Re: [RFC] Don't create sframes during build
From: Indu
Date: Sat Jan 24 2026 - 14:11:31 EST
On 2026-01-24 4:04 a.m., Sven Joachim wrote:
On 2025-09-04 10:14 -0700, Josh Poimboeuf wrote:
On Thu, Sep 04, 2025 at 06:34:04PM +0200, Sebastian Andrzej Siewior wrote:
On 2025-09-04 16:02:42 [+0200], Matthias Klose wrote:
[ CCing binutils@xxxxxxxxxxxxxx ]
On 9/4/25 15:18, Sebastian Andrzej Siewior wrote:
Hi,
gcc in Debian, starting with 15.2.0-2, 14.3.0-6 enables sframe
generation. Unless options like -ffreestanding are passed. Since this
isn't done, there are a few warnings during compile
If there are other options when sframe shouldn't be enabled, please tell.
No, I think this is okay.
…
We could drop the sframe during the final link but this does not get ridThis is what I chose for package builds that need disablement of sframe.
of the objtool warnings so we would have to ignore them. But we don't
need it. So what about the following:
diff --git a/Makefile b/Makefile
--- a/Makefile
+++ b/Makefile
@@ -886,6 +886,8 @@ ifdef CONFIG_CC_IS_GCC
KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
KBUILD_CFLAGS += $(call cc-option,-fno-allow-store-data-races)
endif
+# No sframe generation for kernel if enabled by default
+KBUILD_CFLAGS += $(call cc-option,-Xassembler --gsframe=no)
ifdef CONFIG_READABLE_ASM
# Disable optimizations that make assembler listings hard to read.
I think this would work for now. Longterm we would have to allow sframe
creation and keep section if an architecture decides to use it for its
backtracing. While orc seems fine on x86, there are arm64 patches to use
for as a stack unwinder.
This is probably fine, but... how does this interact with other kernel
makefiles enabling sframe? For example, x86 will soon have a patch to
enable sframe generation for vdso. And as you mentioned, arm64 will
enable it kernel-wide.
Removing the objtool !ENDBR warnings would be trivial (and is a good
thing to do regardless).
What is the status of sframe support in the kernel? With current
binutils (version 2.45.50.20260119-1) from Debian I could not build
Linux 6.18.7:
,----
| # LD arch/x86/boot/compressed/vmlinux
| ld -m elf_x86_64 --no-ld-generated-unwind-info -pie --no-dynamic-linker --orphan-handling=error -z noexecstack --no-warn-rwx-segments -T arch/x86/boot/compressed/vmlinux.lds arch/x86/boot/compressed/kernel_info.o arch/x86/boot/compressed/head_64.o arch/x86/boot/compressed/misc.o arch/x86/boot/compressed/string.o arch/x86/boot/compressed/cmdline.o arch/x86/boot/compressed/error.o arch/x86/boot/compressed/piggy.o arch/x86/boot/compressed/cpuflags.o arch/x86/boot/compressed/early_serial_console.o arch/x86/boot/compressed/kaslr.o arch/x86/boot/compressed/ident_map_64.o arch/x86/boot/compressed/idt_64.o arch/x86/boot/compressed/idt_handlers_64.o arch/x86/boot/compressed/pgtable_64.o arch/x86/boot/compressed/acpi.o arch/x86/boot/startup/lib.a -o arch/x86/boot/compressed/vmlinux
| /usr/bin/x86_64-linux-gnu-ld.bfd: error: unplaced orphan section `.sframe' from `arch/x86/boot/compressed/kernel_info.o'
| /usr/bin/x86_64-linux-gnu-ld.bfd: error: unplaced orphan section `.sframe' from `arch/x86/boot/compressed/kernel_info.o'
| make[6]: *** [arch/x86/boot/compressed/Makefile:116: arch/x86/boot/compressed/vmlinux] Error 1
| make[5]: *** [arch/x86/boot/Makefile:96: arch/x86/boot/compressed/vmlinux] Error 2
`----
Sorry for the breakage.
There is a patch that needs to make it upstream
https://sourceware.org/pipermail/binutils/2026-January/147664.html
(Its a part of a series under review..)
I will work on getting this patch committed.
For immediate relief, please use the new ld option --discard-sframe meanwhile.
Did not test mainline yet, but "git log --grep=sframe master" does not
show anything interesting.
Cheers,
Sven