History log of /linux-6.15/kernel/module/Kconfig (Results 1 – 21 of 21)
Revision (<<< Hide revision tags) (Show revision tags >>>) Date Author Comments
Revision tags: v6.15, v6.15-rc7, v6.15-rc6, v6.15-rc5, v6.15-rc4, v6.15-rc3, v6.15-rc2
# 9520a2b3 07-Apr-2025 Sami Tolvanen <[email protected]>

kbuild: Require pahole <v1.28 or >v1.29 with GENDWARFKSYMS on X86

With CONFIG_GENDWARFKSYMS, __gendwarfksyms_ptr variables are
added to the kernel in EXPORT_SYMBOL() to ensure DWARF type
information

kbuild: Require pahole <v1.28 or >v1.29 with GENDWARFKSYMS on X86

With CONFIG_GENDWARFKSYMS, __gendwarfksyms_ptr variables are
added to the kernel in EXPORT_SYMBOL() to ensure DWARF type
information is available for exported symbols in the TUs where
they're actually exported. These symbols are dropped when linking
vmlinux, but dangling references to them remain in DWARF.

With CONFIG_DEBUG_INFO_BTF enabled on X86, pahole versions after
commit 47dcb534e253 ("btf_encoder: Stop indexing symbols for
VARs") and before commit 9810758003ce ("btf_encoder: Verify 0
address DWARF variables are in ELF section") place these symbols
in the .data..percpu section, which results in an "Invalid
offset" error in btf_datasec_check_meta() during boot, as all
the variables are at zero offset and have non-zero size. If
CONFIG_DEBUG_INFO_BTF_MODULES is enabled, this also results in a
failure to load modules with:

failed to validate module [$module] BTF: -22

As the issue occurs in pahole v1.28 and the fix was merged
after v1.29 was released, require pahole <v1.28 or >v1.29 when
GENDWARFKSYMS is enabled with DEBUG_INFO_BTF on X86.

Reported-by: Paolo Pisati <[email protected]>
Signed-off-by: Sami Tolvanen <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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Revision tags: v6.15-rc1, v6.14, v6.14-rc7, v6.14-rc6, v6.14-rc5, v6.14-rc4, v6.14-rc3, v6.14-rc2, v6.14-rc1, v6.13, v6.13-rc7, v6.13-rc6, v6.13-rc5, v6.13-rc4, v6.13-rc3, v6.13-rc2, v6.13-rc1, v6.12, v6.12-rc7, v6.12-rc6, v6.12-rc5, v6.12-rc4
# f3b93547 16-Oct-2024 Thorsten Leemhuis <[email protected]>

module: sign with sha512 instead of sha1 by default

Switch away from using sha1 for module signing by default and use the
more modern sha512 instead, which is what among others Arch, Fedora,
RHEL, a

module: sign with sha512 instead of sha1 by default

Switch away from using sha1 for module signing by default and use the
more modern sha512 instead, which is what among others Arch, Fedora,
RHEL, and Ubuntu are currently using for their kernels.

Sha1 has not been considered secure against well-funded opponents since
2005[1]; since 2011 the NIST and other organizations furthermore
recommended its replacement[2]. This is why OpenSSL on RHEL9, Fedora
Linux 41+[3], and likely some other current and future distributions
reject the creation of sha1 signatures, which leads to a build error of
allmodconfig configurations:

80A20474797F0000:error:03000098:digital envelope routines:do_sigver_init:invalid digest:crypto/evp/m_sigver.c:342:
make[4]: *** [.../certs/Makefile:53: certs/signing_key.pem] Error 1
make[4]: *** Deleting file 'certs/signing_key.pem'
make[4]: *** Waiting for unfinished jobs....
make[3]: *** [.../scripts/Makefile.build:478: certs] Error 2
make[2]: *** [.../Makefile:1936: .] Error 2
make[1]: *** [.../Makefile:224: __sub-make] Error 2
make[1]: Leaving directory '...'
make: *** [Makefile:224: __sub-make] Error 2

This change makes allmodconfig work again and sets a default that is
more appropriate for current and future users, too.

