2 * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com)
4 * This file implements mcount(), which is used to collect profiling data.
5 * This can also be tweaked for kernel stack overflow detection.
8 #include <linux/linkage.h>
11 * This is the main variant and is called by C code. GCC's -pg option
12 * automatically instruments every C function with a call to this.
18 .type _mcount,#function
20 .type mcount,#function
23 #ifdef CONFIG_FUNCTION_TRACER
24 #ifdef CONFIG_DYNAMIC_FTRACE
25 /* Do nothing, the retl/nop below is all we need. */
27 sethi %hi(function_trace_stop), %g1
28 lduw [%g1 + %lo(function_trace_stop)], %g2
30 sethi %hi(ftrace_trace_function), %g1
31 sethi %hi(ftrace_stub), %g2
32 ldx [%g1 + %lo(ftrace_trace_function)], %g1
33 or %g2, %lo(ftrace_stub), %g2
45 .size _mcount,.-_mcount
48 #ifdef CONFIG_FUNCTION_TRACER
50 .type ftrace_stub,#function
54 .size ftrace_stub,.-ftrace_stub
55 #ifdef CONFIG_DYNAMIC_FTRACE
57 .type ftrace_caller,#function
59 sethi %hi(function_trace_stop), %g1
61 lduw [%g1 + %lo(function_trace_stop)], %g2
62 brnz,pn %g2, ftrace_stub
66 /* If the final kernel link ever turns on relaxation, we'll need
67 * to do something about this tail call. Otherwise the linker
68 * will rewrite the call into a branch and nop out the move
75 .size ftrace_call,.-ftrace_call
76 .size ftrace_caller,.-ftrace_caller