FAILED: patch "[PATCH] powerpc/vdso: Drop -mstack-protector-guard flags in 32-bit" failed to apply to 6.1-stable tree

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x d677ce521334d8f1f327cafc8b1b7854b0833158
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024120642-steep-reply-a3bd@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d677ce521334d8f1f327cafc8b1b7854b0833158 Mon Sep 17 00:00:00 2001
From: Nathan Chancellor <[email protected]>
Date: Wed, 30 Oct 2024 11:41:37 -0700
Subject: [PATCH] powerpc/vdso: Drop -mstack-protector-guard flags in 32-bit
files with clang

Under certain conditions, the 64-bit '-mstack-protector-guard' flags may end up in the 32-bit vDSO flags, resulting in build failures due to the structure of clang's argument parsing of the stack protector options, which validates the arguments of the stack protector guard flags unconditionally in the frontend, choking on the 64-bit values when targeting 32-bit:

clang: error: invalid value 'r13' in 'mstack-protector-guard-reg=', expected one of: r2
clang: error: invalid value 'r13' in 'mstack-protector-guard-reg=', expected one of: r2 make[3]: *** [arch/powerpc/kernel/vdso/Makefile:85: arch/powerpc/kernel/vdso/vgettimeofday-32.o] Error 1 make[3]: *** [arch/powerpc/kernel/vdso/Makefile:87: arch/powerpc/kernel/vdso/vgetrandom-32.o] Error 1

Remove these flags by adding them to the CC32FLAGSREMOVE variable, which already handles situations similar to this. Additionally, reformat and align a comment better for the expanding CONFIG_CC_IS_CLANG block.

index 31ca5a547004..c568cad6a22e 100644
@@ -54,10 +54,14 @@ ldflags-y += $(filter-out $(CC_AUTO_VAR_INIT_ZERO_ENABLER) $(CC_FLAGS_FTRACE) -W
 
 CC32FLAGS := -m32
 CC32FLAGSREMOVE := -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc
-  # This flag is supported by clang for 64-bit but not 32-bit so it will cause
-  # an unused command line flag warning for this file.
 ifdef CONFIG_CC_IS_CLANG
+# This flag is supported by clang for 64-bit but not 32-bit so it will cause
+# an unused command line flag warning for this file.
 CC32FLAGSREMOVE += -fno-stack-clash-protection
+# -mstack-protector-guard values from the 64-bit build are not valid for the
+# 32-bit one. clang validates the values passed to these arguments during
+# parsing, even when -fno-stack-protector is passed afterwards.
+CC32FLAGSREMOVE += -mstack-protector-guard%
 endif
 LD32FLAGS := -Wl,-soname=linux-vdso32.so.1
 AS32FLAGS := -D__VDSO32__

commit d677ce521334d8f1f327cafc8b1b7854b0833158 upstream.

Under certain conditions, the 64-bit '-mstack-protector-guard' flags may end up in the 32-bit vDSO flags, resulting in build failures due to the structure of clang's argument parsing of the stack protector options, which validates the arguments of the stack protector guard flags unconditionally in the frontend, choking on the 64-bit values when targeting 32-bit:

clang: error: invalid value 'r13' in 'mstack-protector-guard-reg=', expected one of: r2
clang: error: invalid value 'r13' in 'mstack-protector-guard-reg=', expected one of: r2 make[3]: *** [arch/powerpc/kernel/vdso/Makefile:85: arch/powerpc/kernel/vdso/vgettimeofday-32.o] Error 1 make[3]: *** [arch/powerpc/kernel/vdso/Makefile:87: arch/powerpc/kernel/vdso/vgetrandom-32.o] Error 1

Remove these flags by adding them to the CC32FLAGSREMOVE variable, which already handles situations similar to this. Additionally, reformat and align a comment better for the expanding CONFIG_CC_IS_CLANG block.

---
 arch/powerpc/kernel/vdso/Makefile | 6 ++++++
 1 file changed, 6 insertions(+)

index a2e7b0ce5b19..48bf579eedae 100644
@@ -16,6 +16,12 @@ ifneq ($(c-gettimeofday-y),)
   CFLAGS_vgettimeofday-32.o += -ffreestanding -fasynchronous-unwind-tables
   CFLAGS_REMOVE_vgettimeofday-32.o = $(CC_FLAGS_FTRACE)
   CFLAGS_REMOVE_vgettimeofday-32.o += -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc
+  ifdef CONFIG_CC_IS_CLANG
+  # -mstack-protector-guard values from the 64-bit build are not valid for the
+  # 32-bit one. clang validates the values passed to these arguments during
+  # parsing, even when -fno-stack-protector is passed afterwards.
+  CFLAGS_REMOVE_vgettimeofday-32.o += -mstack-protector-guard%
+  endif
   CFLAGS_vgettimeofday-64.o += -include $(c-gettimeofday-y)
   CFLAGS_vgettimeofday-64.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
   CFLAGS_vgettimeofday-64.o += $(call cc-option, -fno-stack-protector)

2.47.1

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: d677ce521334d8f1f327cafc8b1b7854b0833158

Status in newer kernel trees:
6.12.y | Not found
6.6.y | Not found
6.1.y | Not found

Note: The patch differs from the upstream commit:
---

1:  d677ce521334d < -:  ------------- powerpc/vdso: Drop -mstack-protector-guard flags in 32-bit files with clang
-:  ------------- > 1:  c84848a9a621d powerpc/vdso: Drop -mstack-protector-guard flags in 32-bit files with clang

---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.1.y        |  Success    |  Success   |