This commit renames the variables in handle_moddevtable() as follows:
name -> type
namelen -> typelen
identifier -> name
These changes align with the definition in include/linux/module.h:
extern typeof(name) __mod_##type##__##name##_device_table
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
do_usb_table() no longer needs to iterate over the usb_device_id array.
Convert it to a generic ->do_entry() handler.
This is the last special case. Clean up handle_moddevtable().
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
do_of_table() no longer needs to iterate over the of_device_id array.
Convert it to a generic ->do_entry() handler.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
do_pnp_device_entry() no longer needs to iterate over the
pnp_device_id array.
Convert it to a generic ->do_entry() handler.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
do_pnp_card_entries() no longer needs to iterate over the
pnp_card_device_id array.
Convert it to a generic ->do_entry() handler.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The do_*_entry() functions cannot check the length of the given buffer.
Use module_alias_printf() helper consistently for these functions.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Replace the first argument with a pointer to struct module.
'filename' can be replaced with mod->name.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
MODULE_DEVICE_TABLE(pnp_card, ...) may have duplicated IDs. For
instance, snd_ad1816a_pnpids[] in sound/isa/ad1816a/ad1816a.c includes
multiple occurrences of the "ADS7180" string within its .devs fields.
Currently, do_pnp_card_entries() handles deduplication on its own, but
this logic should be moved to a common helper function, as drivers in
other subsystems might also have similar duplication issues.
For example, drivers/media/i2c/s5c73m3/s5c73m3.mod.c contains duplicated
MODULE_ALIAS() entries because both s5c73m3-core.c and s5c73m3-spi.c
define the same compatible string.
This commit eliminates redundant MODULE_ALIAS() entries across all
drivers.
[Before]
$ grep MODULE_ALIAS drivers/media/i2c/s5c73m3/s5c73m3.mod.c
MODULE_ALIAS("i2c:S5C73M3");
MODULE_ALIAS("of:N*T*Csamsung,s5c73m3");
MODULE_ALIAS("of:N*T*Csamsung,s5c73m3C*");
MODULE_ALIAS("of:N*T*Csamsung,s5c73m3");
MODULE_ALIAS("of:N*T*Csamsung,s5c73m3C*");
[After]
$ grep MODULE_ALIAS drivers/media/i2c/s5c73m3/s5c73m3.mod.c
MODULE_ALIAS("i2c:S5C73M3");
MODULE_ALIAS("of:N*T*Csamsung,s5c73m3");
MODULE_ALIAS("of:N*T*Csamsung,s5c73m3C*");
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The generic ->do_entry() handler is currently limited to returning
a single alias string.
However, this is not flexible enough for several subsystems, which
currently require their own implementations:
- do_usb_table()
- do_of_table()
- do_pnp_device_entry()
- do_pnp_card_entries()
This commit introduces a helper function so that these special cases can
add multiple MODULE_ALIAS() and then migrate to the generic framework.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The 'id' pointer is never NULL since it has the same address as
'symval'.
Also, checking (*id)[0] is simpler than calling strlen().
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This function contains multiple bugs after the following commits:
- ac55182899 ("modpost: i2c aliases need no trailing wildcard")
- 6543becf26 ("mod/file2alias: make modalias generation safe for cross compiling")
Commit ac55182899 inserted the following code to do_eisa_entry():
else
strcat(alias, "*");
This is incorrect because 'alias' is uninitialized. If it is not
NULL-terminated, strcat() could cause a buffer overrun.
Even if 'alias' happens to be zero-filled, it would output:
MODULE_ALIAS("*");
This would match anything. As a result, the module could be loaded by
any unrelated uevent from an unrelated subsystem.
Commit ac55182899 introduced another bug.
Prior to that commit, the conditional check was:
if (eisa->sig[0])
This checked if the first character of eisa_device_id::sig was not '\0'.
However, commit ac55182899 changed it as follows:
if (sig[0])
sig[0] is NOT the first character of the eisa_device_id::sig. The
type of 'sig' is 'char (*)[8]', meaning that the type of 'sig[0]' is
'char [8]' instead of 'char'. 'sig[0]' and 'symval' refer to the same
address, which never becomes NULL.
