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commit a608da3bd730d718f2d3ebec1c26f9865f8f17ce upstream.
Using REQ_OP_ZONE_APPEND operations for synchronous writes to sequential
files succeeds regardless of the zone write pointer position, as long as
the target zone is not full. This means that if an external (buggy)
application writes to the zone of a sequential file underneath the file
system, subsequent file write() operation will succeed but the file size
will not be correct and the file will contain invalid data written by
another application.
Modify zonefs_file_dio_append() to check the written sector of an append
write (returned in bio->bi_iter.bi_sector) and return -EIO if there is a
mismatch with the file zone wp offset field. This change triggers a call
to zonefs_io_error() and a zone check. Modify zonefs_io_error_cb() to
not expose the unexpected data after the current inode size when the
errors=remount-ro mode is used. Other error modes are correctly handled
already.
Fixes: 02ef12a663c7 ("zonefs: use REQ_OP_ZONE_APPEND for sync DIO")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ed05cb177ae5cd7f02f1d6e7706ba627d30f1696 upstream.
A sanity check was introduced considering maximum flowrings above
256 as insane and effectively aborting the device probe. This
resulted in regression for number of users as the value turns out
to be sane after all.
Fixes: 2aca4f3734bd ("brcmfmac: return error when getting invalid max_flowrings from dongle")
Reported-by: chainofflowers <chainofflowers@posteo.net>
Link: https://lore.kernel.org/all/4781984.GXAFRqVoOG@luna/
Reported-by: Christian Marillat <marillat@debian.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216894
Cc: stable@vger.kernel.org
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230111112419.24185-1-arend.vanspriel@broadcom.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 272970be3dabd24cbe50e393ffee8f04aec3b9a8 upstream.
The driver shutdown callback (which sends EDL_SOC_RESET to the device
over serdev) should not be invoked when HCI device is not open (e.g. if
hci_dev_open_sync() failed), because the serdev and its TTY are not open
either. Also skip this step if device is powered off
(qca_power_shutdown()).
The shutdown callback causes use-after-free during system reboot with
Qualcomm Atheros Bluetooth:
Unable to handle kernel paging request at virtual address
0072662f67726fd7
...
CPU: 6 PID: 1 Comm: systemd-shutdow Tainted: G W
6.1.0-rt5-00325-g8a5f56bcfcca #8
Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
Call trace:
tty_driver_flush_buffer+0x4/0x30
serdev_device_write_flush+0x24/0x34
qca_serdev_shutdown+0x80/0x130 [hci_uart]
device_shutdown+0x15c/0x260
kernel_restart+0x48/0xac
KASAN report:
BUG: KASAN: use-after-free in tty_driver_flush_buffer+0x1c/0x50
Read of size 8 at addr ffff16270c2e0018 by task systemd-shutdow/1
CPU: 7 PID: 1 Comm: systemd-shutdow Not tainted
6.1.0-next-20221220-00014-gb85aaf97fb01-dirty #28
Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
Call trace:
dump_backtrace.part.0+0xdc/0xf0
show_stack+0x18/0x30
dump_stack_lvl+0x68/0x84
print_report+0x188/0x488
kasan_report+0xa4/0xf0
__asan_load8+0x80/0xac
tty_driver_flush_buffer+0x1c/0x50
ttyport_write_flush+0x34/0x44
serdev_device_write_flush+0x48/0x60
qca_serdev_shutdown+0x124/0x274
device_shutdown+0x1e8/0x350
kernel_restart+0x48/0xb0
__do_sys_reboot+0x244/0x2d0
__arm64_sys_reboot+0x54/0x70
invoke_syscall+0x60/0x190
el0_svc_common.constprop.0+0x7c/0x160
do_el0_svc+0x44/0xf0
el0_svc+0x2c/0x6c
el0t_64_sync_handler+0xbc/0x140
el0t_64_sync+0x190/0x194
Fixes: 7e7bbddd029b ("Bluetooth: hci_qca: Fix qca6390 enable failure after warm reboot")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 634cf6ead93988b0da9ac054521ab63a3ba189db ]
The dsi_irq_stats structure is a little too big to fit on the
stack of a 32-bit task, depending on the specific gcc options:
fbdev/omap2/omapfb/dss/dsi.c: In function 'dsi_dump_dsidev_irqs':
fbdev/omap2/omapfb/dss/dsi.c:1621:1: error: the frame size of 1064 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
Since this is only a debugfs file, performance is not critical,
so just dynamically allocate it, and print an error message
in there in place of a failure code when the allocation fails.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c07311b5509f6035f1dd828db3e90ff4859cf3b9 ]
Since Tigerlake seems to have inherited its cstates and other RAPL power
caps from Icelake, assume it also follows Icelake for its RAPL events.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20221228113454.1199118-1-rodrigo.vivi@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 39f501d68ec1ed5cd5c66ac6ec2a7131c517bb92 ]
Currently we have a btrfs_debug() for run_one_delayed_ref() failure, but
if end users hit such problem, there will be no chance that
btrfs_debug() is enabled. This can lead to very little useful info for
debugging.
