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WSL2-Linux-Kernel/arch/x86/kernel/ftrace_64.S

333 строки
7.8 KiB
ArmAsm
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ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
/*
* Copyright (C) 2014 Steven Rostedt, Red Hat Inc
*/
#include <linux/linkage.h>
#include <asm/ptrace.h>
#include <asm/ftrace.h>
x86: move exports to actual definitions Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-11 19:04:34 +03:00
#include <asm/export.h>
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
.code64
.section .entry.text, "ax"
#ifdef CC_USING_FENTRY
# define function_hook __fentry__
x86: Fix export for mcount and __fentry__ Commit 784d5699eddc5 ("x86: move exports to actual definitions") removed the EXPORT_SYMBOL(__fentry__) and EXPORT_SYMBOL(mcount) from x8664_ksyms_64.c, and added EXPORT_SYMBOL(function_hook) in mcount_64.S instead. The problem is that function_hook isn't a function at all, but a macro that is defined as either mcount or __fentry__ depending on the support from gcc. Originally, I thought this was a macro issue, like what __stringify() is used for. But the problem is a bit deeper. The Makefile.build has some magic that does post processing of files to create the CRC bindings. It does some searches for EXPORT_SYMBOL() and because it finds a macro name and not the actual functions, this causes function_hook not to be converted into mcount or __fentry__ and they are missed. Instead of adding more magic to Makefile.build, just add EXPORT_SYMBOL() for mcount and __fentry__ where the ifdef is used. Since this is assembly and not C, it doesn't require being set after the function is defined. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Tested-by: Borislav Petkov <bp@alien8.de> Cc: Gabriel C <nix.or.die@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Link: http://lkml.kernel.org/r/20161024150148.4f9d90e4@gandalf.local.home Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-24 22:01:48 +03:00
EXPORT_SYMBOL(__fentry__)
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
#else
# define function_hook mcount
x86: Fix export for mcount and __fentry__ Commit 784d5699eddc5 ("x86: move exports to actual definitions") removed the EXPORT_SYMBOL(__fentry__) and EXPORT_SYMBOL(mcount) from x8664_ksyms_64.c, and added EXPORT_SYMBOL(function_hook) in mcount_64.S instead. The problem is that function_hook isn't a function at all, but a macro that is defined as either mcount or __fentry__ depending on the support from gcc. Originally, I thought this was a macro issue, like what __stringify() is used for. But the problem is a bit deeper. The Makefile.build has some magic that does post processing of files to create the CRC bindings. It does some searches for EXPORT_SYMBOL() and because it finds a macro name and not the actual functions, this causes function_hook not to be converted into mcount or __fentry__ and they are missed. Instead of adding more magic to Makefile.build, just add EXPORT_SYMBOL() for mcount and __fentry__ where the ifdef is used. Since this is assembly and not C, it doesn't require being set after the function is defined. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Tested-by: Borislav Petkov <bp@alien8.de> Cc: Gabriel C <nix.or.die@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Link: http://lkml.kernel.org/r/20161024150148.4f9d90e4@gandalf.local.home Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-24 22:01:48 +03:00
EXPORT_SYMBOL(mcount)
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
#endif
ftrace/x86: Have save_mcount_regs macro also save stack frames if needed The save_mcount_regs macro saves and restores the required mcount regs that need to be saved before calling C code. It is done for all the function hook utilities (static tracing, dynamic tracing, regs, function graph). When frame pointers are enabled, the ftrace trampolines need to set up frames and pointers such that a back trace (dump stack) can continue passed them. Currently, a separate macro is used (create_frame) to do this, but it's only done for the ftrace_caller and ftrace_reg_caller functions. It is not done for the static tracer or function graph tracing. Instead of having a separate macro doing the recording of the frames, have the save_mcount_regs perform this task. This also has all tracers saving the frame pointers when needed. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@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>
2014-11-25 02:08:48 +03:00
/* All cases save the original rbp (8 bytes) */
#ifdef CONFIG_FRAME_POINTER
# ifdef CC_USING_FENTRY
/* Save parent and function stack frames (rip and rbp) */
# define MCOUNT_FRAME_SIZE (8+16*2)
# else
/* Save just function stack frame (rip and rbp) */
# define MCOUNT_FRAME_SIZE (8+16)
# endif
#else
/* No need to save a stack frame */
# define MCOUNT_FRAME_SIZE 8
#endif /* CONFIG_FRAME_POINTER */
ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs The macro save_mcount_regs saves regs onto the stack. But to uncouple the amount of stack used in that macro from the users of the macro, we need to have a define that tells all the users how much stack is used by that macro. This way we can change the amount of stack the macro uses without breaking its users. Also remove some dead code that was left over from commit fdc841b58cf5 "ftrace: x86: Remove check of obsolete variable function_trace_stop". Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 22:26:38 +03:00
/* Size of stack used to save mcount regs in save_mcount_regs */
ftrace/x86: Have save_mcount_regs macro also save stack frames if needed The save_mcount_regs macro saves and restores the required mcount regs that need to be saved before calling C code. It is done for all the function hook utilities (static tracing, dynamic tracing, regs, function graph). When frame pointers are enabled, the ftrace trampolines need to set up frames and pointers such that a back trace (dump stack) can continue passed them. Currently, a separate macro is used (create_frame) to do this, but it's only done for the ftrace_caller and ftrace_reg_caller functions. It is not done for the static tracer or function graph tracing. Instead of having a separate macro doing the recording of the frames, have the save_mcount_regs perform this task. This also has all tracers saving the frame pointers when needed. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@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>
2014-11-25 02:08:48 +03:00
#define MCOUNT_REG_SIZE (SS+8 + MCOUNT_FRAME_SIZE)
ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs The macro save_mcount_regs saves regs onto the stack. But to uncouple the amount of stack used in that macro from the users of the macro, we need to have a define that tells all the users how much stack is used by that macro. This way we can change the amount of stack the macro uses without breaking its users. Also remove some dead code that was left over from commit fdc841b58cf5 "ftrace: x86: Remove check of obsolete variable function_trace_stop". Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 22:26:38 +03:00
ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments The name MCOUNT_SAVE_FRAME is rather confusing as it really isn't a function frame that is saved, but just the required mcount registers that are needed to be saved before C code may be called. The word "frame" confuses it as being a function frame which it is not. Rename MCOUNT_SAVE_FRAME and MCOUNT_RESTORE_FRAME to save_mcount_regs and restore_mcount_regs respectively. Noticed the lower case, which keeps it from screaming at the reviewers. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 19:43:39 +03:00
/*
* gcc -pg option adds a call to 'mcount' in most functions.