Link: https://www.schneier.com/blog/archives/2005/02/cryptanalysis_o.html [1]
Link: https://csrc.nist.gov/projects/hash-functions [2]
Link: https://fedoraproject.org/wiki/Changes/OpenSSLDistrustsha1SigVer [3]
Signed-off-by: Thorsten Leemhuis <[email protected]>
Reviewed-by: Sami Tolvanen <[email protected]>
Tested-by: kdevops <[email protected]> [0]
Link: https://github.com/linux-kdevops/linux-modules-kpd/actions/runs/11420092929/job/31775404330 [0]
Link: https://lore.kernel.org/r/52ee32c0c92afc4d3263cea1f8a1cdc809728aff.1729088288.git.linux@leemhuis.info
Signed-off-by: Petr Pavlu <[email protected]>

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# e8639b7e 03-Jan-2025 Matthew Maurer <[email protected]>

modpost: Allow extended modversions without basic MODVERSIONS

If you know that your kernel modules will only ever be loaded by a newer
kernel, you can disable BASIC_MODVERSIONS to save space. This a

modpost: Allow extended modversions without basic MODVERSIONS

If you know that your kernel modules will only ever be loaded by a newer
kernel, you can disable BASIC_MODVERSIONS to save space. This also
allows easy creation of test modules to see how tooling will respond to
modules that only have the new format.

Signed-off-by: Matthew Maurer <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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# fc7d5e32 03-Jan-2025 Matthew Maurer <[email protected]>

modpost: Produce extended MODVERSIONS information

Generate both the existing modversions format and the new extended one
when running modpost. Presence of this metadata in the final .ko is
guarded b

modpost: Produce extended MODVERSIONS information

Generate both the existing modversions format and the new extended one
when running modpost. Presence of this metadata in the final .ko is
guarded by CONFIG_EXTENDED_MODVERSIONS.

We no longer generate an error on long symbols in modpost if
CONFIG_EXTENDED_MODVERSIONS is set, as they can now be appropriately
encoded in the extended section. These symbols will be skipped in the
previous encoding. An error will still be generated if
CONFIG_EXTENDED_MODVERSIONS is not set.

Reviewed-by: Sami Tolvanen <[email protected]>
Signed-off-by: Matthew Maurer <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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# 9c3681f9 03-Jan-2025 Sami Tolvanen <[email protected]>

kbuild: Add gendwarfksyms as an alternative to genksyms

When MODVERSIONS is enabled, allow selecting gendwarfksyms as the
implementation, but default to genksyms.

Signed-off-by: Sami Tolvanen <sami

kbuild: Add gendwarfksyms as an alternative to genksyms

When MODVERSIONS is enabled, allow selecting gendwarfksyms as the
implementation, but default to genksyms.

Signed-off-by: Sami Tolvanen <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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# f2856884 03-Jan-2025 Sami Tolvanen <[email protected]>

tools: Add gendwarfksyms

Add a basic DWARF parser, which uses libdw to traverse the debugging
information in an object file and looks for functions and variables.
In follow-up patches, this will be

tools: Add gendwarfksyms

Add a basic DWARF parser, which uses libdw to traverse the debugging
information in an object file and looks for functions and variables.
In follow-up patches, this will be expanded to produce symbol versions
for CONFIG_MODVERSIONS from DWARF.

Signed-off-by: Sami Tolvanen <[email protected]>
Reviewed-by: Petr Pavlu <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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# cdd30ebb 02-Dec-2024 Peter Zijlstra <[email protected]>

module: Convert symbol namespace to string literal

Clean up the existing export namespace code along the same lines of
commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo)
to __s

module: Convert symbol namespace to string literal

Clean up the existing export namespace code along the same lines of
commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo)
to __section("foo")") and for the same reason, it is not desired for the
namespace argument to be a macro expansion itself.

Scripted using

git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file;
do
awk -i inplace '
/^#define EXPORT_SYMBOL_NS/ {
gsub(/__stringify\(ns\)/, "ns");
print;
next;
}
/^#define MODULE_IMPORT_NS/ {
gsub(/__stringify\(ns\)/, "ns");
print;
next;
}
/MODULE_IMPORT_NS/ {
$0 = gensub(/MODULE_IMPORT_NS\(([^)]*)\)/, "MODULE_IMPORT_NS(\"\\1\")", "g");
}
/EXPORT_SYMBOL_NS/ {
if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+),/) {
if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/ &&
$0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(\)/ &&
$0 !~ /^my/) {
getline line;
gsub(/[[:space:]]*\\$/, "");
gsub(/[[:space:]]/, "", line);
$0 = $0 " " line;
}

