Commit 800618f9 authored Apr 08, 2021 by Sami Tolvanen Committed by Kees Cook Apr 08, 2021

arm64: ftrace: use function_nocfi for ftrace_call



With CONFIG_CFI_CLANG, the compiler replaces function pointers with
jump table addresses, which breaks dynamic ftrace as the address of
ftrace_call is replaced with the address of ftrace_call.cfi_jt. Use
function_nocfi() to get the address of the actual function instead.

Suggested-by: Ben Dai <ben.dai@unisoc.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-17-samitolvanen@google.com

parent 9562f3dc

arch/arm64/kernel/ftrace.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -55,7 +55,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
		unsigned long pc;
		u32 new;

		pc = (unsigned long)&ftrace_call;
		pc = (unsigned long)function_nocfi(ftrace_call);
		new = aarch64_insn_gen_branch_imm(pc, (unsigned long)func,
		AARCH64_INSN_BRANCH_LINK);