diff options
Diffstat (limited to 'arch/x86/kernel/ftrace_64.S')
| -rw-r--r-- | arch/x86/kernel/ftrace_64.S | 37 |
1 files changed, 34 insertions, 3 deletions
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S index 2a4be92fd144..1265ad519249 100644 --- a/arch/x86/kernel/ftrace_64.S +++ b/arch/x86/kernel/ftrace_64.S @@ -3,8 +3,9 @@ * Copyright (C) 2014 Steven Rostedt, Red Hat Inc */ -#include <linux/linkage.h> #include <linux/cfi_types.h> +#include <linux/linkage.h> +#include <asm/asm-offsets.h> #include <asm/ptrace.h> #include <asm/ftrace.h> #include <asm/export.h> @@ -131,16 +132,19 @@ .endm SYM_TYPED_FUNC_START(ftrace_stub) + CALL_DEPTH_ACCOUNT RET SYM_FUNC_END(ftrace_stub) SYM_TYPED_FUNC_START(ftrace_stub_graph) + CALL_DEPTH_ACCOUNT RET SYM_FUNC_END(ftrace_stub_graph) #ifdef CONFIG_DYNAMIC_FTRACE SYM_FUNC_START(__fentry__) + CALL_DEPTH_ACCOUNT RET SYM_FUNC_END(__fentry__) EXPORT_SYMBOL(__fentry__) @@ -149,6 +153,8 @@ SYM_FUNC_START(ftrace_caller) /* save_mcount_regs fills in first two parameters */ save_mcount_regs + CALL_DEPTH_ACCOUNT + /* Stack - skipping return address of ftrace_caller */ leaq MCOUNT_REG_SIZE+8(%rsp), %rcx movq %rcx, RSP(%rsp) @@ -164,6 +170,9 @@ SYM_INNER_LABEL(ftrace_caller_op_ptr, SYM_L_GLOBAL) /* Only ops with REGS flag set should have CS register set */ movq $0, CS(%rsp) + /* Account for the function call below */ + CALL_DEPTH_ACCOUNT + SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) ANNOTATE_NOENDBR call ftrace_stub @@ -193,6 +202,8 @@ SYM_FUNC_START(ftrace_regs_caller) save_mcount_regs 8 /* save_mcount_regs fills in first two parameters */ + CALL_DEPTH_ACCOUNT + SYM_INNER_LABEL(ftrace_regs_caller_op_ptr, SYM_L_GLOBAL) ANNOTATE_NOENDBR /* Load the ftrace_ops into the 3rd parameter */ @@ -223,6 +234,9 @@ SYM_INNER_LABEL(ftrace_regs_caller_op_ptr, SYM_L_GLOBAL) /* regs go into 4th parameter */ leaq (%rsp), %rcx + /* Account for the function call below */ + CALL_DEPTH_ACCOUNT + SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL) ANNOTATE_NOENDBR call ftrace_stub @@ -275,7 +289,20 @@ SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL) /* Restore flags */ popfq UNWIND_HINT_FUNC - RET + + /* + * The above left an extra return value on the stack; effectively + * doing a tail-call without using a register. This PUSH;RET + * pattern unbalances the RSB, inject a pointless CALL to rebalance. + */ + ANNOTATE_INTRA_FUNCTION_CALL + CALL .Ldo_rebalance + int3 +.Ldo_rebalance: + add $8, %rsp + ALTERNATIVE __stringify(RET), \ + __stringify(ANNOTATE_UNRET_SAFE; ret; int3), \ + X86_FEATURE_CALL_DEPTH SYM_FUNC_END(ftrace_regs_caller) STACK_FRAME_NON_STANDARD_FP(ftrace_regs_caller) @@ -284,6 +311,8 @@ STACK_FRAME_NON_STANDARD_FP(ftrace_regs_caller) #else /* ! CONFIG_DYNAMIC_FTRACE */ SYM_FUNC_START(__fentry__) + CALL_DEPTH_ACCOUNT + cmpq $ftrace_stub, ftrace_trace_function jnz trace RET @@ -337,6 +366,8 @@ SYM_CODE_START(return_to_handler) int3 .Ldo_rop: mov %rdi, (%rsp) - RET + ALTERNATIVE __stringify(RET), \ + __stringify(ANNOTATE_UNRET_SAFE; ret; int3), \ + X86_FEATURE_CALL_DEPTH SYM_CODE_END(return_to_handler) #endif |