* When -mfentry is used, the call is to 'fentry' and not 'mcount'
* and is done before the function's stack frame is set up.
* They both require a set of regs to be saved before calling
* any C code and restored before returning back to the function.
*
* On boot up, all these calls are converted into nops. When tracing
* is enabled, the call can jump to either ftrace_caller or
* ftrace_regs_caller. Callbacks (tracing functions) that require
* ftrace_regs_caller (like kprobes) need to have pt_regs passed to
* it. For this reason, the size of the pt_regs structure will be
* allocated on the stack and the required mcount registers will
* be saved in the locations that pt_regs has them in.
*/
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>
2014-11-25 05:38:40 +03:00
/*
* @added: the amount of stack added before calling this
*
* After this is called, the following registers contain:
*
* %rdi - holds the address that called the trampoline
* %rsi - holds the parent function (traced function's return address)
* %rdx - holds the original %rbp
*/
ftrace/x86: Simplify save_mcount_regs on getting RIP Currently save_mcount_regs is passed a "skip" parameter to know how much stack updated the pt_regs, as it tries to keep the saved pt_regs in the same location for all users. This is rather stupid, especially since the part stored on the pt_regs has nothing to do with what is suppose to be in that location. Instead of doing that, just pass in an "added" parameter that lets that macro know how much stack was added before it was called so that it can get to the RIP. But the difference is that it will now offset the pt_regs by that "added" count. The caller now needs to take care of the offset of the pt_regs. This will make it easier to simplify the code later. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 21:06:05 +03:00
.macro save_mcount_regs added=0
ftrace/x86: Have save_mcount_regs macro also save stack frames if needed The save_mcount_regs macro saves and restores the required mcount regs that need to be saved before calling C code. It is done for all the function hook utilities (static tracing, dynamic tracing, regs, function graph). When frame pointers are enabled, the ftrace trampolines need to set up frames and pointers such that a back trace (dump stack) can continue passed them. Currently, a separate macro is used (create_frame) to do this, but it's only done for the ftrace_caller and ftrace_reg_caller functions. It is not done for the static tracer or function graph tracing. Instead of having a separate macro doing the recording of the frames, have the save_mcount_regs perform this task. This also has all tracers saving the frame pointers when needed. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@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>
2014-11-25 02:08:48 +03:00
/* Always save the original rbp */
pushq %rbp
#ifdef CONFIG_FRAME_POINTER
/*
* Stack traces will stop at the ftrace trampoline if the frame pointer
* is not set up properly. If fentry is used, we need to save a frame
* pointer for the parent as well as the function traced, because the
* fentry is called before the stack frame is set up, where as mcount
* is called afterward.
*/
#ifdef CC_USING_FENTRY
/* Save the parent pointer (skip orig rbp and our return address) */
pushq \added+8*2(%rsp)
pushq %rbp
movq %rsp, %rbp
/* Save the return address (now skip orig rbp, rbp and parent) */
pushq \added+8*3(%rsp)
#else
/* Can't assume that rip is before this (unless added was zero) */
pushq \added+8(%rsp)
#endif
pushq %rbp
movq %rsp, %rbp
#endif /* CONFIG_FRAME_POINTER */
/*
* We add enough stack to save all regs.
