I received a build failure for a new patch I'm working on the nds32
architecture, and when I went to test it, I couldn't get to my build error,
because it failed to build with a bunch of:
Error: invalid operands (*UND* and *UND* sections) for `^'
issues with various files. Those files were temporary asm files that looked
like: kernel/.tmp_mc_fork.s
I decided to look deeper, and found that the "mc" portion of that name
stood for "mcount", and was created by the recordmcount.pl script. One that
I wrote over a decade ago. Once I knew the source of the problem, I was
able to investigate it further.
The way the recordmcount.pl script works (BTW, there's a C version that
simply modifies the ELF object) is by doing an "objdump" on the object
file. Looks for all the calls to "mcount", and creates an offset of those
locations from some global variable it can use (usually a global function
name, found with <.*>:). Creates a asm file that is a table of references
to these locations, using the found variable/function. Compiles it and
links it back into the original object file. This asm file is called
".tmp_mc_<object_base_name>.s".
The problem here is that the objdump produced by the nds32 object file,
contains things that look like:
0000159a <.L3^B1>:
159a: c6 00 beqz38 $r6, 159a <.L3^B1>
159a: R_NDS32_9_PCREL_RELA .text+0x159e
159c: 84 d2 movi55 $r6, #-14
159e: 80 06 mov55 $r0, $r6
15a0: ec 3c addi10.sp #0x3c
Where ".L3^B1 is somehow selected as the "global" variable to index off of.
Then the assembly file that holds the mcount locations looks like this:
.section __mcount_loc,"a",@progbits
.align 2
.long .L3^B1 + -5522
.long .L3^B1 + -5384
.long .L3^B1 + -5270
.long .L3^B1 + -5098
.long .L3^B1 + -4970
.long .L3^B1 + -4758
.long .L3^B1 + -4122
[...]
And when it is compiled back to an object to link to the original object,
the compile fails on the "^" symbol.
Simple solution for now, is to have the perl script ignore using function
symbols that have an "^" in the name.
Link: https://lkml.kernel.org/r/20211014143507.4ad2c0f7@gandalf.local.home
Cc: stable@vger.kernel.org
Acked-by: Greentime Hu <green.hu@gmail.com>
Fixes: fbf58a52ac ("nds32/ftrace: Add RECORD_MCOUNT support")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When building ARCH=riscv allmodconfig with llvm-objcopy, the objcopy
version warning from this script appears:
WARNING: could not find objcopy version or version is less than 2.17.
Local function references are disabled.
The check_objcopy() function in scripts/recordmcount.pl is set up to
parse GNU objcopy's version string, not llvm-objcopy's, which triggers
the warning.
Commit 799c434154 ("kbuild: thin archives make default for all archs")
made binutils 2.20 mandatory and commit ba64beb174 ("kbuild: check the
minimum assembler version in Kconfig") enforces this at configuration
time so just remove check_objcopy() and $can_use_local instead, assuming
--globalize-symbol is always available.
llvm-objcopy has supported --globalize-symbol since LLVM 7.0.0 in 2018
and the minimum version for building the kernel with LLVM is 10.0.1 so
there is no issue introduced:
Link: ee5be798da
Link: https://lkml.kernel.org/r/20210802210307.3202472-1-nathan@kernel.org
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull more Kbuild updates from Masahiro Yamada:
- Convert sh and sparc to use generic shell scripts to generate the
syscall headers
- refactor .gitignore files
- Update kernel/config_data.gz only when the content of the .config
is really changed, which avoids the unneeded re-link of vmlinux
- move "remove stale files" workarounds to scripts/remove-stale-files
- suppress unused-but-set-variable warnings by default for Clang
as well
- fix locale setting LANG=C to LC_ALL=C
- improve 'make distclean'
- always keep intermediate objects from scripts/link-vmlinux.sh
- move IF_ENABLED out of <linux/kconfig.h> to make it self-contained
- misc cleanups
* tag 'kbuild-v5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits)
linux/kconfig.h: replace IF_ENABLED() with PTR_IF() in <linux/kernel.h>
kbuild: Don't remove link-vmlinux temporary files on exit/signal
kbuild: remove the unneeded comments for external module builds
kbuild: make distclean remove tag files in sub-directories
kbuild: make distclean work against $(objtree) instead of $(srctree)
kbuild: refactor modname-multi by using suffix-search
kbuild: refactor fdtoverlay rule
kbuild: parameterize the .o part of suffix-search
arch: use cross_compiling to check whether it is a cross build or not
kbuild: remove ARCH=sh64 support from top Makefile
.gitignore: prefix local generated files with a slash
kbuild: replace LANG=C with LC_ALL=C
Makefile: Move -Wno-unused-but-set-variable out of GCC only block
kbuild: add a script to remove stale generated files
kbuild: update config_data.gz only when the content of .config is changed
.gitignore: ignore only top-level modules.builtin
.gitignore: move tags and TAGS close to other tag files
kernel/.gitgnore: remove stale timeconst.h and hz.bc
usr/include: refactor .gitignore
genksyms: fix stale comment
...