This patch will:
- Add extra info for error reporting
Including:
* logical bytenr
* num_bytes
* type
* action
* ref_mod
- Replace the btrfs_debug() with btrfs_err()
- Move the error reporting into run_one_delayed_ref()
This is to avoid use-after-free, the @node can be freed in the caller.
This error should only be triggered at most once.
As if run_one_delayed_ref() failed, we trigger the error message, then
causing the call chain to error out:
btrfs_run_delayed_refs()
`- btrfs_run_delayed_refs()
`- btrfs_run_delayed_refs_for_head()
`- run_one_delayed_ref()
And we will abort the current transaction in btrfs_run_delayed_refs().
If we have to run delayed refs for the abort transaction,
run_one_delayed_ref() will just cleanup the refs and do nothing, thus no
new error messages would be output.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 56c5dab20a6391604df9521f812c01d1e3fe1bd0 ]
Since gcc13, each member of an enum has the same type as the enum [1]. And
that is inherited from its members. Provided these two:
SRP_TAG_NO_REQ = ~0U,
SRP_TAG_TSK_MGMT = 1U << 31
all other members are unsigned ints.
Esp. with SRP_MAX_SGE and SRP_TSK_MGMT_SQ_SIZE and their use in min(),
this results in the following warnings:
include/linux/minmax.h:20:35: error: comparison of distinct pointer types lacks a cast
drivers/infiniband/ulp/srp/ib_srp.c:563:42: note: in expansion of macro 'min'
include/linux/minmax.h:20:35: error: comparison of distinct pointer types lacks a cast
drivers/infiniband/ulp/srp/ib_srp.c:2369:27: note: in expansion of macro 'min'
So move the large values away to a separate enum, so that they don't
affect other members.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36113
Link: https://lore.kernel.org/r/20221212120411.13750-1-jirislaby@kernel.org
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ad425666a1f05d9b215a84cf010c3789b2ea8206 ]
There is no functional change. Moving these two functions for following
patch "r8169: fix dmar pte write access is not set error".
Signed-off-by: Chunhao Lin <hau@realtek.com>
Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9deb1e9fb88b1120a908676fa33bdf9e2eeaefce ]
It's not very useful to copy back an empty ethtool_stats struct and
return 0 if we didn't actually have any stats. This also allows for
further simplification of this function in the future commits.
Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 937c783aa3d8d77963ec91918d3298edb45b9161 ]
Add a limit to 'config->vq_num' which is user controlled data which
comes from an vduse_ioctl to prevent large memory allocations.
Micheal says - This limit is somewhat arbitrary.
However, currently virtio pci and ccw are limited to a 16 bit vq number.
While MMIO isn't it is also isn't used with lots of VQs due to
current lack of support for per-vq interrupts.
Thus, the 0xffff limit on number of VQs corresponding
to a 16-bit VQ number seems sufficient for now.
This is found using static analysis with smatch.
Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Message-Id: <20221128155717.2579992-1-harshit.m.mogalapalli@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b66ead2d0ecac00c3a06a6218af5411cb5fcb5d5 ]
Virtio_crypto use max_data_queues+1 to setup vqs,
we use vp_modern_get_num_queues to protect the vq range in setup_vq.
We could enter index >= vp_modern_get_num_queues(mdev) in setup_vq
if common->num_queues is not set well,and it return -ENOENT.
It is better to use -EINVAL instead.
Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com>
Message-Id: <20221101111655.1947-1-angus.chen@jaguarmicro.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c262f75cb6bb5a63828e72ce3b8fe808e5029479 ]
The virtio_device vqs_list spinlocks must be initialized before use to
prevent functions that manipulate the device virtualqueues, such as
vring_new_virtqueue(), from blocking indefinitely.
Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com>
Message-Id: <20221012062949.1526176-1-ricardo.canuelo@collabora.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cedebd74cf3883f0384af9ec26b4e6f8f1964dd4 ]
Verify that nullness information is not porpagated in the branches
of register to register JEQ and JNE operations if one of them is
PTR_TO_BTF_ID. Implement this in C level so we can use CO-RE.
Signed-off-by: Hao Sun <sunhao.th@gmail.com>
Suggested-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20221222024414.29539-2-sunhao.th@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a6b9d2fa0024e7e399c26facd0fb466b7396e2b9 ]
When there is a single DS no striping constraints need to be placed on
the IO. When such constraint is applied then buffered reads don't
coalesce to the DS's rsize.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1d66e379731f79ae5039a869c0fde22a4f6a6a91 upstream.
Some laptops have been reported to wake up from s2idle when plugging
in the AC adapter or by closing the lid. This is a surprising
behavior that is further clarified by commit cb3e7d624c3ff ("PM:
wakeup: Add extra debugging statement for multiple active IRQs").
