Commit eaaaeef3 authored by Paul Mundt's avatar Paul Mundt
Browse files

sh: Add kprobe-based event tracer. 



This follows the x86/ppc changes for kprobe-based event tracing on sh.
While kprobes is only supported on 32-bit sh, we provide the API for
HAVE_REGS_AND_STACK_ACCESS_API for both 32 and 64-bit.

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 9973e385

arch/sh/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ config SUPERH 
	select HAVE_KERNEL_LZMA

	select HAVE_KERNEL_LZO

	select HAVE_SYSCALL_TRACEPOINTS

	select HAVE_REGS_AND_STACK_ACCESS_API

	select RTC_LIB

	select GENERIC_ATOMIC64

	help

arch/sh/include/asm/kprobes.h

+0 −1
Original line number Diff line number Diff line
@@ -16,7 +16,6 @@ typedef insn_size_t kprobe_opcode_t; 
	? (MAX_STACK_SIZE) \

	: (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))



#define regs_return_value(_regs)		((_regs)->regs[0])

#define flush_insn_slot(p)		do { } while (0)

#define kretprobe_blacklist_size	0

arch/sh/include/asm/processor_32.h

+0 −3
Original line number Diff line number Diff line
@@ -13,7 +13,6 @@ 
#include <linux/linkage.h>

#include <asm/page.h>

#include <asm/types.h>

#include <asm/ptrace.h>

#include <asm/hw_breakpoint.h>



/*
@@ -194,8 +193,6 @@ extern unsigned long get_wchan(struct task_struct *p); 
#define KSTK_EIP(tsk)  (task_pt_regs(tsk)->pc)

#define KSTK_ESP(tsk)  (task_pt_regs(tsk)->regs[15])



#define user_stack_pointer(_regs)	((_regs)->regs[15])



#if defined(CONFIG_CPU_SH2A) || defined(CONFIG_CPU_SH4)

#define PREFETCH_STRIDE		L1_CACHE_BYTES

#define ARCH_HAS_PREFETCH

arch/sh/include/asm/processor_64.h

+0 −3
Original line number Diff line number Diff line
@@ -17,7 +17,6 @@ 
#include <linux/compiler.h>

#include <asm/page.h>

#include <asm/types.h>

#include <asm/ptrace.h>

#include <cpu/registers.h>



/*
@@ -231,7 +230,5 @@ extern unsigned long get_wchan(struct task_struct *p); 
#define KSTK_EIP(tsk)  ((tsk)->thread.pc)

#define KSTK_ESP(tsk)  ((tsk)->thread.sp)



#define user_stack_pointer(_regs)	((_regs)->regs[15])



#endif	/* __ASSEMBLY__ */

#endif /* __ASM_SH_PROCESSOR_64_H */

arch/sh/include/asm/ptrace.h

+86 −3
Original line number Diff line number Diff line 
#ifndef __ASM_SH_PTRACE_H

#define __ASM_SH_PTRACE_H



#include <linux/stringify.h>



/*

 * Copyright (C) 1999, 2000  Niibe Yutaka

 *
@@ -14,6 +16,13 @@ struct pt_regs { 
	unsigned long long tregs[8];

	unsigned long long pad[2];

};



#define MAX_REG_OFFSET		offsetof(struct pt_regs, tregs[7])

#define regs_return_value(regs)	((regs)->regs[3])



#define TREGS_OFFSET_NAME(num)	\

	{.name = __stringify(tr##num), .offset = offsetof(struct pt_regs, tregs[num])}



#else

/*

 * GCC defines register number like this:
@@ -66,6 +75,9 @@ struct pt_regs { 
	long tra;

};



#define MAX_REG_OFFSET		offsetof(struct pt_regs, tra)

#define regs_return_value(regs)	((regs)->regs[0])



/*

 * This struct defines the way the DSP registers are stored on the

 * kernel stack during a system call or other kernel entry.
@@ -113,16 +125,87 @@ struct pt_dspregs { 
#include <asm/system.h>



#define user_mode(regs)			(((regs)->sr & 0x40000000)==0)

#define user_stack_pointer(regs)	((unsigned long)(regs)->regs[15])

#define kernel_stack_pointer(regs)	((unsigned long)(regs)->regs[15])

#define instruction_pointer(regs)	((unsigned long)(regs)->pc)



extern void show_regs(struct pt_regs *);



#define arch_has_single_step()	(1)



/*

 * These are defined as per linux/ptrace.h.

 * kprobe-based event tracer support

 */

struct task_struct;

#include <linux/stddef.h>

#include <linux/thread_info.h>



#define arch_has_single_step()	(1)

struct pt_regs_offset {

	const char *name;

	int offset;

};



#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}

#define REGS_OFFSET_NAME(num)	\

	{.name = __stringify(r##num), .offset = offsetof(struct pt_regs, regs[num])}

#define REG_OFFSET_END {.name = NULL, .offset = 0}



/* Query offset/name of register from its name/offset */

extern int regs_query_register_offset(const char *name);

extern const char *regs_query_register_name(unsigned int offset);



extern const struct pt_regs_offset regoffset_table[];



/**

 * regs_get_register() - get register value from its offset

 * @regs:	pt_regs from which register value is gotten.

 * @offset:	offset number of the register.

 *

 * regs_get_register returns the value of a register. The @offset is the

 * offset of the register in struct pt_regs address which specified by @regs.

 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.

 */

static inline unsigned long regs_get_register(struct pt_regs *regs,

					      unsigned int offset)

{

	if (unlikely(offset > MAX_REG_OFFSET))

		return 0;

	return *(unsigned long *)((unsigned long)regs + offset);

}



/**

 * regs_within_kernel_stack() - check the address in the stack

 * @regs:	pt_regs which contains kernel stack pointer.

 * @addr:	address which is checked.

 *

 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).

 * If @addr is within the kernel stack, it returns true. If not, returns false.

 */

static inline int regs_within_kernel_stack(struct pt_regs *regs,

					   unsigned long addr)

{

	return ((addr & ~(THREAD_SIZE - 1))  ==

		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));

}



/**

 * regs_get_kernel_stack_nth() - get Nth entry of the stack

 * @regs:	pt_regs which contains kernel stack pointer.

 * @n:		stack entry number.

 *

 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which

 * is specified by @regs. If the @n th entry is NOT in the kernel stack,

 * this returns 0.

 */

static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,

						      unsigned int n)

{

	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);

	addr += n;

	if (regs_within_kernel_stack(regs, (unsigned long)addr))

		return *addr;

	else

		return 0;

}



struct perf_event;

struct perf_sample_data;

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