*/
subq $(MCOUNT_REG_SIZE - MCOUNT_FRAME_SIZE), %rsp
ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file Linus pointed out that MCOUNT_SAVE_FRAME is used in only a single file and that there's no reason that it should be in a header file. Move the macro to the code that uses it. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 19:30:58 +03:00
movq %rax, RAX(%rsp)
movq %rcx, RCX(%rsp)
movq %rdx, RDX(%rsp)
movq %rsi, RSI(%rsp)
movq %rdi, RDI(%rsp)
movq %r8, R8(%rsp)
movq %r9, R9(%rsp)
ftrace/x86: Have save_mcount_regs macro also save stack frames if needed The save_mcount_regs macro saves and restores the required mcount regs that need to be saved before calling C code. It is done for all the function hook utilities (static tracing, dynamic tracing, regs, function graph). When frame pointers are enabled, the ftrace trampolines need to set up frames and pointers such that a back trace (dump stack) can continue passed them. Currently, a separate macro is used (create_frame) to do this, but it's only done for the ftrace_caller and ftrace_reg_caller functions. It is not done for the static tracer or function graph tracing. Instead of having a separate macro doing the recording of the frames, have the save_mcount_regs perform this task. This also has all tracers saving the frame pointers when needed. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@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>
2014-11-25 02:08:48 +03:00
/*
* Save the original RBP. Even though the mcount ABI does not
* require this, it helps out callers.
*/
movq MCOUNT_REG_SIZE-8(%rsp), %rdx
movq %rdx, RBP(%rsp)
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>
2014-11-25 05:38:40 +03:00
/* Copy the parent address into %rsi (second parameter) */
#ifdef CC_USING_FENTRY
movq MCOUNT_REG_SIZE+8+\added(%rsp), %rsi
#else
/* %rdx contains original %rbp */
movq 8(%rdx), %rsi
#endif
ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file Linus pointed out that MCOUNT_SAVE_FRAME is used in only a single file and that there's no reason that it should be in a header file. Move the macro to the code that uses it. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 19:30:58 +03:00
/* Move RIP to its proper location */
ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs The macro save_mcount_regs saves regs onto the stack. But to uncouple the amount of stack used in that macro from the users of the macro, we need to have a define that tells all the users how much stack is used by that macro. This way we can change the amount of stack the macro uses without breaking its users. Also remove some dead code that was left over from commit fdc841b58cf5 "ftrace: x86: Remove check of obsolete variable function_trace_stop". Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 22:26:38 +03:00
movq MCOUNT_REG_SIZE+\added(%rsp), %rdi
ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameter Instead of having save_mcount_regs store the RIP in %rdx as a temp register to place it in the proper location of the pt_regs on the stack. Use the %rdi register as the temp register. This lets us remove the extra store in the ftrace_caller_setup macro. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@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>
2014-11-24 21:21:09 +03:00
movq %rdi, RIP(%rsp)
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>
2014-11-25 05:38:40 +03:00
/*
* Now %rdi (the first parameter) has the return address of
* where ftrace_call returns. But the callbacks expect the
ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter The function graph helper function prepare_ftrace_return() which does the work to hijack the parent pointer has that parent pointer as its first parameter. Instead, if we make it the second parameter and have ip as the first parameter (self_addr), then it can use the %rdi from save_mcount_regs that loads it already. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-25 05:00:34 +03:00
* address of the call itself.
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>
2014-11-25 05:38:40 +03:00
*/
subq $MCOUNT_INSN_SIZE, %rdi
ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file Linus pointed out that MCOUNT_SAVE_FRAME is used in only a single file and that there's no reason that it should be in a header file. Move the macro to the code that uses it. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 19:30:58 +03:00
.endm
ftrace/x86: Simplify save_mcount_regs on getting RIP Currently save_mcount_regs is passed a "skip" parameter to know how much stack updated the pt_regs, as it tries to keep the saved pt_regs in the same location for all users. This is rather stupid, especially since the part stored on the pt_regs has nothing to do with what is suppose to be in that location. Instead of doing that, just pass in an "added" parameter that lets that macro know how much stack was added before it was called so that it can get to the RIP. But the difference is that it will now offset the pt_regs by that "added" count. The caller now needs to take care of the offset of the pt_regs. This will make it easier to simplify the code later. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 21:06:05 +03:00
.macro restore_mcount_regs
ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file Linus pointed out that MCOUNT_SAVE_FRAME is used in only a single file and that there's no reason that it should be in a header file. Move the macro to the code that uses it. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 19:30:58 +03:00
movq R9(%rsp), %r9
movq R8(%rsp), %r8
movq RDI(%rsp), %rdi
movq RSI(%rsp), %rsi
movq RDX(%rsp), %rdx
movq RCX(%rsp), %rcx
movq RAX(%rsp), %rax
ftrace/x86: Have save_mcount_regs macro also save stack frames if needed The save_mcount_regs macro saves and restores the required mcount regs that need to be saved before calling C code. It is done for all the function hook utilities (static tracing, dynamic tracing, regs, function graph). When frame pointers are enabled, the ftrace trampolines need to set up frames and pointers such that a back trace (dump stack) can continue passed them. Currently, a separate macro is used (create_frame) to do this, but it's only done for the ftrace_caller and ftrace_reg_caller functions. It is not done for the static tracer or function graph tracing. Instead of having a separate macro doing the recording of the frames, have the save_mcount_regs perform this task. This also has all tracers saving the frame pointers when needed. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@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>
2014-11-25 02:08:48 +03:00
/* ftrace_regs_caller can modify %rbp */
movq RBP(%rsp), %rbp
ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs The macro save_mcount_regs saves regs onto the stack. But to uncouple the amount of stack used in that macro from the users of the macro, we need to have a define that tells all the users how much stack is used by that macro. This way we can change the amount of stack the macro uses without breaking its users. Also remove some dead code that was left over from commit fdc841b58cf5 "ftrace: x86: Remove check of obsolete variable function_trace_stop". Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 22:26:38 +03:00
addq $MCOUNT_REG_SIZE, %rsp
