summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/ftrace_64.S
diff options
context:
space:
mode:
authorSteven Rostedt (VMware) <rostedt@goodmis.org>2021-10-08 11:13:31 +0200
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2021-10-21 05:44:43 +0200
commit0c0593b45c9b4e5b212ffb3fb28bb8d3c0ec0dc8 (patch)
tree59c3f8fe9cfa47a20889f8264b6f6a12f27ccfeb /arch/x86/kernel/ftrace_64.S
parentftrace/x86_64: Have function graph tracer depend on DYNAMIC_FTRACE (diff)
downloadlinux-0c0593b45c9b4e5b212ffb3fb28bb8d3c0ec0dc8.tar.xz
linux-0c0593b45c9b4e5b212ffb3fb28bb8d3c0ec0dc8.zip
x86/ftrace: Make function graph use ftrace directly
We don't need special hook for graph tracer entry point, but instead we can use graph_ops::func function to install the return_hooker. This moves the graph tracing setup _before_ the direct trampoline prepares the stack, so the return_hooker will be called when the direct trampoline is finished. This simplifies the code, because we don't need to take into account the direct trampoline setup when preparing the graph tracer hooker and we can allow function graph tracer on entries registered with direct trampoline. Link: https://lkml.kernel.org/r/20211008091336.33616-4-jolsa@kernel.org [fixed compile error reported by kernel test robot <lkp@intel.com>] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'arch/x86/kernel/ftrace_64.S')
-rw-r--r--arch/x86/kernel/ftrace_64.S29
1 files changed, 1 insertions, 28 deletions
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index a8eb084a7a9a..7a879901f103 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -174,11 +174,6 @@ SYM_INNER_LABEL(ftrace_caller_end, SYM_L_GLOBAL)
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
-#endif
-
/*
* This is weak to keep gas from relaxing the jumps.
* It is also used to copy the retq for trampolines.
@@ -288,15 +283,6 @@ SYM_FUNC_START(__fentry__)
cmpq $ftrace_stub, ftrace_trace_function
jnz trace
-fgraph_trace:
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- cmpq $ftrace_stub, ftrace_graph_return
- jnz ftrace_graph_caller
-
- cmpq $ftrace_graph_entry_stub, ftrace_graph_entry
- jnz ftrace_graph_caller
-#endif
-
SYM_INNER_LABEL(ftrace_stub, SYM_L_GLOBAL)
retq
@@ -314,25 +300,12 @@ trace:
CALL_NOSPEC r8
restore_mcount_regs
- jmp fgraph_trace
+ jmp ftrace_stub
SYM_FUNC_END(__fentry__)
EXPORT_SYMBOL(__fentry__)
#endif /* CONFIG_DYNAMIC_FTRACE */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-SYM_FUNC_START(ftrace_graph_caller)
- /* Saves rbp into %rdx and fills first parameter */
- save_mcount_regs
-
- leaq MCOUNT_REG_SIZE+8(%rsp), %rsi
- movq $0, %rdx /* No framepointers needed */
- call prepare_ftrace_return
-
- restore_mcount_regs
-
- retq
-SYM_FUNC_END(ftrace_graph_caller)
-
SYM_FUNC_START(return_to_handler)
subq $24, %rsp