| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* | 
 | 2 |  * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com) | 
 | 3 |  * | 
 | 4 |  * This file implements mcount(), which is used to collect profiling data. | 
 | 5 |  * This can also be tweaked for kernel stack overflow detection. | 
 | 6 |  */ | 
 | 7 |  | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | #include <linux/linkage.h> | 
 | 9 |  | 
 | 10 | #include <asm/ptrace.h> | 
 | 11 | #include <asm/thread_info.h> | 
 | 12 |  | 
 | 13 | /* | 
 | 14 |  * This is the main variant and is called by C code.  GCC's -pg option | 
 | 15 |  * automatically instruments every C function with a call to this. | 
 | 16 |  */ | 
 | 17 |  | 
 | 18 | #ifdef CONFIG_STACK_DEBUG | 
 | 19 |  | 
 | 20 | #define OVSTACKSIZE	4096		/* lets hope this is enough */ | 
 | 21 |  | 
 | 22 | 	.data | 
 | 23 | 	.align		8 | 
 | 24 | panicstring: | 
 | 25 | 	.asciz		"Stack overflow\n" | 
 | 26 | 	.align		8 | 
 | 27 | ovstack: | 
 | 28 | 	.skip		OVSTACKSIZE | 
 | 29 | #endif | 
 | 30 | 	.text | 
| David Miller | d05f5f9 | 2008-05-13 22:06:59 -0700 | [diff] [blame] | 31 | 	.align		32 | 
 | 32 | 	.globl		_mcount | 
 | 33 | 	.type		_mcount,#function | 
 | 34 | 	.globl		mcount | 
 | 35 | 	.type		mcount,#function | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | _mcount: | 
| David Miller | d05f5f9 | 2008-05-13 22:06:59 -0700 | [diff] [blame] | 37 | mcount: | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | #ifdef CONFIG_STACK_DEBUG | 
 | 39 | 	/* | 
 | 40 | 	 * Check whether %sp is dangerously low. | 
 | 41 | 	 */ | 
 | 42 | 	ldub		[%g6 + TI_FPDEPTH], %g1 | 
 | 43 | 	srl		%g1, 1, %g3 | 
 | 44 | 	add		%g3, 1, %g3 | 
 | 45 | 	sllx		%g3, 8, %g3			! each fpregs frame is 256b | 
 | 46 | 	add		%g3, 192, %g3 | 
 | 47 | 	add		%g6, %g3, %g3			! where does task_struct+frame end? | 
 | 48 | 	sub		%g3, STACK_BIAS, %g3 | 
 | 49 | 	cmp		%sp, %g3 | 
 | 50 | 	bg,pt		%xcc, 1f | 
| David S. Miller | c749808 | 2008-08-12 02:03:49 -0700 | [diff] [blame] | 51 | 	 nop | 
| David S. Miller | 4f70f7a | 2008-08-12 18:33:56 -0700 | [diff] [blame] | 52 | 	lduh		[%g6 + TI_CPU], %g1 | 
 | 53 | 	sethi		%hi(hardirq_stack), %g3 | 
 | 54 | 	or		%g3, %lo(hardirq_stack), %g3 | 
 | 55 | 	sllx		%g1, 3, %g1 | 
 | 56 | 	ldx		[%g3 + %g1], %g7 | 
 | 57 | 	sub		%g7, STACK_BIAS, %g7 | 
 | 58 | 	cmp		%sp, %g7 | 
 | 59 | 	bleu,pt		%xcc, 2f | 
 | 60 | 	 sethi		%hi(THREAD_SIZE), %g3 | 
 | 61 | 	add		%g7, %g3, %g7 | 
 | 62 | 	cmp		%sp, %g7 | 
 | 63 | 	blu,pn		%xcc, 1f | 
 | 64 | 2:	 sethi		%hi(softirq_stack), %g3 | 
 | 65 | 	or		%g3, %lo(softirq_stack), %g3 | 
 | 66 | 	ldx		[%g3 + %g1], %g7 | 
| David S. Miller | 166e553 | 2009-12-09 01:43:45 -0800 | [diff] [blame] | 67 | 	sub		%g7, STACK_BIAS, %g7 | 
| David S. Miller | 4f70f7a | 2008-08-12 18:33:56 -0700 | [diff] [blame] | 68 | 	cmp		%sp, %g7 | 
| David S. Miller | 166e553 | 2009-12-09 01:43:45 -0800 | [diff] [blame] | 69 | 	bleu,pt		%xcc, 3f | 
| David S. Miller | 4f70f7a | 2008-08-12 18:33:56 -0700 | [diff] [blame] | 70 | 	 sethi		%hi(THREAD_SIZE), %g3 | 
 | 71 | 	add		%g7, %g3, %g7 | 
 | 72 | 	cmp		%sp, %g7 | 
 | 73 | 	blu,pn		%xcc, 1f | 
