d6a0af236d
from the kernel. Make use of this to restrict accessing userspace to just the functions that explicitly handle crossing the user kernel boundary. Reported by: kib Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D10371
94 lines
3.0 KiB
C
94 lines
3.0 KiB
C
/*-
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* Copyright (c) 2014 Andrew Turner
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef _MACHINE_ASM_H_
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#define _MACHINE_ASM_H_
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#undef __FBSDID
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#if !defined(lint) && !defined(STRIP_FBSDID)
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#define __FBSDID(s) .ident s
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#else
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#define __FBSDID(s) /* nothing */
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#endif
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#define _C_LABEL(x) x
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#define ENTRY(sym) \
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.text; .globl sym; .align 2; .type sym,#function; sym:
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#define EENTRY(sym) \
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.globl sym; sym:
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#define END(sym) .size sym, . - sym
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#define EEND(sym)
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#define WEAK_REFERENCE(sym, alias) \
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.weak alias; \
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.set alias,sym
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#define UINT64_C(x) (x)
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#if defined(PIC)
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#define PIC_SYM(x,y) x ## @ ## y
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#else
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#define PIC_SYM(x,y) x
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#endif
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/* Alias for link register x30 */
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#define lr x30
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/*
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* Sets the trap fault handler. The exception handler will return to the
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* address in the handler register on a data abort or the xzr register to
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* clear the handler. The tmp parameter should be a register able to hold
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* the temporary data.
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*/
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#define SET_FAULT_HANDLER(handler, tmp) \
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ldr tmp, [x18, #PC_CURTHREAD]; /* Load curthread */ \
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ldr tmp, [tmp, #TD_PCB]; /* Load the pcb */ \
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str handler, [tmp, #PCB_ONFAULT] /* Set the handler */
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#define ENTER_USER_ACCESS(reg, tmp) \
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ldr tmp, =has_pan; /* Get the addr of has_pan */ \
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ldr reg, [tmp]; /* Read it */ \
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cbz reg, 997f; /* If no PAN skip */ \
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.inst 0xd500409f | (0 << 8); /* Clear PAN */ \
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997:
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#define EXIT_USER_ACCESS(reg) \
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cbz reg, 998f; /* If no PAN skip */ \
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.inst 0xd500409f | (1 << 8); /* Set PAN */ \
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998:
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#define EXIT_USER_ACCESS_CHECK(reg, tmp) \
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ldr tmp, =has_pan; /* Get the addr of has_pan */ \
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ldr reg, [tmp]; /* Read it */ \
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cbz reg, 999f; /* If no PAN skip */ \
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.inst 0xd500409f | (1 << 8); /* Set PAN */ \
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999:
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#endif /* _MACHINE_ASM_H_ */
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