From: Borislav Petkov <b...@suse.de>
One of ftrace_caller_and and ftrace_return is redundant so unify them.
Rename ftrace_return to ftrace_epilogue to mean that everything after
that label represents, like an afterword, work which happens *after* the
ftrace call, e.g., the function graph tracer for one.
Beef up the comment about the code contents and layout before
ftrace_epilogue label.
Signed-off-by: Borislav Petkov <b...@suse.de>
Cc: Steven Rostedt <rost...@goodmis.org>
---
arch/x86/kernel/ftrace.c | 11 +++++------
arch/x86/kernel/mcount_64.S | 14 ++++++++------
2 files changed, 13 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 311bcf338f07..26ad092ac0dc 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -690,9 +690,8 @@ static inline void tramp_free(void *tramp) { }
#endif
/* Defined as markers to the end of the ftrace default trampolines */
-extern void ftrace_caller_end(void);
extern void ftrace_regs_caller_end(void);
-extern void ftrace_return(void);
+extern void ftrace_epilogue(void);
extern void ftrace_caller_op_ptr(void);
extern void ftrace_regs_caller_op_ptr(void);
@@ -739,7 +738,7 @@ create_trampoline(struct ftrace_ops *ops, unsigned int
*tramp_size)
op_offset = (unsigned long)ftrace_regs_caller_op_ptr;
} else {
start_offset = (unsigned long)ftrace_caller;
- end_offset = (unsigned long)ftrace_caller_end;
+ end_offset = (unsigned long)ftrace_epilogue;
op_offset = (unsigned long)ftrace_caller_op_ptr;
}
@@ -747,7 +746,7 @@ create_trampoline(struct ftrace_ops *ops, unsigned int
*tramp_size)
/*
* Allocate enough size to store the ftrace_caller code,
- * the jmp to ftrace_return, as well as the address of
+ * the jmp to ftrace_epilogue, as well as the address of
* the ftrace_ops this trampoline is used for.
*/
trampoline = alloc_tramp(size + MCOUNT_INSN_SIZE + sizeof(void *));
@@ -765,8 +764,8 @@ create_trampoline(struct ftrace_ops *ops, unsigned int
*tramp_size)
ip = (unsigned long)trampoline + size;
- /* The trampoline ends with a jmp to ftrace_return */
- jmp = ftrace_jmp_replace(ip, (unsigned long)ftrace_return);
+ /* The trampoline ends with a jmp to ftrace_epilogue */
+ jmp = ftrace_jmp_replace(ip, (unsigned long)ftrace_epilogue);
memcpy(trampoline + size, jmp, MCOUNT_INSN_SIZE);
/*
diff --git a/arch/x86/kernel/mcount_64.S b/arch/x86/kernel/mcount_64.S
index 87e1762e2bca..ed48a9f465f8 100644
--- a/arch/x86/kernel/mcount_64.S
+++ b/arch/x86/kernel/mcount_64.S
@@ -168,12 +168,14 @@ GLOBAL(ftrace_call)
restore_mcount_regs
/*
- * The copied trampoline must call ftrace_return as it
+ * The copied trampoline must call ftrace_epilogue as it
* still may need to call the function graph tracer.
+ *
+ * The code up to this label is copied into trampolines so
+ * think twice before adding any new code or changing the
+ * layout here.
*/
-GLOBAL(ftrace_caller_end)
-
-GLOBAL(ftrace_return)
+GLOBAL(ftrace_epilogue)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
GLOBAL(ftrace_graph_call)
@@ -244,14 +246,14 @@ GLOBAL(ftrace_regs_call)
popfq
/*
- * As this jmp to ftrace_return can be a short jump
+ * As this jmp to ftrace_epilogue can be a short jump
* it must not be copied into the trampoline.
* The trampoline will add the code to jump
* to the return.
*/
GLOBAL(ftrace_regs_caller_end)
- jmp ftrace_return
+ jmp ftrace_epilogue
END(ftrace_regs_caller)
--
2.3.5
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