Pull RISC-V updates from Palmer Dabbelt:
- Support for the memtest= kernel command-line argument.
- Support for building the kernel with FORTIFY_SOURCE.
- Support for generic clockevent broadcasts.
- Support for the buildtar build target.
- Some build system cleanups to pass more LLVM-friendly arguments.
- Support for kprobes.
- A rearranged kernel memory map, the first part of supporting sv48
systems.
- Improvements to kexec, along with support for kdump and crash
kernels.
- An alternatives-based errata framework, along with support for
handling a pair of errata that manifest on some SiFive designs
(including the HiFive Unmatched).
- Support for XIP.
- A device tree for the Microchip PolarFire ICICLE SoC and associated
dev board.
... along with a bunch of cleanups. There are already a handful of fixes
on the list so there will likely be a part 2.
* tag 'riscv-for-linus-5.13-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (45 commits)
RISC-V: Always define XIP_FIXUP
riscv: Remove 32b kernel mapping from page table dump
riscv: Fix 32b kernel build with CONFIG_DEBUG_VIRTUAL=y
RISC-V: Fix error code returned by riscv_hartid_to_cpuid()
RISC-V: Enable Microchip PolarFire ICICLE SoC
RISC-V: Initial DTS for Microchip ICICLE board
dt-bindings: riscv: microchip: Add YAML documentation for the PolarFire SoC
RISC-V: Add Microchip PolarFire SoC kconfig option
RISC-V: enable XIP
RISC-V: Add crash kernel support
RISC-V: Add kdump support
RISC-V: Improve init_resources()
RISC-V: Add kexec support
RISC-V: Add EM_RISCV to kexec UAPI header
riscv: vdso: fix and clean-up Makefile
riscv/mm: Use BUG_ON instead of if condition followed by BUG.
riscv/kprobe: fix kernel panic when invoking sys_read traced by kprobe
riscv: Set ARCH_HAS_STRICT_MODULE_RWX if MMU
riscv: module: Create module allocations without exec permissions
riscv: bpf: Avoid breaking W^X
...
LANG gives a weak default to each LC_* in case it is not explicitly
defined. LC_ALL, if set, overrides all other LC_* variables.
LANG < LC_CTYPE, LC_COLLATE, LC_MONETARY, LC_NUMERIC, ... < LC_ALL
This is why documentation such as [1] suggests to set LC_ALL in build
scripts to get the deterministic result.
LANG=C is not strong enough to override LC_* that may be set by end
users.
[1]: https://reproducible-builds.org/docs/locales/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Matthias Maennich <maennich@google.com>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net> (mptcp)
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Prior to clang 13.0.0, the RISC-V name for the mcount symbol was
"mcount", which differs from the GCC version of "_mcount", which results
in the following errors:
riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_level':
main.c:(.text+0xe): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_start':
main.c:(.text+0x4e): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_finish':
main.c:(.text+0x92): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `.LBB32_28':
main.c:(.text+0x30c): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `free_initmem':
main.c:(.text+0x54c): undefined reference to `mcount'
This has been corrected in https://reviews.llvm.org/D98881 but the
minimum supported clang version is 10.0.1. To avoid build errors and to
gain a working function tracer, adjust the name of the mcount symbol for
older versions of clang in mount.S and recordmcount.pl.
Link: https://github.com/ClangBuiltLinux/linux/issues/1331
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
By default, emacs indents Perl files with 4 spaces, but will use tabs
where 8 spaces are used. Add a vim command of softtabstop=4, to make vim
behave the same. This should remove the issue of developers using vim
having causing different indentation.
"John (Warthog9) Hawley" <warthog9@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Emacs by default will have perl files have 4 space indents, where 8 spaces
are represented with a single tab. There are some places in
recordmcount.pl that has 8 spaces where a tab should be used. Replace them
to make the file consistent.
No functional changes.
