[ Upstream commit 69bc8d386a ]
The external module build shows the following warning if Module.symvers
is missing in the kernel tree.
WARNING: Symbol version dump "Module.symvers" is missing.
Modules may not have dependencies or modversions.
I think this is an important heads-up because the resulting modules may
not work as expected. This happens when you did not build the entire
kernel tree, for example, you might have prepared the minimal setups
for external modules by 'make defconfig && make modules_preapre'.
A problem is that 'make modules' creates Module.symvers even without
vmlinux. In this case, that warning is suppressed since Module.symvers
already exists in spite of its incomplete content.
The incomplete (i.e. invalid) Module.symvers should not be created.
This commit changes the second pass of modpost to dump symbols into
modules-only.symvers. The final Module.symvers is created by
concatenating vmlinux.symvers and modules-only.symvers if both exist.
Module.symvers is supposed to collect symbols from both vmlinux and
modules. It might be a bit confusing, and I am not quite sure if it
is an official interface, but presumably it is difficult to rename it
because some tools (e.g. kmod) parse it.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Mention why we open-code strsep, so it is clear that it is intentional.
Fixes: 736bb11898 ("modpost: remove use of non-standard strsep() in HOSTCC code")
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
strsep() is neither standard C nor POSIX and used outside
the kernel code here. Using it here requires that the
build host supports it out of the box which is e.g.
not true for a Darwin build host and using a cross-compiler.
This leads to:
scripts/mod/modpost.c:145:2: warning: implicit declaration of function 'strsep' [-Wimplicit-function-declaration]
return strsep(stringp, "\n");
^
and a segfault when running MODPOST.
See also: https://stackoverflow.com/a/7219504
So let's replace this by strchr() instead of using strsep().
It does not hurt kernel size or speed since this code is run
on the build host.
Fixes: ac5100f543 ("modpost: add read_text_file() and get_line() helpers")
Co-developed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull Kbuild updates from Masahiro Yamada:
- fix warnings in 'make clean' for ARCH=um, hexagon, h8300, unicore32
- ensure to rebuild all objects when the compiler is upgraded
- exclude system headers from dependency tracking and fixdep processing
- fix potential bit-size mismatch between the kernel and BPF user-mode
helper
- add the new syntax 'userprogs' to build user-space programs for the
target architecture (the same arch as the kernel)
- compile user-space sample code under samples/ for the target arch
instead of the host arch
- make headers_install fail if a CONFIG option is leaked to user-space
- sanitize the output format of scripts/checkstack.pl
- handle ARM 'push' instruction in scripts/checkstack.pl
- error out before modpost if a module name conflict is found
- error out when multiple directories are passed to M= because this
feature is broken for a long time
- add CONFIG_DEBUG_INFO_COMPRESSED to support compressed debug info
- a lot of cleanups of modpost
- dump vmlinux symbols out into vmlinux.symvers, and reuse it in the
second pass of modpost
- do not run the second pass of modpost if nothing in modules is
updated
- install modules.builtin(.modinfo) by 'make install' as well as by
'make modules_install' because it is useful even when
CONFIG_MODULES=n
- add new command line variables, GZIP, BZIP2, LZOP, LZMA, LZ4, and XZ
to allow users to use alternatives such as pigz, pbzip2, etc.
* tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (96 commits)
kbuild: add variables for compression tools
Makefile: install modules.builtin even if CONFIG_MODULES=n
mksysmap: Fix the mismatch of '.L' symbols in System.map
kbuild: doc: rename LDFLAGS to KBUILD_LDFLAGS
modpost: change elf_info->size to size_t
modpost: remove is_vmlinux() helper
modpost: strip .o from modname before calling new_module()
modpost: set have_vmlinux in new_module()
modpost: remove mod->skip struct member
modpost: add mod->is_vmlinux struct member
modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}()
modpost: remove mod->is_dot_o struct member
modpost: move -d option in scripts/Makefile.modpost
modpost: remove -s option
modpost: remove get_next_text() and make {grab,release_}file static
modpost: use read_text_file() and get_line() for reading text files
modpost: avoid false-positive file open error
modpost: fix potential mmap'ed file overrun in get_src_version()
modpost: add read_text_file() and get_line() helpers
modpost: do not call get_modinfo() for vmlinux(.o)
...
Now that is_vmlinux() is called only in new_module(), we can inline
the function call.
modname is the basename with '.o' is stripped. No need to compare it
with 'vmlinux.o'.
vmlinux is always located at the current working directory. No need
to strip the directory path.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
new_module() conditionally strips the .o because the modname has .o
suffix when it is called from read_symbols(), but no .o when it is
called from read_dump().
It is clearer to strip .o in read_symbols().