With that commit in place the following interaction can be seen
when the lid is closed:
[ 28.946038] PM: suspend-to-idle
[ 28.946083] ACPI: EC: ACPI EC GPE status set
[ 28.946101] ACPI: PM: Rearming ACPI SCI for wakeup
[ 28.950152] Timekeeping suspended for 3.320 seconds
[ 28.950152] PM: Triggering wakeup from IRQ 9
[ 28.950152] ACPI: EC: ACPI EC GPE status set
[ 28.950152] ACPI: EC: ACPI EC GPE dispatched
[ 28.995057] ACPI: EC: ACPI EC work flushed
[ 28.995075] ACPI: PM: Rearming ACPI SCI for wakeup
[ 28.995131] PM: Triggering wakeup from IRQ 9
[ 28.995271] ACPI: EC: ACPI EC GPE status set
[ 28.995291] ACPI: EC: ACPI EC GPE dispatched
[ 29.098556] ACPI: EC: ACPI EC work flushed
[ 29.207020] ACPI: EC: ACPI EC work flushed
[ 29.207037] ACPI: PM: Rearming ACPI SCI for wakeup
[ 29.211095] Timekeeping suspended for 0.739 seconds
[ 29.211095] PM: Triggering wakeup from IRQ 9
[ 29.211079] PM: Triggering wakeup from IRQ 7
[ 29.211095] ACPI: PM: ACPI non-EC GPE wakeup
[ 29.211095] PM: resume from suspend-to-idle
* IRQ9 on this laptop is used for the ACPI SCI.
* IRQ7 on this laptop is used for the GPIO controller.
What has occurred is when the lid was closed the EC woke up the
SoC from it's deepest sleep state and the kernel's s2idle loop
processed all EC events. When it was finished processing EC events,
it checked for any other reasons to wake (break the s2idle loop).
The IRQ for the GPIO controller was active so the loop broke, and
then this IRQ was processed. This is not a kernel bug but it is
certainly a surprising behavior, and to better debug it we should
have a dynamic debugging message that we can enact to catch it.
Acked-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Acked-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Acked-by: Mark Pearson <markpearson@lenovo.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20221013134729.5592-2-mario.limonciello@amd.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b659b613cea2ae39746ca8bd2b69d1985dd9d770 upstream.
This reverts commit 8a7b31d545d3a15f0e6f5984ae16f0ca4fd76aac.
This patch results in some qemu test failures, specifically xilinx-zynq-a9
machine and zynq-zc702 as well as zynq-zed devicetree files, when trying
to boot from USB drive.
Link: https://lore.kernel.org/lkml/20221220194334.GA942039@roeck-us.net/
Fixes: 8a7b31d545d3 ("usb: ulpi: defer ulpi_register on ulpi_read_id timeout")
Cc: stable@vger.kernel.org
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Ferry Toth <ftoth@exalondelft.nl>
Link: https://lore.kernel.org/r/20221222205302.45761-1-ftoth@exalondelft.nl
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 613b14884b8595e20b9fac4126bf627313827fbe upstream.
This can't happen right now, but in preparation for allowing
bio_split_to_limits() returning NULL if it ended the bio, check for it
in all the callers.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e6db6f9398dadcbc06318a133d4c44a2d3844e61 upstream.
We have two types of task_work based creation, one is using an existing
worker to setup a new one (eg when going to sleep and we have no free
workers), and the other is allocating a new worker. Only the latter
should be freed when we cancel task_work creation for a new worker.
Fixes: af82425c6a2d ("io_uring/io-wq: free worker if task_work creation is canceled")
Reported-by: syzbot+d56ec896af3637bdb7e4@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit af82425c6a2d2f347c79b63ce74fca6dc6be157f upstream.
If we cancel the task_work, the worker will never come into existance.
As this is the last reference to it, ensure that we get it freed
appropriately.
Cc: stable@vger.kernel.org
Reported-by: 진호 <wnwlsgh98@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0c25422d34b4726b2707d5f38560943155a91b80 upstream.
When scsi_dma_map() fails by returning a sges_left value less than zero,
the amount of logging produced can be extremely high. In a recent end-user
environment, 1200 messages per second were being sent to the log buffer.
This eventually overwhelmed the system and it stalled.
These error messages are not needed. Remove them.
Link: https://lore.kernel.org/r/20220303140203.12642-1-sreekanth.reddy@broadcom.com
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 703c13fe3c9af557d312f5895ed6a5fda2711104 ]
In cases where runtime services are not supported or have been disabled,
the runtime services workqueue will never have been allocated.
Do not try to destroy the workqueue unconditionally in the unlikely
event that EFI initialisation fails to avoid dereferencing a NULL
pointer.
Fixes: 98086df8b70c ("efi: add missed destroy_workqueue when efisubsys_init fails")
Cc: stable@vger.kernel.org
Cc: Li Heng <liheng40@huawei.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b2c3ccbd0011bb3b51d0fec24cb3a5812b1ec8ea ]
When CONFIG_ARM64_LSE_ATOMICS=y, each use of an LL/SC atomic results in
a fragment of code being generated in a subsection without a clear
association with its caller. A trampoline in the caller branches to the
LL/SC atomic with with a direct branch, and the atomic directly branches
back into its trampoline.
