Add support to libkvm for reading minidumps on arm64. The kernel side is

missing until it can be cleaned up.

Reviewed by:	jhb
Approved by:	ABT Systems Ltd
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D3319

lib/libkvm/kvm_aarch64.c

@@ -1,5 +1,6 @@
 /*-
- * Copyright (c) 2014 The FreeBSD Foundation
+ * Copyright (C) 2006 Bruce M. Simpson.
+ * Copyright (c) 2015 The FreeBSD Foundation
  * All rights reserved.
  *
  * This software was developed by Andrew Turner under
@@ -27,38 +28,78 @@
  * SUCH DAMAGE.
  */
 
+/*
+ * arm64 (AArch64) machine dependent routines for kvm.
+ */
+
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
+#include <sys/mman.h>
+
+#include <vm/vm.h>
+#include <vm/vm_param.h>
+#include <vm/pmap.h>
+
+#include <machine/pmap.h>
 
 #include <limits.h>
 #include <kvm.h>
-#include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 
 #include "kvm_private.h"
 
+/* minidump must be the first item! */
+struct vmstate {
+	int minidump;		/* 1 = minidump mode */
+	void *mmapbase;
+	size_t mmapsize;
+};
+
 void
 _kvm_freevtop(kvm_t *kd)
 {
 
-	printf("_kvm_freevtop\n");
-	abort();
+	if (kd->vmst != 0) {
+		if (kd->vmst->minidump)
+			return (_kvm_minidump_freevtop(kd));
+		if (kd->vmst->mmapbase != NULL)
+			munmap(kd->vmst->mmapbase, kd->vmst->mmapsize);
+		free(kd->vmst);
+		kd->vmst = NULL;
+	}
 }
 
 int
 _kvm_initvtop(kvm_t *kd)
 {
+	char minihdr[8];
 
-	printf("_kvm_initvtop\n");
-	abort();
+	if (!kd->rawdump) {
+		if (pread(kd->pmfd, &minihdr, 8, 0) == 8) {
+			if (memcmp(&minihdr, "minidump", 8) == 0)
+				return (_kvm_minidump_initvtop(kd));
+		} else {
+			_kvm_err(kd, kd->program, "cannot read header");
+			return (-1);
+		}
+	}
+
+	_kvm_err(kd, 0, "_kvm_initvtop: Unsupported image type");
+	return (-1);
 }
 
 int
 _kvm_kvatop(kvm_t *kd, u_long va, off_t *pa)
 {
 
-	printf("_kvm_kvatop\n");
-	abort();
+	if (kd->vmst->minidump)
+		return _kvm_minidump_kvatop(kd, va, pa);
+
+
+	_kvm_err(kd, 0, "_kvm_kvatop: Unsupported image type");
+	return (0);
 }

