Arnd Bergmann reported false-positive modpost warnings detected by his
randconfig testing of linux-next.
Actually, this happens under the combination of CONFIG_MODVERSIONS
and CONFIG_TRIM_UNUSED_KSYMS since commit 15bfc2348d ("modpost:
check for static EXPORT_SYMBOL* functions").
For example, arch/arm/config/multi_v7_defconfig + CONFIG_MODVERSIONS
+ CONFIG_TRIM_UNUSED_KSYMS produces the following false-positives:
WARNING: "__lshrdi3" [vmlinux] is a static (unknown)
WARNING: "__ashrdi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_lasr" [vmlinux] is a static (unknown)
WARNING: "__aeabi_llsr" [vmlinux] is a static (unknown)
WARNING: "ftrace_set_clr_event" [vmlinux] is a static (unknown)
WARNING: "__muldi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_ulcmp" [vmlinux] is a static (unknown)
WARNING: "__ucmpdi2" [vmlinux] is a static (unknown)
WARNING: "__aeabi_lmul" [vmlinux] is a static (unknown)
WARNING: "__bswapsi2" [vmlinux] is a static (unknown)
WARNING: "__bswapdi2" [vmlinux] is a static (unknown)
WARNING: "__ashldi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_llsl" [vmlinux] is a static (unknown)
The root cause of the problem is not in the modpost, but in the
implementation of CONFIG_TRIM_UNUSED_KSYMS.
If there is at least one untrimmed symbol in the file, genksyms is
invoked to calculate CRC of *all* the exported symbols in that file
even if some of them have been trimmed due to no caller existing.
As a result, .tmp_*.ver files contain CRC of trimmed symbols, thus
unneeded, orphan __crc* symbols are added to objects. It had been
harmless until recently.
With commit 15bfc2348d ("modpost: check for static EXPORT_SYMBOL*
functions"), it is now harmful because the bogus __crc* symbols make
modpost call sym_update_crc() to add the symbols to the hash table,
but there is no one that clears the ->is_static member.
I gave Fixes to the first commit that uncovered the issue, but the
potential problem has long existed since commit f235541699
("export.h: allow for per-symbol configurable EXPORT_SYMBOL()").
Fixes: 15bfc2348d ("modpost: check for static EXPORT_SYMBOL* functions")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Arnd Bergmann <arnd@arndb.de>
__uint128_t crops up in a few files that export symbols to modules, so
teach genksyms about it and the other GCC built-in 128-bit integer types
so that we don't end up skipping the CRC generation for some symbols due
to the parser failing to spot them:
| WARNING: EXPORT symbol "kernel_neon_begin" [vmlinux] version
| generation failed, symbol will not be versioned.
| ld: arch/arm64/kernel/fpsimd.o: relocation R_AARCH64_ABS32 against
| `__crc_kernel_neon_begin' can not be used when making a shared
| object
| ld: arch/arm64/kernel/fpsimd.o:(.data+0x0): dangerous relocation:
| unsupported relocation
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It turns out that gperf-3.1 changed types in the generated code in ways
that aren't even trivially detectable without having to generate a test-file.
It's just not worth using tools and libraries from clowns that don't
understand or care about compatibility. So get rid of gperf.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
