Tudor Ambarus [Wed, 7 Feb 2024 12:04:25 +0000 (12:04 +0000)]
spi: s3c64xx: propagate the dma_submit_error() error code
DMA submit should just add the dma descriptor to a queue, without firing
it. EIO is misleading and hides what happens in DMA. Propagate the
dma_submit_error() error code, don't overwrite it.
Tudor Ambarus [Wed, 7 Feb 2024 12:04:19 +0000 (12:04 +0000)]
spi: s3c64xx: avoid possible negative array index
The platform id is used as an index into the fifo_lvl_mask array.
Platforms can come with a negative device ID, PLATFORM_DEVID_NONE (-1),
thus we risked a negative array index. Catch such cases and fail to
probe.
Tudor Ambarus [Wed, 7 Feb 2024 12:04:18 +0000 (12:04 +0000)]
spi: s3c64xx: explicitly include <linux/types.h>
The driver uses u32 and relies on an implicit inclusion of
<linux/types.h>.
It is good practice to directly include all headers used, it avoids
implicit dependencies and spurious breakage if someone rearranges
headers and causes the implicit include to vanish.
Tudor Ambarus [Wed, 7 Feb 2024 12:04:17 +0000 (12:04 +0000)]
spi: s3c64xx: explicitly include <linux/bits.h>
The driver uses GENMASK() but does not include <linux/bits.h>.
It is good practice to directly include all headers used, it avoids
implicit dependencies and spurious breakage if someone rearranges
headers and causes the implicit include to vanish.
Tudor Ambarus [Wed, 7 Feb 2024 12:04:16 +0000 (12:04 +0000)]
spi: s3c64xx: explicitly include <linux/io.h>
The driver uses readl() but does not include <linux/io.h>.
It is good practice to directly include all headers used, it avoids
implicit dependencies and spurious breakage if someone rearranges
headers and causes the implicit include to vanish.
David Lechner [Wed, 7 Feb 2024 14:51:25 +0000 (08:51 -0600)]
spi: axi-spi-engine: move msg finalization out of irq handler
As a general principal, it is best to do as little as possible in an
interrupt handler. This patch reworks the AXI SPI Engine driver to move
timer_delete_sync() and spi_finalize_current_message() out of the
interrupt handler. Instead, spi_finalize_current_message() is moved to
the transfer_one_message function (similar to nearly all other SPI
controllers). A completion is now used to wait for the sync interrupt
that indicates that the message is complete. The watchdog timer is no
longer needed since we can use the wait_for_completion_timeout()
function to wait for the message to complete with the same effect.
As a bonus, these changes also improve throughput of the SPI controller.
For example, this was tested on a ZynqMP with a 80MHz SCLK reading 4
byte samples from an ADC. The max measured throughput increased from
26k to 28k samples per second.
David Lechner [Wed, 7 Feb 2024 14:51:24 +0000 (08:51 -0600)]
spi: axi-spi-engine: remove use of ida for sync id
Profiling has shown that ida_alloc_range() accounts for about 10% of the
time spent in spi_sync() when using the AXI SPI Engine controller. This
call is used to create a unique id for each SPI message to match to an
IRQ when the message is complete.
Since the core SPI code serializes messages in a message queue, we can
only have one message in flight at a time, namely host->cur_msg. This
means that we can use a fixed value instead of a unique id for each
message since there can never be more than one message pending at a
time.
This patch removes the use of ida for the sync id and replaces it with a
constant value. This simplifies the driver and improves performance.
David Lechner [Tue, 6 Feb 2024 20:06:46 +0000 (14:06 -0600)]
spi: drop gpf arg from __spi_split_transfer_maxsize()
The __spi_split_transfer_maxsize() function has a gpf argument to allow
callers to specify the type of memory allocation that needs to be used.
However, this function only allocates struct spi_transfer and is not
intended to be used from atomic contexts so this type should always be
GFP_KERNEL, so we can just drop the argument.
