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msan.h revision 1.1.8.3
      1  1.1.8.2  martin /*	$NetBSD: msan.h,v 1.1.8.3 2020/04/21 18:42:03 martin Exp $	*/
      2  1.1.8.2  martin 
      3  1.1.8.2  martin /*
      4  1.1.8.2  martin  * Copyright (c) 2019 The NetBSD Foundation, Inc.
      5  1.1.8.2  martin  * All rights reserved.
      6  1.1.8.2  martin  *
      7  1.1.8.2  martin  * This code is derived from software contributed to The NetBSD Foundation
      8  1.1.8.2  martin  * by Maxime Villard.
      9  1.1.8.2  martin  *
     10  1.1.8.2  martin  * Redistribution and use in source and binary forms, with or without
     11  1.1.8.2  martin  * modification, are permitted provided that the following conditions
     12  1.1.8.2  martin  * are met:
     13  1.1.8.2  martin  * 1. Redistributions of source code must retain the above copyright
     14  1.1.8.2  martin  *    notice, this list of conditions and the following disclaimer.
     15  1.1.8.2  martin  * 2. Redistributions in binary form must reproduce the above copyright
     16  1.1.8.2  martin  *    notice, this list of conditions and the following disclaimer in the
     17  1.1.8.2  martin  *    documentation and/or other materials provided with the distribution.
     18  1.1.8.2  martin  *
     19  1.1.8.2  martin  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  1.1.8.2  martin  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  1.1.8.2  martin  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  1.1.8.2  martin  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  1.1.8.2  martin  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  1.1.8.2  martin  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  1.1.8.2  martin  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  1.1.8.2  martin  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  1.1.8.2  martin  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  1.1.8.2  martin  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  1.1.8.2  martin  * POSSIBILITY OF SUCH DAMAGE.
     30  1.1.8.2  martin  */
     31  1.1.8.2  martin 
     32  1.1.8.2  martin #include <sys/ksyms.h>
     33  1.1.8.2  martin 
     34  1.1.8.2  martin #include <amd64/pmap.h>
     35  1.1.8.2  martin #include <amd64/vmparam.h>
     36  1.1.8.2  martin 
     37  1.1.8.2  martin #ifdef __HAVE_PCPU_AREA
     38  1.1.8.2  martin #error "PCPU area not allowed with KMSAN"
     39  1.1.8.2  martin #endif
     40  1.1.8.2  martin #ifdef __HAVE_DIRECT_MAP
     41  1.1.8.2  martin #error "DMAP not allowed with KMSAN"
     42  1.1.8.2  martin #endif
     43  1.1.8.2  martin 
     44  1.1.8.2  martin /*
     45  1.1.8.2  martin  * One big shadow, divided in two sub-shadows (SHAD and ORIG), themselves
     46  1.1.8.2  martin  * divided in two regions (MAIN and KERN).
     47  1.1.8.2  martin  */
     48  1.1.8.2  martin 
     49  1.1.8.2  martin #define __MD_SHADOW_SIZE	0x20000000000ULL	/* 4 * NBPD_L4 */
     50  1.1.8.2  martin #define __MD_SHADOW_START	(VA_SIGN_NEG((L4_SLOT_KMSAN * NBPD_L4)))
     51  1.1.8.2  martin #define __MD_SHADOW_END		(__MD_SHADOW_START + __MD_SHADOW_SIZE)
     52  1.1.8.2  martin 
     53  1.1.8.2  martin #define __MD_SHAD_MAIN_START	(__MD_SHADOW_START)
     54  1.1.8.2  martin #define __MD_SHAD_KERN_START	(__MD_SHADOW_START + 0x8000000000ULL)
     55  1.1.8.2  martin 