$0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/,
"\\1(\\2, \"\\3\")", "g");
}
}
{ print }' $file;
done

Requested-by: Masahiro Yamada <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc
Acked-by: Greg KH <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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Revision tags: v6.12-rc3, v6.12-rc2, v6.12-rc1
# 1f9c4a99 25-Sep-2024 Linus Torvalds <[email protected]>

Kbuild: make MODVERSIONS support depend on not being a compile test build

Currently the Rust support is gated on not having MODVERSIONS enabled,
and as a result an "allmodconfig" build will disable

Kbuild: make MODVERSIONS support depend on not being a compile test build

Currently the Rust support is gated on not having MODVERSIONS enabled,
and as a result an "allmodconfig" build will disable Rust build tests.

While MODVERSIONS configurations are worth build testing, the feature is
not actually meaningful unless you run the result, and I'd rather get
build coverage of Rust than MODVERSIONS. So let's disable MODVERSIONS
for build testing until the Rust side clears up.

Signed-off-by: Linus Torvalds <[email protected]>

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Revision tags: v6.11, v6.11-rc7, v6.11-rc6, v6.11-rc5, v6.11-rc4, v6.11-rc3, v6.11-rc2, v6.11-rc1
# f94ce04e 22-Jul-2024 Petr Pavlu <[email protected]>

module: Clean up the description of MODULE_SIG_<type>

The MODULE_SIG_<type> config choice has an inconsistent prompt styled as
a question and lengthy option names.

Simplify the prompt and option na

module: Clean up the description of MODULE_SIG_<type>

The MODULE_SIG_<type> config choice has an inconsistent prompt styled as
a question and lengthy option names.

Simplify the prompt and option names to be consistent with other module
options.

Signed-off-by: Petr Pavlu <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

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# c7ff693f 22-Jul-2024 Petr Pavlu <[email protected]>

module: Split modules_install compression and in-kernel decompression

The kernel configuration allows specifying a module compression mode. If
one is selected then each module gets compressed during

module: Split modules_install compression and in-kernel decompression

The kernel configuration allows specifying a module compression mode. If
one is selected then each module gets compressed during
'make modules_install' and additionally one can also enable support for
a respective direct in-kernel decompression support. This means that the
decompression support cannot be enabled without the automatic compression.

Some distributions, such as the (open)SUSE family, use a signer service for
modules. A build runs on a worker machine but signing is done by a separate
locked-down server that is in possession of the signing key. The build
invokes 'make modules_install' to create a modules tree, collects
information about the modules, asks the signer service for their signature,
appends each signature to the respective module and compresses all modules.

When using this arrangment, the 'make modules_install' step produces
unsigned+uncompressed modules and the distribution's own build recipe takes
care of signing and compression later.

The signing support can be currently enabled without automatically signing
modules during 'make modules_install'. However, the in-kernel decompression
support can be selected only after first enabling automatic compression
during this step.

To allow only enabling the in-kernel decompression support without the
automatic compression during 'make modules_install', separate the
compression options similarly to the signing options, as follows:

> Enable loadable module support
[*] Module compression
Module compression type (GZIP) --->
[*] Automatically compress all modules
[ ] Support in-kernel module decompression

* "Module compression" (MODULE_COMPRESS) is a new main switch for the
compression/decompression support. It replaces MODULE_COMPRESS_NONE.
* "Module compression type" (MODULE_COMPRESS_<type>) chooses the
compression type, one of GZ, XZ, ZSTD.
* "Automatically compress all modules" (MODULE_COMPRESS_ALL) is a new
option to enable module compression during 'make modules_install'. It
defaults to Y.
* "Support in-kernel module decompression" (MODULE_DECOMPRESS) enables
in-kernel decompression.

Signed-off-by: Petr Pavlu <[email protected]>
Acked-by: Masahiro Yamada <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

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Revision tags: v6.10, v6.10-rc7, v6.10-rc6, v6.10-rc5, v6.10-rc4, v6.10-rc3, v6.10-rc2, v6.10-rc1, v6.9, v6.9-rc7
# 12af2b83 05-May-2024 Mike Rapoport (IBM) <[email protected]>

mm: introduce execmem_alloc() and execmem_free()

module_alloc() is used everywhere as a mean to allocate memory for code.

Beside being semantically wrong, this unnecessarily ties all subsystems
tha

mm: introduce execmem_alloc() and execmem_free()

module_alloc() is used everywhere as a mean to allocate memory for code.

