forked from Minki/linux
ftrace/x86: Get rid of ftrace_caller_setup
Move all the work from ftrace_caller_setup into save_mcount_regs. This simplifies the code and makes it easier to understand. Link: http://lkml.kernel.org/r/CA+55aFxUTUbdxpjVMW8X9c=o8sui7OB_MYPfcbJuDyfUWtNrNg@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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@ -54,7 +54,15 @@
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* be saved in the locations that pt_regs has them in.
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*/
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/* @added: the amount of stack added before calling this */
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/*
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* @added: the amount of stack added before calling this
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*
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* After this is called, the following registers contain:
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*
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* %rdi - holds the address that called the trampoline
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* %rsi - holds the parent function (traced function's return address)
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* %rdx - holds the original %rbp
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*/
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.macro save_mcount_regs added=0
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/* Always save the original rbp */
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@ -101,9 +109,24 @@
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movq MCOUNT_REG_SIZE-8(%rsp), %rdx
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movq %rdx, RBP(%rsp)
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/* Copy the parent address into %rsi (second parameter) */
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#ifdef CC_USING_FENTRY
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movq MCOUNT_REG_SIZE+8+\added(%rsp), %rsi
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#else
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/* %rdx contains original %rbp */
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movq 8(%rdx), %rsi
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#endif
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/* Move RIP to its proper location */
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movq MCOUNT_REG_SIZE+\added(%rsp), %rdi
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movq %rdi, RIP(%rsp)
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/*
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* Now %rdi (the first parameter) has the return address of
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* where ftrace_call returns. But the callbacks expect the
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* the address of the call itself.
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*/
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subq $MCOUNT_INSN_SIZE, %rdi
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.endm
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.macro restore_mcount_regs
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@ -122,28 +145,6 @@
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.endm
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/* skip is set if stack has been adjusted */
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.macro ftrace_caller_setup trace_label added=0
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save_mcount_regs \added
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/* Save this location */
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GLOBAL(\trace_label)
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/* Load the ftrace_ops into the 3rd parameter */
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movq function_trace_op(%rip), %rdx
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/* %rdi already has %rip from the save_mcount_regs macro */
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subq $MCOUNT_INSN_SIZE, %rdi
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/* Load the parent_ip into the second parameter */
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#ifdef CC_USING_FENTRY
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movq MCOUNT_REG_SIZE+8+\added(%rsp), %rsi
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#else
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/* Need to grab the original %rbp */
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movq RBP(%rsp), %rsi
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/* Now parent address is 8 above original %rbp */
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movq 8(%rsi), %rsi
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#endif
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.endm
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#ifdef CONFIG_DYNAMIC_FTRACE
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ENTRY(function_hook)
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@ -151,7 +152,13 @@ ENTRY(function_hook)
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END(function_hook)
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ENTRY(ftrace_caller)
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ftrace_caller_setup ftrace_caller_op_ptr
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/* save_mcount_regs fills in first two parameters */
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save_mcount_regs
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GLOBAL(ftrace_caller_op_ptr)
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/* Load the ftrace_ops into the 3rd parameter */
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movq function_trace_op(%rip), %rdx
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/* regs go into 4th parameter (but make it NULL) */
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movq $0, %rcx
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@ -182,7 +189,12 @@ ENTRY(ftrace_regs_caller)
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pushfq
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/* added 8 bytes to save flags */
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ftrace_caller_setup ftrace_regs_caller_op_ptr 8
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save_mcount_regs 8
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/* save_mcount_regs fills in first two parameters */
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GLOBAL(ftrace_regs_caller_op_ptr)
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/* Load the ftrace_ops into the 3rd parameter */
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movq function_trace_op(%rip), %rdx
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/* Save the rest of pt_regs */
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movq %r15, R15(%rsp)
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@ -263,7 +275,8 @@ GLOBAL(ftrace_stub)
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retq
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trace:
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ftrace_caller_setup ftrace_caller_op_ptr
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/* save_mcount_regs fills in first two parameters */
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save_mcount_regs
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call *ftrace_trace_function
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@ -276,16 +289,16 @@ END(function_hook)
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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ENTRY(ftrace_graph_caller)
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/* Saves rbp into %rdx */
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save_mcount_regs
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#ifdef CC_USING_FENTRY
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leaq MCOUNT_REG_SIZE+8(%rsp), %rdi
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movq $0, %rdx /* No framepointers needed */
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#else
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/* Need to grab the original %rbp */
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movq RBP(%rsp), %rdx
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/* Now parent address is 8 above original %rbp */
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/* Save address of the return address of traced function */
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leaq 8(%rdx), %rdi
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/* ftrace does sanity checks against frame pointers */
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movq (%rdx), %rdx
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#endif
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movq RIP(%rsp), %rsi
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