This breaks backtracing, as any PC within the out-of-line fragment will
be symbolized as an offset from the nearest prior symbol (which may not
be the function using the atomic), and since the atomic returns with a
direct branch, the caller's PC may be missing from the backtrace.
For example, with secondary_start_kernel() hacked to contain
atomic_inc(NULL), the resulting exception can be reported as being taken
from cpus_are_stuck_in_kernel():
| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
| Mem abort info:
| ESR = 0x0000000096000004
| EC = 0x25: DABT (current EL), IL = 32 bits
| SET = 0, FnV = 0
| EA = 0, S1PTW = 0
| FSC = 0x04: level 0 translation fault
| Data abort info:
| ISV = 0, ISS = 0x00000004
| CM = 0, WnR = 0
| [0000000000000000] user address but active_mm is swapper
| Internal error: Oops: 96000004 [#1] PREEMPT SMP
| Modules linked in:
| CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.19.0-11219-geb555cb5b794-dirty #3
| Hardware name: linux,dummy-virt (DT)
| pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : cpus_are_stuck_in_kernel+0xa4/0x120
| lr : secondary_start_kernel+0x164/0x170
| sp : ffff80000a4cbe90
| x29: ffff80000a4cbe90 x28: 0000000000000000 x27: 0000000000000000
| x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
| x23: 0000000000000000 x22: 0000000000000000 x21: 0000000000000000
| x20: 0000000000000001 x19: 0000000000000001 x18: 0000000000000008
| x17: 3030383832343030 x16: 3030303030307830 x15: ffff80000a4cbab0
| x14: 0000000000000001 x13: 5d31666130663133 x12: 3478305b20313030
| x11: 3030303030303078 x10: 3020726f73736563 x9 : 726f737365636f72
| x8 : ffff800009ff2ef0 x7 : 0000000000000003 x6 : 0000000000000000
| x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000100
| x2 : 0000000000000000 x1 : ffff0000029bd880 x0 : 0000000000000000
| Call trace:
| cpus_are_stuck_in_kernel+0xa4/0x120
| __secondary_switched+0xb0/0xb4
| Code: 35ffffa3 17fffc6c d53cd040 f9800011 (885f7c01)
| ---[ end trace 0000000000000000 ]---
This is confusing and hinders debugging, and will be problematic for
CONFIG_LIVEPATCH as these cases cannot be unwound reliably.
This is very similar to recent issues with out-of-line exception fixups,
which were removed in commits:
35d67794b8828333 ("arm64: lib: __arch_clear_user(): fold fixups into body")
4012e0e22739eef9 ("arm64: lib: __arch_copy_from_user(): fold fixups into body")
139f9ab73d60cf76 ("arm64: lib: __arch_copy_to_user(): fold fixups into body")
When the trampolines were introduced in commit:
addfc38672c73efd ("arm64: atomics: avoid out-of-line ll/sc atomics")
The rationale was to improve icache performance by grouping the LL/SC
atomics together. This has never been measured, and this theoretical
benefit is outweighed by other factors:
* As the subsections are collapsed into sections at object file
granularity, these are spread out throughout the kernel and can share
cachelines with unrelated code regardless.
* GCC 12.1.0 has been observed to place the trampoline out-of-line in
specialised __ll_sc_*() functions, introducing more branching than was
intended.
* Removing the trampolines has been observed to shrink a defconfig
kernel Image by 64KiB when building with GCC 12.1.0.
This patch removes the LL/SC trampolines, meaning that the LL/SC atomics
will be inlined into their callers (or placed in out-of line functions
using regular BL/RET pairs). When CONFIG_ARM64_LSE_ATOMICS=y, the LL/SC
atomics are always called in an unlikely branch, and will be placed in a
cold portion of the function, so this should have minimal impact to the
hot paths.
Other than the improved backtracing, there should be no functional
change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220817155914.3975112-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Stable-dep-of: 031af50045ea ("arm64: cmpxchg_double*: hazard against entire exchange variable")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8e6082e94aac6d0338883b5953631b662a5a9188 ]
The code for the atomic ops is formatted inconsistently, and while this
is not a functional problem it is rather distracting when working on
them.
Some have ops have consistent indentation, e.g.
| #define ATOMIC_OP_ADD_RETURN(name, mb, cl...) \
| static inline int __lse_atomic_add_return##name(int i, atomic_t *v) \
| { \
| u32 tmp; \
| \
| asm volatile( \
| __LSE_PREAMBLE \
| " ldadd" #mb " %w[i], %w[tmp], %[v]\n" \
| " add %w[i], %w[i], %w[tmp]" \
| : [i] "+r" (i), [v] "+Q" (v->counter), [tmp] "=&r" (tmp) \
| : "r" (v) \
| : cl); \
| \
| return i; \
| }
While others have negative indentation for some lines, and/or have
misaligned trailing backslashes, e.g.
| static inline void __lse_atomic_##op(int i, atomic_t *v) \
| { \
| asm volatile( \
| __LSE_PREAMBLE \
| " " #asm_op " %w[i], %[v]\n" \
| : [i] "+r" (i), [v] "+Q" (v->counter) \
| : "r" (v)); \
| }
This patch makes the indentation consistent and also aligns the trailing
backslashes. This makes the code easier to read for those (like myself)
who are easily distracted by these inconsistencies.