Some callers of these functions also passed GFP_DMA, but since only
struct spi_transfer is allocated and not any tx/rx buffers, this is
not actually necessary and is removed in this commit.
Luis de Arquer [Fri, 26 Jan 2024 19:46:22 +0000 (20:46 +0100)]
spi: spi-rockchip: Fix out of bounds array access
Since spi-rockchip enables use_gpio_descriptors and the
SPI_CONTROLLER_GPIO_SS flag, the spi subsytem may call set_cs()
for spi devices with indexes above ROCKCHIP_SPI_MAX_CS_NUM
Remove array cs_asserted[] which held a shadow copy of the state
of the chip select lines with the only purpose of optimizing out
rewriting a chip select line to the current state (no-op)
This case is already handled by spi.c
David Lechner [Fri, 26 Jan 2024 22:00:23 +0000 (16:00 -0600)]
spi: bcm2835: implement ctlr->max_transfer_size
The core SPI code will handle splitting transfers if needed as long
as ctlr->max_transfer_size is implemented. It does this in
__spi_pump_transfer_message() immediately before calling
ctlr->prepare_message. So effectively, this change does not
alter the behavior of the driver.
Also, several peripheral drivers make use of spi_max_transfer_size(),
so this should improve compatibility with those drivers.
David Lechner [Fri, 26 Jan 2024 21:23:57 +0000 (15:23 -0600)]
spi: move split xfers for CS_WORD emulation
This moves splitting transfers for CS_WORD software emulation to the
same place where we split transfers for controller-specific reasons.
This fixes a few subtle bugs.
The calculation for maxsize was wrong for bit sizes between 17 and 24.
This is fixed by making use of spi_split_transfers_maxwords() which
already has the correct calculation.
Also, since this indirectly calls spi_res_alloc(), to avoid leaking
resources, spi_finalize_current_message() would need to be called
on all error paths in __spi_validate() and callers of __spi_validate()
would need to do the same. This is fixed by moving the call to
__spi_pump_transfer_message() where it is already splitting transfers
for other reasons and correctly releases resources in the subsequent
error paths.
andy.shevchenko@gmail.com [Sun, 4 Feb 2024 20:29:19 +0000 (22:29 +0200)]
spi: fsl-dspi: Unify error messaging in dspi_request_dma()
Use dev_err_probe() for all messages in dspi_request_dma() for the sake of
making them uniform. While at it, fix indentation issue reported by Vladimir
Oltean.
Charles Keepax [Fri, 2 Feb 2024 10:34:30 +0000 (10:34 +0000)]
spi: cs42l43: Clean up of firmware node
As we get a child node in the OF case, we should also clean up the
reference, add code to do so.
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com> Link: https://msgid.link/r/20240202103430.951598-1-ckeepax@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
David Lechner [Wed, 31 Jan 2024 17:07:27 +0000 (11:07 -0600)]
spi: reorder spi_message struct member doc comments
The members of `struct spi_message` were reordered in commit ae2ade4ba581 ("spi: Reorder fields in 'struct spi_message'")
but the documentation comments were not updated to match.
This commit updates the comments to match the new order.
David Lechner [Thu, 25 Jan 2024 23:47:31 +0000 (17:47 -0600)]
spi: avoid double validation in __spi_sync()
The __spi_sync() function calls __spi_validate() early in the function.
Later, it can call spi_async_locked() which calls __spi_validate()
again. __spi_validate() is an expensive function, so we can improve
performance measurably by avoiding calling it twice.
Instead of calling spi_async_locked(), we can call __spi_async() with
the spin lock held.
spi_async_locked() is removed since there are no more callers.
Charles Keepax [Thu, 25 Jan 2024 10:34:26 +0000 (10:34 +0000)]
spi: cs42l43: Handle error from devm_pm_runtime_enable()
As it devm_pm_runtime_enable() can fail due to memory allocations, it
is best to handle the error.
