The previous commit removed the subshell execution from scripts/mksysmap,
which is now simple enough to become a sed script.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Since commit 951bcae6c5 ("kallsyms: Avoid weak references for kallsyms
symbols"), the kallsyms step 3 always occurs.
You can compare the build logs.
[Before 951bcae6c5]
$ git checkout 951bcae6c5a0^
$ make defconfig all
[ snip ]
LD .tmp_vmlinux.kallsyms1
NM .tmp_vmlinux.kallsyms1.syms
KSYMS .tmp_vmlinux.kallsyms1.S
AS .tmp_vmlinux.kallsyms1.S
LD .tmp_vmlinux.kallsyms2
NM .tmp_vmlinux.kallsyms2.syms
KSYMS .tmp_vmlinux.kallsyms2.S
AS .tmp_vmlinux.kallsyms2.S
LD vmlinux
[After 951bcae6c5]
$ git checkout 951bcae6c5
$ make defconfig all
[ snip ]
LD .tmp_vmlinux.kallsyms1
NM .tmp_vmlinux.kallsyms1.syms
KSYMS .tmp_vmlinux.kallsyms1.S
AS .tmp_vmlinux.kallsyms1.S
LD .tmp_vmlinux.kallsyms2
NM .tmp_vmlinux.kallsyms2.syms
KSYMS .tmp_vmlinux.kallsyms2.S
AS .tmp_vmlinux.kallsyms2.S
LD .tmp_vmlinux.kallsyms3 # should not happen
NM .tmp_vmlinux.kallsyms3.syms # should not happen
KSYMS .tmp_vmlinux.kallsyms3.S # should not happen
AS .tmp_vmlinux.kallsyms3.S # should not happen
LD vmlinux
The resulting vmlinux is correct, but it always requires an additional
linking step.
The symbols produced by kallsyms are excluded from kallsyms itself
because they were previously missing in step 1. With those symbols
excluded, the symbol lists matched between step 1 and step 2,
eliminating the need for step 3. Now, this has a negative effect.
Since 951bcae6c5, the PROVIDE() directives provide the fallback
definitions, which are not trimmed from the sysbol list in step 1
because ${kallsymso_prev} is empty at this point.
In step 2, ${kallsymso_prev} is set, and the kallsyms_* symbols are
trimmed from the symbol list.
Due to the table size difference between step 1 and step 2 (the former
is larger due to the presence of kallsyms_*), step 3 is triggered.
Now that the kallsyms_* symbols are always linked, let's stop omitting
them from kallsyms. This avoids unnecessary step 3.
Fixes: 951bcae6c5 ("kallsyms: Avoid weak references for kallsyms symbols")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
lld is now able to build ARMv4 and ARMv4T kernels, which means it can
generate thunks for those (__ARMv4PILongThunk_*, __ARMv4PILongBXThunk_*)
that can interfere with kallsyms table generation since they do not get
ignore like the corresponding ARMv5+ ones are:
Inconsistent kallsyms data
Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
Replace the hardcoded list of thunk symbols with a more general regex that
covers this one along with future symbols that follow the same pattern.
Fixes: 5eb6e28043 ("ARM: 9289/1: Allow pre-ARMv5 builds with ld.lld 16.0.0 and newer")
Fixes: efe6e30680 ("kallsyms: fix nonconverging kallsyms table with lld")
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The (relatively) new KCFI feature in LLVM/Clang encodes type information
for C functions by generating symbols named __kcfi_typeid_<fname>, which
can then be referenced from assembly. However, some custom build rules
(e.g. nVHE or early PIE on arm64) use objcopy to add a prefix to all the
symbols in their object files, making mksysmap's ignore filter miss
those KCFI symbols.
Therefore, explicitly list those twice-prefixed KCFI symbols as ignored.
Alternatively, this could also be achieved in a less verbose way by
ignoring any symbol containing the string "__kcfi_typeid_". However,
listing the combined prefixes explicitly saves us from running the small
risk of ignoring symbols that should be kept.
Signed-off-by: Pierre-Clément Tosi <ptosi@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Similarly to "__kvm_nvhe_", filter out any local symbol that was
prefixed with "__pi_" (generated when CONFIG_RANDOMIZE_BASE=y) when
compiling System.map and in kallsyms.
Signed-off-by: Pierre-Clément Tosi <ptosi@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The backslash characters escaping '$' in the command to sed (intended to
prevent it from interpreting '$' as "end-of-line") are currently being
consumed by the Shell (where they mean that sh should not evaluate what
follows '$' as a variable name). This means that
sed -e "/ \$/d"
executes the script
/ $/d
instead of the intended
/ \$/d
So escape twice in mksysmap any '$' that actually needs to reach sed
escaped so that the backslash survives the Shell.
Fixes: c4802044a0 ("scripts/mksysmap: use sed with in-line comments")
Fixes: 320e7c9d44 ("scripts/kallsyms: move compiler-generated symbol patterns to mksysmap")
Signed-off-by: Pierre-Clément Tosi <ptosi@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
scripts/kallsyms.c maintains compiler-generated symbols, but we end up
with something similar in scripts/mksysmap to avoid the "Inconsistent
kallsyms data" error. For example, commit c17a253870 ("mksysmap: Fix
the mismatch of 'L0' symbols in System.map").