This is intended as a cleanup.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20211210151410.2782645-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Stable-dep-of: 031af50045ea ("arm64: cmpxchg_double*: hazard against entire exchange variable")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 544d163d659d45a206d8929370d5a2984e546cb7 upstream.
syzbot reports an issue with overflow filling for IOPOLL:
WARNING: CPU: 0 PID: 28 at io_uring/io_uring.c:734 io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734
CPU: 0 PID: 28 Comm: kworker/u4:1 Not tainted 6.2.0-rc3-syzkaller-16369-g358a161a6a9e #0
Workqueue: events_unbound io_ring_exit_work
Call trace:
io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734
io_req_cqe_overflow+0x5c/0x70 io_uring/io_uring.c:773
io_fill_cqe_req io_uring/io_uring.h:168 [inline]
io_do_iopoll+0x474/0x62c io_uring/rw.c:1065
io_iopoll_try_reap_events+0x6c/0x108 io_uring/io_uring.c:1513
io_uring_try_cancel_requests+0x13c/0x258 io_uring/io_uring.c:3056
io_ring_exit_work+0xec/0x390 io_uring/io_uring.c:2869
process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
worker_thread+0x340/0x610 kernel/workqueue.c:2436
kthread+0x12c/0x158 kernel/kthread.c:376
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863
There is no real problem for normal IOPOLL as flush is also called with
uring_lock taken, but it's getting more complicated for IOPOLL|SQPOLL,
for which __io_cqring_overflow_flush() happens from the CQ waiting path.
Reported-and-tested-by: syzbot+6805087452d72929404e@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 45e966fcca03ecdcccac7cb236e16eea38cc18af ]
Passing the host topology to the guest is almost certainly wrong
and will confuse the scheduler. In addition, several fields of
these CPUID leaves vary on each processor; it is simply impossible to
return the right values from KVM_GET_SUPPORTED_CPUID in such a way that
they can be passed to KVM_SET_CPUID2.
The values that will most likely prevent confusion are all zeroes.
Userspace will have to override it anyway if it wishes to present a
specific topology to the guest.
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cde363ab7ca7aea7a853851cd6a6745a9e1aaf5e ]
Add a section to document all the different ways in which the KVM API sucks.
I am sure there are way more, give people a place to vent so that userspace
authors are aware.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220322110712.222449-4-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 115d9d77bb0f9152c60b6e8646369fa7f6167593 ]
If CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, memblock_free_pages()
only releases pages to the buddy allocator if they are not in the
deferred range. This is correct for free pages (as defined by
for_each_free_mem_pfn_range_in_zone()) because free pages in the
deferred range will be initialized and released as part of the deferred
init process. memblock_free_pages() is called by memblock_free_late(),
which is used to free reserved ranges after memblock_free_all() has
run. All pages in reserved ranges have been initialized at that point,
and accordingly, those pages are not touched by the deferred init
process. This means that currently, if the pages that
memblock_free_late() intends to release are in the deferred range, they
will never be released to the buddy allocator. They will forever be
reserved.
In addition, memblock_free_pages() calls kmsan_memblock_free_pages(),
which is also correct for free pages but is not correct for reserved
pages. KMSAN metadata for reserved pages is initialized by
kmsan_init_shadow(), which runs shortly before memblock_free_all().
For both of these reasons, memblock_free_pages() should only be called
for free pages, and memblock_free_late() should call __free_pages_core()
directly instead.
One case where this issue can occur in the wild is EFI boot on
x86_64. The x86 EFI code reserves all EFI boot services memory ranges
via memblock_reserve() and frees them later via memblock_free_late()
(efi_reserve_boot_services() and efi_free_boot_services(),
respectively). If any of those ranges happens to fall within the
deferred init range, the pages will not be released and that memory will
be unavailable.
For example, on an Amazon EC2 t3.micro VM (1 GB) booting via EFI:
v6.2-rc2:
# grep -E 'Node|spanned|present|managed' /proc/zoneinfo
Node 0, zone DMA
spanned 4095
present 3999
managed 3840
Node 0, zone DMA32
spanned 246652
present 245868
managed 178867
v6.2-rc2 + patch:
# grep -E 'Node|spanned|present|managed' /proc/zoneinfo
Node 0, zone DMA
spanned 4095
present 3999
managed 3840
Node 0, zone DMA32
spanned 246652
present 245868
managed 222816 # +43,949 pages
Fixes: 3a80a7fa7989 ("mm: meminit: initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set")
Signed-off-by: Aaron Thompson <dev@aaront.org>
Link: https://lore.kernel.org/r/01010185892de53e-e379acfb-7044-4b24-b30a-e2657c1ba989-000000@us-west-2.amazonses.com
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c965daac370f08a9b71d573a71d13cda76f2a884 ]
Although rare, ssam_request_sync_init() can fail. In that case, the
request should be freed via ssam_request_sync_free(). Currently it is
leaked instead. Fix this.
