5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Borislav Petkov (AMD)" <bp@xxxxxxxxx> This reverts commit 3eb602ad6a94a76941f93173131a71ad36fa1324. Revert the backport of upstream commit 1f001e9da6bb ("x86/ftrace: Use alternative RET encoding") in favor of a proper backport after backporting the commit which adds __text_gen_insn(). Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/ftrace.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -311,7 +311,7 @@ union ftrace_op_code_union { } __attribute__((packed)); }; -#define RET_SIZE (IS_ENABLED(CONFIG_RETPOLINE) ? 5 : 1 + IS_ENABLED(CONFIG_SLS)) +#define RET_SIZE 1 + IS_ENABLED(CONFIG_SLS) static unsigned long create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) @@ -367,12 +367,7 @@ create_trampoline(struct ftrace_ops *ops goto fail; ip = trampoline + size; - - /* The trampoline ends with ret(q) */ - if (cpu_feature_enabled(X86_FEATURE_RETHUNK)) - memcpy(ip, text_gen_insn(JMP32_INSN_OPCODE, ip, &__x86_return_thunk), JMP32_INSN_SIZE); - else - memcpy(ip, retq, sizeof(retq)); + memcpy(ip, retq, RET_SIZE); /* No need to test direct calls on created trampolines */ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {