On Mon, Jan 4, 2021 at 9:49 PM Nathan Chancellor natechancellor@gmail.com wrote:
Commit eff8728fe698 ("vmlinux.lds.h: Add PGO and AutoFDO input sections") added ".text.unlikely.*" and ".text.hot.*" due to an LLVM change [1].
After another LLVM change [2], these sections are seen in some PowerPC builds, where there is a orphan section warning then build failure:
Looks like you forgot to add your references/links to [1] and [2].
Might be good to mention...?
With CONFIG_LD_ORPHAN_WARN=y is enabled
- Sedat
$ make -skj"$(nproc)" \ ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- LLVM=1 O=out \ distclean powernv_defconfig zImage.epapr ld.lld: warning: kernel/built-in.a(panic.o):(.text.unlikely.) is being placed in '.text.unlikely.' ... ld.lld: warning: address (0xc000000000009314) of section .text is not a multiple of alignment (256) ... ERROR: start_text address is c000000000009400, should be c000000000008000 ERROR: try to enable LD_HEAD_STUB_CATCH config option ERROR: see comments in arch/powerpc/tools/head_check.sh ...
Explicitly handle these sections like in the main linker script so there is no more build failure.
Cc: stable@vger.kernel.org Fixes: 83a092cf95f2 ("powerpc: Link warning for orphan sections") Link: https://github.com/ClangBuiltLinux/linux/issues/1218 Signed-off-by: Nathan Chancellor natechancellor@gmail.com
arch/powerpc/kernel/vmlinux.lds.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index 0318ba436f34..8e0b1298bf19 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -85,7 +85,7 @@ SECTIONS ALIGN_FUNCTION(); #endif /* careful! __ftr_alt_* sections need to be close to .text */
*(.text.hot TEXT_MAIN .text.fixup .text.unlikely .fixup __ftr_alt_* .ref.text);
*(.text.hot .text.hot.* TEXT_MAIN .text.fixup .text.unlikely .text.unlikely.* .fixup __ftr_alt_* .ref.text);#ifdef CONFIG_PPC64 *(.tramp.ftrace.text); #endif
base-commit: d8a4f20584d5906093a8fc6aa06622102a501095
2.30.0
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