 | 74 | 	 nop | 
| David S. Miller | c749808 | 2008-08-12 02:03:49 -0700 | [diff] [blame] | 75 | 	/* If we are already on ovstack, don't hop onto it | 
 | 76 | 	 * again, we are already trying to output the stack overflow | 
 | 77 | 	 * message. | 
 | 78 | 	 */ | 
| David S. Miller | 166e553 | 2009-12-09 01:43:45 -0800 | [diff] [blame] | 79 | 3:	sethi		%hi(ovstack), %g7		! cant move to panic stack fast enough | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | 	 or		%g7, %lo(ovstack), %g7 | 
| David S. Miller | c749808 | 2008-08-12 02:03:49 -0700 | [diff] [blame] | 81 | 	add		%g7, OVSTACKSIZE, %g3 | 
 | 82 | 	sub		%g3, STACK_BIAS + 192, %g3 | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | 	sub		%g7, STACK_BIAS, %g7 | 
| David S. Miller | c749808 | 2008-08-12 02:03:49 -0700 | [diff] [blame] | 84 | 	cmp		%sp, %g7 | 
 | 85 | 	blu,pn		%xcc, 2f | 
 | 86 | 	 cmp		%sp, %g3 | 
 | 87 | 	bleu,pn		%xcc, 1f | 
 | 88 | 	 nop | 
 | 89 | 2:	mov		%g3, %sp | 
 | 90 | 	sethi		%hi(panicstring), %g3 | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | 	call		prom_printf | 
 | 92 | 	 or		%g3, %lo(panicstring), %o0 | 
 | 93 | 	call		prom_halt | 
 | 94 | 	 nop | 
| David Miller | d05f5f9 | 2008-05-13 22:06:59 -0700 | [diff] [blame] | 95 | 1: | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | #endif | 
| Steven Rostedt | 606576c | 2008-10-06 19:06:12 -0400 | [diff] [blame] | 97 | #ifdef CONFIG_FUNCTION_TRACER | 
| David Miller | d05f5f9 | 2008-05-13 22:06:59 -0700 | [diff] [blame] | 98 | #ifdef CONFIG_DYNAMIC_FTRACE | 
 | 99 | 	mov		%o7, %o0 | 
 | 100 | 	.globl		mcount_call | 
 | 101 | mcount_call: | 
 | 102 | 	call		ftrace_stub | 
 | 103 | 	 mov		%o0, %o7 | 
 | 104 | #else | 
 | 105 | 	sethi		%hi(ftrace_trace_function), %g1 | 
 | 106 | 	sethi		%hi(ftrace_stub), %g2 | 
 | 107 | 	ldx		[%g1 + %lo(ftrace_trace_function)], %g1 | 
 | 108 | 	or		%g2, %lo(ftrace_stub), %g2 | 
 | 109 | 	cmp		%g1, %g2 | 
 | 110 | 	be,pn		%icc, 1f | 
 | 111 | 	 mov		%i7, %o1 | 
 | 112 | 	jmpl		%g1, %g0 | 
 | 113 | 	 mov		%o7, %o0 | 
 | 114 | 	/* not reached */ | 
 | 115 | 1: | 
 | 116 | #endif | 
 | 117 | #endif | 
 | 118 | 	retl | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | 	 nop | 
| David Miller | d05f5f9 | 2008-05-13 22:06:59 -0700 | [diff] [blame] | 120 | 	.size		_mcount,.-_mcount | 
 | 121 | 	.size		mcount,.-mcount | 
 | 122 |  | 
| Steven Rostedt | 606576c | 2008-10-06 19:06:12 -0400 | [diff] [blame] | 123 | #ifdef CONFIG_FUNCTION_TRACER | 
| David Miller | d05f5f9 | 2008-05-13 22:06:59 -0700 | [diff] [blame] | 124 | 	.globl		ftrace_stub | 
 | 125 | 	.type		ftrace_stub,#function | 
 | 126 | ftrace_stub: | 
 | 127 | 	retl | 
 | 128 | 	 nop | 
 | 129 | 	.size		ftrace_stub,.-ftrace_stub | 
 | 130 | #ifdef CONFIG_DYNAMIC_FTRACE | 
 | 131 | 	.globl		ftrace_caller | 
 | 132 | 	.type		ftrace_caller,#function | 
 | 133 | ftrace_caller: | 
 | 134 | 	mov		%i7, %o1 | 
 | 135 | 	mov		%o7, %o0 | 
 | 136 | 	.globl		ftrace_call | 
 | 137 | ftrace_call: | 
 | 138 | 	call		ftrace_stub | 
 | 139 | 	 mov		%o0, %o7 | 
 | 140 | 	retl | 
 | 141 | 	 nop | 
 | 142 | 	.size		ftrace_caller,.-ftrace_caller | 
 | 143 | #endif | 
 | 144 | #endif |