History log of /openbmc/linux/kernel/module/main.c (Results 1 – 25 of 239)
Revision (<<< Hide revision tags) (Show revision tags >>>) Date Author Comments
Revision tags: v6.6.67, v6.6.66, v6.6.65, v6.6.64, v6.6.63, v6.6.62, v6.6.61, v6.6.60, v6.6.59, v6.6.58, v6.6.57, v6.6.56, v6.6.55, v6.6.54, v6.6.53, v6.6.52, v6.6.51, v6.6.50, v6.6.49, v6.6.48, v6.6.47
# c005e2f6 14-Aug-2024 Andrew Jeffery <andrew@codeconstruct.com.au>

Merge tag 'v6.6.46' into for/openbmc/dev-6.6

This is the 6.6.46 stable release


Revision tags: v6.6.46, v6.6.45
# 81ac1e88 09-Aug-2024 Linus Torvalds <torvalds@linux-foundation.org>

module: make waiting for a concurrent module loader interruptible

[ Upstream commit 2124d84db293ba164059077944e6b429ba530495 ]

The recursive aes-arm-bs module load situation reported by Russell Kin

module: make waiting for a concurrent module loader interruptible

[ Upstream commit 2124d84db293ba164059077944e6b429ba530495 ]

The recursive aes-arm-bs module load situation reported by Russell King
is getting fixed in the crypto layer, but this in the meantime fixes the
"recursive load hangs forever" by just making the waiting for the first
module load be interruptible.

This should now match the old behavior before commit 9b9879fc0327
("modules: catch concurrent module loads, treat them as idempotent"),
which used the different "wait for module to be ready" code in
module_patient_check_exists().

End result: a recursive module load will still block, but now a signal
will interrupt it and fail the second module load, at which point the
first module will successfully complete loading.

Fixes: 9b9879fc0327 ("modules: catch concurrent module loads, treat them as idempotent")
Cc: Russell King <linux@armlinux.org.uk>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...


# bdb3679c 08-Aug-2024 Linus Torvalds <torvalds@linux-foundation.org>

module: warn about excessively long module waits

[ Upstream commit cb5b81bc9a448f8db817566f60f92e2ea788ea0f ]

Russell King reported that the arm cbc(aes) crypto module hangs when
loaded, and Herber

module: warn about excessively long module waits

[ Upstream commit cb5b81bc9a448f8db817566f60f92e2ea788ea0f ]

Russell King reported that the arm cbc(aes) crypto module hangs when
loaded, and Herbert Xu bisected it to commit 9b9879fc0327 ("modules:
catch concurrent module loads, treat them as idempotent"), and noted:

"So what's happening here is that the first modprobe tries to load a
fallback CBC implementation, in doing so it triggers a load of the
exact same module due to module aliases.

IOW we're loading aes-arm-bs which provides cbc(aes). However, this
needs a fallback of cbc(aes) to operate, which is made out of the
generic cbc module + any implementation of aes, or ecb(aes). The
latter happens to also be provided by aes-arm-cb so that's why it
tries to load the same module again"

So loading the aes-arm-bs module ends up wanting to recursively load
itself, and the recursive load then ends up waiting for the original
module load to complete.

This is a regression, in that it used to be that we just tried to load
the module multiple times, and then as we went on to install it the
second time we would instead just error out because the module name
already existed.

That is actually also exactly what the original "catch concurrent loads"
patch did in commit 9828ed3f695a ("module: error out early on concurrent
load of the same module file"), but it turns out that it ends up being
racy, in that erroring out before the module has been fully initialized
will cause failures in dependent module loading.

See commit ac2263b588df (which was the revert of that "error out early")
commit for details about why erroring out before the module has been
initialized is actually fundamentally racy.

Now, for the actual recursive module load (as opposed to just
concurrently loading the same module twice), the race is not an issue.

At the same time it's hard for the kernel to see that this is recursion,
because the module load is always done from a usermode helper, so the
recursion is not some simple callchain within the kernel.

End result: this is not the real fix, but this at least adds a warning
for the situation (admittedly much too late for all the debugging pain
that Russell and Herbert went through) and if we can come to a
resolution on how to detect the recursion properly, this re-organizes
the code to make that easier.

Link: https://lore.kernel.org/all/ZrFHLqvFqhzykuYw@shell.armlinux.org.uk/
Reported-by: Russell King <linux@armlinux.org.uk>
Debugged-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stable-dep-of: 2124d84db293 ("module: make waiting for a concurrent module loader interruptible")
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...


