From 73cdf24e81e4eba52a40a6b10c6cf285d0ac23fd Mon Sep 17 00:00:00 2001
From: Hari Bathini <hbathini@linux.ibm.com>
Date: Tue, 27 Jan 2026 14:19:24 +0530
Subject: powerpc64: make clang cross-build friendly

ARCH_USING_PATCHABLE_FUNCTION_ENTRY depends on toolchain support for
-fpatchable-function-entry option. The current script that checks
for this support only handles GCC. Rename the script and extend it
to detect support for -fpatchable-function-entry with Clang as well,
allowing clean cross-compilation with Clang toolchains.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260127084926.34497-2-hbathini@linux.ibm.com
---
 arch/powerpc/Kconfig                               |  4 ++--
 .../tools/check-fpatchable-function-entry.sh       | 25 ++++++++++++++++++++++
 .../tools/gcc-check-fpatchable-function-entry.sh   | 25 ----------------------
 3 files changed, 27 insertions(+), 27 deletions(-)
 create mode 100755 arch/powerpc/tools/check-fpatchable-function-entry.sh
 delete mode 100755 arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index ad7a2fe63a2a..10240cb80904 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -573,8 +573,8 @@ config ARCH_USING_PATCHABLE_FUNCTION_ENTRY
 	depends on FUNCTION_TRACER && (PPC32 || PPC64_ELF_ABI_V2)
 	depends on $(cc-option,-fpatchable-function-entry=2)
 	def_bool y if PPC32
-	def_bool $(success,$(srctree)/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh $(CC) -mlittle-endian) if PPC64 && CPU_LITTLE_ENDIAN
-	def_bool $(success,$(srctree)/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh $(CC) -mbig-endian) if PPC64 && CPU_BIG_ENDIAN
+	def_bool $(success,$(srctree)/arch/powerpc/tools/check-fpatchable-function-entry.sh $(CC) $(CLANG_FLAGS) -mlittle-endian) if PPC64 && CPU_LITTLE_ENDIAN
+	def_bool $(success,$(srctree)/arch/powerpc/tools/check-fpatchable-function-entry.sh $(CC) -mbig-endian) if PPC64 && CPU_BIG_ENDIAN
 
 config PPC_FTRACE_OUT_OF_LINE
 	def_bool PPC64 && ARCH_USING_PATCHABLE_FUNCTION_ENTRY
diff --git a/arch/powerpc/tools/check-fpatchable-function-entry.sh b/arch/powerpc/tools/check-fpatchable-function-entry.sh
new file mode 100755
index 000000000000..baed467a016b
--- /dev/null
+++ b/arch/powerpc/tools/check-fpatchable-function-entry.sh
@@ -0,0 +1,25 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+set -e
+
+# To debug, uncomment the following line
+# set -x
+
+# Output from -fpatchable-function-entry can only vary on ppc64 elfv2, so this
+# should not be invoked for other targets. Therefore we can pass in -m64 and
+# -mabi explicitly, to take care of toolchains defaulting to other targets.
+
+# Test whether the compile option -fpatchable-function-entry exists and
+# generates appropriate code
+echo "int func() { return 0; }" | \
+    $* -m64 -mabi=elfv2 -S -x c -O2 -fpatchable-function-entry=2 - -o - 2> /dev/null | \
+    grep -q "__patchable_function_entries"
+
+# Test whether nops are generated after the local entry point
+echo "int x; int func() { return x; }" | \
+    $* -m64 -mabi=elfv2 -S -x c -O2 -fpatchable-function-entry=2 - -o - 2> /dev/null | \
+    awk 'BEGIN { RS = ";" } /\.localentry.*nop.*\n[[:space:]]*nop/ { print $0 }' | \
+    grep -q "func:"
+
+exit 0
diff --git a/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh b/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh
deleted file mode 100755
index baed467a016b..000000000000
--- a/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh
+++ /dev/null
@@ -1,25 +0,0 @@
-#!/bin/bash
-# SPDX-License-Identifier: GPL-2.0
-
-set -e
-
-# To debug, uncomment the following line
-# set -x
-
-# Output from -fpatchable-function-entry can only vary on ppc64 elfv2, so this
-# should not be invoked for other targets. Therefore we can pass in -m64 and
-# -mabi explicitly, to take care of toolchains defaulting to other targets.
-
-# Test whether the compile option -fpatchable-function-entry exists and
-# generates appropriate code
-echo "int func() { return 0; }" | \
-    $* -m64 -mabi=elfv2 -S -x c -O2 -fpatchable-function-entry=2 - -o - 2> /dev/null | \
-    grep -q "__patchable_function_entries"
-
-# Test whether nops are generated after the local entry point
-echo "int x; int func() { return x; }" | \
-    $* -m64 -mabi=elfv2 -S -x c -O2 -fpatchable-function-entry=2 - -o - 2> /dev/null | \
-    awk 'BEGIN { RS = ";" } /\.localentry.*nop.*\n[[:space:]]*nop/ { print $0 }' | \
-    grep -q "func:"
-
-exit 0
-- 
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