ftrace/x86: Have save_mcount_regs macro also save stack frames if needed The save_mcount_regs macro saves and restores the required mcount regs that need to be saved before calling C code. It is done for all the function hook utilities (static tracing, dynamic tracing, regs, function graph). When frame pointers are enabled, the ftrace trampolines need to set up frames and pointers such that a back trace (dump stack) can continue passed them. Currently, a separate macro is used (create_frame) to do this, but it's only done for the ftrace_caller and ftrace_reg_caller functions. It is not done for the static tracer or function graph tracing. Instead of having a separate macro doing the recording of the frames, have the save_mcount_regs perform this task. This also has all tracers saving the frame pointers when needed. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@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>
2014-11-25 02:08:48 +03:00
ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file Linus pointed out that MCOUNT_SAVE_FRAME is used in only a single file and that there's no reason that it should be in a header file. Move the macro to the code that uses it. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 19:30:58 +03:00
.endm
ftrace/x86: Have static tracing also use ftrace_caller_setup Linus pointed out that there were locations that did the hard coded update of the parent and rip parameters. One of them was the static tracer which could also use the ftrace_caller_setup to do that work. In fact, because it did not use it, it is prone to bugs, and since the static tracer is hardly ever used (who wants function tracing code always being called?) it doesn't get tested very often. I only run a few "does it still work" tests on it. But I do not run stress tests on that code. Although, since it is never turned off, just having it on should be stressful enough. (especially for the performance folks) There's no reason that the static tracer can't also use ftrace_caller_setup. Have it do so. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 22:54:27 +03:00
#ifdef CONFIG_DYNAMIC_FTRACE
ENTRY(function_hook)
retq
END(function_hook)
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
ENTRY(ftrace_caller)
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>
2014-11-25 05:38:40 +03:00
/* save_mcount_regs fills in first two parameters */
save_mcount_regs
GLOBAL(ftrace_caller_op_ptr)
/* Load the ftrace_ops into the 3rd parameter */
movq function_trace_op(%rip), %rdx
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
/* regs go into 4th parameter (but make it NULL) */
movq $0, %rcx
GLOBAL(ftrace_call)
call ftrace_stub
ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments The name MCOUNT_SAVE_FRAME is rather confusing as it really isn't a function frame that is saved, but just the required mcount registers that are needed to be saved before C code may be called. The word "frame" confuses it as being a function frame which it is not. Rename MCOUNT_SAVE_FRAME and MCOUNT_RESTORE_FRAME to save_mcount_regs and restore_mcount_regs respectively. Noticed the lower case, which keeps it from screaming at the reviewers. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 19:43:39 +03:00
restore_mcount_regs
ftrace/x86: Add dynamic allocated trampoline for ftrace_ops The current method of handling multiple function callbacks is to register a list function callback that calls all the other callbacks based on their hash tables and compare it to the function that the callback was called on. But this is very inefficient. For example, if you are tracing all functions in the kernel and then add a kprobe to a function such that the kprobe uses ftrace, the mcount trampoline will switch from calling the function trace callback to calling the list callback that will iterate over all registered ftrace_ops (in this case, the function tracer and the kprobes callback). That means for every function being traced it checks the hash of the ftrace_ops for function tracing and kprobes, even though the kprobes is only set at a single function. The kprobes ftrace_ops is checked for every function being traced! Instead of calling the list function for functions that are only being traced by a single callback, we can call a dynamically allocated trampoline that calls the callback directly. The function graph tracer already uses a direct call trampoline when it is being traced by itself but it is not dynamically allocated. It's trampoline is static in the kernel core. The infrastructure that called the function graph trampoline can also be used to call a dynamically allocated one. For now, only ftrace_ops that are not dynamically allocated can have a trampoline. That is, users such as function tracer or stack tracer. kprobes and perf allocate their ftrace_ops, and until there's a safe way to free the trampoline, it can not be used. The dynamically allocated ftrace_ops may, although, use the trampoline if the kernel is not compiled with CONFIG_PREEMPT. But that will come later. Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-03 07:23:31 +04:00
/*
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@suse.de> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1455612202-14414-4-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-16 11:43:21 +03:00
* The copied trampoline must call ftrace_epilogue as it
ftrace/x86: Add dynamic allocated trampoline for ftrace_ops The current method of handling multiple function callbacks is to register a list function callback that calls all the other callbacks based on their hash tables and compare it to the function that the callback was called on. But this is very inefficient. For example, if you are tracing all functions in the kernel and then add a kprobe to a function such that the kprobe uses ftrace, the mcount trampoline will switch from calling the function trace callback to calling the list callback that will iterate over all registered ftrace_ops (in this case, the function tracer and the kprobes callback). That means for every function being traced it checks the hash of the ftrace_ops for function tracing and kprobes, even though the kprobes is only set at a single function. The kprobes ftrace_ops is checked for every function being traced! Instead of calling the list function for functions that are only being traced by a single callback, we can call a dynamically allocated trampoline that calls the callback directly. The function graph tracer already uses a direct call trampoline when it is being traced by itself but it is not dynamically allocated. It's trampoline is static in the kernel core. The infrastructure that called the function graph trampoline can also be used to call a dynamically allocated one. For now, only ftrace_ops that are not dynamically allocated can have a trampoline. That is, users such as function tracer or stack tracer. kprobes and perf allocate their ftrace_ops, and until there's a safe way to free the trampoline, it can not be used. The dynamically allocated ftrace_ops may, although, use the trampoline if the kernel is not compiled with CONFIG_PREEMPT. But that will come later. Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-03 07:23:31 +04:00
* still may need to call the function graph tracer.
