Commit-ID: f1b92bb6b5a4e17b508f128b084fa00e0eda590c
Gitweb: http://git.kernel.org/tip/f1b92bb6b5a4e17b508f128b084fa00e0eda590c
Author: Borislav Petkov <bp@xxxxxxx>
AuthorDate: Tue, 16 Feb 2016 09:43:21 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 17 Feb 2016 08:47:22 +0100
x86/ftrace, x86/asm: Kill ftrace_caller_end label
One of ftrace_caller_end 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.
Steve wants this to rather mean "[a]n event which reflects meaningfully
on a recently ended conflict or struggle." I can imagine that ftrace can
be a struggle sometimes.
Anyway, beef up the comment about the code contents and layout before
ftrace_epilogue label.
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1455612202-14414-4-git-send-email-bp@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
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 29408d6..04f9641e 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -697,9 +697,8 @@ 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);
@@ -746,7 +745,7 @@ 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;
}
@@ -754,7 +753,7 @@ 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 *));
@@ -772,8 +771,8 @@ 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 87e1762..ed48a9f 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)
--
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