linux-stable/arch/sparc/lib/mcount.S
David S. Miller 035df35d96 sparc64: Allocate sufficient stack space in ftrace stubs.
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>
2010-04-13 18:59:02 -07:00

129 lines
2.7 KiB
ArmAsm

/*
* 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 <linux/linkage.h>
/*
* 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, 2f
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, %g3
save %sp, -176, %sp
mov %g3, %o1
jmpl %g1, %o7
mov %i7, %o0
ret
restore
/* not reached */
1:
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
sethi %hi(ftrace_graph_return), %g1
ldx [%g1 + %lo(ftrace_graph_return)], %g3
cmp %g2, %g3
bne,pn %xcc, 5f
sethi %hi(ftrace_graph_entry_stub), %g2
sethi %hi(ftrace_graph_entry), %g1
or %g2, %lo(ftrace_graph_entry_stub), %g2
ldx [%g1 + %lo(ftrace_graph_entry)], %g1
cmp %g1, %g2
be,pt %xcc, 2f
nop
5: mov %i7, %g2
mov %fp, %g3
save %sp, -176, %sp
mov %g2, %l0
ba,pt %xcc, ftrace_graph_caller
mov %g3, %l1
#endif
2:
#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, %g2
lduw [%g1 + %lo(function_trace_stop)], %g1
brnz,pn %g1, ftrace_stub
mov %fp, %g3
save %sp, -176, %sp
mov %g2, %o1
mov %g2, %l0
mov %g3, %l1
.globl ftrace_call
ftrace_call:
call ftrace_stub
mov %i7, %o0
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
.globl ftrace_graph_call
ftrace_graph_call:
call ftrace_stub
nop
#endif
ret
restore
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
.size ftrace_graph_call,.-ftrace_graph_call
#endif
.size ftrace_call,.-ftrace_call
.size ftrace_caller,.-ftrace_caller
#endif
#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
ENTRY(ftrace_graph_caller)
mov %l0, %o0
mov %i7, %o1
call prepare_ftrace_return
mov %l1, %o2
ret
restore %o0, -8, %i7
END(ftrace_graph_caller)
ENTRY(return_to_handler)
save %sp, -176, %sp
call ftrace_return_to_handler
mov %fp, %o0
jmpl %o0 + 8, %g0
restore
END(return_to_handler)
#endif