     56  1.1.8.2  martin #define __MD_ORIG_MAIN_START	(__MD_SHAD_KERN_START + 0x8000000000ULL)
     57  1.1.8.2  martin #define __MD_ORIG_KERN_START	(__MD_ORIG_MAIN_START + 0x8000000000ULL)
     58  1.1.8.2  martin 
     59  1.1.8.2  martin #define __MD_PTR_BASE		0xFFFFFFFF80000000ULL
     60  1.1.8.2  martin #define __MD_ORIG_TYPE		__BITS(31,28)
     61  1.1.8.2  martin 
     62  1.1.8.2  martin static inline int8_t *
     63  1.1.8.2  martin kmsan_md_addr_to_shad(const void *addr)
     64  1.1.8.2  martin {
     65  1.1.8.2  martin 	vaddr_t va = (vaddr_t)addr;
     66  1.1.8.2  martin 
     67  1.1.8.2  martin 	if (va >= vm_min_kernel_address && va < vm_max_kernel_address) {
     68  1.1.8.2  martin 		return (int8_t *)(__MD_SHAD_MAIN_START + (va - vm_min_kernel_address));
     69  1.1.8.2  martin 	} else if (va >= KERNBASE) {
     70  1.1.8.2  martin 		return (int8_t *)(__MD_SHAD_KERN_START + (va - KERNBASE));
     71  1.1.8.2  martin 	} else {
     72  1.1.8.2  martin 		panic("%s: impossible, va=%p", __func__, (void *)va);
     73  1.1.8.2  martin 	}
     74  1.1.8.2  martin }
     75  1.1.8.2  martin 
     76  1.1.8.2  martin static inline int8_t *
     77  1.1.8.2  martin kmsan_md_addr_to_orig(const void *addr)
     78  1.1.8.2  martin {
     79  1.1.8.2  martin 	vaddr_t va = (vaddr_t)addr;
     80  1.1.8.2  martin 
     81  1.1.8.2  martin 	if (va >= vm_min_kernel_address && va < vm_max_kernel_address) {
     82  1.1.8.2  martin 		return (int8_t *)(__MD_ORIG_MAIN_START + (va - vm_min_kernel_address));
     83  1.1.8.2  martin 	} else if (va >= KERNBASE) {
     84  1.1.8.2  martin 		return (int8_t *)(__MD_ORIG_KERN_START + (va - KERNBASE));
     85  1.1.8.2  martin 	} else {
     86  1.1.8.2  martin 		panic("%s: impossible, va=%p", __func__, (void *)va);
     87  1.1.8.2  martin 	}
     88  1.1.8.2  martin }
     89  1.1.8.2  martin 
     90  1.1.8.2  martin static inline bool
     91  1.1.8.2  martin kmsan_md_unsupported(vaddr_t addr)
     92  1.1.8.2  martin {
     93  1.1.8.2  martin 	return (addr >= (vaddr_t)PTE_BASE &&
     94  1.1.8.2  martin 	    addr < ((vaddr_t)PTE_BASE + NBPD_L4));
     95  1.1.8.2  martin }
     96  1.1.8.2  martin 
     97  1.1.8.2  martin static inline paddr_t
     98  1.1.8.2  martin __md_palloc(void)
     99  1.1.8.2  martin {
    100  1.1.8.3  martin 	/* The page is zeroed. */
    101  1.1.8.2  martin 	return pmap_get_physpage();
    102  1.1.8.2  martin }
    103  1.1.8.2  martin 
    104  1.1.8.3  martin static inline paddr_t
    105  1.1.8.3  martin __md_palloc_large(void)
    106  1.1.8.3  martin {
    107  1.1.8.3  martin 	struct pglist pglist;
    108  1.1.8.3  martin 	int ret;
    109  1.1.8.3  martin 
    110  1.1.8.3  martin 	if (!uvm.page_init_done)
    111  1.1.8.3  martin 		return 0;
    112  1.1.8.3  martin 
    113  1.1.8.3  martin 	kmsan_init_arg(sizeof(psize_t) + 4 * sizeof(paddr_t) +
    114  1.1.8.3  martin 	    sizeof(struct pglist *) + 2 * sizeof(int));
    115  1.1.8.3  martin 	ret = uvm_pglistalloc(NBPD_L2, 0, ~0UL, NBPD_L2, 0,
    116  1.1.8.3  martin 	    &pglist, 1, 0);
    117  1.1.8.3  martin 	if (ret != 0)
    118  1.1.8.3  martin 		return 0;
    119  1.1.8.3  martin 
    120  1.1.8.3  martin 	/* The page may not be zeroed. */
    121  1.1.8.3  martin 	return VM_PAGE_TO_PHYS(TAILQ_FIRST(&pglist));
    122  1.1.8.3  martin }
    123  1.1.8.3  martin 
    124  1.1.8.2  martin static void
    125  1.1.8.2  martin kmsan_md_shadow_map_page(vaddr_t va)