They were separately maintained prior to commit 94ff2f63d6 ("kbuild:
reuse mksysmap output for kallsyms").
Now that scripts/kallsyms.c parses the output of scripts/mksysmap,
it makes more sense to collect all the ignored patterns to mksysmap.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Drop the symbols generated by scripts/kallsyms itself automatically
instead of maintaining the symbol list manually.
Pass the kallsyms object from the previous kallsyms step (if it exists)
as the third parameter of scripts/mksysmap, which will weed out the
generated symbols from the input to the next kallsyms step.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
It is not feasible to insert comments in a multi-line shell command.
Use sed, and move comments close to the code.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Every EXPORT_SYMBOL creates __kstrtab_* and __kstrtabns_*, which
consumes 15-20% of the kallsyms entries.
For example, on the system built from the x86_64 defconfig,
$ cat /proc/kallsyms | wc
129527 388581 5685465
$ cat /proc/kallsyms | grep __kstrtab | wc
23489 70467 1187932
We already ignore __crc_* symbols populated by EXPORT_SYMBOL, so it
should be fine to ignore __kstrtab_* and __kstrtabns_* as well.
This makes vmlinux a bit smaller.
$ size vmlinux.before vmlinux.after
text data bss dec hex filename
22785374 8559694 1413328 32758396 1f3da7c vmlinux.before
22785374 8137806 1413328 32336508 1ed6a7c vmlinux.after
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Now that kallsyms.c parses the output from mksysmap, some symbols have
already been dropped.
Move comments to scripts/mksysmap. Also, make the grep command readable.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Since commit 7b4537199a ("kbuild: link symbol CRCs at final link,
removing CONFIG_MODULE_REL_CRCS"), __crc_* symbols never become
absolute.
Keep ignoring __crc_*, but update the comment.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
When System.map was generated, the kernel used mksysmap to filter the
kernel symbols, we need to filter "L0" symbols in LoongArch architecture.
$ cat System.map | grep L0
9000000000221540 t L0
The L0 symbol exists in System.map, but not in .tmp_System.map. When
"cmp -s System.map .tmp_System.map" will show "Inconsistent kallsyms
data" error message in link-vmlinux.sh script.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
When System.map was generated, the kernel used mksysmap to
filter the kernel symbols, but all the symbols with the
second letter 'L' in the kernel were filtered out, not just
the symbols starting with 'dot + L'.
For example:
ashimida@ubuntu:~/linux$ cat System.map |grep ' .L'
ashimida@ubuntu:~/linux$ nm -n vmlinux |grep ' .L'
ffff0000088028e0 t bLength_show
......
ffff0000092e0408 b PLLP_OUTC_lock
ffff0000092e0410 b PLLP_OUTA_lock
The original intent should be to filter out all local symbols
starting with '.L', so the dot should be escaped.
Fixes: 00902e9847 ("mksysmap: Add h8300 local symbol pattern")
Signed-off-by: ashimida <ashimida@linux.alibaba.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
h8300's nm output have a lot of local symbols.
ex)
00000000 N .Lframe0
00000013 N .LLST1
00000026 N .LLST2
00000039 N .LLST3
0000004c N .LLST4
Added new pattern " .L" to filter rule.
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
The Makefiles call the respective interpreter explicitly, but this makes
it easier to use the scripts manually.
Signed-off-by: Michal Marek <mmarek@suse.cz>
This reverts commit ad7a953c52.
And commit: ("allow stripping of generated symbols under CONFIG_KALLSYMS_ALL")
9bb482476c
These stripping patches has caused a set of issues:
1) People have reported compatibility issues with binutils due to
lack of support for `--strip-unneeded-symbols' with objcopy 2.15.92.0.2
Reported by: Wenji
2) ccache and distcc no longer works as expeced
Reported by: Ted, Roland, + others
3) The installed modules increased a lot in size
Reported by: Ted, Davej + others
Reported-by: Wenji Huang <wenji.huang@oracle.com>
Reported-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: Dave Jones <davej@redhat.com>
Reported-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
This patch changes the way __crc_ symbols are being resolved from
using ld to do so to using the assembler, thus allowing these symbols
to be marked local (the linker creates then as global ones) and hence
allow stripping (for modules) or ignoring (for vmlinux) them. While at
this, also strip other generated symbols during module installation.
One potentially debatable point is the handling of the flags passeed
to gcc when translating the intermediate assembly file into an object:
passing $(c_flags) unchanged doesn't work as gcc passes --gdwarf2 to
gas whenever is sees any -g* option, even for -g0, and despite the
fact that the compiler would have already produced all necessary debug
info in the C->assembly translation phase. I took the approach of just
filtering out all -g* options, but an alternative to such negative
filtering might be to have a positive filter which might, in the ideal
case allow just all the -Wa,* options to pass through.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Andi Kleen <andi@firstfloor.org>
reported that he saw a lot of symbols like this:
0000000000000b24 N DW.aio.h.903a6d92.2
0000000000000bce N DW.task_io_accounting.h.8d8de327.0
0000000000000bec N DW.hrtimer.h.c23659c6.0
in his System.map / kallsyms output.
Simple solution is to skip all debugging
symbols (they are marked 'N').
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Paulo Marques <pmarques@grupopie.com>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