Revision tags: v6.6.44, v6.6.43, v6.6.42, v6.6.41, v6.6.40, v6.6.39, v6.6.38, v6.6.37, v6.6.36, v6.6.35, v6.6.34, v6.6.33, v6.6.32, v6.6.31, v6.6.30, v6.6.29, v6.6.28, v6.6.27, v6.6.26, v6.6.25, v6.6.24
# 5ee9cd06 27-Mar-2024 Andrew Jeffery <andrew@codeconstruct.com.au>

Merge tag 'v6.6.23' into dev-6.6

Linux 6.6.23


Revision tags: v6.6.23
# 8c61e3be 26-Feb-2024 Changbin Du <changbin.du@huawei.com>

modules: wait do_free_init correctly

[ Upstream commit 8f8cd6c0a43ed637e620bbe45a8d0e0c2f4d5130 ]

The synchronization here is to ensure the ordering of freeing of a module
init so that it happens b

modules: wait do_free_init correctly

[ Upstream commit 8f8cd6c0a43ed637e620bbe45a8d0e0c2f4d5130 ]

The synchronization here is to ensure the ordering of freeing of a module
init so that it happens before W+X checking. It is worth noting it is not
that the freeing was not happening, it is just that our sanity checkers
raced against the permission checkers which assume init memory is already
gone.

Commit 1a7b7d922081 ("modules: Use vmalloc special flag") moved calling
do_free_init() into a global workqueue instead of relying on it being
called through call_rcu(..., do_free_init), which used to allowed us call
do_free_init() asynchronously after the end of a subsequent grace period.
The move to a global workqueue broke the gaurantees for code which needed
to be sure the do_free_init() would complete with rcu_barrier(). To fix
this callers which used to rely on rcu_barrier() must now instead use
flush_work(&init_free_wq).

Without this fix, we still could encounter false positive reports in W+X
checking since the rcu_barrier() here can not ensure the ordering now.

Even worse, the rcu_barrier() can introduce significant delay. Eric
Chanudet reported that the rcu_barrier introduces ~0.1s delay on a
PREEMPT_RT kernel.

[ 0.291444] Freeing unused kernel memory: 5568K
[ 0.402442] Run /sbin/init as init process

With this fix, the above delay can be eliminated.

Link: https://lkml.kernel.org/r/20240227023546.2490667-1-changbin.du@huawei.com
Fixes: 1a7b7d922081 ("modules: Use vmalloc special flag")
Signed-off-by: Changbin Du <changbin.du@huawei.com>
Tested-by: Eric Chanudet <echanude@redhat.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Xiaoyi Su <suxiaoyi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...


Revision tags: v6.6.16, v6.6.15, v6.6.14, v6.6.13, v6.6.12, v6.6.11, v6.6.10, v6.6.9, v6.6.8, v6.6.7, v6.6.6, v6.6.5, v6.6.4, v6.6.3, v6.6.2, v6.5.11, v6.6.1, v6.5.10, v6.6, v6.5.9, v6.5.8, v6.5.7, v6.5.6, v6.5.5, v6.5.4, v6.5.3
# c900529f 12-Sep-2023 Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-fixes into drm-misc-fixes

Forwarding to v6.6-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>


Revision tags: v6.5.2, v6.1.51, v6.5.1
# 1ac731c5 30-Aug-2023 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge branch 'next' into for-linus

Prepare input updates for 6.6 merge window.


Revision tags: v6.1.50
# daa22f5a 29-Aug-2023 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'modules-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull modules updates from Luis Chamberlain:
"Summary of the changes worth highlighting from most interestin

Merge tag 'modules-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull modules updates from Luis Chamberlain:
"Summary of the changes worth highlighting from most interesting to
boring below:

- Christoph Hellwig's symbol_get() fix to Nvidia's efforts to
circumvent the protection he put in place in year 2020 to prevent
proprietary modules from using GPL only symbols, and also ensuring
proprietary modules which export symbols grandfather their taint.

That was done through year 2020 commit 262e6ae7081d ("modules:
inherit TAINT_PROPRIETARY_MODULE"). Christoph's new fix is done by
clarifing __symbol_get() was only ever intended to prevent module
reference loops by Linux kernel modules and so making it only find
symbols exported via EXPORT_SYMBOL_GPL(). The circumvention tactic
used by Nvidia was to use symbol_get() to purposely swift through
proprietary module symbols and completely bypass our traditional
EXPORT_SYMBOL*() annotations and community agreed upon
restrictions.