Fixes: c167b9c7e3d6 ("platform/surface: Add Surface Aggregator subsystem")
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20221220175608.1436273-1-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5e91c72e560cc85f7163bbe3d14197268de31383 ]
This patch fix the pulse per second output delta between
two synchronized end-points.
Based on Intel Discrete I225 Software User Manual Section
4.2.15 TimeSync Auxiliary Control Register, ST0[Bit 4] and
ST1[Bit 7] must be set to ensure that clock output will be
toggles based on frequency value defined. This is to ensure
that output of the PPS is aligned with the clock.
How to test:
1) Running time synchronization on both end points.
Ex: ptp4l --step_threshold=1 -m -f gPTP.cfg -i <interface name>
2) Configure PPS output using below command for both end-points
Ex: SDP0 on I225 REV4 SKU variant
./testptp -d /dev/ptp0 -L 0,2
./testptp -d /dev/ptp0 -p 1000000000
3) Measure the output using analyzer for both end-points
Fixes: 87938851b6ef ("igc: enable auxiliary PHC functions for the i225")
Signed-off-by: Christopher S Hall <christopher.s.hall@intel.com>
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Acked-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d891f2b724b39a2a41e3ad7b57110193993242ff ]
Including libbpf header files should be guarded by HAVE_LIBBPF_SUPPORT.
In bpf_counter.h, move the skeleton utilities under HAVE_BPF_SKEL.
Fixes: d6a735ef3277c45f ("perf bpf_counter: Move common functions to bpf_counter.h")
Reported-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Mike Leach <mike.leach@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20230105172243.7238-1-mike.leach@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d515d63cae2cd186acf40deaa8ef33067bb7f637 ]
Previously, encap rules with gbp option would be offloaded by mistake but
driver does not support gbp option offload.
To fix this issue, check if the encap rule has gbp option and don't
offload the rule
Fixes: d8f9dfae49ce ("net: sched: allow flower to match vxlan options")
Signed-off-by: Gavin Li <gavinl@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fe91d57277eef8bb4aca05acfa337b4a51d0bba4 ]
.max_adj of ptp_clock_info acts as an absolute value for the amount in ppb
that can be set for a single call of .adjfine. This means that a single
call to .getfine cannot be greater than .max_adj or less than -(.max_adj).
Provides correct value for max frequency adjustment value supported by
devices.
Fixes: 3d8c38af1493 ("net/mlx5e: Add PTP Hardware Clock (PHC) support")
Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Reviewed-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9e17f99220d111ea031b44153fdfe364b0024ff2 ]
The 'TCA_MPLS_LABEL' attribute is of 'NLA_U32' type, but has a
validation type of 'NLA_VALIDATE_FUNCTION'. This is an invalid
combination according to the comment above 'struct nla_policy':
"
Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
NLA_BINARY Validation function called for the attribute.
All other Unused - but note that it's a union
"
This can trigger the warning [1] in nla_get_range_unsigned() when
validation of the attribute fails. Despite being of 'NLA_U32' type, the
associated 'min'/'max' fields in the policy are negative as they are
aliased by the 'validate' field.
Fix by changing the attribute type to 'NLA_BINARY' which is consistent
with the above comment and all other users of NLA_POLICY_VALIDATE_FN().
As a result, move the length validation to the validation function.
No regressions in MPLS tests:
# ./tdc.py -f tc-tests/actions/mpls.json
[...]
# echo $?
0
[1]
WARNING: CPU: 0 PID: 17743 at lib/nlattr.c:118
nla_get_range_unsigned+0x1d8/0x1e0 lib/nlattr.c:117
Modules linked in:
CPU: 0 PID: 17743 Comm: syz-executor.0 Not tainted 6.1.0-rc8 #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.13.0-48-gd9c812dda519-prebuilt.qemu.org 04/01/2014
RIP: 0010:nla_get_range_unsigned+0x1d8/0x1e0 lib/nlattr.c:117
[...]
