[PATCH] powerpc: Handle .text.{hot,unlikely}.* in linker script

From: Nathan Chancellor
Date: Mon Jan 04 2021 - 19:00:18 EST


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:

$ 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@xxxxxxxxxxxxxxx
Fixes: 83a092cf95f2 ("powerpc: Link warning for orphan sections")
Link: https://github.com/ClangBuiltLinux/linux/issues/1218
Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
---
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