A small set of preamble patches fix up a few symbols which just
needed adjusting for this on two modules, the rtc ds1685 and the
networking enetc module. Two other modules just needed some build
fixing and removal of use of __symbol_get() as they can't ever be
modular, as was done by Arnd on the ARM pxa module and Christoph
did on the mmc au1xmmc driver.

This is a good reminder to us that symbol_get() is just a hack to
address things which should be fixed through Kconfig at build time
as was done in the later patches, and so ultimately it should just
go.

- Extremely late minor fix for old module layout 055f23b74b20
("module: check for exit sections in layout_sections() instead of
module_init_section()") by James Morse for arm64. Note that this
layout thing is old, it is *not* Song Liu's commit ac3b43283923
("module: replace module_layout with module_memory"). The issue
however is very odd to run into and so there was no hurry to get
this in fast.

- Although the fix did not go through the modules tree I'd like to
highlight the fix by Peter Zijlstra in commit 54097309620e
("x86/static_call: Fix __static_call_fixup()") now merged in your
tree which came out of what was originally suspected to be a
fallout of the the newer module layout changes by Song Liu commit
ac3b43283923 ("module: replace module_layout with module_memory")
instead of module_init_section()"). Thanks to the report by
Christian Bricart and the debugging by Song Liu & Peter that turned
to be noted as a kernel regression in place since v5.19 through
commit ee88d363d156 ("x86,static_call: Use alternative RET
encoding").

I highlight this to reflect and clarify that we haven't seen more
fallout from ac3b43283923 ("module: replace module_layout with
module_memory").

- RISC-V toolchain got mapping symbol support which prefix symbols
with "$" to help with alignment considerations for disassembly.

This is used to differentiate between incompatible instruction
encodings when disassembling. RISC-V just matches what ARM/AARCH64
did for alignment considerations and Palmer Dabbelt extended
is_mapping_symbol() to accept these symbols for RISC-V. We already
had support for this for all architectures but it also checked for
the second character, the RISC-V check Dabbelt added was just for
the "$". After a bit of testing and fallout on linux-next and based
on feedback from Masahiro Yamada it was decided to simplify the
check and treat the first char "$" as unique for all architectures,
and so we no make is_mapping_symbol() for all archs if the symbol
starts with "$".

The most relevant commit for this for RISC-V on binutils was:

https://sourceware.org/pipermail/binutils/2021-July/117350.html

- A late fix by Andrea Righi (today) to make module zstd
decompression use vmalloc() instead of kmalloc() to account for
large compressed modules. I suspect we'll see similar things for
other decompression algorithms soon.

- samples/hw_breakpoint minor fixes by Rong Tao, Arnd Bergmann and
Chen Jiahao"

* tag 'modules-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
module/decompress: use vmalloc() for zstd decompression workspace
kallsyms: Add more debug output for selftest
ARM: module: Use module_init_layout_section() to spot init sections
arm64: module: Use module_init_layout_section() to spot init sections
module: Expose module_init_layout_section()
modules: only allow symbol_get of EXPORT_SYMBOL_GPL modules
rtc: ds1685: use EXPORT_SYMBOL_GPL for ds1685_rtc_poweroff
net: enetc: use EXPORT_SYMBOL_GPL for enetc_phc_index
mmc: au1xmmc: force non-modular build and remove symbol_get usage
ARM: pxa: remove use of symbol_get()
samples/hw_breakpoint: mark sample_hbp as static
samples/hw_breakpoint: fix building without module unloading
samples/hw_breakpoint: Fix kernel BUG 'invalid opcode: 0000'
modpost, kallsyms: Treat add '$'-prefixed symbols as mapping symbols
kernel: params: Remove unnecessary ‘0’ values from err
module: Ignore RISC-V mapping symbols too

show more ...


Revision tags: v6.5, v6.1.49, v6.1.48, v6.1.46, v6.1.45, v6.1.44
# 2612e3bb 07-Aug-2023 Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge drm/drm-next into drm-intel-next

Catching-up with drm-next and drm-intel-gt-next.
It will unblock a code refactor around the platform
definitions (names vs acronyms).

