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2021-06-17kbuild: modpost: Explicitly warn about unprototyped symbolsMark Brown
One common cause of modpost version generation failures is a failure to prototype exported assembly functions - the tooling requires this for exported functions even if they are not and should not be called from C code in order to do the version mangling for symbols. Unfortunately the error message is currently rather abstruse, simply saying that "version generation failed" and even diving into the code doesn't directly show what's going on since there's several steps between the problem and it being observed. Provide an explicit hint as to the likely cause of a version generation failure to help anyone who runs into this in future more readily diagnose and fix the problem. Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25kbuild: add an elfnote for whether vmlinux is built with ltoYonghong Song
Currently, clang LTO built vmlinux won't work with pahole. LTO introduced cross-cu dwarf tag references and broke current pahole model which handles one cu as a time. The solution is to merge all cu's as one pahole cu as in [1]. We would like to do this merging only if cross-cu dwarf references happens. The LTO build mode is a pretty good indication for that. In earlier version of this patch ([2]), clang flag -grecord-gcc-switches is proposed to add to compilation flags so pahole could detect "-flto" and then merging cu's. This will increate the binary size of 1% without LTO though. Arnaldo suggested to use a note to indicate the vmlinux is built with LTO. Such a cheap way to get whether the vmlinux is built with LTO or not helps pahole but is also useful for tracing as LTO may inline/delete/demote global functions, promote static functions, etc. So this patch added an elfnote with a new type LINUX_ELFNOTE_LTO_INFO. The owner of the note is "Linux". With gcc 8.4.1 and clang trunk, without LTO, I got $ readelf -n vmlinux Displaying notes found in: .notes Owner Data size Description ... Linux 0x00000004 func description data: 00 00 00 00 ... With "readelf -x ".notes" vmlinux", I can verify the above "func" with type code 0x101. With clang thin-LTO, I got the same as above except the following: description data: 01 00 00 00 which indicates the vmlinux is built with LTO. [1] https://lore.kernel.org/bpf/20210325065316.3121287-1-yhs@fb.com/ [2] https://lore.kernel.org/bpf/20210331001623.2778934-1-yhs@fb.com/ Suggested-by: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com> Signed-off-by: Yonghong Song <yhs@fb.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v12.0.0-rc4 (x86-64) Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25scripts: modpost.c: Fix a few typosBhaskar Chowdhury
s/agorithm/algorithm/ s/criterias/criteria/ s/targetting/targeting/ ....two different places. Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25kbuild: fix false-positive modpost warning when all symbols are trimmedMasahiro Yamada
Nathan reports that the mips defconfig emits the following warning: WARNING: modpost: Symbol info of vmlinux is missing. Unresolved symbol check will be entirely skipped. This false-positive happens when CONFIG_TRIM_UNUSED_KSYMS is enabled, but no CONFIG option is set to 'm'. Commit a0590473c5e6 ("nfs: fix PNFS_FLEXFILE_LAYOUT Kconfig default") turned the last 'm' into 'y' for the mips defconfig, and uncovered this issue. In this case, the module feature itself is enabled, but we have no module to build. As a result, CONFIG_TRIM_UNUSED_KSYMS drops all the instances of EXPORT_SYMBOL. Then, modpost wrongly assumes vmlinux is missing because vmlinux.symvers is empty. (As another false-positive case, you can create a module that does not use any symbol of vmlinux). The current behavior is to entirely suppress the unresolved symbol warnings when vmlinux is missing just because there are too many. I found the origin of this code in the historical git tree. [1] If this is a matter of noisiness, I think modpost can display the first 10 warnings, and the number of suppressed warnings at the end. You will get a bit noisier logs when you run 'make modules' without vmlinux, but such warnings are better to show because you never know the resulting modules are actually loadable or not. This commit changes the following: - If any of input *.symver files is missing, pass -w option to let the module build keep going with warnings instead of errors. - If there are too many (10+) unresolved symbol warnings, show only the first 10, and also the number of suppressed warnings. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=1cc0e0529569bf6a94f6d49770aa6d4b599d2c46 Reported-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25kbuild: generate Module.symvers only when vmlinux existsMasahiro Yamada