Beside being semantically wrong, this unnecessarily ties all subsystems
that need to allocate code, such as ftrace, kprobes and BPF to modules and
puts the burden of code allocation to the modules code.

Several architectures override module_alloc() because of various
constraints where the executable memory can be located and this causes
additional obstacles for improvements of code allocation.

Start splitting code allocation from modules by introducing execmem_alloc()
and execmem_free() APIs.

Initially, execmem_alloc() is a wrapper for module_alloc() and
execmem_free() is a replacement of module_memfree() to allow updating all
call sites to use the new APIs.

Since architectures define different restrictions on placement,
permissions, alignment and other parameters for memory that can be used by
different subsystems that allocate executable memory, execmem_alloc() takes
a type argument, that will be used to identify the calling subsystem and to
allow architectures define parameters for ranges suitable for that
subsystem.

No functional changes.

Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Acked-by: Song Liu <[email protected]>
Acked-by: Steven Rostedt (Google) <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

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Revision tags: v6.9-rc6, v6.9-rc5, v6.9-rc4
# 8d0b7288 10-Apr-2024 Yifan Hong <[email protected]>

module: allow UNUSED_KSYMS_WHITELIST to be relative against objtree.

If UNUSED_KSYMS_WHITELIST is a file generated
before Kbuild runs, and the source tree is in
a read-only filesystem, the developer

module: allow UNUSED_KSYMS_WHITELIST to be relative against objtree.

If UNUSED_KSYMS_WHITELIST is a file generated
before Kbuild runs, and the source tree is in
a read-only filesystem, the developer must put
the file somewhere and specify an absolute
path to UNUSED_KSYMS_WHITELIST. This worked,
but if IKCONFIG=y, an absolute path is embedded
into .config and eventually into vmlinux, causing
the build to be less reproducible when building
on a different machine.

This patch makes the handling of
UNUSED_KSYMS_WHITELIST to be similar to
MODULE_SIG_KEY.

First, check if UNUSED_KSYMS_WHITELIST is an
absolute path, just as before this patch. If so,
use the path as is.

If it is a relative path, use wildcard to check
the existence of the file below objtree first.
If it does not exist, fall back to the original
behavior of adding $(srctree)/ before the value.

After this patch, the developer can put the generated
file in objtree, then use a relative path against
objtree in .config, eradicating any absolute paths
that may be evaluated differently on different machines.

Signed-off-by: Yifan Hong <[email protected]>
Reviewed-by: Elliot Berman <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

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Revision tags: v6.9-rc3, v6.9-rc2, v6.9-rc1
# 203a6763 13-Mar-2024 Eric Biggers <[email protected]>

Revert "crypto: pkcs7 - remove sha1 support"

This reverts commit 16ab7cb5825fc3425c16ad2c6e53d827f382d7c6 because it
broke iwd. iwd uses the KEYCTL_PKEY_* UAPIs via its dependency libell,
and appar

Revert "crypto: pkcs7 - remove sha1 support"

This reverts commit 16ab7cb5825fc3425c16ad2c6e53d827f382d7c6 because it
broke iwd. iwd uses the KEYCTL_PKEY_* UAPIs via its dependency libell,
and apparently it is relying on SHA-1 signature support. These UAPIs
are fairly obscure, and their documentation does not mention which
algorithms they support. iwd really should be using a properly
supported userspace crypto library instead. Regardless, since something
broke we have to revert the change.

It may be possible that some parts of this commit can be reinstated
without breaking iwd (e.g. probably the removal of MODULE_SIG_SHA1), but
for now this just does a full revert to get things working again.

Reported-by: Karel Balej <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]
Cc: Dimitri John Ledkov <[email protected]>
Signed-off-by: Eric Biggers <[email protected]>
Tested-by: Karel Balej <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>

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Revision tags: v6.8, v6.8-rc7, v6.8-rc6, v6.8-rc5
# d2d5cba5 15-Feb-2024 Masahiro Yamada <[email protected]>

kbuild: remove EXPERT and !COMPILE_TEST guarding from TRIM_UNUSED_KSYMS

This reverts the following two commits:

- a555bdd0c58c ("Kbuild: enable TRIM_UNUSED_KSYMS again, with some guarding")
- 5

kbuild: remove EXPERT and !COMPILE_TEST guarding from TRIM_UNUSED_KSYMS

This reverts the following two commits:

- a555bdd0c58c ("Kbuild: enable TRIM_UNUSED_KSYMS again, with some guarding")
- 5cf0fd591f2e ("Kbuild: disable TRIM_UNUSED_KSYMS option")

Commit 5e9e95cc9148 ("kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without
recursion") solved the build time issue.

