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