Similar as other architectures such as arm64, x86 and so on, use
offsets relative to the exception table entry values rather than
absolute addresses for both the exception locationand the fixup.
However, RISCV label difference will actually produce two relocations,
a pair of R_RISCV_ADD32 and R_RISCV_SUB32. Take below simple code for
example:
$ cat test.S
.section .text
1:
nop
.section __ex_table,"a"
.balign 4
.long (1b - .)
.previous
$ riscv64-linux-gnu-gcc -c test.S
$ riscv64-linux-gnu-readelf -r test.o
Relocation section '.rela__ex_table' at offset 0x100 contains 2 entries:
Offset Info Type Sym. Value Sym. Name + Addend
000000000000 000600000023 R_RISCV_ADD32 0000000000000000 .L1^B1 + 0
000000000000 000500000027 R_RISCV_SUB32 0000000000000000 .L0 + 0
The modpost will complain the R_RISCV_SUB32 relocation, so we need to
patch modpost.c to skip this relocation for .rela__ex_table section.
After this patch, the __ex_table section size of defconfig vmlinux is
reduced from 7072 Bytes to 3536 Bytes.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
- Add -s option (strict mode) to merge_config.sh to make it fail when
any symbol is redefined.
- Show a warning if a different compiler is used for building external
modules.
- Infer --target from ARCH for CC=clang to let you cross-compile the
kernel without CROSS_COMPILE.
- Make the integrated assembler default (LLVM_IAS=1) for CC=clang.
- Add <linux/stdarg.h> to the kernel source instead of borrowing
<stdarg.h> from the compiler.
- Add Nick Desaulniers as a Kbuild reviewer.
- Drop stale cc-option tests.
- Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
to handle symbols in inline assembly.
- Show a warning if 'FORCE' is missing for if_changed rules.
- Various cleanups
-----BEGIN PGP SIGNATURE-----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=lw3M
-----END PGP SIGNATURE-----
Merge tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Add -s option (strict mode) to merge_config.sh to make it fail when
any symbol is redefined.
- Show a warning if a different compiler is used for building external
modules.
- Infer --target from ARCH for CC=clang to let you cross-compile the
kernel without CROSS_COMPILE.
- Make the integrated assembler default (LLVM_IAS=1) for CC=clang.
- Add <linux/stdarg.h> to the kernel source instead of borrowing
<stdarg.h> from the compiler.
- Add Nick Desaulniers as a Kbuild reviewer.
- Drop stale cc-option tests.
- Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
to handle symbols in inline assembly.
- Show a warning if 'FORCE' is missing for if_changed rules.
- Various cleanups
* tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
kbuild: redo fake deps at include/ksym/*.h
kbuild: clean up objtool_args slightly
modpost: get the *.mod file path more simply
checkkconfigsymbols.py: Fix the '--ignore' option
kbuild: merge vmlinux_link() between ARCH=um and other architectures
kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh
kbuild: merge vmlinux_link() between the ordinary link and Clang LTO
kbuild: remove stale *.symversions
kbuild: remove unused quiet_cmd_update_lto_symversions
gen_compile_commands: extract compiler command from a series of commands
x86: remove cc-option-yn test for -mtune=
arc: replace cc-option-yn uses with cc-option
s390: replace cc-option-yn uses with cc-option
ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild
sparc: move the install rule to arch/sparc/Makefile
security: remove unneeded subdir-$(CONFIG_...)
kbuild: sh: remove unused install script
kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y
kbuild: Switch to 'f' variants of integrated assembler flag
kbuild: Shuffle blank line to improve comment meaning
...
get_src_version() strips 'o' or 'lto.o' from the end of the object file
path (so, postfixlen is 1 or 5), then adds 'mod'.
If you look at the code closely, mod->name already holds the base path
with the extension stripped.
Most of the code changes made by commit 7ac204b545 ("modpost: lto:
strip .lto from module names") was actually unneeded.
sumversion.c does not need strends(), so it can get back local in
modpost.c again.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Using asm goto in __WARN_FLAGS() and WARN_ON() allows more
flexibility to GCC.
For that add an entry to the exception table so that
program_check_exception() knowns where to resume execution
after a WARNING.
Here are two exemples. The first one is done on PPC32 (which
benefits from the previous patch), the second is on PPC64.
unsigned long test(struct pt_regs *regs)
{
int ret;
WARN_ON(regs->msr & MSR_PR);
return regs->gpr[3];
}
unsigned long test9w(unsigned long a, unsigned long b)
{
if (WARN_ON(!b))
return 0;
return a / b;
}
Before the patch:
000003a8 <test>:
3a8: 81 23 00 84 lwz r9,132(r3)
3ac: 71 29 40 00 andi. r9,r9,16384
3b0: 40 82 00 0c bne 3bc <test+0x14>
3b4: 80 63 00 0c lwz r3,12(r3)
3b8: 4e 80 00 20 blr
3bc: 0f e0 00 00 twui r0,0
3c0: 80 63 00 0c lwz r3,12(r3)
3c4: 4e 80 00 20 blr
0000000000000bf0 <.test9w>:
bf0: 7c 89 00 74 cntlzd r9,r4
bf4: 79 29 d1 82 rldicl r9,r9,58,6
bf8: 0b 09 00 00 tdnei r9,0
bfc: 2c 24 00 00 cmpdi r4,0
c00: 41 82 00 0c beq c0c <.test9w+0x1c>
c04: 7c 63 23 92 divdu r3,r3,r4
c08: 4e 80 00 20 blr
c0c: 38 60 00 00 li r3,0
c10: 4e 80 00 20 blr
After the patch:
000003a8 <test>:
3a8: 81 23 00 84 lwz r9,132(r3)
3ac: 71 29 40 00 andi. r9,r9,16384
3b0: 40 82 00 0c bne 3bc <test+0x14>
3b4: 80 63 00 0c lwz r3,12(r3)
3b8: 4e 80 00 20 blr
3bc: 0f e0 00 00 twui r0,0
0000000000000c50 <.test9w>:
c50: 7c 89 00 74 cntlzd r9,r4
c54: 79 29 d1 82 rldicl r9,r9,58,6
c58: 0b 09 00 00 tdnei r9,0
c5c: 7c 63 23 92 divdu r3,r3,r4
c60: 4e 80 00 20 blr
c70: 38 60 00 00 li r3,0
c74: 4e 80 00 20 blr
In the first exemple, we see GCC doesn't need to duplicate what
happens after the trap.