Cc: "John (Warthog9) Hawley" <warthog9@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The kernel test robot reported the following issue:
CC [M] drivers/soc/litex/litex_soc_ctrl.o
sh4-linux-objcopy: Unable to change endianness of input file(s)
sh4-linux-ld: cannot find drivers/soc/litex/.tmp_gl_litex_soc_ctrl.o: No such file or directory
sh4-linux-objcopy: 'drivers/soc/litex/.tmp_mx_litex_soc_ctrl.o': No such file
The problem is that the format of input file is elf32-shbig-linux, but
sh4-linux-objcopy wants to output a file which format is elf32-sh-linux:
$ sh4-linux-objdump -d drivers/soc/litex/litex_soc_ctrl.o | grep format
drivers/soc/litex/litex_soc_ctrl.o: file format elf32-shbig-linux
Link: https://lkml.kernel.org/r/20210210150435.2171567-1-rong.a.chen@intel.com
Link: https://lore.kernel.org/linux-mm/202101261118.GbbYSlHu-lkp@intel.com
Signed-off-by: Rong Chen <rong.a.chen@intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Cc: Rich Felker <dalias@libc.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently the kernel minimal compiler requirement is gcc 4.9 or
clang 10.0.1.
* gcc -mhotpatch option is supported since 4.8.
* A combination of -pg -mrecord-mcount -mnop-mcount -mfentry flags is
supported since gcc 9 and since clang 10.
Drop support for old -pg function prologues. Which leaves binary
compatible -mhotpatch / -mnop-mcount -mfentry prologues in a form:
brcl 0,0
Which are also do not require initial nop optimization / conversion and
presence of _mcount symbol.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Pull Kbuild updates from Masahiro Yamada:
- allow users to invoke 'make' out of the source tree
- refactor scripts/mkmakefile
- deprecate KBUILD_SRC, which was used to track the source tree
location for O= build.
- fix recordmcount.pl in case objdump output is localized
- turn unresolved symbols in external modules to errors from warnings
by default; pass KBUILD_MODPOST_WARN=1 to get them back to warnings
- generate modules.builtin.modinfo to collect .modinfo data from
built-in modules
- misc Makefile cleanups
* tag 'kbuild-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (21 commits)
.gitignore: add more all*.config patterns
moduleparam: Save information about built-in modules in separate file
Remove MODULE_ALIAS() calls that take undefined macro
.gitignore: add leading and trailing slashes to generated directories
scripts/tags.sh: fix direct execution of scripts/tags.sh
scripts: override locale from environment when running recordmcount.pl
samples: kobject: allow CONFIG_SAMPLE_KOBJECT to become y
samples: seccomp: turn CONFIG_SAMPLE_SECCOMP into a bool option
kbuild: move Documentation to vmlinux-alldirs
kbuild: move samples/ to KBUILD_VMLINUX_OBJS
modpost: make KBUILD_MODPOST_WARN also configurable for external modules
kbuild: check arch/$(SRCARCH)/include/generated before out-of-tree build
kbuild: remove unneeded dependency for include/config/kernel.release
memory: squash drivers/memory/Makefile.asm-offsets
kbuild: use $(srctree) instead of KBUILD_SRC to check out-of-tree build
kbuild: mkmakefile: generate a simple wrapper of top Makefile
kbuild: mkmakefile: do not check the generated Makefile marker
kbuild: allow Kbuild to start from any directory
kbuild: pass $(MAKECMDGOALS) to sub-make as is
kbuild: fix warning "overriding recipe for target 'Makefile'"
...
recordmcount.pl uses a set of regular expressions to parse the output of
objdump(1). However, if objdump(1) output is localized, it may not match
the regular expressions, thereby preventing recordmcount.pl from parsing
object files correctly.
In order to allow recordmcount.pl to function correctly regardless of the
current locale settings, set LANG=C when running objdump(1). LC_ALL is
already unset in the top-level Makefile, so it is not necessary to also
override that environment variable.
Signed-off-by: Daniel Dadap <ddadap@nvidia.com>
Reviewed-by: Robert Morell <rmorell@nvidia.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Support dynamic ftrace including dynamic graph tracer. Gcc-csky with -pg
will produce call site in every function prologue and we can use these
call site to hook trace function.
gcc with -pg origin call site:
push lr
jbsr _mcount
nop32
nop32
If the (callee - caller)'s offset is in range of bsr instruction, we'll
modify code with:
push lr
bsr _mcount
nop32
nop32
Else if the (callee - caller)'s offset is out of bsr instrunction, we'll
modify code with:
push lr
movih r26, ...
ori r26, ...
jsr r26
(r26 is reserved for jsr link reg in csky abiv2 spec.)