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com> Link: https://msgid.link/r/20240125103426.2622549-1-ckeepax@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
Mark Brown [Wed, 24 Jan 2024 19:41:45 +0000 (19:41 +0000)]
arm64: exynos: Enable SPI for Exynos850
Merge series from Sam Protsenko <semen.protsenko@linaro.org>:
This series enables SPI for Exynos850 SoC, there are also some
dependencies that will be needed at runtime which were sent as part of
the same series but will be separately applied:
1. Enable PDMA, it's needed for SPI (dts, clk)
2. Propagate SPI src clock rate change up to DIV clocks, to make it
possible to change SPI frequency (clk driver)
4. Add SPI nodes to Exynos850 SoC dtsi
All SPI instances were tested using `spidev_test' tool in all 3 possible
modes:
with 200 kHz ... 49.9 MHz SPI frequencies. The next 3 approaches were
used:
1. Software loopback ('-l' option for `spidev_test' tool)
2. Hardware loopback (by connecting MISO line to MOSI)
3. By communicating with ATMega found on Sensors Mezzanine board [1],
programmed to act as an SPI device
and all the transactions were additionally checked on my Logic Analyzer
to make sure the SCK frequencies were actually correct.
David Lechner [Tue, 23 Jan 2024 21:49:46 +0000 (15:49 -0600)]
spi: consolidate setting message->spi
Previously, __spi_sync() and __spi_async() set message->spi to the spi
device independently after calling __spi_validate(). __spi_validate()
also would conditionally set this if it needed to split the message
since it wasn't set yet.
Since both __spi_sync() and __spi_async() call __spi_validate(), we can
consolidate this into only setting message->spi once (unconditionally)
in __spi_validate(). This will also save any future callers of
__spi_validate() from also needing to set message->spi.
Sam Protsenko [Sat, 20 Jan 2024 01:29:43 +0000 (19:29 -0600)]
spi: dt-bindings: samsung: Add Exynos850 SPI
Document samsung,exynos850-spi compatible which will be used on
Exynos850 SoC. Exynos850 doesn't have ioclk, so only two clocks are
needed (bus clock and functional SPI clock).
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org> Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Link: https://msgid.link/r/20240120012948.8836-3-semen.protsenko@linaro.org Signed-off-by: Mark Brown <broonie@kernel.org>
SPI FIFO depth is 64 bytes for all those SPI blocks, so the
.fifo_lvl_mask value is set to 0x7f. All blocks have DIV_4 as the
default internal clock divider, and an internal loopback mode to run
a loopback test.
Greg Kroah-Hartman [Fri, 5 Jan 2024 10:32:50 +0000 (11:32 +0100)]
spi: make spi_bus_type const
Now that the driver core can properly handle constant struct bus_type,
move the spi_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.
Cc: Mark Brown <broonie@kernel.org> Cc: <linux-spi@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://msgid.link/r/2024010549-erasure-swoop-1cc6@gregkh Signed-off-by: Mark Brown <broonie@kernel.org>
Linus Torvalds [Sun, 21 Jan 2024 22:01:12 +0000 (14:01 -0800)]
Merge tag 'bcachefs-2024-01-21' of https://evilpiepirate.org/git/bcachefs
Pull more bcachefs updates from Kent Overstreet:
"Some fixes, Some refactoring, some minor features:
- Assorted prep work for disk space accounting rewrite
- BTREE_TRIGGER_ATOMIC: after combining our trigger callbacks, this
makes our trigger context more explicit
- A few fixes to avoid excessive transaction restarts on
multithreaded workloads: fstests (in addition to ktest tests) are
now checking slowpath counters, and that's shaking out a few bugs
- Assorted tracepoint improvements
- Starting to break up bcachefs_format.h and move on disk types so
they're with the code they belong to; this will make room to start
documenting the on disk format better.
