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| author | Naveen N Rao <naveen@kernel.org> | 2023-05-30 11:44:36 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-06-27 16:19:06 +1000 |
| commit | 25ea739ea1d4d3de41acc4f4eb2d1a97eee0eb75 (patch) | |
| tree | c132cee36129c7223b6306f890f58c53d92be310 | |
| parent | d61cd13e732c0eaa7d66b45edb2d0de8eab65a1e (diff) | |
| download | livepatching-25ea739ea1d4d3de41acc4f4eb2d1a97eee0eb75.tar.gz | |
powerpc: Fail build if using recordmcount with binutils v2.37
binutils v2.37 drops unused section symbols, which prevents recordmcount
from capturing mcount locations in sections that have no non-weak
symbols. This results in a build failure with a message such as:
Cannot find symbol for section 12: .text.perf_callchain_kernel.
kernel/events/callchain.o: failed
The change to binutils was reverted for v2.38, so this behavior is
specific to binutils v2.37:
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=c09c8b42021180eee9495bd50d8b35e683d3901b
Objtool is able to cope with such sections, so this issue is specific to
recordmcount.
Fail the build and print a warning if binutils v2.37 is detected and if
we are using recordmcount.
Cc: stable@vger.kernel.org
Suggested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230530061436.56925-1-naveen@kernel.org
| -rw-r--r-- | arch/powerpc/Makefile | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 76fc7cc2678024..449514ec1fdf3a 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -409,3 +409,11 @@ checkbin: echo -n '*** Please use a different binutils version.' ; \ false ; \ fi + @if test "x${CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT}" = "xy" -a \ + "x${CONFIG_LD_IS_BFD}" = "xy" -a \ + "${CONFIG_LD_VERSION}" = "23700" ; then \ + echo -n '*** binutils 2.37 drops unused section symbols, which recordmcount ' ; \ + echo 'is unable to handle.' ; \ + echo '*** Please use a different binutils version.' ; \ + false ; \ + fi |