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@suse.de> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1455612202-14414-4-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-16 11:43:21 +03:00
*
* The code up to this label is copied into trampolines so
* think twice before adding any new code or changing the
* layout here.
ftrace/x86: Add dynamic allocated trampoline for ftrace_ops The current method of handling multiple function callbacks is to register a list function callback that calls all the other callbacks based on their hash tables and compare it to the function that the callback was called on. But this is very inefficient. For example, if you are tracing all functions in the kernel and then add a kprobe to a function such that the kprobe uses ftrace, the mcount trampoline will switch from calling the function trace callback to calling the list callback that will iterate over all registered ftrace_ops (in this case, the function tracer and the kprobes callback). That means for every function being traced it checks the hash of the ftrace_ops for function tracing and kprobes, even though the kprobes is only set at a single function. The kprobes ftrace_ops is checked for every function being traced! Instead of calling the list function for functions that are only being traced by a single callback, we can call a dynamically allocated trampoline that calls the callback directly. The function graph tracer already uses a direct call trampoline when it is being traced by itself but it is not dynamically allocated. It's trampoline is static in the kernel core. The infrastructure that called the function graph trampoline can also be used to call a dynamically allocated one. For now, only ftrace_ops that are not dynamically allocated can have a trampoline. That is, users such as function tracer or stack tracer. kprobes and perf allocate their ftrace_ops, and until there's a safe way to free the trampoline, it can not be used. The dynamically allocated ftrace_ops may, although, use the trampoline if the kernel is not compiled with CONFIG_PREEMPT. But that will come later. Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-03 07:23:31 +04:00
*/
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@suse.de> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1455612202-14414-4-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-16 11:43:21 +03:00
GLOBAL(ftrace_epilogue)
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
GLOBAL(ftrace_graph_call)
jmp ftrace_stub
#endif
ftrace/x86: Set ftrace_stub to weak to prevent gcc from using short jumps to it Matt Fleming reported seeing crashes when enabling and disabling function profiling which uses function graph tracer. Later Namhyung Kim hit a similar issue and he found that the issue was due to the jmp to ftrace_stub in ftrace_graph_call was only two bytes, and when it was changed to jump to the tracing code, it overwrote the ftrace_stub that was after it. Masami Hiramatsu bisected this down to a binutils change: 8dcea93252a9ea7dff57e85220a719e2a5e8ab41 is the first bad commit commit 8dcea93252a9ea7dff57e85220a719e2a5e8ab41 Author: H.J. Lu <hjl.tools@gmail.com> Date: Fri May 15 03:17:31 2015 -0700 Add -mshared option to x86 ELF assembler This patch adds -mshared option to x86 ELF assembler. By default, assembler will optimize out non-PLT relocations against defined non-weak global branch targets with default visibility. The -mshared option tells the assembler to generate code which may go into a shared library where all non-weak global branch targets with default visibility can be preempted. The resulting code is slightly bigger. This option only affects the handling of branch instructions. Declaring ftrace_stub as a weak call prevents gas from using two byte jumps to it, which would be converted to a jump to the function graph code. Link: http://lkml.kernel.org/r/20160516230035.1dbae571@gandalf.local.home Reported-by: Matt Fleming <matt@codeblueprint.co.uk> Reported-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-05-17 06:00:35 +03:00
/* This is weak to keep gas from relaxing the jumps */
WEAK(ftrace_stub)
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
retq
END(ftrace_caller)
ENTRY(ftrace_regs_caller)
ftrace/x86: Simplify save_mcount_regs on getting RIP Currently save_mcount_regs is passed a "skip" parameter to know how much stack updated the pt_regs, as it tries to keep the saved pt_regs in the same location for all users. This is rather stupid, especially since the part stored on the pt_regs has nothing to do with what is suppose to be in that location. Instead of doing that, just pass in an "added" parameter that lets that macro know how much stack was added before it was called so that it can get to the RIP. But the difference is that it will now offset the pt_regs by that "added" count. The caller now needs to take care of the offset of the pt_regs. This will make it easier to simplify the code later. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 21:06:05 +03:00
/* Save the current flags before any operations that can change them */
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
pushfq
ftrace/x86: Simplify save_mcount_regs on getting RIP Currently save_mcount_regs is passed a "skip" parameter to know how much stack updated the pt_regs, as it tries to keep the saved pt_regs in the same location for all users. This is rather stupid, especially since the part stored on the pt_regs has nothing to do with what is suppose to be in that location. Instead of doing that, just pass in an "added" parameter that lets that macro know how much stack was added before it was called so that it can get to the RIP. But the difference is that it will now offset the pt_regs by that "added" count. The caller now needs to take care of the offset of the pt_regs. This will make it easier to simplify the code later. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 21:06:05 +03:00
/* added 8 bytes to save flags */