- A few minor fixes"
* tag 'bcachefs-2024-01-21' of https://evilpiepirate.org/git/bcachefs: (46 commits)
bcachefs: Improve inode_to_text()
bcachefs: logged_ops_format.h
bcachefs: reflink_format.h
bcachefs; extents_format.h
bcachefs: ec_format.h
bcachefs: subvolume_format.h
bcachefs: snapshot_format.h
bcachefs: alloc_background_format.h
bcachefs: xattr_format.h
bcachefs: dirent_format.h
bcachefs: inode_format.h
bcachefs; quota_format.h
bcachefs: sb-counters_format.h
bcachefs: counters.c -> sb-counters.c
bcachefs: comment bch_subvolume
bcachefs: bch_snapshot::btime
bcachefs: add missing __GFP_NOWARN
bcachefs: opts->compression can now also be applied in the background
bcachefs: Prep work for variable size btree node buffers
bcachefs: grab s_umount only if snapshotting
...
Linus Torvalds [Sun, 21 Jan 2024 19:14:40 +0000 (11:14 -0800)]
Merge tag 'timers-core-2024-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"Updates for time and clocksources:
- A fix for the idle and iowait time accounting vs CPU hotplug.
The time is reset on CPU hotplug which makes the accumulated
systemwide time jump backwards.
- Assorted fixes and improvements for clocksource/event drivers"
* tag 'timers-core-2024-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug
clocksource/drivers/ep93xx: Fix error handling during probe
clocksource/drivers/cadence-ttc: Fix some kernel-doc warnings
clocksource/drivers/timer-ti-dm: Fix make W=n kerneldoc warnings
clocksource/timer-riscv: Add riscv_clock_shutdown callback
dt-bindings: timer: Add StarFive JH8100 clint
dt-bindings: timer: thead,c900-aclint-mtimer: separate mtime and mtimecmp regs
Kent Overstreet [Tue, 16 Jan 2024 21:20:21 +0000 (16:20 -0500)]
bcachefs: opts->compression can now also be applied in the background
The "apply this compression method in the background" paths now use the
compression option if background_compression is not set; this means that
setting or changing the compression option will cause existing data to
be compressed accordingly in the background.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Tue, 16 Jan 2024 18:29:59 +0000 (13:29 -0500)]
bcachefs: Prep work for variable size btree node buffers
bcachefs btree nodes are big - typically 256k - and btree roots are
pinned in memory. As we're now up to 18 btrees, we now have significant
memory overhead in mostly empty btree roots.
And in the future we're going to start enforcing that certain btree node
boundaries exist, to solve lock contention issues - analagous to XFS's
AGIs.
Thus, we need to start allocating smaller btree node buffers when we
can. This patch changes code that refers to the filesystem constant
c->opts.btree_node_size to refer to the btree node buffer size -
btree_buf_bytes() - where appropriate.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In __bch2_ioctl_subvolume_create(), we grab s_umount unconditionally
and unlock it at the end of the function. There is a comment
"why do we need this lock?" about the lock coming from
commit 42d237320e98 ("bcachefs: Snapshot creation, deletion")
The reason is that __bch2_ioctl_subvolume_create() calls
sync_inodes_sb() which enforce locked s_umount to writeback all dirty
nodes before doing snapshot works.
Fix it by read locking s_umount for snapshotting only and unlocking
s_umount after sync_inodes_sb().
Signed-off-by: Su Yue <glass.su@suse.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Colin Ian King [Tue, 16 Jan 2024 11:07:23 +0000 (11:07 +0000)]
bcachefs: remove redundant variable tmp
The variable tmp is being assigned a value but it isn't being
read afterwards. The assignment is redundant and so tmp can be
removed.