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>
2021-02-23Merge tag 'modules-for-v5.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux Pull module updates from Jessica Yu: - Retire EXPORT_UNUSED_SYMBOL() and EXPORT_SYMBOL_GPL_FUTURE(). These export types were introduced between 2006 - 2008. All the of the unused symbols have been long removed and gpl future symbols were converted to gpl quite a long time ago, and I don't believe these export types have been used ever since. So, I think it should be safe to retire those export types now (Christoph Hellwig) - Refactor and clean up some aged code cruft in the module loader (Christoph Hellwig) - Build {,module_}kallsyms_on_each_symbol only when livepatching is enabled, as it is the only caller (Christoph Hellwig) - Unexport find_module() and module_mutex and fix the last module callers to not rely on these anymore. Make module_mutex internal to the module loader (Christoph Hellwig) - Harden ELF checks on module load and validate ELF structures before checking the module signature (Frank van der Linden) - Fix undefined symbol warning for clang (Fangrui Song) - Fix smatch warning (Dan Carpenter) * tag 'modules-for-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: module: potential uninitialized return in module_kallsyms_on_each_symbol() module: remove EXPORT_UNUSED_SYMBOL* module: remove EXPORT_SYMBOL_GPL_FUTURE module: move struct symsearch to module.c module: pass struct find_symbol_args to find_symbol module: merge each_symbol_section into find_symbol module: remove each_symbol_in_section module: mark module_mutex static kallsyms: only build {,module_}kallsyms_on_each_symbol when required kallsyms: refactor {,module_}kallsyms_on_each_symbol module: use RCU to synchronize find_module module: unexport find_module and module_mutex drm: remove drm_fb_helper_modinit powerpc/powernv: remove get_cxl_module module: harden ELF info handling module: Ignore _GLOBAL_OFFSET_TABLE_ when warning for undefined symbols
2021-02-08module: remove EXPORT_UNUSED_SYMBOL*Christoph Hellwig
EXPORT_UNUSED_SYMBOL* is not actually used anywhere. Remove the unused functionality as we generally just remove unused code anyway. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2021-02-08module: remove EXPORT_SYMBOL_GPL_FUTUREChristoph Hellwig
As far as I can tell this has never been used at all, and certainly not any time recently. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2021-01-14modpost: lto: strip .lto from module namesSami Tolvanen
With LTO, everything is compiled into LLVM bitcode, so we have to link each module into native code before modpost. Kbuild uses the .lto.o suffix for these files, which also ends up in module information. This change strips the unnecessary .lto suffix from the module name. Suggested-by: Bill Wendling <morbo@google.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201211184633.3213045-11-samitolvanen@google.com
2020-12-21modpost: turn static exports into errorQuentin Perret
Using EXPORT_SYMBOL*() on static functions is fundamentally wrong. Modpost currently reports that as a warning, but clearly this is not a pattern we should allow, and all in-tree occurences should have been fixed by now. So, promote the warn() message to error() to make sure this never happens again. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Matthias Maennich <maennich@google.com> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-21modpost: turn section mismatches to error from fatal()Masahiro Yamada
There is code that reports static EXPORT_SYMBOL a few lines below. It is not a good idea to bail out here. I renamed sec_mismatch_fatal to sec_mismatch_warn_only (with logical inversion) to match to CONFIG_SECTION_MISMATCH_WARN_ONLY. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-21modpost: change license incompatibility to error() from fatal()Masahiro Yamada
Change fatal() to error() to continue running to report more possible issues. There is no difference in the fact that modpost will fail anyway. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-21modpost: turn missing MODULE_LICENSE() into errorMasahiro Yamada
Do not create modules with no license tag. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-21modpost: refactor error handling and clarify error/fatal differenceMasahiro Yamada
