| From: |
| Ard Biesheuvel <ardb-AT-kernel.org> |
| To: |
| linux-arm-kernel-AT-lists.infradead.org |
| Subject: |
| [PATCH v6 0/2] static call support for arm64 |
| Date: |
| Fri, 05 Nov 2021 15:59:15 +0100 |
| Message-ID: |
| <20211105145917.2828911-1-ardb@kernel.org> |
| Cc: |
| linux-kernel-AT-vger.kernel.org, Ard Biesheuvel <ardb-AT-kernel.org>, Mark Rutland <mark.rutland-AT-arm.com>, Quentin Perret <qperret-AT-google.com>, Catalin Marinas <catalin.marinas-AT-arm.com>, James Morse <james.morse-AT-arm.com>, Will Deacon <will-AT-kernel.org>, Frederic Weisbecker <frederic-AT-kernel.org>, Peter Zijlstra <peterz-AT-infradead.org>, Kees Cook <keescook-AT-chromium.org>, Sami Tolvanen <samitolvanen-AT-google.com>, Andy Lutomirski <luto-AT-kernel.org>, Josh Poimboeuf <jpoimboe-AT-redhat.com>, Steven Rostedt <rostedt-AT-goodmis.org> |
| Archive-link: |
| Article |
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