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>
2014-11-25 05:38:40 +03:00
save_mcount_regs 8
/* save_mcount_regs fills in first two parameters */
GLOBAL(ftrace_regs_caller_op_ptr)
/* Load the ftrace_ops into the 3rd parameter */
movq function_trace_op(%rip), %rdx
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
/* Save the rest of pt_regs */
movq %r15, R15(%rsp)
movq %r14, R14(%rsp)
movq %r13, R13(%rsp)
movq %r12, R12(%rsp)
movq %r11, R11(%rsp)
movq %r10, R10(%rsp)
movq %rbx, RBX(%rsp)
/* Copy saved flags */
ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs The macro save_mcount_regs saves regs onto the stack. But to uncouple the amount of stack used in that macro from the users of the macro, we need to have a define that tells all the users how much stack is used by that macro. This way we can change the amount of stack the macro uses without breaking its users. Also remove some dead code that was left over from commit fdc841b58cf5 "ftrace: x86: Remove check of obsolete variable function_trace_stop". Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 22:26:38 +03:00
movq MCOUNT_REG_SIZE(%rsp), %rcx
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
movq %rcx, EFLAGS(%rsp)
/* Kernel segments */
movq $__KERNEL_DS, %rcx
movq %rcx, SS(%rsp)
movq $__KERNEL_CS, %rcx
movq %rcx, CS(%rsp)
ftrace/x86: Simplify save_mcount_regs on getting RIP Currently save_mcount_regs is passed a "skip" parameter to know how much stack updated the pt_regs, as it tries to keep the saved pt_regs in the same location for all users. This is rather stupid, especially since the part stored on the pt_regs has nothing to do with what is suppose to be in that location. Instead of doing that, just pass in an "added" parameter that lets that macro know how much stack was added before it was called so that it can get to the RIP. But the difference is that it will now offset the pt_regs by that "added" count. The caller now needs to take care of the offset of the pt_regs. This will make it easier to simplify the code later. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 21:06:05 +03:00
/* Stack - skipping return address and flags */
ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs The macro save_mcount_regs saves regs onto the stack. But to uncouple the amount of stack used in that macro from the users of the macro, we need to have a define that tells all the users how much stack is used by that macro. This way we can change the amount of stack the macro uses without breaking its users. Also remove some dead code that was left over from commit fdc841b58cf5 "ftrace: x86: Remove check of obsolete variable function_trace_stop". Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 22:26:38 +03:00
leaq MCOUNT_REG_SIZE+8*2(%rsp), %rcx
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
movq %rcx, RSP(%rsp)
/* regs go into 4th parameter */
leaq (%rsp), %rcx
GLOBAL(ftrace_regs_call)
call ftrace_stub
/* Copy flags back to SS, to restore them */
movq EFLAGS(%rsp), %rax
ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs The macro save_mcount_regs saves regs onto the stack. But to uncouple the amount of stack used in that macro from the users of the macro, we need to have a define that tells all the users how much stack is used by that macro. This way we can change the amount of stack the macro uses without breaking its users. Also remove some dead code that was left over from commit fdc841b58cf5 "ftrace: x86: Remove check of obsolete variable function_trace_stop". Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 22:26:38 +03:00
movq %rax, MCOUNT_REG_SIZE(%rsp)
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
/* Handlers can change the RIP */
movq RIP(%rsp), %rax
ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs The macro save_mcount_regs saves regs onto the stack. But to uncouple the amount of stack used in that macro from the users of the macro, we need to have a define that tells all the users how much stack is used by that macro. This way we can change the amount of stack the macro uses without breaking its users. Also remove some dead code that was left over from commit fdc841b58cf5 "ftrace: x86: Remove check of obsolete variable function_trace_stop". Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 22:26:38 +03:00
movq %rax, MCOUNT_REG_SIZE+8(%rsp)
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
/* restore the rest of pt_regs */
movq R15(%rsp), %r15
movq R14(%rsp), %r14
movq R13(%rsp), %r13
movq R12(%rsp), %r12
movq R10(%rsp), %r10
movq RBX(%rsp), %rbx
ftrace/x86: Simplify save_mcount_regs on getting RIP Currently save_mcount_regs is passed a "skip" parameter to know how much stack updated the pt_regs, as it tries to keep the saved pt_regs in the same location for all users. This is rather stupid, especially since the part stored on the pt_regs has nothing to do with what is suppose to be in that location. Instead of doing that, just pass in an "added" parameter that lets that macro know how much stack was added before it was called so that it can get to the RIP. But the difference is that it will now offset the pt_regs by that "added" count. The caller now needs to take care of the offset of the pt_regs. This will make it easier to simplify the code later. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 21:06:05 +03:00
restore_mcount_regs
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
/* Restore flags */
popfq