The correct conversion would have been:
if ((*sig)[0])
However, this if-conditional was meaningless because the earlier change
in commit ac551828993e was incorrect.
This commit removes the entire incorrect code, which should never have
been executed.
Fixes: ac55182899 ("modpost: i2c aliases need no trailing wildcard")
Fixes: 6543becf26 ("mod/file2alias: make modalias generation safe for cross compiling")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Set the -e option to ensure this script fails on any unexpected errors.
Without this change, the kernel build may continue running with an
incorrect string in include/config/kernel.release.
Currently, try_tag() returns 1 when the expected tag is not found as an
ancestor, but this is a case where the script should continue.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Contrary to expectations, passing a single candidate tag to "git
describe" is slower than not passing any --match options.
$ time git describe --debug
...
traversed 10619 commits
...
v6.12-rc5-63-g0fc810ae3ae1
real 0m0.169s
$ time git describe --match=v6.12-rc5 --debug
...
traversed 1310024 commits
v6.12-rc5-63-g0fc810ae3ae1
real 0m1.281s
In fact, the --debug output shows that git traverses all or most of
history. For some repositories and/or git versions, those 1.3s are
actually 10-15 seconds.
This has been acknowledged as a performance bug in git [1], and a fix
is on its way [2]. However, no solution is yet in git.git, and even
when one lands, it will take quite a while before it finds its way to
a release and for $random_kernel_developer to pick that up.
So rewrite the logic to use plumbing commands. For each of the
candidate values of $tag, we ask: (1) is $tag even an annotated
tag? (2) Is it eligible to describe HEAD, i.e. an ancestor of
HEAD? (3) If so, how many commits are in $tag..HEAD?
I have tested that this produces the same output as the current script
for ~700 random commits between v6.9..v6.10. For those 700 commits,
and in my git repo, the 'make -s kernelrelease' command is on average
~4 times faster with this patch applied (geometric mean of ratios).
For the commit mentioned in Josh's original report [3], the
time-consuming part of setlocalversion goes from
$ time git describe --match=v6.12-rc5 c1e939a21e
v6.12-rc5-44-gc1e939a21eb1
real 0m1.210s
to
$ time git rev-list --count --left-right v6.12-rc5..c1e939a21eb1
0 44
real 0m0.037s
[1] https://lore.kernel.org/git/20241101113910.GA2301440@coredump.intra.peff.net/
[2] https://lore.kernel.org/git/20241106192236.GC880133@coredump.intra.peff.net/
[3] https://lore.kernel.org/lkml/309549cafdcfe50c4fceac3263220cc3d8b109b2.1730337435.git.jpoimboe@kernel.org/
Reported-by: Sean Christopherson <seanjc@google.com>
Closes: https://lore.kernel.org/lkml/ZPtlxmdIJXOe0sEy@google.com/
Reported-by: Josh Poimboeuf <jpoimboe@kernel.org>
Closes: https://lore.kernel.org/lkml/309549cafdcfe50c4fceac3263220cc3d8b109b2.1730337435.git.jpoimboe@kernel.org/
Tested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Replace lz4c with lz4 for kernel image compression.
Although lz4 and lz4c are functionally similar, lz4c has been deprecated
upstream since 2018. Since as early as Ubuntu 16.04 and Fedora 25, lz4
and lz4c have been packaged together, making it safe to update the
requirement from lz4c to lz4.
Consequently, some distributions and build systems, such as OpenEmbedded,
have fully transitioned to using lz4. OpenEmbedded core adopted this
change in commit fe167e082cbd ("bitbake.conf: require lz4 instead of
lz4c"), causing compatibility issues when building the mainline kernel
in the latest OpenEmbedded environment, as seen in the errors below.
This change also updates the LZ4 compression commands to make it backward
compatible by replacing stdin and stdout with the '-' option, due to some
unclear reason, the stdout keyword does not work for lz4 and '-' works for
both. In addition, this modifies the legacy '-c1' with '-9' which is also
compatible with both. This fixes the mainline kernel build failures with
the latest master OpenEmbedded builds associated with the mentioned
compatibility issues.
