| Message ID | 20230530061436.56925-1-naveen@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 25ea739ea1d4d3de41acc4f4eb2d1a97eee0eb75 |
| Headers | show |
| Series | [v2] powerpc: Fail build if using recordmcount with binutils v2.37 | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 24 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 6 jobs. |
On Tue, 30 May 2023 11:44:36 +0530, Naveen N Rao wrote: > 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 > > [...] Applied to powerpc/next. [1/1] powerpc: Fail build if using recordmcount with binutils v2.37 https://git.kernel.org/powerpc/c/25ea739ea1d4d3de41acc4f4eb2d1a97eee0eb75 cheers
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index dca73f673d7046..fc76eb9830fdfa 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
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> --- v2: Check directly against $CONFIG_LD_VERSION arch/powerpc/Makefile | 8 ++++++++ 1 file changed, 8 insertions(+) base-commit: 7b2f56d76feff3b494d6e77950ab97987323d3c5