ftrace/x86: Add dynamic allocated trampoline for ftrace_ops The current method of handling multiple function callbacks is to register a list function callback that calls all the other callbacks based on their hash tables and compare it to the function that the callback was called on. But this is very inefficient. For example, if you are tracing all functions in the kernel and then add a kprobe to a function such that the kprobe uses ftrace, the mcount trampoline will switch from calling the function trace callback to calling the list callback that will iterate over all registered ftrace_ops (in this case, the function tracer and the kprobes callback). That means for every function being traced it checks the hash of the ftrace_ops for function tracing and kprobes, even though the kprobes is only set at a single function. The kprobes ftrace_ops is checked for every function being traced! Instead of calling the list function for functions that are only being traced by a single callback, we can call a dynamically allocated trampoline that calls the callback directly. The function graph tracer already uses a direct call trampoline when it is being traced by itself but it is not dynamically allocated. It's trampoline is static in the kernel core. The infrastructure that called the function graph trampoline can also be used to call a dynamically allocated one. For now, only ftrace_ops that are not dynamically allocated can have a trampoline. That is, users such as function tracer or stack tracer. kprobes and perf allocate their ftrace_ops, and until there's a safe way to free the trampoline, it can not be used. The dynamically allocated ftrace_ops may, although, use the trampoline if the kernel is not compiled with CONFIG_PREEMPT. But that will come later. Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-03 07:23:31 +04:00
/*
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@suse.de> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1455612202-14414-4-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-16 11:43:21 +03:00
* As this jmp to ftrace_epilogue can be a short jump
ftrace/x86: Add dynamic allocated trampoline for ftrace_ops The current method of handling multiple function callbacks is to register a list function callback that calls all the other callbacks based on their hash tables and compare it to the function that the callback was called on. But this is very inefficient. For example, if you are tracing all functions in the kernel and then add a kprobe to a function such that the kprobe uses ftrace, the mcount trampoline will switch from calling the function trace callback to calling the list callback that will iterate over all registered ftrace_ops (in this case, the function tracer and the kprobes callback). That means for every function being traced it checks the hash of the ftrace_ops for function tracing and kprobes, even though the kprobes is only set at a single function. The kprobes ftrace_ops is checked for every function being traced! Instead of calling the list function for functions that are only being traced by a single callback, we can call a dynamically allocated trampoline that calls the callback directly. The function graph tracer already uses a direct call trampoline when it is being traced by itself but it is not dynamically allocated. It's trampoline is static in the kernel core. The infrastructure that called the function graph trampoline can also be used to call a dynamically allocated one. For now, only ftrace_ops that are not dynamically allocated can have a trampoline. That is, users such as function tracer or stack tracer. kprobes and perf allocate their ftrace_ops, and until there's a safe way to free the trampoline, it can not be used. The dynamically allocated ftrace_ops may, although, use the trampoline if the kernel is not compiled with CONFIG_PREEMPT. But that will come later. Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-03 07:23:31 +04:00
* it must not be copied into the trampoline.
* The trampoline will add the code to jump
* to the return.
*/
GLOBAL(ftrace_regs_caller_end)
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@suse.de> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1455612202-14414-4-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-16 11:43:21 +03:00
jmp ftrace_epilogue
ftrace: x86: Remove check of obsolete variable function_trace_stop Nothing sets function_trace_stop to disable function tracing anymore. Remove the check for it in the arch code. Link: http://lkml.kernel.org/r/53C54D32.6000000@zytor.com Acked-by: H. Peter Anvin <hpa@linux.intel.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-25 19:59:45 +04:00
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
END(ftrace_regs_caller)
#else /* ! CONFIG_DYNAMIC_FTRACE */
ENTRY(function_hook)
cmpq $ftrace_stub, ftrace_trace_function
jnz trace
ftrace/x86: Have static function tracing always test for function graph New updates to the ftrace generic code had ftrace_stub not always being called when ftrace is off. This causes the static tracer to always save and restore functions. But it also showed that when function tracing is running, the function graph tracer can not. We should always check to see if function graph tracing is running even if the function tracer is running too. The function tracer code is not the only one that uses the hook to function mcount. Cc: Markos Chandras <Markos.Chandras@imgtec.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 22:58:17 +03:00
fgraph_trace:
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
#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
GLOBAL(ftrace_stub)
retq
trace:
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>
2014-11-25 05:38:40 +03:00
/* save_mcount_regs fills in first two parameters */
save_mcount_regs
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
x86/ftrace: Add comment on static function tracing There was a confusion between update_ftrace_function() and static function tracing trampoline regarding 3rd parameter (ftrace_ops). Add a comment for clarification. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1447721004-2551-1-git-send-email-namhyung@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-11-17 03:43:24 +03:00
/*
* When DYNAMIC_FTRACE is not defined, ARCH_SUPPORTS_FTRACE_OPS is not
* set (see include/asm/ftrace.h and include/linux/ftrace.h). Only the
* ip and parent ip are used and the list function is called when
* function tracing is enabled.
