035df35d96
128 bytes is sufficient for the register window save area, but the calling conventions allow the callee to save up to 6 incoming argument registers into the stack frame after the register window save area. This means a minimal stack frame is 176 bytes (128 + (6 * 8)). This fixes random crashes when using the function tracer. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
129 lines
2.7 KiB
ArmAsm
129 lines
2.7 KiB
ArmAsm
/*
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* Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com)
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*
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* This file implements mcount(), which is used to collect profiling data.
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* This can also be tweaked for kernel stack overflow detection.
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*/
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#include <linux/linkage.h>
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/*
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* This is the main variant and is called by C code. GCC's -pg option
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* automatically instruments every C function with a call to this.
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*/
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.text
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.align 32
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.globl _mcount
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.type _mcount,#function
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.globl mcount
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.type mcount,#function
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_mcount:
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mcount:
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#ifdef CONFIG_FUNCTION_TRACER
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#ifdef CONFIG_DYNAMIC_FTRACE
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/* Do nothing, the retl/nop below is all we need. */
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#else
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sethi %hi(function_trace_stop), %g1
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lduw [%g1 + %lo(function_trace_stop)], %g2
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brnz,pn %g2, 2f
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sethi %hi(ftrace_trace_function), %g1
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sethi %hi(ftrace_stub), %g2
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ldx [%g1 + %lo(ftrace_trace_function)], %g1
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or %g2, %lo(ftrace_stub), %g2
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cmp %g1, %g2
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be,pn %icc, 1f
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mov %i7, %g3
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save %sp, -176, %sp
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mov %g3, %o1
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jmpl %g1, %o7
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mov %i7, %o0
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ret
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restore
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/* not reached */
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1:
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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sethi %hi(ftrace_graph_return), %g1
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ldx [%g1 + %lo(ftrace_graph_return)], %g3
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cmp %g2, %g3
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bne,pn %xcc, 5f
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sethi %hi(ftrace_graph_entry_stub), %g2
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sethi %hi(ftrace_graph_entry), %g1
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or %g2, %lo(ftrace_graph_entry_stub), %g2
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ldx [%g1 + %lo(ftrace_graph_entry)], %g1
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cmp %g1, %g2
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be,pt %xcc, 2f
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nop
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5: mov %i7, %g2
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mov %fp, %g3
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save %sp, -176, %sp
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mov %g2, %l0
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ba,pt %xcc, ftrace_graph_caller
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mov %g3, %l1
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#endif
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2:
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#endif
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#endif
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retl
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nop
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.size _mcount,.-_mcount
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.size mcount,.-mcount
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#ifdef CONFIG_FUNCTION_TRACER
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.globl ftrace_stub
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.type ftrace_stub,#function
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ftrace_stub:
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retl
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nop
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.size ftrace_stub,.-ftrace_stub
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#ifdef CONFIG_DYNAMIC_FTRACE
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.globl ftrace_caller
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.type ftrace_caller,#function
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ftrace_caller:
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sethi %hi(function_trace_stop), %g1
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mov %i7, %g2
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lduw [%g1 + %lo(function_trace_stop)], %g1
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brnz,pn %g1, ftrace_stub
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mov %fp, %g3
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save %sp, -176, %sp
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mov %g2, %o1
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mov %g2, %l0
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mov %g3, %l1
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.globl ftrace_call
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ftrace_call:
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call ftrace_stub
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mov %i7, %o0
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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.globl ftrace_graph_call
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ftrace_graph_call:
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call ftrace_stub
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nop
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#endif
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ret
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restore
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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.size ftrace_graph_call,.-ftrace_graph_call
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#endif
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.size ftrace_call,.-ftrace_call
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.size ftrace_caller,.-ftrace_caller
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#endif
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#endif
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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ENTRY(ftrace_graph_caller)
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mov %l0, %o0
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mov %i7, %o1
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call prepare_ftrace_return
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mov %l1, %o2
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ret
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restore %o0, -8, %i7
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END(ftrace_graph_caller)
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ENTRY(return_to_handler)
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save %sp, -176, %sp
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call ftrace_return_to_handler
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mov %fp, %o0
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jmpl %o0 + 8, %g0
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restore
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END(return_to_handler)
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#endif
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