Call Trace:
<TASK>
__netlink_policy_dump_write_attr+0x23d/0x990 net/netlink/policy.c:310
netlink_policy_dump_write_attr+0x22/0x30 net/netlink/policy.c:411
netlink_ack_tlv_fill net/netlink/af_netlink.c:2454 [inline]
netlink_ack+0x546/0x760 net/netlink/af_netlink.c:2506
netlink_rcv_skb+0x1b7/0x240 net/netlink/af_netlink.c:2546
rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:6109
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x5e9/0x6b0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x739/0x860 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg net/socket.c:734 [inline]
____sys_sendmsg+0x38f/0x500 net/socket.c:2482
___sys_sendmsg net/socket.c:2536 [inline]
__sys_sendmsg+0x197/0x230 net/socket.c:2565
__do_sys_sendmsg net/socket.c:2574 [inline]
__se_sys_sendmsg net/socket.c:2572 [inline]
__x64_sys_sendmsg+0x42/0x50 net/socket.c:2572
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Link: https://lore.kernel.org/netdev/CAO4mrfdmjvRUNbDyP0R03_DrD_eFCLCguz6OxZ2TYRSv0K9gxA@mail.gmail.com/
Fixes: 2a2ea50870ba ("net: sched: add mpls manipulation actions to TC")
Reported-by: Wei Chen <harperchen1110@gmail.com>
Tested-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Link: https://lore.kernel.org/r/20230107171004.608436-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 00b18da4089330196906b9fe075c581c17eb726c ]
When RISCV port was imported in 5.2, the O_* macros were taken with
their octal value and written as-is in hex, resulting in the getdents64()
to fail in nolibc-test.
Fixes: 582e84f7b779 ("tool headers nolibc: add RISCV support") #5.2
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 184177c3d6e023da934761e198c281344d7dd65b ]
Depending on the compiler used and the optimization options, the sbrk()
test was crashing, both on real hardware (mips-24kc) and in qemu. One
such example is kernel.org toolchain in version 11.3 optimizing at -Os.
Inspecting the sys_brk() call shows the following code:
0040047c <sys_brk>:
40047c: 24020fcd li v0,4045
400480: 27bdffe0 addiu sp,sp,-32
400484: 0000000c syscall
400488: 27bd0020 addiu sp,sp,32
40048c: 10e00001 beqz a3,400494 <sys_brk+0x18>
400490: 00021023 negu v0,v0
400494: 03e00008 jr ra
It is obviously wrong, the "negu" instruction is placed in beqz's
delayed slot, and worse, there's no nop nor instruction after the
return, so the next function's first instruction (addiu sip,sip,-32)
will also be executed as part of the delayed slot that follows the
return.
This is caused by the ".set noreorder" directive in the _start block,
that applies to the whole program. The compiler emits code without the
delayed slots and relies on the compiler to swap instructions when this
option is not set. Removing the option would require to change the
startup code in a way that wouldn't make it look like the resulting
code, which would not be easy to debug. Instead let's just save the
default ordering before changing it, and restore it at the end of the
_start block. Now the code is correct:
0040047c <sys_brk>:
40047c: 24020fcd li v0,4045
400480: 27bdffe0 addiu sp,sp,-32
400484: 0000000c syscall
400488: 10e00002 beqz a3,400494 <sys_brk+0x18>
40048c: 27bd0020 addiu sp,sp,32
400490: 00021023 negu v0,v0
400494: 03e00008 jr ra
400498: 00000000 nop
Fixes: 66b6f755ad45 ("rcutorture: Import a copy of nolibc") #5.0
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dffeb81af5fe5eedccf5ea4a8a120d8c3accd26e ]
By doing so we can link together multiple C files that have been compiled
with nolibc and which each have a _start symbol.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Stable-dep-of: 184177c3d6e0 ("tools/nolibc: restore mips branch ordering in the _start block")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 271661c1cde5ff47eb7af9946866cd66b70dc328 ]
In order to ease maintenance, this splits the arch-specific code into
one file per architecture. A common file "arch.h" is used to include the
right file among arch-* based on the detected architecture. Projects
which are already split per architecture could simply rename these
files to $arch/arch.h and get rid of the common arch.h. For this
reason, include guards were placed into each arch-specific file.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Stable-dep-of: 184177c3d6e0 ("tools/nolibc: restore mips branch ordering in the _start block")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cc7a492ad0a076dff5cb4281b1516676d7924fcf ]
The macros and type definitions used by a number of syscalls were moved
to types.h where they will be easier to maintain. A few of them
are arch-specific and must not be moved there (e.g. O_*, sys_stat_struct).
A warning about them was placed at the top of the file.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Stable-dep-of: 184177c3d6e0 ("tools/nolibc: restore mips branch ordering in the _start block")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 967cce191f50090d5cbd3841ee2bbb7835afeae2 ]
The ordering of includes and definitions for now is a bit of a mess, as
for example asm/signal.h is included after int definitions, but plenty of
structures are defined later as they rely on other includes.
Let's move the standard type definitions to a dedicated file that is
included first. We also move NULL there. This way all other includes
are aware of it, and we can bring asm/signal.h back to the top of the
file.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Stable-dep-of: 184177c3d6e0 ("tools/nolibc: restore mips branch ordering in the _start block")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9c2970fbb425cca0256ecf0f96490e4f253fda24 ]
This arch doesn't provide the old-style select() syscall, we have to
use pselect6().
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Stable-dep-of: 184177c3d6e0 ("tools/nolibc: restore mips branch ordering in the _start block")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7bdc0e7a390511cd3df8194003b908f15a6170a5 ]
Note that mov to 32-bit register will zero extend to 64-bit register.