LZ4 arch/arm/boot/compressed/piggy_data
/bin/sh: 1: lz4c: not found
...
...
ERROR: oe_runmake failed
Link: https://github.com/lz4/lz4/pull/553
Suggested-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Signed-off-by: Parth Pancholi <parth.pancholi@toradex.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This reverts commit 54babdc034 ("kbuild: Disable KCSAN for
autogenerated *.mod.c intermediaries").
Now that objtool is enabled for *.mod.c, there is no need to filter
out CFLAGS_KCSAN.
I no longer see "Unpatched return thunk in use. This should not happen!"
error with KCSAN when loading a module.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Currently, objtool is disabled in scripts/Makefile.{modfinal,vmlinux}.
This commit moves rule_cc_o_c and rule_as_o_S to scripts/Makefile.lib
and set objtool-enabled to y there.
With this change, *.mod.o, .module-common.o, builtin-dtb.o, and
vmlinux.export.o will now be covered by objtool.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The cmd_cc_o_c and cmd_as_o_S macros are duplicated in
scripts/Makefile.{build,modfinal,vmlinux}.
This commit factors them out to scripts/Makefile.lib.
No functional changes are intended.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This rule is unnecessary because you can generate foo/bar.symtypes
as a side effect using:
$ make KBUILD_SYMTYPES=1 foo/bar.o
While compiling *.o is slower than preprocessing, the impact is
negligible. I prioritize keeping the code simpler.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
There is no need to pass '-r /dev/null', which is no-op.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
There has been a long-standing request to support building external
modules in a separate build directory.
This commit introduces a new environment variable, KBUILD_EXTMOD_OUTPUT,
and its shorthand Make variable, MO.
A simple usage:
$ make -C <kernel-dir> M=<module-src-dir> MO=<module-build-dir>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
With the previous changes, $(extmod_prefix), $(MODORDER), and
$(MODULES_NSDEPS) are constant. (empty, modules.order, and
modules.nsdeps, respectively).
Remove these variables and hard-code their values.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Currently, Kbuild always operates in the output directory of the kernel,
even when building external modules. This increases the risk of external
module Makefiles attempting to write to the kernel directory.
This commit switches the working directory to the external module
directory, allowing the removal of the $(KBUILD_EXTMOD)/ prefix from
some build artifacts.
The command for building external modules maintains backward
compatibility, but Makefiles that rely on working in the kernel
directory may break. In such cases, $(objtree) and $(srctree) should
be used to refer to the output and source directories of the kernel.
The appearance of the build log will change as follows:
[Before]
$ make -C /path/to/my/linux M=/path/to/my/externel/module
make: Entering directory '/path/to/my/linux'
CC [M] /path/to/my/externel/module/helloworld.o
MODPOST /path/to/my/externel/module/Module.symvers
CC [M] /path/to/my/externel/module/helloworld.mod.o
CC [M] /path/to/my/externel/module/.module-common.o
LD [M] /path/to/my/externel/module/helloworld.ko
make: Leaving directory '/path/to/my/linux'
[After]
$ make -C /path/to/my/linux M=/path/to/my/externel/module
make: Entering directory '/path/to/my/linux'
make[1]: Entering directory '/path/to/my/externel/module'
CC [M] helloworld.o
MODPOST Module.symvers
CC [M] helloworld.mod.o
CC [M] .module-common.o
LD [M] helloworld.ko
make[1]: Leaving directory '/path/to/my/externel/module'
make: Leaving directory '/path/to/my/linux'
Printing "Entering directory" twice is cumbersome. This will be
addressed later.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
$(objtree) refers to the top of the output directory of kernel builds.
This commit adds the explicit $(objtree)/ prefix to build artifacts
needed for building external modules.
This change has no immediate impact, as the top-level Makefile
currently defines:
objtree := .
This commit prepares for supporting the building of external modules
in a different directory.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Masahiro Yamada
Rasmus Villemoes
Parth Pancholi