Cleans up clang scan build warning:
warning: Although the value stored to 'ret' is used in the enclosing
expression, the value is never actually read from 'ret'
[deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Tue, 16 Jan 2024 01:37:23 +0000 (20:37 -0500)]
bcachefs: Fix excess transaction restarts in __bchfs_fallocate()
drop_locks_do() should not be used in a fastpath without first trying
the do in nonblocking mode - the unlock and relock will cause excessive
transaction restarts and potentially livelocking with other threads that
are contending for the same locks.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Mon, 15 Jan 2024 22:59:51 +0000 (17:59 -0500)]
bcachefs: Better journal tracepoints
Factor out bch2_journal_bufs_to_text(), and use it in the
journal_entry_full() tracepoint; when we can't get a journal reservation
we need to know the outstanding journal entry sizes to know if the
problem is due to excessive flushing.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Mon, 15 Jan 2024 22:56:22 +0000 (17:56 -0500)]
bcachefs: Avoid flushing the journal in the discard path
When issuing discards, we may need to flush the journal if there's too
many buckets that can't be discarded until a journal flush.
But the heuristic was bad; we should be comparing the number of buckets
that need to flushes against the number of free buckets, not the number
of buckets we saw.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Mon, 15 Jan 2024 19:15:26 +0000 (14:15 -0500)]
bcachefs: bch2_kthread_io_clock_wait() no longer sleeps until full amount
Drop t he loop in bch2_kthread_io_clock_wait(): this allows the code
that uses it to be woken up for other reasons, and fixes a bug where
rebalance wouldn't wake up when a scan was requested.
This raises the possibility of spurious wakeups, but callers should
always be able to handle that reasonably well.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Thu, 11 Jan 2024 04:47:04 +0000 (23:47 -0500)]
bcachefs: Reduce would_deadlock restarts
We don't have to take locks in any particular ordering - we'll make
forward progress just fine - but if we try to stick to an ordering, it
can help to avoid excessive would_deadlock transaction restarts.
This tweaks the reflink path to take extents btree locks in the right
order.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Kent Overstreet [Thu, 11 Jan 2024 04:08:30 +0000 (23:08 -0500)]
bcachefs: Don't log errors if BCH_WRITE_ALLOC_NOWAIT
Previously, we added logging in the write path to ensure that any
unexpected errors getting reported to userspace have a log message; but
BCH_WRITE_ALLOC_NOWAIT is a special case, it's used for promotes where
errors are expected and not reported out to userspace - so we need to
silence those.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
- retry (reconnect) improvement including new retrans mount parm, and
handling of two additional return codes that need to be retried on
- two minor cleanup patches and another to remove duplicate query
info code
- two documentation cleanup, and one reviewer email correction"
* tag 'v6.8-rc-part2-smb-client' of git://git.samba.org/sfrench/cifs-2.6:
cifs: update iface_last_update on each query-and-update
cifs: handle servers that still advertise multichannel after disabling
cifs: new mount option called retrans
cifs: reschedule periodic query for server interfaces
smb: client: don't clobber ->i_rdev from cached reparse points
smb: client: get rid of smb311_posix_query_path_info()
smb: client: parse owner/group when creating reparse points
smb: client: fix parsing of SMB3.1.1 POSIX create context
cifs: update known bugs mentioned in kernel docs for cifs
cifs: new nt status codes from MS-SMB2
cifs: pick channel for tcon and tdis
cifs: open_cached_dir should not rely on primary channel
smb3: minor documentation updates
Update MAINTAINERS email address
cifs: minor comment cleanup
smb3: show beginning time for per share stats
cifs: remove redundant variable tcon_exist
Linus Torvalds [Sat, 20 Jan 2024 23:03:25 +0000 (15:03 -0800)]
Merge tag 'dmaengine-fix-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine
Pull dmaengine updates from Vinod Koul:
"New support:
- Loongson LS2X APB DMA controller
- sf-pdma: mpfs-pdma support
- Qualcomm X1E80100 GPI dma controller support
Updates:
- Xilinx XDMA updates to support interleaved DMA transfers
- TI PSIL threads for AM62P and J722S and cfg register regions
description
- axi-dmac Improving the cyclic DMA transfers
- Tegra Support dma-channel-mask property
- Remaining platform remove callback returning void conversions
Driver fixes for:
- Xilinx xdma driver operator precedence and initialization fix
- Excess kernel-doc warning fix in imx-sdma xilinx xdma drivers
- format-overflow warning fix for rz-dmac, sh usb dmac drivers
- 'output may be truncated' fix for shdma, fsl-qdma and dw-edma
drivers"
* tag 'dmaengine-fix-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (58 commits)
dmaengine: dw-edma: increase size of 'name' in debugfs code
dmaengine: fsl-qdma: increase size of 'irq_name'
dmaengine: shdma: increase size of 'dev_id'
dmaengine: xilinx: xdma: Fix kernel-doc warnings
dmaengine: usb-dmac: Avoid format-overflow warning
dmaengine: sh: rz-dmac: Avoid format-overflow warning
dmaengine: imx-sdma: fix Excess kernel-doc warnings
dmaengine: xilinx: xdma: Fix initialization location of desc in xdma_channel_isr()
dmaengine: xilinx: xdma: Fix operator precedence in xdma_prep_interleaved_dma()
dmaengine: xilinx: xdma: statify xdma_prep_interleaved_dma
dmaengine: xilinx: xdma: Workaround truncation compilation error
dmaengine: pl330: issue_pending waits until WFP state
dmaengine: xilinx: xdma: Implement interleaved DMA transfers
dmaengine: xilinx: xdma: Prepare the introduction of interleaved DMA transfers
dmaengine: xilinx: xdma: Add transfer error reporting
dmaengine: xilinx: xdma: Add error checking in xdma_channel_isr()
dmaengine: xilinx: xdma: Rework xdma_terminate_all()
dmaengine: xilinx: xdma: Ease dma_pool alignment requirements
dmaengine: xilinx: xdma: Add necessary macro definitions
dmaengine: xilinx: xdma: Get rid of unused code
...
Linus Torvalds [Sat, 20 Jan 2024 22:20:34 +0000 (14:20 -0800)]
Merge tag 'coccinelle-for-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linux
Pull coccinelle updates from Julia Lawall:
"Updates to the device_attr_show semantic patch to reflect the new
guidelines of the Linux kernel documentation.
The problem was identified by Li Zhijian <lizhijian@fujitsu.com>, who
proposed an initial fix"
* tag 'coccinelle-for-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linux:
coccinelle: device_attr_show: simplify patch case
coccinelle: device_attr_show: Adapt to the latest Documentation/filesystems/sysfs.rst
Aurelien Jarno [Sat, 13 Jan 2024 18:33:31 +0000 (19:33 +0100)]
media: solo6x10: replace max(a, min(b, c)) by clamp(b, a, c)
This patch replaces max(a, min(b, c)) by clamp(b, a, c) in the solo6x10
driver. This improves the readability and more importantly, for the
solo6x10-p2m.c file, this reduces on my system (x86-64, gcc 13):
- the preprocessed size from 121 MiB to 4.5 MiB;
- the build CPU time from 46.8 s to 1.6 s;
- the build memory from 2786 MiB to 98MiB.
In fine, this allows this relatively simple C file to be built on a
32-bit system.
Reported-by: Jiri Slaby <jirislaby@gmail.com> Closes: https://lore.kernel.org/lkml/18c6df0d-45ed-450c-9eda-95160a2bbb8e@gmail.com/ Cc: <stable@vger.kernel.org> # v6.7+ Suggested-by: David Laight <David.Laight@ACULAB.COM> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Reviewed-by: David Laight <David.Laight@ACULAB.COM> Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Tue, 9 Jan 2024 00:43:04 +0000 (16:43 -0800)]
execve: open the executable file before doing anything else
No point in allocating a new mm, counting arguments and environment
variables etc if we're just going to return ENOENT.
This patch does expose the fact that 'do_filp_open()' that execve() uses
is still unnecessarily expensive in the failure case, because it
allocates the 'struct file *' early, even if the path lookup (which is
heavily optimized) fails.
So that remains an unnecessary cost in the "no such executable" case,
but it's a separate issue. Regardless, I do not want to do _both_ a
filename_lookup() and a later do_filp_open() like the origin patch by
Josh Triplett did in [1].