5.15-stable review patch. If anyone has any objections, please let me know.
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From: "Borislav Petkov (AMD)" bp@alien8.de
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@alien8.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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) {