lib/libkvm/kvm_minidump_aarch64.c

@@ -0,0 +1,269 @@
+/*-
+ * Copyright (c) 2006 Peter Wemm
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * From: FreeBSD: src/lib/libkvm/kvm_minidump_amd64.c r261799
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * ARM64 (AArch64) machine dependent routines for kvm and minidumps. 
+ */
+
+#include <sys/param.h>
+#include <sys/user.h>
+#include <sys/proc.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/fnv_hash.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <nlist.h>
+#include <kvm.h>
+
+#include <vm/vm.h>
+#include <vm/vm_param.h>
+
+#include <machine/elf.h>
+#include <machine/cpufunc.h>
+#include <machine/pte.h>
+#include <machine/minidump.h>
+
+#include <limits.h>
+#include <stdint.h>
+
+#include "kvm_private.h"
+
+struct hpte {
+	struct hpte *next;
+	vm_paddr_t pa;
+	int64_t off;
+};
+
+#define HPT_SIZE 1024
+
+/* minidump must be the first item! */
+struct vmstate {
+	int minidump;		/* 1 = minidump mode */
+	struct minidumphdr hdr;
+	void *hpt_head[HPT_SIZE];
+	uint64_t *bitmap;
+	uint64_t *page_map;
+};
+
+static void
+hpt_insert(kvm_t *kd, vm_paddr_t pa, int64_t off)
+{
+	struct hpte *hpte;
+	uint32_t fnv = FNV1_32_INIT;
+
+	fnv = fnv_32_buf(&pa, sizeof(pa), fnv);
+	fnv &= (HPT_SIZE - 1);
+	hpte = malloc(sizeof(*hpte));
+	hpte->pa = pa;
+	hpte->off = off;
+	hpte->next = kd->vmst->hpt_head[fnv];
+	kd->vmst->hpt_head[fnv] = hpte;
+}
+
+static int64_t
+hpt_find(kvm_t *kd, vm_paddr_t pa)
+{
+	struct hpte *hpte;
+	uint32_t fnv = FNV1_32_INIT;
+
+	fnv = fnv_32_buf(&pa, sizeof(pa), fnv);
+	fnv &= (HPT_SIZE - 1);
+	for (hpte = kd->vmst->hpt_head[fnv]; hpte != NULL; hpte = hpte->next) {
+		if (pa == hpte->pa)
+			return (hpte->off);
+	}
+	return (-1);
+}
+
+static int
+inithash(kvm_t *kd, uint64_t *base, int len, off_t off)
+{
+	uint64_t idx;
+	uint64_t bit, bits;
+	vm_paddr_t pa;
+
+	for (idx = 0; idx < len / sizeof(*base); idx++) {
+		bits = base[idx];
+		while (bits) {
+			bit = ffsl(bits) - 1;
+			bits &= ~(1ul << bit);
+			pa = (idx * sizeof(*base) * NBBY + bit) * PAGE_SIZE;
+			hpt_insert(kd, pa, off);
+			off += PAGE_SIZE;
+		}
+	}
+	return (off);
+}
+
+void
+_kvm_minidump_freevtop(kvm_t *kd)
+{
+	struct vmstate *vm = kd->vmst;
+
+	free(vm->bitmap);
+	free(vm->page_map);
+	free(vm);
+	kd->vmst = NULL;
+}
+
+int
+_kvm_minidump_initvtop(kvm_t *kd)
+{
+	struct vmstate *vmst;
+	off_t off;
+
+	vmst = _kvm_malloc(kd, sizeof(*vmst));
+	if (vmst == 0) {
+		_kvm_err(kd, kd->program, "cannot allocate vm");
+		return (-1);
+	}
+	kd->vmst = vmst;
+	vmst->minidump = 1;
+	if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
+	    sizeof(vmst->hdr)) {
+		_kvm_err(kd, kd->program, "cannot read dump header");
+		return (-1);
+	}
+	if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic,
+	    sizeof(vmst->hdr.magic)) != 0) {
+		_kvm_err(kd, kd->program, "not a minidump for this platform");
+		return (-1);
+	}
+
+	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
+		_kvm_err(kd, kd->program, "wrong minidump version. "
+		    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
+		return (-1);
+	}
+
+	/* Skip header and msgbuf */
+	off = PAGE_SIZE + round_page(vmst->hdr.msgbufsize);