We have 3 log functions. fatal() is special because it lets modpost bail out immediately. The difference between warn() and error() is the only prefix parts ("WARNING:" vs "ERROR:"). In my understanding, the expected handling of error() is to propagate the return code of the function to the exit code of modpost, as check_exports() etc. already does. This is a good manner in general because we should display as many error messages as possible in a single run of modpost. What is annoying about fatal() is that it kills modpost at the first error. People would need to run Kbuild again and again until they fix all errors. But, unfortunately, people tend to do: "This case should not be allowed. Let's replace warn() with fatal()." One of the reasons is probably it is tedious to manually hoist the error code to the main() function. This commit refactors error() so any single call for it automatically makes modpost return the error code. I also added comments in modpost.h for warn(), error(), and fatal(). Please use fatal() only when you have a strong reason to do so. For example: - Memory shortage (i.e. malloc() etc. has failed) - The ELF file is broken, and there is no point to continue parsing - Something really odd has happened For general coding errors, please use error(). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Quentin Perret <qperret@google.com>
2020-12-21modpost: rename merror() to error()Masahiro Yamada
The log function names, warn(), merror(), fatal() are inconsistent. Commit 2a11665945d5 ("kbuild: distinguish between errors and warnings in modpost") intentionally chose merror() to avoid the conflict with the library function error(). See man page of error(3). But, we are already causing the conflict with warn() because it is also a library function. See man page of warn(3). err() would be a problem for the same reason. The common technique to work around name conflicts is to use macros. For example: /* in a header */ #define error(fmt, ...) __error(fmt, ##__VA_ARGS__) #define warn(fmt, ...) __warn(fmt, ##__VA_ARGS__) /* function definition */ void __error(const char *fmt, ...) { <our implementation> } void __warn(const char *fmt, ...) { <our implementation> } In this way, we can implement our own warn() and error(), still we can include <error.h> and <err.h> with no problem. And, commit 93c95e526a4e ("modpost: rework and consolidate logging interface") already did that. Since the log functions are all macros, we can use error() without causing "conflicting types" errors. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-10-25treewide: Convert macro and uses of __section(foo) to __section("foo")Joe Perches
Use a more generic form for __section that requires quotes to avoid complications with clang and gcc differences. Remove the quote operator # from compiler_attributes.h __section macro. Convert all unquoted __section(foo) uses to quoted __section("foo"). Also convert __attribute__((section("foo"))) uses to __section("foo") even if the __attribute__ has multiple list entry forms. Conversion done using the script at: https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-27modpost: explain why we can't use strsepWolfram Sang
Mention why we open-code strsep, so it is clear that it is intentional. Fixes: 736bb11898ef ("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>
2020-07-07modpost: remove use of non-standard strsep() in HOSTCC codeH. Nikolaus Schaller
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: ac5100f5432967 ("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>
2020-06-06Merge tag 'kbuild-v5.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild 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) ...
2020-06-06modpost: change elf_info->size to size_tMasahiro Yamada
Align with the mmap / munmap APIs. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: remove is_vmlinux() helperMasahiro Yamada
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>
2020-06-06modpost: strip .o from modname before calling new_module()Masahiro Yamada
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>
2020-06-06modpost: set have_vmlinux in new_module()Masahiro Yamada
Set have_vmlinux flag in a single place. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: remove mod->skip struct memberMasahiro Yamada
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>
2020-06-06modpost: add mod->is_vmlinux struct memberMasahiro Yamada
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>
2020-06-06modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}()Masahiro Yamada
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>
2020-06-06modpost: remove mod->is_dot_o struct memberMasahiro Yamada
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>
2020-06-06modpost: remove -s optionMasahiro Yamada
The -s option was added by commit 8d8d8289df65 ("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>
2020-06-06modpost: remove get_next_text() and make {grab,release_}file staticMasahiro Yamada
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>
2020-06-06modpost: use read_text_file() and get_line() for reading text filesMasahiro Yamada
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>
2020-06-06modpost: add read_text_file() and get_line() helpersMasahiro Yamada
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>