I also used flexible-array for mod->name.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The meaning of 'skip' is obscure since it does not explain
"what to skip".
mod->skip is set when it is vmlinux or the module info came from
a dump file.
So, mod->skip is equivalent to (mod->is_vmlinux || mod->from_dump).
For the check in write_namespace_deps_files(), mod->is_vmlinux is
unneeded because the -d option is not passed in the first pass of
modpost.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
is_vmlinux() is called in several places to check whether the current
module is vmlinux or not.
It is faster and clearer to check mod->is_vmlinux flag.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
check_exports() is never called for vmlinux because mod->skip is set
for vmlinux.
Hence, check_for_gpl_usage() and check_for_unused() are not called
for vmlinux, either. is_vmlinux() is always false here.
Remove the is_vmlinux() calls, and hard-code the ".ko" suffix.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Previously, there were two cases where mod->is_dot_o is unset:
[1] the executable 'vmlinux' in the second pass of modpost
[2] modules loaded by read_dump()
I think [1] was intended usage to distinguish 'vmlinux.o' and 'vmlinux'.
Now that modpost does not parse the executable 'vmlinux', this case
does not happen.
[2] is obscure, maybe a bug. Module.symver stores module paths without
extension. So, none of modules loaded by read_dump() has the .o suffix,
and new_module() unsets ->is_dot_o. Anyway, it is not a big deal because
handle_symbol() is not called for the case.
To sum up, all the parsed ELF files are .o files.
mod->is_dot_o is unneeded.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The -s option was added by commit 8d8d8289df ("kbuild: do not do
section mismatch checks on vmlinux in 2nd pass").
Now that the second pass does not parse vmlinux, this option is
unneeded.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
get_next_line() is no longer used. Remove.
grab_file() and release_file() are only used in modpost.c. Make them
static.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
grab_file() mmaps a file, but it is not so efficient here because
get_next_line() copies every line to the temporary buffer anyway.
read_text_file() and get_line() are simpler. get_line() exploits the
library function strchr().
Going forward, the missing *.symvers or *.cmd is a fatal error.
This should not happen because scripts/Makefile.modpost guards the
-i option files with $(wildcard $(input-symdump)).
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
modpost uses grab_file() to open a file, but it is not suitable for
a text file because the mmap'ed file is not terminated by null byte.
Actually, I see some issues for the use of grab_file().
The new helper, read_text_file() loads the whole file content into a
malloc'ed buffer, and appends a null byte. Then, get_line() reads
each line.
To handle text files, I intend to replace as follows:
grab_file() -> read_text_file()
get_new_line() -> get_line()
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The three calls of get_modinfo() ("license", "import_ns", "version")
always return NULL for vmlinux(.o) because the built-in module info is
prefixed with __MODULE_INFO_PREFIX.
It is harmless to call get_modinfo(), but there is no point to search
for what apparently does not exist.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
As far as I understood, this code gets rid of '$Revision$' or '$Revision:'
of CVS, RCS or whatever in MODULE_VERSION() tags.
Remove the primeval code.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
check_exports() does not print warnings about unresolved symbols if
vmlinux is missing because there would be too many.
This situation happens when you do 'make modules' from the clean
tree, or compile external modules against a kernel tree that has
not been completely built.
It is dangerous to not check unresolved symbols because you might be
building useless modules. At least it should be warned.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Currently, the second pass of modpost is always invoked when you run
'make' or 'make modules' even if none of modules is changed.
Use if_changed to invoke it only when it is necessary.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Previously, the -i option had two functions; load a symbol dump file,
and set the external_module flag.
I want to assign a dedicate option for each of them.
Going forward, the -i is used to load a symbol dump file, and the -e
to set the external_module flag.
With this, we will be able to use -i for loading in-kernel symbols.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The -i option is used to include Modules.symver as well as files from
$(KBUILD_EXTRA_SYMBOLS).
Make the struct and variable names more generic.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Now that there is no difference between -i and -e, they can be unified.
Make modpost accept the -i option multiple times, then remove -e.
I will reuse -e for a different purpose.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The meaning of sym->kernel is obscure; it is set for in-kernel symbols
loaded from Modules.symvers. This happens only when we are building
external modules, and it is used to determine whether to dump symbols
to $(KBUILD_EXTMOD)/Modules.symvers
It is clearer to remember whether the symbol or module came from a dump
file or ELF object.
This changes the KBUILD_EXTRA_SYMBOLS behavior. Previously, symbols
loaded from KBUILD_EXTRA_SYMBOLS are accumulated into the current
$(KBUILD_EXTMOD)/Modules.symvers
Going forward, they will be only used to check symbol references, but
not dumped into the current $(KBUILD_EXTMOD)/Modules.symvers. I believe
this makes more sense.
sym->vmlinux will have no user. Remove it too.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
