/* * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com) * * This file implements mcount(), which is used to collect profiling data. * This can also be tweaked for kernel stack overflow detection. */ #include /* * This is the main variant and is called by C code. GCC's -pg option * automatically instruments every C function with a call to this. */ .text .align 32 .globl _mcount .type _mcount,#function .globl mcount .type mcount,#function _mcount: mcount: #ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE /* Do nothing, the retl/nop below is all we need. */ #else sethi %hi(function_trace_stop), %g1 lduw [%g1 + %lo(function_trace_stop)], %g2 brnz,pn %g2, 1f sethi %hi(ftrace_trace_function), %g1 sethi %hi(ftrace_stub), %g2 ldx [%g1 + %lo(ftrace_trace_function)], %g1 or %g2, %lo(ftrace_stub), %g2 cmp %g1, %g2 be,pn %icc, 1f mov %i7, %o1 jmpl %g1, %g0 mov %o7, %o0 /* not reached */ 1: #endif #endif retl nop .size _mcount,.-_mcount .size mcount,.-mcount #ifdef CONFIG_FUNCTION_TRACER .globl ftrace_stub .type ftrace_stub,#function ftrace_stub: retl nop .size ftrace_stub,.-ftrace_stub #ifdef CONFIG_DYNAMIC_FTRACE .globl ftrace_caller .type ftrace_caller,#function ftrace_caller: sethi %hi(function_trace_stop), %g1 mov %i7, %o1 lduw [%g1 + %lo(function_trace_stop)], %g2 brnz,pn %g2, ftrace_stub mov %o7, %o0 .globl ftrace_call ftrace_call: /* If the final kernel link ever turns on relaxation, we'll need * to do something about this tail call. Otherwise the linker * will rewrite the call into a branch and nop out the move * instruction. */ call ftrace_stub mov %o0, %o7 retl nop .size ftrace_call,.-ftrace_call .size ftrace_caller,.-ftrace_caller #endif #endif