    126  1.1.8.2  martin {
    127  1.1.8.3  martin 	const pt_entry_t pteflags = PTE_W | pmap_pg_nx | PTE_P;
    128  1.1.8.2  martin 	paddr_t pa;
    129  1.1.8.2  martin 
    130  1.1.8.2  martin 	KASSERT(va >= __MD_SHADOW_START && va < __MD_SHADOW_END);
    131  1.1.8.2  martin 
    132  1.1.8.2  martin 	if (!pmap_valid_entry(L4_BASE[pl4_i(va)])) {
    133  1.1.8.2  martin 		pa = __md_palloc();
    134  1.1.8.3  martin 		L4_BASE[pl4_i(va)] = pa | pteflags;
    135  1.1.8.2  martin 	}
    136  1.1.8.2  martin 	if (!pmap_valid_entry(L3_BASE[pl3_i(va)])) {
    137  1.1.8.2  martin 		pa = __md_palloc();
    138  1.1.8.3  martin 		L3_BASE[pl3_i(va)] = pa | pteflags;
    139  1.1.8.2  martin 	}
    140  1.1.8.2  martin 	if (!pmap_valid_entry(L2_BASE[pl2_i(va)])) {
    141  1.1.8.3  martin 		if ((pa = __md_palloc_large()) != 0) {
    142  1.1.8.3  martin 			L2_BASE[pl2_i(va)] = pa | pteflags | PTE_PS |
    143  1.1.8.3  martin 			    pmap_pg_g;
    144  1.1.8.3  martin 			__insn_barrier();
    145  1.1.8.3  martin 			__builtin_memset(va, 0, NBPD_L2);
    146  1.1.8.3  martin 			return;
    147  1.1.8.3  martin 		}
    148  1.1.8.2  martin 		pa = __md_palloc();
    149  1.1.8.3  martin 		L2_BASE[pl2_i(va)] = pa | pteflags;
    150  1.1.8.3  martin 	} else if (L2_BASE[pl2_i(va)] & PTE_PS) {
    151  1.1.8.3  martin 		return;
    152  1.1.8.2  martin 	}
    153  1.1.8.2  martin 	if (!pmap_valid_entry(L1_BASE[pl1_i(va)])) {
    154  1.1.8.2  martin 		pa = __md_palloc();
    155  1.1.8.3  martin 		L1_BASE[pl1_i(va)] = pa | pteflags | pmap_pg_g;
    156  1.1.8.2  martin 	}
    157  1.1.8.2  martin }
    158  1.1.8.2  martin 
    159  1.1.8.2  martin static void
    160  1.1.8.2  martin kmsan_md_init(void)
    161  1.1.8.2  martin {
    162  1.1.8.2  martin 	extern struct bootspace bootspace;
    163  1.1.8.2  martin 	size_t i;
    164  1.1.8.2  martin 
    165  1.1.8.2  martin 	CTASSERT((__MD_SHADOW_SIZE / NBPD_L4) == NL4_SLOT_KMSAN);
    166  1.1.8.2  martin 
    167  1.1.8.2  martin 	/* Kernel. */
    168  1.1.8.2  martin 	for (i = 0; i < BTSPACE_NSEGS; i++) {
    169  1.1.8.2  martin 		if (bootspace.segs[i].type == BTSEG_NONE) {
    170  1.1.8.2  martin 			continue;
    171  1.1.8.2  martin 		}
    172  1.1.8.2  martin 		kmsan_shadow_map((void *)bootspace.segs[i].va,
    173  1.1.8.2  martin 		    bootspace.segs[i].sz);
    174  1.1.8.2  martin 	}
    175  1.1.8.2  martin 
    176  1.1.8.2  martin 	/* Boot region. */
    177  1.1.8.2  martin 	kmsan_shadow_map((void *)bootspace.boot.va, bootspace.boot.sz);
    178  1.1.8.2  martin 
    179  1.1.8.2  martin 	/* Module map. */
    180  1.1.8.2  martin 	kmsan_shadow_map((void *)bootspace.smodule,
    181  1.1.8.2  martin 	    (size_t)(bootspace.emodule - bootspace.smodule));
    182  1.1.8.2  martin 
    183  1.1.8.2  martin 	/* The bootstrap spare va. */
    184  1.1.8.2  martin 	kmsan_shadow_map((void *)bootspace.spareva, PAGE_SIZE);
    185  1.1.8.2  martin }
    186  1.1.8.2  martin 
    187  1.1.8.2  martin static inline msan_orig_t
    188  1.1.8.2  martin kmsan_md_orig_encode(int type, uintptr_t ptr)
    189  1.1.8.2  martin {
    190  1.1.8.2  martin 	msan_orig_t ret;
    191  1.1.8.2  martin 
    192  1.1.8.2  martin 	ret = (ptr & 0xFFFFFFFF) & ~__MD_ORIG_TYPE;
    193  1.1.8.2  martin 	ret |= __SHIFTIN(type, __MD_ORIG_TYPE);
    194  1.1.8.2  martin 
