Changes in check-fpatchable-function-entry.sh

73cdf24e81e4eba52a40a6b10c6cf285d0ac23fd - powerpc64: make clang cross-build friendly

Tue, 27 Jan 2026 08:49:24 +0000

powerpc64: make clang cross-build friendlyARCH_USING_PATCHABLE_FUNCTION_ENTRY depends on toolchain support for-fpatchable-function-entry option. The current script that checksfor this support only handles GCC. Rename the script and extend itto detect support for -fpatchable-function-entry with Clang as well,allowing clean cross-compilation with Clang toolchains.Signed-off-by: Hari Bathini Tested-by: Venkat Rao Bagalkote Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260127084926.34497-2-hbathini@linux.ibm.com List of files: /linux/arch/powerpc/tools/check-fpatchable-function-entry.sh

f1164534ad62f0cc247d99650b07bd59ad2a49fd - powerpc/tools: drop `-o pipefail` in gcc check scripts

Tue, 23 Sep 2025 15:32:16 +0000

powerpc/tools: drop `-o pipefail` in gcc check scriptsFixes: 0f71dcfb4aef ("powerpc/ftrace: Add support for -fpatchable-function-entry")Fixes: b71c9ffb1405 ("powerpc: Add arch/powerpc/tools directory")Reported-by: Joe Lawrence Acked-by: Joe Lawrence Signed-off-by: Jan Stancek Fixes: 8c50b72a3b4f ("powerpc/ftrace: Add Kconfig & Make glue for mprofile-kernel")Fixes: abba759796f9 ("powerpc/kbuild: move -mprofile-kernel check to Kconfig")Tested-by: Justin M. Forbes Reviewed-by: Naveen N Rao (AMD) Reviewed-by: Josh Poimboeuf Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/cc6cdd116c3ad9d990df21f13c6d8e8a83815bbd.1758641374.git.jstancek@redhat.com List of files: /linux/arch/powerpc/tools/check-fpatchable-function-entry.sh

0f71dcfb4aef6043da6cc509e7a7f6a3ae87c12d - powerpc/ftrace: Add support for -fpatchable-function-entry

Mon, 19 Jun 2023 09:47:34 +0000

powerpc/ftrace: Add support for -fpatchable-function-entryGCC v13.1 updated support for -fpatchable-function-entry on ppc64le toemit nops after the local entry point, rather than before it. Thisallows us to use this in the kernel for ftrace purposes. A new script isadded under arch/powerpc/tools/ to help detect if nops are emitted afterthe function local entry point, or before the global entry point.With -fpatchable-function-entry, we no longer have the profilinginstructions generated at function entry, so we only need to validatethe presence of two nops at the ftrace location in ftrace_init_nop(). Wepatch the preceding instruction with 'mflr r0' to match the-mprofile-kernel ABI for subsequent ftrace use.This changes the profiling instructions used on ppc32. The default -pgoption emits an additional 'stw' instruction after 'mflr r0' and beforethe branch to _mcount 'bl _mcount'. This is very similar to the original-mprofile-kernel implementation on ppc64le, where an additional 'std'instruction was used to save LR to its save location in the caller'sstackframe. Subsequently, this additional store was removed in latercompiler versions for performance reasons. The same reasons apply forppc32 so we only patch in a 'mflr r0'.Signed-off-by: Naveen N Rao Reviewed-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/68586d22981a2c3bb45f27a2b621173d10a7d092.1687166935.git.naveen@kernel.org List of files: /linux/arch/powerpc/tools/check-fpatchable-function-entry.sh