+
+	vmst->bitmap = _kvm_malloc(kd, vmst->hdr.bitmapsize);
+	if (vmst->bitmap == NULL) {
+		_kvm_err(kd, kd->program,
+		    "cannot allocate %d bytes for bitmap",
+		    vmst->hdr.bitmapsize);
+		return (-1);
+	}
+	if (pread(kd->pmfd, vmst->bitmap, vmst->hdr.bitmapsize, off) !=
+	    vmst->hdr.bitmapsize) {
+		_kvm_err(kd, kd->program,
+		    "cannot read %d bytes for page bitmap",
+		    vmst->hdr.bitmapsize);
+		return (-1);
+	}
+	off += round_page(vmst->hdr.bitmapsize);
+
+	vmst->page_map = _kvm_malloc(kd, vmst->hdr.pmapsize);
+	if (vmst->page_map == NULL) {
+		_kvm_err(kd, kd->program,
+		    "cannot allocate %d bytes for page_map",
+		    vmst->hdr.pmapsize);
+		return (-1);
+	}
+	/* This is the end of the dump, savecore may have truncated it. */
+	if (pread(kd->pmfd, vmst->page_map, vmst->hdr.pmapsize, off) <
+	    PAGE_SIZE) {
+		_kvm_err(kd, kd->program, "cannot read %d bytes for page_map",
+		    vmst->hdr.pmapsize);
+	}
+	off += vmst->hdr.pmapsize;
+
+	/* build physical address hash table for sparse pages */
+	inithash(kd, vmst->bitmap, vmst->hdr.bitmapsize, off);
+
+	return (0);
+}
+
+static int
+_kvm_minidump_vatop(kvm_t *kd, u_long va, off_t *pa)
+{
+	struct vmstate *vm;
+	u_long offset;
+	pt_entry_t l3;
+	u_long l3_index;
+	u_long a;
+	off_t ofs;
+
+	vm = kd->vmst;
+	offset = va & PAGE_MASK;
+
+	if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
+		a = (va - vm->hdr.dmapbase + vm->hdr.dmapphys) & ~PAGE_MASK;
+		ofs = hpt_find(kd, a);
+		if (ofs == -1) {
+			_kvm_err(kd, kd->program, "_kvm_vatop: "
+			    "direct map address 0x%lx not in minidump", va);
+			goto invalid;
+		}
+		*pa = ofs + offset;
+		return (PAGE_SIZE - offset);
+	} else if (va >= vm->hdr.kernbase) {
+		l3_index = (va - vm->hdr.kernbase) >> L3_SHIFT;
+		if (l3_index >= vm->hdr.pmapsize / sizeof(*vm->page_map))
+			goto invalid;
+		l3 = vm->page_map[l3_index];
+		if ((l3 & ATTR_DESCR_MASK) != L3_PAGE) {
+			_kvm_err(kd, kd->program, "_kvm_vatop: pde not valid");
+			goto invalid;
+		}
+		a = l3 & ~ATTR_MASK;
+		ofs = hpt_find(kd, a);
+		if (ofs == -1) {
+			_kvm_err(kd, kd->program, "_kvm_vatop: "
+			    "physical address 0x%lx not in minidump", a);
+			goto invalid;
+		}
+		*pa = ofs + offset;
+		return (PAGE_SIZE - offset);
+	} else {
+		_kvm_err(kd, kd->program,
+		    "_kvm_vatop: virtual address 0x%lx not minidumped", va);
+		goto invalid;
+	}
+
+invalid:
+	_kvm_err(kd, 0, "invalid address (0x%lx)", va);
+	return (0);
+}
+
+int
+_kvm_minidump_kvatop(kvm_t *kd, u_long va, off_t *pa)
+{
+
+	if (ISALIVE(kd)) {
+		_kvm_err(kd, 0, "kvm_kvatop called in live kernel!");
+		return (0);
+	}
+	return (_kvm_minidump_vatop(kd, va, pa));
+}

lib/libkvm/kvm_private.h

@@ -104,8 +104,8 @@ uintptr_t _kvm_vnet_validaddr(kvm_t *, uintptr_t);
 int	 _kvm_dpcpu_initialized(kvm_t *, int);
 uintptr_t _kvm_dpcpu_validaddr(kvm_t *, uintptr_t);
 
-#if defined(__amd64__) || defined(__i386__) || defined(__arm__) || \
-    defined(__mips__)
+#if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \
+    defined(__i386__) || defined(__mips__)
 void	 _kvm_minidump_freevtop(kvm_t *);
 int	 _kvm_minidump_initvtop(kvm_t *);
 int	 _kvm_minidump_kvatop(kvm_t *, u_long, off_t *);