*/
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
call *ftrace_trace_function
ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments The name MCOUNT_SAVE_FRAME is rather confusing as it really isn't a function frame that is saved, but just the required mcount registers that are needed to be saved before C code may be called. The word "frame" confuses it as being a function frame which it is not. Rename MCOUNT_SAVE_FRAME and MCOUNT_RESTORE_FRAME to save_mcount_regs and restore_mcount_regs respectively. Noticed the lower case, which keeps it from screaming at the reviewers. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 19:43:39 +03:00
restore_mcount_regs
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
ftrace/x86: Have static function tracing always test for function graph New updates to the ftrace generic code had ftrace_stub not always being called when ftrace is off. This causes the static tracer to always save and restore functions. But it also showed that when function tracing is running, the function graph tracer can not. We should always check to see if function graph tracing is running even if the function tracer is running too. The function tracer code is not the only one that uses the hook to function mcount. Cc: Markos Chandras <Markos.Chandras@imgtec.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 22:58:17 +03:00
jmp fgraph_trace
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
END(function_hook)
#endif /* CONFIG_DYNAMIC_FTRACE */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
ENTRY(ftrace_graph_caller)
ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter The function graph helper function prepare_ftrace_return() which does the work to hijack the parent pointer has that parent pointer as its first parameter. Instead, if we make it the second parameter and have ip as the first parameter (self_addr), then it can use the %rdi from save_mcount_regs that loads it already. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-25 05:00:34 +03:00
/* Saves rbp into %rdx and fills first parameter */
ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments The name MCOUNT_SAVE_FRAME is rather confusing as it really isn't a function frame that is saved, but just the required mcount registers that are needed to be saved before C code may be called. The word "frame" confuses it as being a function frame which it is not. Rename MCOUNT_SAVE_FRAME and MCOUNT_RESTORE_FRAME to save_mcount_regs and restore_mcount_regs respectively. Noticed the lower case, which keeps it from screaming at the reviewers. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 19:43:39 +03:00
save_mcount_regs
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
#ifdef CC_USING_FENTRY
ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter The function graph helper function prepare_ftrace_return() which does the work to hijack the parent pointer has that parent pointer as its first parameter. Instead, if we make it the second parameter and have ip as the first parameter (self_addr), then it can use the %rdi from save_mcount_regs that loads it already. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-25 05:00:34 +03:00
leaq MCOUNT_REG_SIZE+8(%rsp), %rsi
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
movq $0, %rdx /* No framepointers needed */
#else
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>
2014-11-25 05:38:40 +03:00
/* Save address of the return address of traced function */
ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter The function graph helper function prepare_ftrace_return() which does the work to hijack the parent pointer has that parent pointer as its first parameter. Instead, if we make it the second parameter and have ip as the first parameter (self_addr), then it can use the %rdi from save_mcount_regs that loads it already. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-25 05:00:34 +03:00
leaq 8(%rdx), %rsi
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>
2014-11-25 05:38:40 +03:00
/* ftrace does sanity checks against frame pointers */
ftrace/x86: Have save_mcount_regs macro also save stack frames if needed The save_mcount_regs macro saves and restores the required mcount regs that need to be saved before calling C code. It is done for all the function hook utilities (static tracing, dynamic tracing, regs, function graph). When frame pointers are enabled, the ftrace trampolines need to set up frames and pointers such that a back trace (dump stack) can continue passed them. Currently, a separate macro is used (create_frame) to do this, but it's only done for the ftrace_caller and ftrace_reg_caller functions. It is not done for the static tracer or function graph tracing. Instead of having a separate macro doing the recording of the frames, have the save_mcount_regs perform this task. This also has all tracers saving the frame pointers when needed. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@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>
2014-11-25 02:08:48 +03:00
movq (%rdx), %rdx
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
#endif
call prepare_ftrace_return
ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments The name MCOUNT_SAVE_FRAME is rather confusing as it really isn't a function frame that is saved, but just the required mcount registers that are needed to be saved before C code may be called. The word "frame" confuses it as being a function frame which it is not. Rename MCOUNT_SAVE_FRAME and MCOUNT_RESTORE_FRAME to save_mcount_regs and restore_mcount_regs respectively. Noticed the lower case, which keeps it from screaming at the reviewers. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-24 19:43:39 +03:00
restore_mcount_regs
ftrace/x86: Move the mcount/fentry code out of entry_64.S As the mcount code gets more complex, it really does not belong in the entry.S file. By moving it into its own file "mcount.S" keeps things a bit cleaner. Link: http://lkml.kernel.org/p/20140508152152.2130e8cf@gandalf.local.home Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-08 23:21:52 +04:00
retq
END(ftrace_graph_caller)
GLOBAL(return_to_handler)
subq $24, %rsp
/* Save the return values */
movq %rax, (%rsp)
movq %rdx, 8(%rsp)
movq %rbp, %rdi
call ftrace_return_to_handler
movq %rax, %rdi
movq 8(%rsp), %rdx
movq (%rsp), %rax
addq $24, %rsp
jmp *%rdi
#endif