| /* | 
 |  * 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 | 
 | 	lduh		[%g6 + TI_CPU], %g1 | 
 | 	sethi		%hi(hardirq_stack), %g3 | 
 | 	or		%g3, %lo(hardirq_stack), %g3 | 
 | 	sllx		%g1, 3, %g1 | 
 | 	ldx		[%g3 + %g1], %g7 | 
 | 	sub		%g7, STACK_BIAS, %g7 | 
 | 	cmp		%sp, %g7 | 
 | 	bleu,pt		%xcc, 2f | 
 | 	 sethi		%hi(THREAD_SIZE), %g3 | 
 | 	add		%g7, %g3, %g7 | 
 | 	cmp		%sp, %g7 | 
 | 	blu,pn		%xcc, 1f | 
 | 2:	 sethi		%hi(softirq_stack), %g3 | 
 | 	or		%g3, %lo(softirq_stack), %g3 | 
 | 	ldx		[%g3 + %g1], %g7 | 
 | 	cmp		%sp, %g7 | 
 | 	bleu,pt		%xcc, 2f | 
 | 	 sethi		%hi(THREAD_SIZE), %g3 | 
 | 	add		%g7, %g3, %g7 | 
 | 	cmp		%sp, %g7 | 
 | 	blu,pn		%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_FUNCTION_TRACER | 
 | #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_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: | 
 | 	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 |