Signed-off-by: Masahiro Yamada <[email protected]>

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Revision tags: v6.8-rc4, v6.8-rc3, v6.8-rc2, v6.8-rc1, v6.7, v6.7-rc8, v6.7-rc7, v6.7-rc6, v6.7-rc5, v6.7-rc4, v6.7-rc3, v6.7-rc2, v6.7-rc1, v6.6, v6.6-rc7
# 446b1e0b 22-Oct-2023 Dimitri John Ledkov <[email protected]>

module: enable automatic module signing with FIPS 202 SHA-3

Add Kconfig options to use SHA-3 for kernel module signing. 256 size
for RSA only, and higher sizes for RSA and NIST P-384.

Signed-off-by

module: enable automatic module signing with FIPS 202 SHA-3

Add Kconfig options to use SHA-3 for kernel module signing. 256 size
for RSA only, and higher sizes for RSA and NIST P-384.

Signed-off-by: Dimitri John Ledkov <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>

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Revision tags: v6.6-rc6
# fc3225fd 10-Oct-2023 Dimitri John Ledkov <[email protected]>

module: Do not offer sha224 for built-in module signing

sha224 does not provide enough security against collision attacks
relative to the default keys used for signing (RSA 4k & P-384). Also
sha224

module: Do not offer sha224 for built-in module signing

sha224 does not provide enough security against collision attacks
relative to the default keys used for signing (RSA 4k & P-384). Also
sha224 never became popular, as sha256 got widely adopter ahead of
sha224 being introduced.

Signed-off-by: Dimitri John Ledkov <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>

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# 16ab7cb5 10-Oct-2023 Dimitri John Ledkov <[email protected]>

crypto: pkcs7 - remove sha1 support

Removes support for sha1 signed kernel modules, importing sha1 signed
x.509 certificates.

rsa-pkcs1pad keeps sha1 padding support, which seems to be used by
virt

crypto: pkcs7 - remove sha1 support

Removes support for sha1 signed kernel modules, importing sha1 signed
x.509 certificates.

rsa-pkcs1pad keeps sha1 padding support, which seems to be used by
virtio driver.

sha1 remains available as there are many drivers and subsystems using
it. Note only hmac(sha1) with secret keys remains cryptographically
secure.

In the kernel there are filesystems, IMA, tpm/pcr that appear to be
using sha1. Maybe they can all start to be slowly upgraded to
something else i.e. blake3, ParallelHash, SHAKE256 as needed.

Signed-off-by: Dimitri John Ledkov <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>

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Revision tags: v6.6-rc5, v6.6-rc4, v6.6-rc3, v6.6-rc2, v6.6-rc1, v6.5, v6.5-rc7, v6.5-rc6, v6.5-rc5, v6.5-rc4, v6.5-rc3, v6.5-rc2, v6.5-rc1, v6.4, v6.4-rc7, v6.4-rc6, v6.4-rc5, v6.4-rc4, v6.4-rc3, v6.4-rc2, v6.4-rc1, v6.3, v6.3-rc7
# 8660484e 14-Apr-2023 Luis Chamberlain <[email protected]>

module: add debugging auto-load duplicate module support

The finit_module() system call can in the worst case use up to more than
twice of a module's size in virtual memory. Duplicate finit_module()

module: add debugging auto-load duplicate module support

The finit_module() system call can in the worst case use up to more than
twice of a module's size in virtual memory. Duplicate finit_module()
system calls are non fatal, however they unnecessarily strain virtual
memory during bootup and in the worst case can cause a system to fail
to boot. This is only known to currently be an issue on systems with
larger number of CPUs.

To help debug this situation we need to consider the different sources for
finit_module(). Requests from the kernel that rely on module auto-loading,
ie, the kernel's *request_module() API, are one source of calls. Although
modprobe checks to see if a module is already loaded prior to calling
finit_module() there is a small race possible allowing userspace to
trigger multiple modprobe calls racing against modprobe and this not
seeing the module yet loaded.

