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x86/ftrace: Move the ftrace specific code out of entry_32.S
The function tracing hook code for ftrace is not an entry point from userspace and does not belong in the entry_*.S files. It has already been moved out of entry_64.S. Move it out of entry_32.S into its own ftrace_32.S file. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20170323143445.645218946@goodmis.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Steven Rostedt (VMware)
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Thomas Gleixner
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Mar 24, 2017
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,175 @@ | ||
| /* | ||
| * Copyright (C) 2017 Steven Rostedt, VMware Inc. | ||
| */ | ||
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| #include <linux/linkage.h> | ||
| #include <asm/page_types.h> | ||
| #include <asm/segment.h> | ||
| #include <asm/export.h> | ||
| #include <asm/ftrace.h> | ||
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| #ifdef CONFIG_FUNCTION_TRACER | ||
| #ifdef CONFIG_DYNAMIC_FTRACE | ||
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| ENTRY(mcount) | ||
| ret | ||
| END(mcount) | ||
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||
| ENTRY(ftrace_caller) | ||
| pushl %eax | ||
| pushl %ecx | ||
| pushl %edx | ||
| pushl $0 /* Pass NULL as regs pointer */ | ||
| movl 4*4(%esp), %eax | ||
| movl 0x4(%ebp), %edx | ||
| movl function_trace_op, %ecx | ||
| subl $MCOUNT_INSN_SIZE, %eax | ||
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| .globl ftrace_call | ||
| ftrace_call: | ||
| call ftrace_stub | ||
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| addl $4, %esp /* skip NULL pointer */ | ||
| popl %edx | ||
| popl %ecx | ||
| popl %eax | ||
| .Lftrace_ret: | ||
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER | ||
| .globl ftrace_graph_call | ||
| ftrace_graph_call: | ||
| jmp ftrace_stub | ||
| #endif | ||
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| /* This is weak to keep gas from relaxing the jumps */ | ||
| WEAK(ftrace_stub) | ||
| ret | ||
| END(ftrace_caller) | ||
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| ENTRY(ftrace_regs_caller) | ||
| pushf /* push flags before compare (in cs location) */ | ||
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| /* | ||
| * i386 does not save SS and ESP when coming from kernel. | ||
| * Instead, to get sp, ®s->sp is used (see ptrace.h). | ||
| * Unfortunately, that means eflags must be at the same location | ||
| * as the current return ip is. We move the return ip into the | ||
| * ip location, and move flags into the return ip location. | ||
| */ | ||
| pushl 4(%esp) /* save return ip into ip slot */ | ||
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| pushl $0 /* Load 0 into orig_ax */ | ||
| pushl %gs | ||
| pushl %fs | ||
| pushl %es | ||
| pushl %ds | ||
| pushl %eax | ||
| pushl %ebp | ||
| pushl %edi | ||
| pushl %esi | ||
| pushl %edx | ||
| pushl %ecx | ||
| pushl %ebx | ||
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| movl 13*4(%esp), %eax /* Get the saved flags */ | ||
| movl %eax, 14*4(%esp) /* Move saved flags into regs->flags location */ | ||
| /* clobbering return ip */ | ||
| movl $__KERNEL_CS, 13*4(%esp) | ||
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| movl 12*4(%esp), %eax /* Load ip (1st parameter) */ | ||
| subl $MCOUNT_INSN_SIZE, %eax /* Adjust ip */ | ||
| movl 0x4(%ebp), %edx /* Load parent ip (2nd parameter) */ | ||
| movl function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */ | ||
| pushl %esp /* Save pt_regs as 4th parameter */ | ||
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| GLOBAL(ftrace_regs_call) | ||
| call ftrace_stub | ||
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| addl $4, %esp /* Skip pt_regs */ | ||
| movl 14*4(%esp), %eax /* Move flags back into cs */ | ||
| movl %eax, 13*4(%esp) /* Needed to keep addl from modifying flags */ | ||
| movl 12*4(%esp), %eax /* Get return ip from regs->ip */ | ||
| movl %eax, 14*4(%esp) /* Put return ip back for ret */ | ||
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| popl %ebx | ||
| popl %ecx | ||
| popl %edx | ||
| popl %esi | ||
| popl %edi | ||
| popl %ebp | ||
| popl %eax | ||
| popl %ds | ||
| popl %es | ||
| popl %fs | ||
| popl %gs | ||
| addl $8, %esp /* Skip orig_ax and ip */ | ||
| popf /* Pop flags at end (no addl to corrupt flags) */ | ||
| jmp .Lftrace_ret | ||
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| popf | ||
| jmp ftrace_stub | ||
| #else /* ! CONFIG_DYNAMIC_FTRACE */ | ||
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| ENTRY(mcount) | ||
| cmpl $__PAGE_OFFSET, %esp | ||
| jb ftrace_stub /* Paging not enabled yet? */ | ||
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| cmpl $ftrace_stub, ftrace_trace_function | ||
| jnz .Ltrace | ||
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER | ||
| cmpl $ftrace_stub, ftrace_graph_return | ||
| jnz ftrace_graph_caller | ||
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| cmpl $ftrace_graph_entry_stub, ftrace_graph_entry | ||
| jnz ftrace_graph_caller | ||
| #endif | ||
| .globl ftrace_stub | ||
| ftrace_stub: | ||
| ret | ||
|
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||
| /* taken from glibc */ | ||
| .Ltrace: | ||
| pushl %eax | ||
| pushl %ecx | ||
| pushl %edx | ||
| movl 0xc(%esp), %eax | ||
| movl 0x4(%ebp), %edx | ||
| subl $MCOUNT_INSN_SIZE, %eax | ||
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| call *ftrace_trace_function | ||
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| popl %edx | ||
| popl %ecx | ||
| popl %eax | ||
| jmp ftrace_stub | ||
| END(mcount) | ||
| #endif /* CONFIG_DYNAMIC_FTRACE */ | ||
| EXPORT_SYMBOL(mcount) | ||
| #endif /* CONFIG_FUNCTION_TRACER */ | ||
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| #ifdef CONFIG_FUNCTION_GRAPH_TRACER | ||
| ENTRY(ftrace_graph_caller) | ||
| pushl %eax | ||
| pushl %ecx | ||
| pushl %edx | ||
| movl 0xc(%esp), %eax | ||
| lea 0x4(%ebp), %edx | ||
| movl (%ebp), %ecx | ||
| subl $MCOUNT_INSN_SIZE, %eax | ||
| call prepare_ftrace_return | ||
| popl %edx | ||
| popl %ecx | ||
| popl %eax | ||
| ret | ||
| END(ftrace_graph_caller) | ||
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| .globl return_to_handler | ||
| return_to_handler: | ||
| pushl %eax | ||
| pushl %edx | ||
| movl %ebp, %eax | ||
| call ftrace_return_to_handler | ||
| movl %eax, %ecx | ||
| popl %edx | ||
| popl %eax | ||
| jmp *%ecx | ||
| #endif |