diff options
| -rw-r--r-- | arch/x86/kernel/ftrace.c | 12 | ||||
| -rw-r--r-- | arch/x86/kernel/ftrace_64.S | 32 |
2 files changed, 25 insertions, 19 deletions
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 37a0aeaf89e7..867c126ddabe 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -282,7 +282,8 @@ static inline void tramp_free(void *tramp) { } /* Defined as markers to the end of the ftrace default trampolines */ extern void ftrace_regs_caller_end(void); -extern void ftrace_epilogue(void); +extern void ftrace_regs_caller_ret(void); +extern void ftrace_caller_end(void); extern void ftrace_caller_op_ptr(void); extern void ftrace_regs_caller_op_ptr(void); @@ -334,7 +335,7 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) call_offset = (unsigned long)ftrace_regs_call; } else { start_offset = (unsigned long)ftrace_caller; - end_offset = (unsigned long)ftrace_epilogue; + end_offset = (unsigned long)ftrace_caller_end; op_offset = (unsigned long)ftrace_caller_op_ptr; call_offset = (unsigned long)ftrace_call; } @@ -366,6 +367,13 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) if (WARN_ON(ret < 0)) goto fail; + if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { + ip = trampoline + (ftrace_regs_caller_ret - ftrace_regs_caller); + ret = probe_kernel_read(ip, (void *)retq, RET_SIZE); + if (WARN_ON(ret < 0)) + goto fail; + } + /* * The address of the ftrace_ops that is used for this trampoline * is stored at the end of the trampoline. This will be used to diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S index 369e61faacfe..7657dc782828 100644 --- a/arch/x86/kernel/ftrace_64.S +++ b/arch/x86/kernel/ftrace_64.S @@ -157,8 +157,12 @@ SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) * think twice before adding any new code or changing the * layout here. */ -SYM_INNER_LABEL(ftrace_epilogue, SYM_L_GLOBAL) +SYM_INNER_LABEL(ftrace_caller_end, SYM_L_GLOBAL) + jmp ftrace_epilogue +SYM_FUNC_END(ftrace_caller); + +SYM_FUNC_START(ftrace_epilogue) #ifdef CONFIG_FUNCTION_GRAPH_TRACER SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL) jmp ftrace_stub @@ -170,14 +174,12 @@ SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL) */ SYM_INNER_LABEL_ALIGN(ftrace_stub, SYM_L_WEAK) retq -SYM_FUNC_END(ftrace_caller) +SYM_FUNC_END(ftrace_epilogue) SYM_FUNC_START(ftrace_regs_caller) /* Save the current flags before any operations that can change them */ pushfq - UNWIND_HINT_SAVE - /* added 8 bytes to save flags */ save_mcount_regs 8 /* save_mcount_regs fills in first two parameters */ @@ -233,7 +235,10 @@ SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL) movq ORIG_RAX(%rsp), %rax movq %rax, MCOUNT_REG_SIZE-8(%rsp) - /* If ORIG_RAX is anything but zero, make this a call to that */ + /* + * If ORIG_RAX is anything but zero, make this a call to that. + * See arch_ftrace_set_direct_caller(). + */ movq ORIG_RAX(%rsp), %rax cmpq $0, %rax je 1f @@ -244,20 +249,14 @@ SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL) movq %rax, MCOUNT_REG_SIZE(%rsp) restore_mcount_regs 8 + /* Restore flags */ + popfq - jmp 2f +SYM_INNER_LABEL(ftrace_regs_caller_ret, SYM_L_GLOBAL); + UNWIND_HINT_RET_OFFSET + jmp ftrace_epilogue 1: restore_mcount_regs - - -2: - /* - * The stack layout is nondetermistic here, depending on which path was - * taken. This confuses objtool and ORC, rightfully so. For now, - * pretend the stack always looks like the non-direct case. - */ - UNWIND_HINT_RESTORE - /* Restore flags */ popfq @@ -268,7 +267,6 @@ SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL) * to the return. */ SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL) - jmp ftrace_epilogue SYM_FUNC_END(ftrace_regs_caller) |