Thus `mov $60,%eax` has the same effect with `mov $60,%rax`. Use the
shorter opcode to achieve the same thing.
```
b8 3c 00 00 00 mov $60,%eax (5 bytes) [1]
48 c7 c0 3c 00 00 00 mov $60,%rax (7 bytes) [2]
```
Currently, we use [2]. Change it to [1] for shorter code.
Signed-off-by: Ammar Faizi <ammar.faizi@students.amikom.ac.id>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Stable-dep-of: 184177c3d6e0 ("tools/nolibc: restore mips branch ordering in the _start block")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bf91666959eeac44fb686e9359e37830944beef2 ]
Linux x86-64 syscall only clobbers rax, rcx and r11 (and "memory").
- rax for the return value.
- rcx to save the return address.
- r11 to save the rflags.
Other registers are preserved.
Having r8, r9 and r10 in the syscall clobber list is harmless, but this
results in a missed-optimization.
As the syscall doesn't clobber r8-r10, GCC should be allowed to reuse
their value after the syscall returns to userspace. But since they are
in the clobber list, GCC will always miss this opportunity.
Remove them from the x86-64 syscall clobber list to help GCC generate
better code and fix the comment.
See also the x86-64 ABI, section A.2 AMD64 Linux Kernel Conventions,
A.2.1 Calling Conventions [1].
Extra note:
Some people may think it does not really give a benefit to remove r8,
r9 and r10 from the syscall clobber list because the impression of
syscall is a C function call, and function call always clobbers those 3.
However, that is not the case for nolibc.h, because we have a potential
to inline the "syscall" instruction (which its opcode is "0f 05") to the
user functions.
All syscalls in the nolibc.h are written as a static function with inline
ASM and are likely always inline if we use optimization flag, so this is
a profit not to have r8, r9 and r10 in the clobber list.
Here is the example where this matters.
Consider the following C code:
```
#include "tools/include/nolibc/nolibc.h"
#define read_abc(a, b, c) __asm__ volatile("nop"::"r"(a),"r"(b),"r"(c))
int main(void)
{
int a = 0xaa;
int b = 0xbb;
int c = 0xcc;
read_abc(a, b, c);
write(1, "test\n", 5);
read_abc(a, b, c);
return 0;
}
```
Compile with:
gcc -Os test.c -o test -nostdlib
With r8, r9, r10 in the clobber list, GCC generates this:
0000000000001000 <main>:
1000: f3 0f 1e fa endbr64
1004: 41 54 push %r12
1006: 41 bc cc 00 00 00 mov $0xcc,%r12d
100c: 55 push %rbp
100d: bd bb 00 00 00 mov $0xbb,%ebp
1012: 53 push %rbx
1013: bb aa 00 00 00 mov $0xaa,%ebx
1018: 90 nop
1019: b8 01 00 00 00 mov $0x1,%eax
101e: bf 01 00 00 00 mov $0x1,%edi
1023: ba 05 00 00 00 mov $0x5,%edx
1028: 48 8d 35 d1 0f 00 00 lea 0xfd1(%rip),%rsi
102f: 0f 05 syscall
1031: 90 nop
1032: 31 c0 xor %eax,%eax
1034: 5b pop %rbx
1035: 5d pop %rbp
1036: 41 5c pop %r12
1038: c3 ret
GCC thinks that syscall will clobber r8, r9, r10. So it spills 0xaa,
0xbb and 0xcc to callee saved registers (r12, rbp and rbx). This is
clearly extra memory access and extra stack size for preserving them.
But syscall does not actually clobber them, so this is a missed
optimization.
Now without r8, r9, r10 in the clobber list, GCC generates better code:
0000000000001000 <main>:
1000: f3 0f 1e fa endbr64
1004: 41 b8 aa 00 00 00 mov $0xaa,%r8d
100a: 41 b9 bb 00 00 00 mov $0xbb,%r9d
1010: 41 ba cc 00 00 00 mov $0xcc,%r10d
1016: 90 nop
1017: b8 01 00 00 00 mov $0x1,%eax
101c: bf 01 00 00 00 mov $0x1,%edi
1021: ba 05 00 00 00 mov $0x5,%edx
1026: 48 8d 35 d3 0f 00 00 lea 0xfd3(%rip),%rsi
102d: 0f 05 syscall
102f: 90 nop
1030: 31 c0 xor %eax,%eax
1032: c3 ret
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Acked-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Ammar Faizi <ammar.faizi@students.amikom.ac.id>
Link: https://gitlab.com/x86-psABIs/x86-64-ABI/-/wikis/x86-64-psABI [1]
Link: https://lore.kernel.org/lkml/20211011040344.437264-1-ammar.faizi@students.amikom.ac.id/
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Stable-dep-of: 184177c3d6e0 ("tools/nolibc: restore mips branch ordering in the _start block")
Signed-off-by: Sasha Levin <sashal@kernel.org>
