[v7,3/4] powerpc/purgatory: Remove PGO flags

Message ID 20230321-kexec_clang16-v7-3-b05c520b7296@chromium.org
State New
Headers
Series kexec: Fix kexec_file_load for llvm16 with PGO |

Commit Message

Ricardo Ribalda May 19, 2023, 2:47 p.m. UTC
  If profile-guided optimization is enabled, the purgatory ends up with
multiple .text sections.
This is not supported by kexec and crashes the system.

Cc: stable@vger.kernel.org
Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 arch/powerpc/purgatory/Makefile | 5 +++++
 1 file changed, 5 insertions(+)
  

Comments

Michael Ellerman May 22, 2023, 4:16 a.m. UTC | #1
Ricardo Ribalda <ribalda@chromium.org> writes:
> If profile-guided optimization is enabled, the purgatory ends up with
> multiple .text sections.
> This is not supported by kexec and crashes the system.
>
> Cc: stable@vger.kernel.org
> Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>  arch/powerpc/purgatory/Makefile | 5 +++++
>  1 file changed, 5 insertions(+)

Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)

cheers
  

Patch

diff --git a/arch/powerpc/purgatory/Makefile b/arch/powerpc/purgatory/Makefile
index 6f5e2727963c..78473d69cd2b 100644
--- a/arch/powerpc/purgatory/Makefile
+++ b/arch/powerpc/purgatory/Makefile
@@ -5,6 +5,11 @@  KCSAN_SANITIZE := n
 
 targets += trampoline_$(BITS).o purgatory.ro
 
+# When profile-guided optimization is enabled, llvm emits two different
+# overlapping text sections, which is not supported by kexec. Remove profile
+# optimization flags.
+KBUILD_CFLAGS := $(filter-out -fprofile-sample-use=% -fprofile-use=%,$(KBUILD_CFLAGS))
+
 LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined
 
 $(obj)/purgatory.ro: $(obj)/trampoline_$(BITS).o FORCE