2020-06-06modpost: do not call get_modinfo() for vmlinux(.o)Masahiro Yamada
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>
2020-06-06modpost: drop RCS/CVS $Revision handling in MODULE_VERSION()Masahiro Yamada
As far as I understood, this code gets rid of '$Revision$' or '$Revision:' of CVS, RCS or whatever in MODULE_VERSION() tags. Remove the primeval code. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: show warning if vmlinux is not found when processing modulesMasahiro Yamada
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>
2020-06-06modpost: invoke modpost only when input files are updatedMasahiro Yamada
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>
2020-06-06modpost: re-add -e to set external_module flagMasahiro Yamada
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>
2020-06-06modpost: rename ext_sym_list to dump_listMasahiro Yamada
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>
2020-06-06modpost: allow to pass -i option multiple times to remove -e optionMasahiro Yamada
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>
2020-06-06modpost: track if the symbol origin is a dump file or ELF objectMasahiro Yamada
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>
2020-06-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds
Pull networking updates from David Miller: 1) Allow setting bluetooth L2CAP modes via socket option, from Luiz Augusto von Dentz. 2) Add GSO partial support to igc, from Sasha Neftin. 3) Several cleanups and improvements to r8169 from Heiner Kallweit. 4) Add IF_OPER_TESTING link state and use it when ethtool triggers a device self-test. From Andrew Lunn. 5) Start moving away from custom driver versions, use the globally defined kernel version instead, from Leon Romanovsky. 6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin. 7) Allow hard IRQ deferral during NAPI, from Eric Dumazet. 8) Add sriov and vf support to hinic, from Luo bin. 9) Support Media Redundancy Protocol (MRP) in the bridging code, from Horatiu Vultur. 10) Support netmap in the nft_nat code, from Pablo Neira Ayuso. 11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina Dubroca. Also add ipv6 support for espintcp. 12) Lots of ReST conversions of the networking documentation, from Mauro Carvalho Chehab. 13) Support configuration of ethtool rxnfc flows in bcmgenet driver, from Doug Berger. 14) Allow to dump cgroup id and filter by it in inet_diag code, from Dmitry Yakunin. 15) Add infrastructure to export netlink attribute policies to userspace, from Johannes Berg. 16) Several optimizations to sch_fq scheduler, from Eric Dumazet. 17) Fallback to the default qdisc if qdisc init fails because otherwise a packet scheduler init failure will make a device inoperative. From Jesper Dangaard Brouer. 18) Several RISCV bpf jit optimizations, from Luke Nelson. 19) Correct the return type of the ->ndo_start_xmit() method in several drivers, it's netdev_tx_t but many drivers were using 'int'. From Yunjian Wang. 20) Add an ethtool interface for PHY master/slave config, from Oleksij Rempel. 21) Add BPF iterators, from Yonghang Song. 22) Add cable test infrastructure, including ethool interfaces, from Andrew Lunn. Marvell PHY driver is the first to support this facility. 23) Remove zero-length arrays all over, from Gustavo A. R. Silva. 24) Calculate and maintain an explicit frame size in XDP, from Jesper Dangaard Brouer. 25) Add CAP_BPF, from Alexei Starovoitov. 26) Support terse dumps in the packet scheduler, from Vlad Buslov. 27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei. 28) Add devm_register_netdev(), from Bartosz Golaszewski. 29) Minimize qdisc resets, from Cong Wang. 30) Get rid of kernel_getsockopt and kernel_setsockopt in order to eliminate set_fs/get_fs calls. From Christoph Hellwig. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits) selftests: net: ip_defrag: ignore EPERM net_failover: fixed rollback in net_failover_open() Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv" Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv" vmxnet3: allow rx flow hash ops only when rss is enabled hinic: add set_channels ethtool_ops support selftests/bpf: Add a default $(CXX) value tools/bpf: Don't use $(COMPILE.c) bpf, selftests: Use bpf_probe_read_kernel s390/bpf: Use bcr 0,%0 as tail call nop filler s390/bpf: Maintain 8-byte stack alignment selftests/bpf: Fix verifier test selftests/bpf: Fix sample_cnt shared between two threads bpf, selftests: Adapt cls_redirect to call csum_level helper bpf: Add csum_level helper for fixing up csum levels bpf: Fix up bpf_skb_adjust_room helper's skb csum setting sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf() crypto/chtls: IPv6 support for inline TLS Crypto/chcr: Fixes a coccinile check error Crypto/chcr: Fixes compilations warnings ...