This adds debugging support to the kernel module auto-loader (*request_module()
calls) to easily detect duplicate module requests. To aid with possible bootup
failure issues incurred by this, it will converge duplicates requests to a
single request. This avoids any possible strain on virtual memory during
bootup which could be incurred by duplicate module autoloading requests.

Folks debugging virtual memory abuse on bootup can and should enable
this to see what pr_warn()s come on, to see if module auto-loading is to
blame for their wores. If they see duplicates they can further debug this
by enabling the module.enable_dups_trace kernel parameter or by enabling
CONFIG_MODULE_DEBUG_AUTOLOAD_DUPS_TRACE.

Current evidence seems to point to only a few duplicates for module
auto-loading. And so the source for other duplicates creating heavy
virtual memory pressure due to larger number of CPUs should becoming
from another place (likely udev).

Signed-off-by: Luis Chamberlain <[email protected]>

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Revision tags: v6.3-rc6, v6.3-rc5
# df3e764d 29-Mar-2023 Luis Chamberlain <[email protected]>

module: add debug stats to help identify memory pressure

Loading modules with finit_module() can end up using vmalloc(), vmap()
and vmalloc() again, for a total of up to 3 separate allocations in th

module: add debug stats to help identify memory pressure

Loading modules with finit_module() can end up using vmalloc(), vmap()
and vmalloc() again, for a total of up to 3 separate allocations in the
worst case for a single module. We always kernel_read*() the module,
that's a vmalloc(). Then vmap() is used for the module decompression,
and if so the last read buffer is freed as we use the now decompressed
module buffer to stuff data into our copy module. The last allocation is
specific to each architectures but pretty much that's generally a series
of vmalloc() calls or a variation of vmalloc to handle ELF sections with
special permissions.

Evaluation with new stress-ng module support [1] with just 100 ops
is proving that you can end up using GiBs of data easily even with all
care we have in the kernel and userspace today in trying to not load modules
which are already loaded. 100 ops seems to resemble the sort of pressure a
system with about 400 CPUs can create on module loading. Although issues
relating to duplicate module requests due to each CPU inucurring a new
module reuest is silly and some of these are being fixed, we currently lack
proper tooling to help diagnose easily what happened, when it happened
and who likely is to blame -- userspace or kernel module autoloading.

Provide an initial set of stats which use debugfs to let us easily scrape
post-boot information about failed loads. This sort of information can
be used on production worklaods to try to optimize *avoiding* redundant
memory pressure using finit_module().

There's a few examples that can be provided:

A 255 vCPU system without the next patch in this series applied:

Startup finished in 19.143s (kernel) + 7.078s (userspace) = 26.221s
graphical.target reached after 6.988s in userspace

And 13.58 GiB of virtual memory space lost due to failed module loading:

root@big ~ # cat /sys/kernel/debug/modules/stats
Mods ever loaded 67
Mods failed on kread 0
Mods failed on decompress 0
Mods failed on becoming 0
Mods failed on load 1411
Total module size 11464704
Total mod text size 4194304
Failed kread bytes 0
Failed decompress bytes 0
Failed becoming bytes 0
Failed kmod bytes 14588526272
Virtual mem wasted bytes 14588526272
Average mod size 171115
Average mod text size 62602
Average fail load bytes 10339140
Duplicate failed modules:
module-name How-many-times Reason
kvm_intel 249 Load
kvm 249 Load
irqbypass 8 Load
crct10dif_pclmul 128 Load
ghash_clmulni_intel 27 Load
sha512_ssse3 50 Load
sha512_generic 200 Load
aesni_intel 249 Load
crypto_simd 41 Load
cryptd 131 Load
evdev 2 Load
serio_raw 1 Load
virtio_pci 3 Load
nvme 3 Load
nvme_core 3 Load
virtio_pci_legacy_dev 3 Load
virtio_pci_modern_dev 3 Load
t10_pi 3 Load
virtio 3 Load
crc32_pclmul 6 Load
crc64_rocksoft 3 Load
crc32c_intel 40 Load
virtio_ring 3 Load
crc64 3 Load

The following screen shot, of a simple 8vcpu 8 GiB KVM guest with the
next patch in this series applied, shows 226.53 MiB are wasted in virtual
memory allocations which due to duplicate module requests during boot.
It also shows an average module memory size of 167.10 KiB and an an
average module .text + .init.text size of 61.13 KiB. The end shows all
modules which were detected as duplicate requests and whether or not
they failed early after just the first kernel_read*() call or late after
we've already allocated the private space for the module in
layout_and_allocate(). A system with module decompression would reveal
more wasted virtual memory space.

