// SPDX-License-Identifier: GPL-2.0-or-later
|
/**
|
* Copyright (C) 2005 Brian Rogan <bcr6@cornell.edu>, IBM
|
*
|
**/
|
|
#include <linux/time.h>
|
#include <linux/oprofile.h>
|
#include <linux/sched.h>
|
#include <asm/processor.h>
|
#include <linux/uaccess.h>
|
#include <linux/compat.h>
|
#include <asm/oprofile_impl.h>
|
|
#define STACK_SP(STACK) *(STACK)
|
|
#define STACK_LR64(STACK) *((unsigned long *)(STACK) + 2)
|
#define STACK_LR32(STACK) *((unsigned int *)(STACK) + 1)
|
|
#ifdef CONFIG_PPC64
|
#define STACK_LR(STACK) STACK_LR64(STACK)
|
#else
|
#define STACK_LR(STACK) STACK_LR32(STACK)
|
#endif
|
|
static unsigned int user_getsp32(unsigned int sp, int is_first)
|
{
|
unsigned int stack_frame[2];
|
void __user *p = compat_ptr(sp);
|
|
/*
|
* The most likely reason for this is that we returned -EFAULT,
|
* which means that we've done all that we can do from
|
* interrupt context.
|
*/
|
if (copy_from_user_nofault(stack_frame, (void __user *)p,
|
sizeof(stack_frame)))
|
return 0;
|
|
if (!is_first)
|
oprofile_add_trace(STACK_LR32(stack_frame));
|
|
/*
|
* We do not enforce increasing stack addresses here because
|
* we may transition to a different stack, eg a signal handler.
|
*/
|
return STACK_SP(stack_frame);
|
}
|
|
#ifdef CONFIG_PPC64
|
static unsigned long user_getsp64(unsigned long sp, int is_first)
|
{
|
unsigned long stack_frame[3];
|
|
if (copy_from_user_nofault(stack_frame, (void __user *)sp,
|
sizeof(stack_frame)))
|
return 0;
|
|
if (!is_first)
|
oprofile_add_trace(STACK_LR64(stack_frame));
|
|
return STACK_SP(stack_frame);
|
}
|
#endif
|
|
static unsigned long kernel_getsp(unsigned long sp, int is_first)
|
{
|
unsigned long *stack_frame = (unsigned long *)sp;
|
|
if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD))
|
return 0;
|
|
if (!is_first)
|
oprofile_add_trace(STACK_LR(stack_frame));
|
|
/*
|
* We do not enforce increasing stack addresses here because
|
* we might be transitioning from an interrupt stack to a kernel
|
* stack. validate_sp() is designed to understand this, so just
|
* use it.
|
*/
|
return STACK_SP(stack_frame);
|
}
|
|
void op_powerpc_backtrace(struct pt_regs * const regs, unsigned int depth)
|
{
|
unsigned long sp = regs->gpr[1];
|
int first_frame = 1;
|
|
/* We ditch the top stackframe so need to loop through an extra time */
|
depth += 1;
|
|
if (!user_mode(regs)) {
|
while (depth--) {
|
sp = kernel_getsp(sp, first_frame);
|
if (!sp)
|
break;
|
first_frame = 0;
|
}
|
} else {
|
#ifdef CONFIG_PPC64
|
if (!is_32bit_task()) {
|
while (depth--) {
|
sp = user_getsp64(sp, first_frame);
|
if (!sp)
|
break;
|
first_frame = 0;
|
}
|
return;
|
}
|
#endif
|
|
while (depth--) {
|
sp = user_getsp32(sp, first_frame);
|
if (!sp)
|
break;
|
first_frame = 0;
|
}
|
}
|
}
|
