diff options
Diffstat (limited to 'arch/sh/lib/mcount.S')
| -rw-r--r-- | arch/sh/lib/mcount.S | 228 |
1 files changed, 224 insertions, 4 deletions
diff --git a/arch/sh/lib/mcount.S b/arch/sh/lib/mcount.S index 110fbfe1831f..84a57761f17e 100644 --- a/arch/sh/lib/mcount.S +++ b/arch/sh/lib/mcount.S @@ -1,14 +1,16 @@ /* * arch/sh/lib/mcount.S * - * Copyright (C) 2008 Paul Mundt - * Copyright (C) 2008 Matt Fleming + * Copyright (C) 2008, 2009 Paul Mundt + * Copyright (C) 2008, 2009 Matt Fleming * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. */ #include <asm/ftrace.h> +#include <asm/thread_info.h> +#include <asm/asm-offsets.h> #define MCOUNT_ENTER() \ mov.l r4, @-r15; \ @@ -28,6 +30,55 @@ rts; \ mov.l @r15+, r4 +#ifdef CONFIG_STACK_DEBUG +/* + * Perform diagnostic checks on the state of the kernel stack. + * + * Check for stack overflow. If there is less than 1KB free + * then it has overflowed. + * + * Make sure the stack pointer contains a valid address. Valid + * addresses for kernel stacks are anywhere after the bss + * (after _ebss) and anywhere in init_thread_union (init_stack). + */ +#define STACK_CHECK() \ + mov #(THREAD_SIZE >> 10), r0; \ + shll8 r0; \ + shll2 r0; \ + \ + /* r1 = sp & (THREAD_SIZE - 1) */ \ + mov #-1, r1; \ + add r0, r1; \ + and r15, r1; \ + \ + mov #TI_SIZE, r3; \ + mov #(STACK_WARN >> 8), r2; \ + shll8 r2; \ + add r3, r2; \ + \ + /* Is the stack overflowing? */ \ + cmp/hi r2, r1; \ + bf stack_panic; \ + \ + /* If sp > _ebss then we're OK. */ \ + mov.l .L_ebss, r1; \ + cmp/hi r1, r15; \ + bt 1f; \ + \ + /* If sp < init_stack, we're not OK. */ \ + mov.l .L_init_thread_union, r1; \ + cmp/hs r1, r15; \ + bf stack_panic; \ + \ + /* If sp > init_stack && sp < _ebss, not OK. */ \ + add r0, r1; \ + cmp/hs r1, r15; \ + bt stack_panic; \ +1: +#else +#define STACK_CHECK() +#endif /* CONFIG_STACK_DEBUG */ + .align 2 .globl _mcount .type _mcount,@function @@ -35,6 +86,19 @@ .type mcount,@function _mcount: mcount: + STACK_CHECK() + +#ifndef CONFIG_FUNCTION_TRACER + rts + nop +#else +#ifndef CONFIG_DYNAMIC_FTRACE + mov.l .Lfunction_trace_stop, r0 + mov.l @r0, r0 + tst r0, r0 + bf ftrace_stub +#endif + MCOUNT_ENTER() #ifdef CONFIG_DYNAMIC_FTRACE @@ -52,16 +116,69 @@ mcount_call: jsr @r6 nop +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + mov.l .Lftrace_graph_return, r6 + mov.l .Lftrace_stub, r7 + cmp/eq r6, r7 + bt 1f + + mov.l .Lftrace_graph_caller, r0 + jmp @r0 + nop + +1: + mov.l .Lftrace_graph_entry, r6 + mov.l .Lftrace_graph_entry_stub, r7 + cmp/eq r6, r7 + bt skip_trace + + mov.l .Lftrace_graph_caller, r0 + jmp @r0 + nop + + .align 2 +.Lftrace_graph_return: + .long ftrace_graph_return +.Lftrace_graph_entry: + .long ftrace_graph_entry +.Lftrace_graph_entry_stub: + .long ftrace_graph_entry_stub +.Lftrace_graph_caller: + .long ftrace_graph_caller +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + + .globl skip_trace skip_trace: MCOUNT_LEAVE() .align 2 .Lftrace_trace_function: - .long ftrace_trace_function + .long ftrace_trace_function #ifdef CONFIG_DYNAMIC_FTRACE +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +/* + * NOTE: Do not move either ftrace_graph_call or ftrace_caller + * as this will affect the calculation of GRAPH_INSN_OFFSET. + */ + .globl ftrace_graph_call +ftrace_graph_call: + mov.l .Lskip_trace, r0 + jmp @r0 + nop + + .align 2 +.Lskip_trace: + .long skip_trace +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + .globl ftrace_caller ftrace_caller: + mov.l .Lfunction_trace_stop, r0 + mov.l @r0, r0 + tst r0, r0 + bf ftrace_stub + MCOUNT_ENTER() .globl ftrace_call @@ -70,9 +187,18 @@ ftrace_call: jsr @r6 nop +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + bra ftrace_graph_call + nop +#else MCOUNT_LEAVE() +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ #endif /* CONFIG_DYNAMIC_FTRACE */ + .align 2 +.Lfunction_trace_stop: + .long function_trace_stop + /* * NOTE: From here on the locations of the .Lftrace_stub label and * ftrace_stub itself are fixed. Adding additional data here will skew @@ -80,7 +206,6 @@ ftrace_call: * Place new labels either after the ftrace_stub body, or before * ftrace_caller. You have been warned. */ - .align 2 .Lftrace_stub: .long ftrace_stub @@ -88,3 +213,98 @@ ftrace_call: ftrace_stub: rts nop + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + .globl ftrace_graph_caller +ftrace_graph_caller: + mov.l 2f, r0 + mov.l @r0, r0 + tst r0, r0 + bt 1f + + mov.l 3f, r1 + jmp @r1 + nop +1: + /* + * MCOUNT_ENTER() pushed 5 registers onto the stack, so + * the stack address containing our return address is + * r15 + 20. + */ + mov #20, r0 + add r15, r0 + mov r0, r4 + + mov.l .Lprepare_ftrace_return, r0 + jsr @r0 + nop + + MCOUNT_LEAVE() + + .align 2 +2: .long function_trace_stop +3: .long skip_trace +.Lprepare_ftrace_return: + .long prepare_ftrace_return + + .globl return_to_handler +return_to_handler: + /* + * Save the return values. + */ + mov.l r0, @-r15 + mov.l r1, @-r15 + + mov #0, r4 + + mov.l .Lftrace_return_to_handler, r0 + jsr @r0 + nop + + /* + * The return value from ftrace_return_handler has the real + * address that we should return to. + */ + lds r0, pr + mov.l @r15+, r1 + rts + mov.l @r15+, r0 + + + .align 2 +.Lftrace_return_to_handler: + .long ftrace_return_to_handler +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ +#endif /* CONFIG_FUNCTION_TRACER */ + +#ifdef CONFIG_STACK_DEBUG + .globl stack_panic +stack_panic: + mov.l .Ldump_stack, r0 + jsr @r0 + nop + + mov.l .Lpanic, r0 + jsr @r0 + mov.l .Lpanic_s, r4 + + rts + nop + + .align 2 +.L_ebss: + .long _ebss +.L_init_thread_union: + .long init_thread_union +.Lpanic: + .long panic +.Lpanic_s: + .long .Lpanic_str +.Ldump_stack: + .long dump_stack + + .section .rodata + .align 2 +.Lpanic_str: + .string "Stack error" +#endif /* CONFIG_STACK_DEBUG */ |