Signed-off-by: Rodrigo V

Merge drm/drm-next into drm-intel-next

Catching-up with drm-next and drm-intel-gt-next.
It will unblock a code refactor around the platform
definitions (names vs acronyms).

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

show more ...


# 9f771739 07-Aug-2023 Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Merge drm/drm-next into drm-intel-gt-next

Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as
a dependency for https://patchwork.freedesktop.org/series/1

Merge drm/drm-next into drm-intel-gt-next

Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as
a dependency for https://patchwork.freedesktop.org/series/121735/

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

show more ...


Revision tags: v6.1.43
# 2abcc4b5 01-Aug-2023 James Morse <james.morse@arm.com>

module: Expose module_init_layout_section()

module_init_layout_section() choses whether the core module loader
considers a section as init or not. This affects the placement of the
exit section when

module: Expose module_init_layout_section()

module_init_layout_section() choses whether the core module loader
considers a section as init or not. This affects the placement of the
exit section when module unloading is disabled. This code will never run,
so it can be free()d once the module has been initialised.

arm and arm64 need to count the number of PLTs they need before applying
relocations based on the section name. The init PLTs are stored separately
so they can be free()d. arm and arm64 both use within_module_init() to
decide which list of PLTs to use when applying the relocation.

Because within_module_init()'s behaviour changes when module unloading
is disabled, both architecture would need to take this into account when
counting the PLTs.

Today neither architecture does this, meaning when module unloading is
disabled there are insufficient PLTs in the init section to load some
modules, resulting in warnings:
| WARNING: CPU: 2 PID: 51 at arch/arm64/kernel/module-plts.c:99 module_emit_plt_entry+0x184/0x1cc
| Modules linked in: crct10dif_common
| CPU: 2 PID: 51 Comm: modprobe Not tainted 6.5.0-rc4-yocto-standard-dirty #15208
| Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
| pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : module_emit_plt_entry+0x184/0x1cc
| lr : module_emit_plt_entry+0x94/0x1cc
| sp : ffffffc0803bba60
[...]
| Call trace:
| module_emit_plt_entry+0x184/0x1cc
| apply_relocate_add+0x2bc/0x8e4
| load_module+0xe34/0x1bd4
| init_module_from_file+0x84/0xc0
| __arm64_sys_finit_module+0x1b8/0x27c
| invoke_syscall.constprop.0+0x5c/0x104
| do_el0_svc+0x58/0x160
| el0_svc+0x38/0x110
| el0t_64_sync_handler+0xc0/0xc4
| el0t_64_sync+0x190/0x194

Instead of duplicating module_init_layout_section()s logic, expose it.

Reported-by: Adam Johnston <adam.johnston@arm.com>
Fixes: 055f23b74b20 ("module: check for exit sections in layout_sections() instead of module_init_section()")
Cc: stable@vger.kernel.org
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

show more ...


# 9011e49d 01-Aug-2023 Christoph Hellwig <hch@lst.de>

modules: only allow symbol_get of EXPORT_SYMBOL_GPL modules

It has recently come to my attention that nvidia is circumventing the
protection added in 262e6ae7081d ("modules: inherit
TAINT_PROPRIETAR

modules: only allow symbol_get of EXPORT_SYMBOL_GPL modules

It has recently come to my attention that nvidia is circumventing the
protection added in 262e6ae7081d ("modules: inherit
TAINT_PROPRIETARY_MODULE") by importing exports from their proprietary
modules into an allegedly GPL licensed module and then rexporting them.

Given that symbol_get was only ever intended for tightly cooperating
modules using very internal symbols it is logical to restrict it to
being used on EXPORT_SYMBOL_GPL and prevent nvidia from costly DMCA
Circumvention of Access Controls law suites.

All symbols except for four used through symbol_get were already exported
as EXPORT_SYMBOL_GPL, and the remaining four ones were switched over in
the preparation patches.

Fixes: 262e6ae7081d ("modules: inherit TAINT_PROPRIETARY_MODULE")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

show more ...


Revision tags: v6.1.42, v6.1.41
# 61b73694 24-Jul-2023 Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-next into drm-misc-next

Backmerging to get v6.5-rc2.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>


Revision tags: v6.1.40, v6.1.39
# 50501936 17-Jul-2023 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge tag 'v6.4' into next

Sync up with mainline to bring in updates to shared infrastructure.


# 0791faeb 17-Jul-2023 Mark Brown <broonie@kernel.org>

ASoC: Merge v6.5-rc2

Get a similar baseline to my other branches, and fixes for people using
the branch.