2020-06-03modpost: load KBUILD_EXTRA_SYMBOLS files in orderMasahiro Yamada
Currently, modpost reads extra symbol dump files in the reverse order. If '-e foo -e bar' is given, modpost reads bar, foo, in this order. This is probably not a big deal, but there is no good reason to reverse the order. Read files in the given order. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-29modpost: refactor sech_name()Masahiro Yamada
Use sym_get_data_by_offset() helper to get access to the .shstrtab section data. No functional change is intended because elf->sechdrs[elf->secindex_strings].sh_addr is 0 for both ET_REL and ET_EXEC object types. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-29modpost: fix potential segmentation fault for addend_i386_rel()Masahiro Yamada
This may not be a practical problem, but the second pass of ARCH=i386 modpost causes segmentation fault if the -s option is not passed. MODPOST 12 modules Segmentation fault (core dumped) make[2]: *** [scripts/Makefile.modpost:94: __modpost] Error 139 make[1]: *** [Makefile:1339: modules] Error 2 make[1]: *** Waiting for unfinished jobs.... The segmentation fault occurs when section_rel() is called for vmlinux, which is untested in regular builds. The cause of the problem is reloc_location() returning a wrong pointer for ET_EXEC object type. In this case, you need to subtract sechdr->sh_addr, otherwise it would get access beyond the mmap'ed memory. Add sym_get_data_by_offset() helper to avoid code duplication. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-26modpost,fixdep: Replace zero-length array with flexible-arrayGustavo A. R. Silva
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-19vmlinux.lds.h: Create section for protection against instrumentationThomas Gleixner
Some code pathes, especially the low level entry code, must be protected against instrumentation for various reasons: - Low level entry code can be a fragile beast, especially on x86. - With NO_HZ_FULL RCU state needs to be established before using it. Having a dedicated section for such code allows to validate with tooling that no unsafe functions are invoked. Add the .noinstr.text section and the noinstr attribute to mark functions. noinstr implies notrace. Kprobes will gain a section check later. Provide also a set of markers: instrumentation_begin()/end() These are used to mark code inside a noinstr function which calls into regular instrumentable text section as safe. The instrumentation markers are only active when CONFIG_DEBUG_ENTRY is enabled as the end marker emits a NOP to prevent the compiler from merging the annotation points. This means the objtool verification requires a kernel compiled with this option. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134100.075416272@linutronix.de
2020-04-21kernel/module: Hide vermagic header file from general useLeon Romanovsky
VERMAGIC* definitions are not supposed to be used by the drivers, see this [1] bug report, so introduce special define to guard inclusion of this header file and define it in kernel/modules.h and in internal script that generates *.mod.c files. In-tree module build: ➜ kernel git:(vermagic) ✗ make clean ➜ kernel git:(vermagic) ✗ make M=drivers/infiniband/hw/mlx5 ➜ kernel git:(vermagic) ✗ modinfo drivers/infiniband/hw/mlx5/mlx5_ib.ko filename: /images/leonro/src/kernel/drivers/infiniband/hw/mlx5/mlx5_ib.ko <...> vermagic: 5.6.0+ SMP mod_unload modversions Out-of-tree module build: ➜ mlx5 make -C /images/leonro/src/kernel clean M=/tmp/mlx5 ➜ mlx5 make -C /images/leonro/src/kernel M=/tmp/mlx5 ➜ mlx5 modinfo /tmp/mlx5/mlx5_ib.ko filename: /tmp/mlx5/mlx5_ib.ko <...> vermagic: 5.6.0+ SMP mod_unload modversions [1] https://lore.kernel.org/lkml/20200411155623.GA22175@zn.tnic Reported-by: Borislav Petkov <bp@suse.de> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Jessica Yu <jeyu@kernel.org> Co-developed-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-31Merge tag 'kbuild-v5.7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: "Build system: - add CONFIG_UNUSED_KSYMS_WHITELIST, which will be useful to define a fixed set of export symbols for Generic Kernel Image (GKI) - allow to run 'make dt_binding_check' without .config - use full schema for checking DT examples in *.yaml files - make modpost fail for missing MODULE_IMPORT_NS(), which makes more sense because we know the produced modules are never loadable - Remove unused 'AS' variable Kconfig: - sanitize DEFCONFIG_LIST, and remove ARCH_DEFCONFIG from Kconfig files - relax the 'imply' behavior so that symbols implied by 'y' can become 'm' - make 'imply' obey 'depends on' in order to make 'imply' really weak Misc: - add documentation on building the kernel with Clang/LLVM - revive __HAVE_ARCH_STRLEN for 32bit sparc to use optimized strlen() - fix warning from deb-pkg builds when CONFIG_DEBUG_INFO=n - various script and Makefile cleanups" * tag 'kbuild-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits) Makefile: Update kselftest help information kbuild: deb-pkg: fix warning when CONFIG_DEBUG_INFO is unset kbuild: add outputmakefile to no-dot-config-targets kbuild: remove AS variable net: wan: wanxl: refactor the firmware rebuild rule net: wan: wanxl: use $(M68KCC) instead of $(M68KAS) for rebuilding firmware net: wan: wanxl: use allow to pass CROSS_COMPILE_M68k for rebuilding firmware kbuild: add comment about grouped target kbuild: add -Wall to KBUILD_HOSTCXXFLAGS kconfig: remove unused variable in qconf.cc sparc: revive __HAVE_ARCH_STRLEN for 32bit sparc kbuild: refactor Makefile.dtbinst more kbuild: compute the dtbs_install destination more simply Makefile: disallow data races on gcc-10 as well kconfig: make 'imply' obey the direct dependency kconfig: allow symbols implied by y to become m net: drop_monitor: use IS_REACHABLE() to guard net_dm_hw_report() modpost: return error if module is missing ns imports and MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS=n modpost: rework and consolidate logging interface kbuild: allow to run dt_binding_check without kernel configuration ...