    195  1.1.8.2  martin 	return ret;
    196  1.1.8.2  martin }
    197  1.1.8.2  martin 
    198  1.1.8.2  martin static inline void
    199  1.1.8.2  martin kmsan_md_orig_decode(msan_orig_t orig, int *type, uintptr_t *ptr)
    200  1.1.8.2  martin {
    201  1.1.8.2  martin 	*type = __SHIFTOUT(orig, __MD_ORIG_TYPE);
    202  1.1.8.2  martin 	*ptr = (uintptr_t)(orig & ~__MD_ORIG_TYPE) | __MD_PTR_BASE;
    203  1.1.8.2  martin }
    204  1.1.8.2  martin 
    205  1.1.8.2  martin static inline bool
    206  1.1.8.2  martin kmsan_md_is_pc(uintptr_t ptr)
    207  1.1.8.2  martin {
    208  1.1.8.2  martin 	extern uint8_t __rodata_start;
    209  1.1.8.2  martin 
    210  1.1.8.2  martin 	return (ptr < (uintptr_t)&__rodata_start);
    211  1.1.8.2  martin }
    212  1.1.8.2  martin 
    213  1.1.8.2  martin static inline bool
    214  1.1.8.2  martin __md_unwind_end(const char *name)
    215  1.1.8.2  martin {
    216  1.1.8.2  martin 	if (!strcmp(name, "syscall") ||
    217  1.1.8.2  martin 	    !strcmp(name, "alltraps") ||
    218  1.1.8.2  martin 	    !strcmp(name, "handle_syscall") ||
    219  1.1.8.2  martin 	    !strncmp(name, "Xtrap", 5) ||
    220  1.1.8.2  martin 	    !strncmp(name, "Xintr", 5) ||
    221  1.1.8.2  martin 	    !strncmp(name, "Xhandle", 7) ||
    222  1.1.8.2  martin 	    !strncmp(name, "Xresume", 7) ||
    223  1.1.8.2  martin 	    !strncmp(name, "Xstray", 6) ||
    224  1.1.8.2  martin 	    !strncmp(name, "Xhold", 5) ||
    225  1.1.8.2  martin 	    !strncmp(name, "Xrecurse", 8) ||
    226  1.1.8.2  martin 	    !strcmp(name, "Xdoreti") ||
    227  1.1.8.2  martin 	    !strncmp(name, "Xsoft", 5)) {
    228  1.1.8.2  martin 		return true;
    229  1.1.8.2  martin 	}
    230  1.1.8.2  martin 
    231  1.1.8.2  martin 	return false;
    232  1.1.8.2  martin }
    233  1.1.8.2  martin 
    234  1.1.8.2  martin static void
    235  1.1.8.2  martin kmsan_md_unwind(void)
    236  1.1.8.2  martin {
    237  1.1.8.2  martin 	uint64_t *rbp, rip;
    238  1.1.8.2  martin 	const char *mod;
    239  1.1.8.2  martin 	const char *sym;
    240  1.1.8.2  martin 	size_t nsym;
    241  1.1.8.2  martin 	int error;
    242  1.1.8.2  martin 
    243  1.1.8.2  martin 	rbp = (uint64_t *)__builtin_frame_address(0);
    244  1.1.8.2  martin 	nsym = 0;
    245  1.1.8.2  martin 
    246  1.1.8.2  martin 	while (1) {
    247  1.1.8.2  martin 		/* 8(%rbp) contains the saved %rip. */
    248  1.1.8.2  martin 		rip = *(rbp + 1);
    249  1.1.8.2  martin 
    250  1.1.8.2  martin 		if (rip < KERNBASE) {
    251  1.1.8.2  martin 			break;
    252  1.1.8.2  martin 		}
    253  1.1.8.2  martin 		error = ksyms_getname(&mod, &sym, (vaddr_t)rip, KSYMS_PROC);
    254  1.1.8.2  martin 		if (error) {
    255  1.1.8.2  martin 			break;
    256  1.1.8.2  martin 		}
    257  1.1.8.2  martin 		kmsan_printf("#%zu %p in %s <%s>\n", nsym, (void *)rip, sym, mod);
    258  1.1.8.2  martin 		if (__md_unwind_end(sym)) {
    259  1.1.8.2  martin 			break;
    260  1.1.8.2  martin 		}
    261  1.1.8.2  martin 
    262  1.1.8.2  martin 		rbp = (uint64_t *)*(rbp);
    263  1.1.8.2  martin 		if (rbp == 0) {
    264  1.1.8.2  martin 			break;
    265  1.1.8.2  martin 		}
    266  1.1.8.2  martin 		nsym++;
    267  1.1.8.2  martin 
    268  1.1.8.2  martin 		if (nsym >= 15) {
    269  1.1.8.2  martin 			break;
    270  1.1.8.2  martin 		}
    271  1.1.8.2  martin 	}
    272  1.1.8.2  martin }
    273