diff options
Diffstat (limited to 'arch/x86/kernel/ftrace_64.S')
| -rw-r--r-- | arch/x86/kernel/ftrace_64.S | 88 |
1 files changed, 74 insertions, 14 deletions
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S index 2a4be92fd144..a132608265f6 100644 --- a/arch/x86/kernel/ftrace_64.S +++ b/arch/x86/kernel/ftrace_64.S @@ -3,11 +3,12 @@ * Copyright (C) 2014 Steven Rostedt, Red Hat Inc */ -#include <linux/linkage.h> +#include <linux/export.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> #include <asm/nospec-branch.h> #include <asm/unwind_hints.h> #include <asm/frame.h> @@ -131,24 +132,33 @@ .endm SYM_TYPED_FUNC_START(ftrace_stub) + CALL_DEPTH_ACCOUNT RET SYM_FUNC_END(ftrace_stub) +#ifdef CONFIG_FUNCTION_GRAPH_TRACER SYM_TYPED_FUNC_START(ftrace_stub_graph) + CALL_DEPTH_ACCOUNT RET SYM_FUNC_END(ftrace_stub_graph) +#endif #ifdef CONFIG_DYNAMIC_FTRACE SYM_FUNC_START(__fentry__) + ANNOTATE_NOENDBR + CALL_DEPTH_ACCOUNT RET SYM_FUNC_END(__fentry__) EXPORT_SYMBOL(__fentry__) SYM_FUNC_START(ftrace_caller) + ANNOTATE_NOENDBR /* 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 +174,9 @@ 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 @@ -186,6 +199,7 @@ SYM_FUNC_END(ftrace_caller); STACK_FRAME_NON_STANDARD_FP(ftrace_caller) SYM_FUNC_START(ftrace_regs_caller) + ANNOTATE_NOENDBR /* Save the current flags before any operations that can change them */ pushfq @@ -193,6 +207,8 @@ 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 +239,9 @@ 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 @@ -266,8 +285,18 @@ SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL) ANNOTATE_NOENDBR RET +1: + testb $1, %al + jz 2f + andq $0xfffffffffffffffe, %rax + movq %rax, MCOUNT_REG_SIZE+8(%rsp) + restore_mcount_regs + /* Restore flags */ + popfq + RET + /* Swap the flags with orig_rax */ -1: movq MCOUNT_REG_SIZE(%rsp), %rdi +2: movq MCOUNT_REG_SIZE(%rsp), %rdi movq %rdi, MCOUNT_REG_SIZE-8(%rsp) movq %rax, MCOUNT_REG_SIZE(%rsp) @@ -275,15 +304,36 @@ 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) +SYM_FUNC_START(ftrace_stub_direct_tramp) + ANNOTATE_NOENDBR + CALL_DEPTH_ACCOUNT + RET +SYM_FUNC_END(ftrace_stub_direct_tramp) #else /* ! CONFIG_DYNAMIC_FTRACE */ SYM_FUNC_START(__fentry__) + ANNOTATE_NOENDBR + CALL_DEPTH_ACCOUNT + cmpq $ftrace_stub, ftrace_trace_function jnz trace RET @@ -311,22 +361,30 @@ STACK_FRAME_NON_STANDARD_FP(__fentry__) #ifdef CONFIG_FUNCTION_GRAPH_TRACER SYM_CODE_START(return_to_handler) - UNWIND_HINT_EMPTY + UNWIND_HINT_UNDEFINED ANNOTATE_NOENDBR - subq $16, %rsp - /* Save the return values */ - movq %rax, (%rsp) - movq %rdx, 8(%rsp) - movq %rbp, %rdi + /* Restore return_to_handler value that got eaten by previous ret instruction. */ + subq $8, %rsp + UNWIND_HINT_FUNC + + /* Save ftrace_regs for function exit context */ + subq $(FRAME_SIZE), %rsp + + movq %rax, RAX(%rsp) + movq %rdx, RDX(%rsp) + movq %rbp, RBP(%rsp) + movq %rsp, RSP(%rsp) + movq %rsp, %rdi call ftrace_return_to_handler movq %rax, %rdi - movq 8(%rsp), %rdx - movq (%rsp), %rax + movq RDX(%rsp), %rdx + movq RAX(%rsp), %rax + + addq $(FRAME_SIZE) + 8, %rsp - addq $16, %rsp /* * Jump back to the old return address. This cannot be JMP_NOSPEC rdi * since IBT would demand that contain ENDBR, which simply isn't so for @@ -337,6 +395,8 @@ 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 |