We should put effort now into identifying the source of these duplicate
module requests and trimming these down as much possible. Larger systems
will obviously show much more wasted virtual memory allocations.

root@kmod ~ # cat /sys/kernel/debug/modules/stats
Mods ever loaded 67
Mods failed on kread 0
Mods failed on decompress 0
Mods failed on becoming 83
Mods failed on load 16
Total module size 11464704
Total mod text size 4194304
Failed kread bytes 0
Failed decompress bytes 0
Failed becoming bytes 228959096
Failed kmod bytes 8578080
Virtual mem wasted bytes 237537176
Average mod size 171115
Average mod text size 62602
Avg fail becoming bytes 2758544
Average fail load bytes 536130
Duplicate failed modules:
module-name How-many-times Reason
kvm_intel 7 Becoming
kvm 7 Becoming
irqbypass 6 Becoming & Load
crct10dif_pclmul 7 Becoming & Load
ghash_clmulni_intel 7 Becoming & Load
sha512_ssse3 6 Becoming & Load
sha512_generic 7 Becoming & Load
aesni_intel 7 Becoming
crypto_simd 7 Becoming & Load
cryptd 3 Becoming & Load
evdev 1 Becoming
serio_raw 1 Becoming
nvme 3 Becoming
nvme_core 3 Becoming
t10_pi 3 Becoming
virtio_pci 3 Becoming
crc32_pclmul 6 Becoming & Load
crc64_rocksoft 3 Becoming
crc32c_intel 3 Becoming
virtio_pci_modern_dev 2 Becoming
virtio_pci_legacy_dev 1 Becoming
crc64 2 Becoming
virtio 2 Becoming
virtio_ring 2 Becoming

[0] https://github.com/ColinIanKing/stress-ng.git
[1] echo 0 > /proc/sys/vm/oom_dump_tasks
./stress-ng --module 100 --module-name xfs

Signed-off-by: Luis Chamberlain <[email protected]>

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Revision tags: v6.3-rc4, v6.3-rc3, v6.3-rc2, v6.3-rc1, v6.2, v6.2-rc8, v6.2-rc7, v6.2-rc6, v6.2-rc5, v6.2-rc4, v6.2-rc3, v6.2-rc2, v6.2-rc1, v6.1
# 169a58ad 06-Dec-2022 Stephen Boyd <[email protected]>

module/decompress: Support zstd in-kernel decompression

Add support for zstd compressed modules to the in-kernel decompression
code. This allows zstd compressed modules to be decompressed by the
ker

module/decompress: Support zstd in-kernel decompression

Add support for zstd compressed modules to the in-kernel decompression
code. This allows zstd compressed modules to be decompressed by the
kernel, similar to the existing support for gzip and xz compressed
modules.

Cc: Dmitry Torokhov <[email protected]>
Cc: Piotr Gorski <[email protected]>
Cc: Nick Terrell <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Reviewed-by: Dmitry Torokhov <[email protected]>
Reviewed-by: Piotr Gorski <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

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Revision tags: v6.1-rc8, v6.1-rc7, v6.1-rc6, v6.1-rc5, v6.1-rc4, v6.1-rc3, v6.1-rc2, v6.1-rc1, v6.0, v6.0-rc7, v6.0-rc6, v6.0-rc5, v6.0-rc4, v6.0-rc3, v6.0-rc2, v6.0-rc1, v5.19, v5.19-rc8, v5.19-rc7
# 73b4fc92 12-Jul-2022 Christophe Leroy <[email protected]>

module: Move module's Kconfig items in kernel/module/

In init/Kconfig, the part dedicated to modules is quite large.

Move it into a dedicated Kconfig in kernel/module/

MODULES_TREE_LOOKUP was outs

module: Move module's Kconfig items in kernel/module/

In init/Kconfig, the part dedicated to modules is quite large.

Move it into a dedicated Kconfig in kernel/module/

MODULES_TREE_LOOKUP was outside of the 'if MODULES', but as it is
only used when MODULES are set, move it in with everything else to
avoid confusion.

MODULE_SIG_FORMAT is left in init/Kconfig because this configuration
item is not used in kernel/modules/ but in kernel/ and can be
selected independently from CONFIG_MODULES. It is for instance
selected from security/integrity/ima/Kconfig.

Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

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