# 2f98e686 11-Jul-2023 Maxime Ripard <mripard@kernel.org>

Merge v6.5-rc1 into drm-misc-fixes

Boris needs 6.5-rc1 in drm-misc-fixes to prevent a conflict.

Signed-off-by: Maxime Ripard <mripard@kernel.org>


Revision tags: v6.1.38
# f1962207 04-Jul-2023 Linus Torvalds <torvalds@linux-foundation.org>

module: fix init_module_from_file() error handling

Vegard Nossum pointed out two different problems with the error handling
in init_module_from_file():

(a) the idempotent loading code didn't clean

module: fix init_module_from_file() error handling

Vegard Nossum pointed out two different problems with the error handling
in init_module_from_file():

(a) the idempotent loading code didn't clean up properly in some error
cases, leaving the on-stack 'struct idempotent' element still in
the hash table

(b) failure to read the module file would nonsensically update the
'invalid_kread_bytes' stat counter with the error value

The first error is quite nasty, in that it can then cause subsequent
idempotent loads of that same file to access stale stack contents of the
previous failure. The case may not happen in any normal situation
(explaining all the "Tested-by's on the original change), and requires
admin privileges, but syzkaller triggers random bad behavior as a
result:

BUG: soft lockup in sys_finit_module
BUG: unable to handle kernel paging request in init_module_from_file
general protection fault in init_module_from_file
INFO: task hung in init_module_from_file
KASAN: out-of-bounds Read in init_module_from_file
KASAN: slab-out-of-bounds Read in init_module_from_file
...

The second error is fairly benign and just leads to nonsensical stats
(and has been around since the debug stats were added).

Vegard also provided a patch for the idempotent loading issue, but I'd
rather re-organize the code and make it more legible using another level
of helper functions than add the usual "goto out" error handling.

Link: https://lore.kernel.org/lkml/20230704100852.23452-1-vegard.nossum@oracle.com/
Fixes: 9b9879fc0327 ("modules: catch concurrent module loads, treat them as idempotent")
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Reported-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reported-by: syzbot+9c2bdc9d24e4a7abe741@syzkaller.appspotmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...


Revision tags: v6.1.37
# 44f10dbe 30-Jun-2023 Andrew Morton <akpm@linux-foundation.org>

Merge branch 'master' into mm-hotfixes-stable


# 0a30901b 30-Jun-2023 Andrew Morton <akpm@linux-foundation.org>

Merge branch 'master' into mm-hotfixes-stable


# 4e3c09e9 28-Jun-2023 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'v6.5-rc1-modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull module updates from Luis Chamberlain:
"The changes queued up for modules are pretty tame, mostly

Merge tag 'v6.5-rc1-modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull module updates from Luis Chamberlain:
"The changes queued up for modules are pretty tame, mostly code removal
of moving of code.

Only two minor functional changes are made, the only one which stands
out is Sebastian Andrzej Siewior's simplification of module reference
counting by removing preempt_disable() and that has been tested on
linux-next for well over a month without no regressions.

I'm now, I guess, also a kitchen sink for some kallsyms changes"

[ There was a mis-communication about the concurrent module load changes
that I had expected to come through Luis despite me authoring the
patch. So some of the module updates were left hanging in the email
ether, and I just committed them separately.

It's my bad - I should have made it more clear that I expected my
own patches to come through the module tree too. Now they missed
linux-next, but hopefully that won't cause any issues - Linus ]

* tag 'v6.5-rc1-modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
kallsyms: make kallsyms_show_value() as generic function
kallsyms: move kallsyms_show_value() out of kallsyms.c
kallsyms: remove unsed API lookup_symbol_attrs
kallsyms: remove unused arch_get_kallsym() helper
module: Remove preempt_disable() from module reference counting.

show more ...


Revision tags: v6.1.36, v6.4, v6.1.35, v6.1.34, v6.1.33, v6.1.32, v6.1.31
# 9b9879fc 29-May-2023 Linus Torvalds <torvalds@linux-foundation.org>

modules: catch concurrent module loads, treat them as idempotent

This is the new-and-improved attempt at avoiding huge memory load spikes
when the user space boot sequence tries to load hundreds (or

modules: catch concurrent module loads, treat them as idempotent

This is the new-and-improved attempt at avoiding huge memory load spikes
when the user space boot sequence tries to load hundreds (or even
thousands) of redundant duplicate modules in parallel.

