The BPF tracing multi link updates several direct-call sites through one ftrace_ops. Its implementation is therefore gated by HAVE_SINGLE_FTRACE_DIRECT_OPS in addition to DYNAMIC_FTRACE_WITH_DIRECT_CALLS.
Select HAVE_SINGLE_FTRACE_DIRECT_OPS whenever arm64 enables dynamic ftrace direct calls. This enables BPF tracing multi links on arm64. Also generalize the unreachable-trampoline comment because the single-ops path does not use ops->direct_call. Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Leon Hwang <[email protected]> --- arch/arm64/Kconfig | 2 ++ arch/arm64/kernel/ftrace.c | 3 +-- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 0de419ed780f..c98dca76859b 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -188,6 +188,8 @@ config ARM64 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ if DYNAMIC_FTRACE_WITH_ARGS + select HAVE_SINGLE_FTRACE_DIRECT_OPS \ + if DYNAMIC_FTRACE_WITH_DIRECT_CALLS select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \ (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index e1a3c0b3a051..56ba72a87dfa 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -301,8 +301,7 @@ static bool ftrace_find_callable_addr(struct dyn_ftrace *rec, /* * If a custom trampoline is unreachable, rely on the ftrace_caller - * trampoline which knows how to indirectly reach that trampoline - * through ops->direct_call. + * trampoline which knows how to indirectly reach that trampoline. */ if (*addr != FTRACE_ADDR && !reachable_by_bl(*addr, pc)) *addr = FTRACE_ADDR; -- 2.55.0
