking CLONE_PIDFD.
The check for pidfd == 0 was introduced during the v5.2 merge window by
commit b3e5838252 ("clone: add CLONE_PIDFD") to ensure that
CLONE_PIDFD could be potentially extended by passing in flags through
the return argument.
However, that extension would look horrible, and with the upcoming
introduction of the clone3 syscall in v5.3 there is no need to extend
legacy clone syscall this way. (Even if it would need to be extended,
CLONE_DETACHED can be reused with CLONE_PIDFD.)
So remove the pidfd == 0 check. Userspace that needs to be portable to
kernels without CLONE_PIDFD support can then be advised to initialize
pidfd to -1 and check the pidfd value returned by CLONE_PIDFD.
Fixes: b3e5838252 ("clone: add CLONE_PIDFD")
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Christian Brauner <christian@brauner.io>