2020-03-30Merge tag 'timers-core-2020-03-30' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timekeeping and timer updates from Thomas Gleixner: "Core: - Consolidation of the vDSO build infrastructure to address the difficulties of cross-builds for ARM64 compat vDSO libraries by restricting the exposure of header content to the vDSO build. This is achieved by splitting out header content into separate headers. which contain only the minimaly required information which is necessary to build the vDSO. These new headers are included from the kernel headers and the vDSO specific files. - Enhancements to the generic vDSO library allowing more fine grained control over the compiled in code, further reducing architecture specific storage and preparing for adopting the generic library by PPC. - Cleanup and consolidation of the exit related code in posix CPU timers. - Small cleanups and enhancements here and there Drivers: - The obligatory new drivers: Ingenic JZ47xx and X1000 TCU support - Correct the clock rate of PIT64b global clock - setup_irq() cleanup - Preparation for PWM and suspend support for the TI DM timer - Expand the fttmr010 driver to support ast2600 systems - The usual small fixes, enhancements and cleanups all over the place" * tag 'timers-core-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (80 commits) Revert "clocksource/drivers/timer-probe: Avoid creating dead devices" vdso: Fix clocksource.h macro detection um: Fix header inclusion arm64: vdso32: Enable Clang Compilation lib/vdso: Enable common headers arm: vdso: Enable arm to use common headers x86/vdso: Enable x86 to use common headers mips: vdso: Enable mips to use common headers arm64: vdso32: Include common headers in the vdso library arm64: vdso: Include common headers in the vdso library arm64: Introduce asm/vdso/processor.h arm64: vdso32: Code clean up linux/elfnote.h: Replace elf.h with UAPI equivalent scripts: Fix the inclusion order in modpost common: Introduce processor.h linux/ktime.h: Extract common header for vDSO linux/jiffies.h: Extract common header for vDSO linux/time64.h: Extract common header for vDSO linux/time32.h: Extract common header for vDSO linux/time.h: Extract common header for vDSO ...
2020-03-21scripts: Fix the inclusion order in modpostVincenzo Frascino
In the process of creating the source file of a module modpost injects a set of includes that are not required if the compilation unit is statically built into the kernel. The order of inclusion of the headers can cause redefinition problems (e.g.): In file included from include/linux/elf.h:5:0, from include/linux/module.h:18, from crypto/arc4.mod.c:2: #define ELF_OSABI ELFOSABI_LINUX In file included from include/linux/elfnote.h:62:0, from include/linux/build-salt.h:4, from crypto/arc4.mod.c:1: include/uapi/linux/elf.h:363:0: note: this is the location of the previous definition #define ELF_OSABI ELFOSABI_NONE The issue was exposed during the development of the series [1]. [1] https://lore.kernel.org/lkml/20200306133242.26279-1-vincenzo.frascino@arm.com/ Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Michal Marek <michal.lkml@markovi.net> Link: https://lkml.kernel.org/r/20200320145351.32292-17-vincenzo.frascino@arm.com
2020-03-19modpost: Get proper section index by get_secindex() instead of st_shndxXiao Yang
(uint16_t) st_shndx is limited to 65535(i.e. SHN_XINDEX) so sym_get_data() gets wrong section index by st_shndx if requested symbol contains extended section index that is more than 65535. In this case, we need to get proper section index by .symtab_shndx section. Module.symvers generated by building kernel with "-ffunction-sections -fdata-sections" shows the issue. Fixes: 56067812d5b0 ("kbuild: modversions: add infrastructure for emitting relative CRCs") Fixes: e84f9fbbece1 ("modpost: refactor namespace_from_kstrtabns() to not hard-code section name") Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>