c7498081a6
The calls down into prom_printf() when we detect an overflowed stack can recurse again since the overflow stack will be "below" the current kernel stack limit. Prevent this by just returning straight if we are on the stack overflow safe stack already. Signed-off-by: David S. Miller <davem@davemloft.net>
122 lines
2.4 KiB
ArmAsm
122 lines
2.4 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>
|
|
|
|
#include <asm/ptrace.h>
|
|
#include <asm/thread_info.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.
|
|
*/
|
|
|
|
#ifdef CONFIG_STACK_DEBUG
|
|
|
|
#define OVSTACKSIZE 4096 /* lets hope this is enough */
|
|
|
|
.data
|
|
.align 8
|
|
panicstring:
|
|
.asciz "Stack overflow\n"
|
|
.align 8
|
|
ovstack:
|
|
.skip OVSTACKSIZE
|
|
#endif
|
|
.text
|
|
.align 32
|
|
.globl _mcount
|
|
.type _mcount,#function
|
|
.globl mcount
|
|
.type mcount,#function
|
|
_mcount:
|
|
mcount:
|
|
#ifdef CONFIG_STACK_DEBUG
|
|
/*
|
|
* Check whether %sp is dangerously low.
|
|
*/
|
|
ldub [%g6 + TI_FPDEPTH], %g1
|
|
srl %g1, 1, %g3
|
|
add %g3, 1, %g3
|
|
sllx %g3, 8, %g3 ! each fpregs frame is 256b
|
|
add %g3, 192, %g3
|
|
add %g6, %g3, %g3 ! where does task_struct+frame end?
|
|
sub %g3, STACK_BIAS, %g3
|
|
cmp %sp, %g3
|
|
bg,pt %xcc, 1f
|
|
nop
|
|
/* If we are already on ovstack, don't hop onto it
|
|
* again, we are already trying to output the stack overflow
|
|
* message.
|
|
*/
|
|
sethi %hi(ovstack), %g7 ! cant move to panic stack fast enough
|
|
or %g7, %lo(ovstack), %g7
|
|
add %g7, OVSTACKSIZE, %g3
|
|
sub %g3, STACK_BIAS + 192, %g3
|
|
sub %g7, STACK_BIAS, %g7
|
|
cmp %sp, %g7
|
|
blu,pn %xcc, 2f
|
|
cmp %sp, %g3
|
|
bleu,pn %xcc, 1f
|
|
nop
|
|
2: mov %g3, %sp
|
|
sethi %hi(panicstring), %g3
|
|
call prom_printf
|
|
or %g3, %lo(panicstring), %o0
|
|
call prom_halt
|
|
nop
|
|
1:
|
|
#endif
|
|
#ifdef CONFIG_FTRACE
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
mov %o7, %o0
|
|
.globl mcount_call
|
|
mcount_call:
|
|
call ftrace_stub
|
|
mov %o0, %o7
|
|
#else
|
|
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_FTRACE
|
|
.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:
|
|
mov %i7, %o1
|
|
mov %o7, %o0
|
|
.globl ftrace_call
|
|
ftrace_call:
|
|
call ftrace_stub
|
|
mov %o0, %o7
|
|
retl
|
|
nop
|
|
.size ftrace_caller,.-ftrace_caller
|
|
#endif
|
|
#endif
|