Messages in this thread | | | From | Ard Biesheuvel <> | Subject | [PATCH v6 0/2] static call support for arm64 | Date | Fri, 5 Nov 2021 15:59:15 +0100 |
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This implements non-inline static calls for arm64. This is rather straight-forward, as we don't rely on any tooling to look for static call sites etc. The only minor complication is Clang CFI, which is already in mainline for arm64, and requires a little tweak to ensure that we don't end up patching the CFI jump table instead of the static call trampoline itself.
Changes since v5: - drop the patch that works around issues with references to symbols with static linkage from asm blocks; this is specific to Clang+ThinLTO in versions before 13, so we can just decide not to support that config. - add a patch to use non-function type symbols for the trampolines, to ensure that taking the address gives us the trampoline itself rather than the address of a CFI jump table entry that branches to it.
Changes since v4: - add preparatory patch to address generic CFI/LTO issues with static calls - add comment to patch #2 describing the trampoline layout - add handling of Clang CFI jump table entries - add PeterZ's ack to patch #2
Cc: Mark Rutland <mark.rutland@arm.com> Cc: Quentin Perret <qperret@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kees Cook <keescook@chromium.org> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org>
Ard Biesheuvel (2): static_call: use non-function types to refer to the trampolines arm64: implement support for static call trampolines
arch/arm64/Kconfig | 2 + arch/arm64/include/asm/static_call.h | 40 ++++++++++ arch/arm64/kernel/patching.c | 77 +++++++++++++++++++- arch/arm64/kernel/vmlinux.lds.S | 1 + include/linux/static_call.h | 4 +- include/linux/static_call_types.h | 11 ++- 6 files changed, 127 insertions(+), 8 deletions(-) create mode 100644 arch/arm64/include/asm/static_call.h
-- 2.30.2
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