linux-stable/arch/powerpc/oprofile/backtrace.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

128 lines
2.8 KiB
C

// 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 <asm/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);
if (!access_ok(p, sizeof(stack_frame)))
return 0;
/*
* 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_inatomic(stack_frame, 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 (!access_ok((void __user *)sp, sizeof(stack_frame)))
return 0;
if (__copy_from_user_inatomic(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 {
pagefault_disable();
#ifdef CONFIG_PPC64
if (!is_32bit_task()) {
while (depth--) {
sp = user_getsp64(sp, first_frame);
if (!sp)
break;
first_frame = 0;
}
pagefault_enable();
return;
}
#endif
while (depth--) {
sp = user_getsp32(sp, first_frame);
if (!sp)
break;
first_frame = 0;
}
pagefault_enable();
}
}