In the second exemple, we see that GCC doesn't need to emit a test
and a branch in the likely path in addition to the trap.
We've got some WARN_ON() in .softirqentry.text section so it needs
to be added in the OTHER_TEXT_SECTIONS in modpost.c
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/389962b1b702e3c78d169e59bcfac56282889173.1618331882.git.christophe.leroy@csgroup.eu
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>
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>
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 a0590473c5 ("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>
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>
Summary of modules changes for the 5.12 merge window:
- 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)
Signed-off-by: Jessica Yu <jeyu@kernel.org>
-----BEGIN PGP SIGNATURE-----
iQJEBAABCAAuFiEEVrp26glSWYuDNrCUwEV+OM47wXIFAmA0/KMQHGpleXVAa2Vy
bmVsLm9yZwAKCRDARX44zjvBcu0uD/4nmRp18EKAtdUZivsZHat0aEWGlkmrVueY
5huYw6iwM8b/wIAl3xwLki1Iv0/l0a83WXZhLG4ekl0/Nj8kgllA+jtBrZWpoLMH
CZusN5dS9YwwyD2vu3ak83ARcehcDEPeA9thvc3uRFGis6Hi4bt1rkzGdrzsgqR4
tybfN4qaQx4ZAKFxA8bnS58l7QTFwUzTxJfM6WWzl1Q+mLZDr/WP+loJ/f1/oFFg
ufN31KrqqFpdQY5UKq5P4H8FVq/eXE1Mwl8vo3HsnAj598fznyPUmA3D/j+N4GuR
sTGBVZ9CSehUj7uZRs+Qgg6Bd+y3o44N29BrdZWA6K3ieTeQQpA+VgPUNrDBjGhP
J/9Y4ms4PnuNEWWRaa73m9qsVqAsjh9+T2xp9PYn9uWLCM8BvQFtWcY7tw4/nB0/
INmyiP/tIRpwWkkBl47u1TPR09FzBBGDZjBiSn3lm3VX+zCYtHoma5jWyejG11cf
ybDrTsci9ANyHNP2zFQsUOQJkph78PIal0i3k4ODqGJvaC0iEIH3Xjv+0dmE14rq
kGRrG/HN6HhMZPjashudVUktyTZ63+PJpfFlQbcUzdvjQQIkzW0vrCHMWx9vD1xl
Na7vZLl4Nb03WSJp6saY6j2YSRKL0poGETzGqrsUAHEhpEOPHduaiCVlAr/EmeMk
p6SrWv8+UQ==
=T29Q
-----END PGP SIGNATURE-----
Merge tag 'modules-for-v5.12' of 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
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>
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>
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
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>
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>
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>
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>
The log function names, warn(), merror(), fatal() are inconsistent.
Commit 2a11665945 ("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 93c95e526a ("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>
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>
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>
- 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.
-----BEGIN PGP SIGNATURE-----
iQJJBAABCgAzFiEEbmPs18K1szRHjPqEPYsBB53g2wYFAl7brm0VHG1hc2FoaXJv
eUBrZXJuZWwub3JnAAoJED2LAQed4NsGjeEP/Rrf8H9cp/Tq+ALQCBycI3W5ZEHg
n2EqprZkVP2MlOV0d+8b9t4PdZf6E5Wmfv26sMaBAhl6X1KQI/0NgPMnTINvy5jJ
Q2SMhj9y8Gwr3XKFu9Hd/0U+Sax5rz+LmY84tdF95dXzPIUWjAEVnbmN+ofY6T++
sNf2YGNFSR6iiqr3uCYA0hHZmpKlfhVgDPAdncWa5aadSsuQb79nZQWefGeVEsuD
HrISpwnkhBc0qY1xyWry6agE92xWmkNkdjKq6A7peguZL02XySWLRWjyHoiiaPOB
6U4urKs/NSXqPgxGxwZthhwERHryC3+g4s8wRBDKE6ISRWKBBA2ruHpgdF5h/utu
re1ZP2qRcAt8NBFynr4MEb2AU0mYkv7iEgfLJ7NUCRlMOtqrn5RFwnS4r8ReyQp5
1UM11RbPhYgYjM5g9hBHJ7nK944/kfvy1/4jF4I1+M5O7QL6f00pu3r2bBIa/65g
DWrNOpIliKG27GgnRlxi7HgLfxs9etFcXTpHO0ymgnMmlz+7FQsdceR9qqybGU9o
yBWw6zculMQjb3E+k0DTnE5kLWsycbua921wxM9ABSxRmJi7WciNF73RdLUIBoAY
VUbwrP2aIpdL+2uyX6RqdTaWzEBpW8omszr46aQ96pX+RiqMrPvJRLaA/tr3ZH8g
tdHenJPWdHSaOcO4
=GKe5
-----END PGP SIGNATURE-----
Merge tag 'kbuild-v5.8' of 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)
...
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>
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
...
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>
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>
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>
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 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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
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>
Jisheng Zhang