Re: [PATCH v2] arm64: ftrace: fix unreachable PLT for ftrace_caller in init_module with CONFIG_DYNAMIC_FTRACE
From: Catalin Marinas <catalin.marinas@arm.com>
Date: 2025-09-05 16:13:59
Also in:
linux-trace-kernel, lkml
On Thu, 04 Sep 2025 20:22:36 -0700, panfan wrote:
On arm64, it has been possible for a module's sections to be placed more
than 128M away from each other since commit:
commit 3e35d303ab7d ("arm64: module: rework module VA range selection")
Due to this, an ftrace callsite in a module's .init.text section can be
out of branch range for the module's ftrace PLT entry (in the module's
.text section). Any attempt to enable tracing of that callsite will
result in a BRK being patched into the callsite, resulting in a fatal
exception when the callsite is later executed.
[...]
Applied to arm64 (for-next/fixes), thanks!
[1/1] arm64: ftrace: fix unreachable PLT for ftrace_caller in init_module with CONFIG_DYNAMIC_FTRACE
https://git.kernel.org/arm64/c/a7ed7b9d0ebb
--
Catalin