See commit 9828ed3f695a ("module: error out early on concurrent load of
the same module file") for background and an earlier failed attempt that
was reverted.

That earlier attempt just said "concurrently loading the same module is
silly, just open the module file exclusively and return -ETXTBSY if
somebody else is already loading it".

While it is true that concurrent module loads of the same module is
silly, the reason that earlier attempt then failed was that the
concurrently loaded module would often be a prerequisite for another
module.

Thus failing to load the prerequisite would then cause cascading
failures of the other modules, rather than just short-circuiting that
one unnecessary module load.

At the same time, we still really don't want to load the contents of the
same module file hundreds of times, only to then wait for an eventually
successful load, and have everybody else return -EEXIST.

As a result, this takes another approach, and treats concurrent module
loads from the same file as "idempotent" in the inode. So if one module
load is ongoing, we don't start a new one, but instead just wait for the
first one to complete and return the same return value as it did.

So unlike the first attempt, this does not return early: the intent is
not to speed up the boot, but to avoid a thundering herd problem in
allocating memory (both physical and virtual) for a module more than
once.

Also note that this does change behavior: it used to be that when you
had concurrent loads, you'd have one "winner" that would return success,
and everybody else would return -EEXIST.

In contrast, this idempotent logic goes all Oprah on the problem, and
says "You are a winner! And you are a winner! We are ALL winners". But
since there's no possible actual real semantic difference between "you
loaded the module" and "somebody else already loaded the module", this
is more of a feel-good change than an actual honest-to-goodness semantic
change.

Of course, any true Johnny-come-latelies that don't get caught in the
concurrency filter will still return -EEXIST. It's no different from
not even getting a seat at an Oprah taping. That's life.

See the long thread on the kernel mailing list about this all, which
includes some numbers for memory use before and after the patch.

Link: https://lore.kernel.org/lkml/20230524213620.3509138-1-mcgrof@kernel.org/
Reviewed-by: Johan Hovold <johan@kernel.org>
Tested-by: Johan Hovold <johan@kernel.org>
Tested-by: Luis Chamberlain <mcgrof@kernel.org>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Rudi Heitbaum <rudi@heitbaum..com>
Tested-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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# 054a7300 29-May-2023 Linus Torvalds <torvalds@linux-foundation.org>

module: split up 'finit_module()' into init_module_from_file() helper

This will simplify the next step, where we can then key off the inode to
do one idempotent module load.

Let's do the obvious re

module: split up 'finit_module()' into init_module_from_file() helper

This will simplify the next step, where we can then key off the inode to
do one idempotent module load.

Let's do the obvious re-organization in one step, and then the new code
in another.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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# e80b5003 27-Jun-2023 Jiri Kosina <jkosina@suse.cz>

Merge branch 'for-6.5/apple' into for-linus

- improved support for Keychron K8 keyboard (Lasse Brun)


# 5f004bca 27-Jun-2023 Jason Gunthorpe <jgg@nvidia.com>

Merge tag 'v6.4' into rdma.git for-next

Linux 6.4

Resolve conflicts between rdma rc and next in rxe_cq matching linux-next:

drivers/infiniband/sw/rxe/rxe_cq.c:
https://lore.kernel.org/r/20230622

Merge tag 'v6.4' into rdma.git for-next

Linux 6.4

Resolve conflicts between rdma rc and next in rxe_cq matching linux-next:

drivers/infiniband/sw/rxe/rxe_cq.c:
https://lore.kernel.org/r/20230622115246.365d30ad@canb.auug.org.au

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

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# f121ab7f 26-Jun-2023 Thomas Gleixner <tglx@linutronix.de>

Merge tag 'irqchip-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates from Marc Zyngier:

- A number of Loogson/Loogarch fixes

- Allow th

Merge tag 'irqchip-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates from Marc Zyngier:

- A number of Loogson/Loogarch fixes

- Allow the core code to retrigger an interrupt that has
fired while the same interrupt is being handled on another
CPU, papering over a GICv3 architecture issue

- Work around an integration problem on ASR8601, where the CPU
numbering isn't representable in the GIC implementation...

- Add some missing interrupt to the STM32 irqchip

- A bunch of warning squashing triggered by W=1 builds

Link: https://lore.kernel.org/r/20230623224345.3577134-1-maz@kernel.org

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