166e553a57
Commit 4f70f7a91b
(sparc64: Implement IRQ stacks.) has two bugs.
First, the softirq range check forgets to subtract STACK_BIAS
before comparing with %sp. Next, on failure the wrong label
is jumped to, resulting in a bogus stack being loaded.
Reported-by: Igor Kovalenko <igor.v.kovalenko@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
144 lines
2.9 KiB
ArmAsm
144 lines
2.9 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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#include <asm/ptrace.h>
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#include <asm/thread_info.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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#ifdef CONFIG_STACK_DEBUG
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#define OVSTACKSIZE 4096 /* lets hope this is enough */
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.data
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.align 8
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panicstring:
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.asciz "Stack overflow\n"
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.align 8
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ovstack:
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.skip OVSTACKSIZE
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#endif
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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_STACK_DEBUG
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/*
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* Check whether %sp is dangerously low.
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*/
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ldub [%g6 + TI_FPDEPTH], %g1
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srl %g1, 1, %g3
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add %g3, 1, %g3
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sllx %g3, 8, %g3 ! each fpregs frame is 256b
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add %g3, 192, %g3
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add %g6, %g3, %g3 ! where does task_struct+frame end?
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sub %g3, STACK_BIAS, %g3
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cmp %sp, %g3
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bg,pt %xcc, 1f
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nop
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lduh [%g6 + TI_CPU], %g1
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sethi %hi(hardirq_stack), %g3
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or %g3, %lo(hardirq_stack), %g3
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sllx %g1, 3, %g1
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ldx [%g3 + %g1], %g7
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sub %g7, STACK_BIAS, %g7
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cmp %sp, %g7
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bleu,pt %xcc, 2f
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sethi %hi(THREAD_SIZE), %g3
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add %g7, %g3, %g7
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cmp %sp, %g7
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blu,pn %xcc, 1f
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2: sethi %hi(softirq_stack), %g3
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or %g3, %lo(softirq_stack), %g3
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ldx [%g3 + %g1], %g7
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sub %g7, STACK_BIAS, %g7
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cmp %sp, %g7
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bleu,pt %xcc, 3f
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sethi %hi(THREAD_SIZE), %g3
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add %g7, %g3, %g7
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cmp %sp, %g7
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blu,pn %xcc, 1f
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nop
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/* If we are already on ovstack, don't hop onto it
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* again, we are already trying to output the stack overflow
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* message.
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*/
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3: sethi %hi(ovstack), %g7 ! cant move to panic stack fast enough
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or %g7, %lo(ovstack), %g7
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add %g7, OVSTACKSIZE, %g3
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sub %g3, STACK_BIAS + 192, %g3
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sub %g7, STACK_BIAS, %g7
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cmp %sp, %g7
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blu,pn %xcc, 2f
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cmp %sp, %g3
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bleu,pn %xcc, 1f
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nop
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2: mov %g3, %sp
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sethi %hi(panicstring), %g3
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call prom_printf
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or %g3, %lo(panicstring), %o0
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call prom_halt
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nop
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1:
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#endif
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#ifdef CONFIG_FUNCTION_TRACER
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#ifdef CONFIG_DYNAMIC_FTRACE
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mov %o7, %o0
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.globl mcount_call
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mcount_call:
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call ftrace_stub
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mov %o0, %o7
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#else
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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, %o1
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jmpl %g1, %g0
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mov %o7, %o0
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/* not reached */
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1:
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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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mov %i7, %o1
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mov %o7, %o0
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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 %o0, %o7
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retl
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nop
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.size ftrace_caller,.-ftrace_caller
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#endif
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#endif
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