arch/nios2/kernel/ptrace.c

Source file repositories/reference/linux-study-clean/arch/nios2/kernel/ptrace.c

File Facts

System
Linux kernel
Corpus path
arch/nios2/kernel/ptrace.c
Extension
.c
Size
3893 bytes
Lines
146
Domain
Architecture Layer
Bucket
arch/nios2
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#include <linux/elf.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/ptrace.h>
#include <linux/regset.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/uaccess.h>
#include <linux/user.h>

static int genregs_get(struct task_struct *target,
		       const struct user_regset *regset,
		       struct membuf to)
{
	const struct pt_regs *regs = task_pt_regs(target);
	const struct switch_stack *sw = (struct switch_stack *)regs - 1;

	membuf_zero(&to, 4); // R0
	membuf_write(&to, &regs->r1, 7 * 4); // R1..R7
	membuf_write(&to, &regs->r8, 8 * 4); // R8..R15
	membuf_write(&to, sw, 8 * 4); // R16..R23
	membuf_zero(&to, 2 * 4); /* et and bt */
	membuf_store(&to, regs->gp);
	membuf_store(&to, regs->sp);
	membuf_store(&to, regs->fp);
	membuf_store(&to, regs->ea);
	membuf_zero(&to, 4); // PTR_BA
	membuf_store(&to, regs->ra);
	membuf_store(&to, regs->ea); /* use ea for PC */
	return membuf_zero(&to, (NUM_PTRACE_REG - PTR_PC) * 4);
}

/*
 * Set the thread state from a regset passed in via ptrace
 */
static int genregs_set(struct task_struct *target,
		       const struct user_regset *regset,
		       unsigned int pos, unsigned int count,
		       const void *kbuf, const void __user *ubuf)
{
	struct pt_regs *regs = task_pt_regs(target);
	const struct switch_stack *sw = (struct switch_stack *)regs - 1;
	int ret = 0;

#define REG_IGNORE_RANGE(START, END)		\
	if (!ret)					\
		user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
			START * 4, (END * 4) + 4);

#define REG_IN_ONE(PTR, LOC)	\
	if (!ret)			\
		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
			(void *)(PTR), LOC * 4, (LOC * 4) + 4);

#define REG_IN_RANGE(PTR, START, END)	\
	if (!ret)				\
		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
			(void *)(PTR), START * 4, (END * 4) + 4);

	REG_IGNORE_RANGE(PTR_R0, PTR_R0);
	REG_IN_RANGE(&regs->r1, PTR_R1, PTR_R7);
	REG_IN_RANGE(&regs->r8, PTR_R8, PTR_R15);
	REG_IN_RANGE(sw, PTR_R16, PTR_R23);
	REG_IGNORE_RANGE(PTR_R24, PTR_R25); /* et and bt */
	REG_IN_ONE(&regs->gp, PTR_GP);
	REG_IN_ONE(&regs->sp, PTR_SP);
	REG_IN_ONE(&regs->fp, PTR_FP);
	REG_IN_ONE(&regs->ea, PTR_EA);
	REG_IGNORE_RANGE(PTR_BA, PTR_BA);
	REG_IN_ONE(&regs->ra, PTR_RA);
	REG_IN_ONE(&regs->ea, PTR_PC); /* use ea for PC */
	if (!ret)
		user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
					  PTR_STATUS * 4, -1);

	return ret;
}

/*
 * Define the register sets available on Nios2 under Linux
 */
enum nios2_regset {
	REGSET_GENERAL,
};

static const struct user_regset nios2_regsets[] = {
	[REGSET_GENERAL] = {
		USER_REGSET_NOTE_TYPE(PRSTATUS),
		.n = NUM_PTRACE_REG,

Annotation

Implementation Notes