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
When building with -ffunction-sections, the compiler will place each
function into its own ELF section, prefixed with ".text". For example,
a simple test module with functions test_module_do_work() and
test_module_wq_func():
% objdump --section-headers test_module.o | awk '/\.text/{print $2}'
.text
.text.test_module_do_work
.text.test_module_wq_func
.init.text
.exit.text
Adjust the recordmcount scripts to look for ".text" as a section name
prefix. This will ensure that those functions will be included in the
__mcount_loc relocations:
% objdump --reloc --section __mcount_loc test_module.o
OFFSET TYPE VALUE
0000000000000000 R_X86_64_64 .text.test_module_do_work
0000000000000008 R_X86_64_64 .text.test_module_wq_func
0000000000000010 R_X86_64_64 .init.text
Link: http://lkml.kernel.org/r/1542745158-25392-2-git-send-email-joe.lawrence@redhat.com
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The powerpc toolchain can compile combinations of 32/64 bit and
big/little endian, so it's convenient to consider, e.g.,
`CC -m64 -mbig-endian`
To be the C compiler for the purpose of invoking it to build target
artifacts. So overriding the CC variable to include these flags works
for this purpose.
Unfortunately that is not compatible with the way the proposed new
Kconfig macro language will work.
After previous patches in this series, these flags can be carefully
passed in using flags instead.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pull RISC-V updates from Palmer Dabbelt:
"This contains the new features we'd like to incorporate into the
RISC-V port for 4.17. We might have a bit more stuff land later in the
merge window, but I wanted to get this out earlier just so everyone
can see where we currently stand.
A short summary of the changes is:
- We've added support for dynamic ftrace on RISC-V targets.
- There have been a handful of cleanups to our atomic and locking
routines. They now more closely match the released RISC-V memory
model draft.
- Our module loading support has been cleaned up and is now enabled
by default, despite some limitations still existing.
- A patch to define COMMANDLINE_FORCE instead of COMMANDLINE_OVERRIDE
so the generic device tree code picks up handling all our command
line stuff.
There's more information in the merge commits for each patch set"
* tag 'riscv-for-linus-4.17-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux: (21 commits)
RISC-V: Rename CONFIG_CMDLINE_OVERRIDE to CONFIG_CMDLINE_FORCE
RISC-V: Add definition of relocation types
RISC-V: Enable module support in defconfig
RISC-V: Support SUB32 relocation type in kernel module
RISC-V: Support ADD32 relocation type in kernel module
RISC-V: Support ALIGN relocation type in kernel module
RISC-V: Support RVC_BRANCH/JUMP relocation type in kernel modulewq
RISC-V: Support HI20/LO12_I/LO12_S relocation type in kernel module
RISC-V: Support CALL relocation type in kernel module
RISC-V: Support GOT_HI20/CALL_PLT relocation type in kernel module
RISC-V: Add section of GOT.PLT for kernel module
RISC-V: Add sections of PLT and GOT for kernel module
riscv/atomic: Strengthen implementations with fences
riscv/spinlock: Strengthen implementations with fences
riscv/barrier: Define __smp_{store_release,load_acquire}
riscv/ftrace: Add HAVE_FUNCTION_GRAPH_RET_ADDR_PTR support
riscv/ftrace: Add DYNAMIC_FTRACE_WITH_REGS support
riscv/ftrace: Add ARCH_SUPPORTS_FTRACE_OPS support
riscv/ftrace: Add dynamic function graph tracer support
riscv/ftrace: Add dynamic function tracer support
...
Now recordmcount.pl recognizes RISC-V object files. For the mechanism to
work, we have to disable the linker relaxation.
Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
These two architectures are getting removed, so we no longer
need the special cases.
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The default NetBSD package manager is pkgsrc and it installs Perl
along other third party programs under custom and configurable prefix.
The default prefix for binary prebuilt packages is /usr/pkg, and the
Perl executable lands in /usr/pkg/bin/perl.
This change switches "/usr/bin/perl" to "/usr/bin/env perl" as it's
the most portable solution that should work for almost everybody.
Perl's executable is detected automatically.
This change switches -w option passed to the executable with more
modern "use warnings;" approach. There is no functional change to the
default behavior.
While there, drop "require 5" from scripts/namespace.pl (Perl from 1994?).
Signed-off-by: Kamil Rytarowski <n54@gmx.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
