Support kernel crash mini dumps on ARM architecture.

Obtained from:	Juniper Networks, Semihalf

4 files changed, 286 insertions, 4 deletions

diff --git a/lib/libkvm/Makefile b/lib/libkvm/Makefile
index 3ca8427..52a22ca 100644
--- a/lib/libkvm/Makefile
+++ b/lib/libkvm/Makefile
@@ -11,7 +11,7 @@ CFLAGS+=-DSUN4V
 
 SRCS=	kvm.c kvm_${MACHINE_ARCH}.c kvm_cptime.c kvm_file.c kvm_getloadavg.c \
 	kvm_getswapinfo.c kvm_pcpu.c kvm_proc.c
-.if ${MACHINE_ARCH} == "amd64" || ${MACHINE_ARCH} == "i386"
+.if ${MACHINE_ARCH} == "amd64" || ${MACHINE_ARCH} == "i386" || ${MACHINE_ARCH} == "arm"
 SRCS+=	kvm_minidump_${MACHINE_ARCH}.c
 .endif
 INCS=	kvm.h
diff --git a/lib/libkvm/kvm_arm.c b/lib/libkvm/kvm_arm.c
index 631aff6..489cfe0 100644
--- a/lib/libkvm/kvm_arm.c
+++ b/lib/libkvm/kvm_arm.c
@@ -52,10 +52,13 @@ __FBSDID("$FreeBSD$");
 #include <limits.h>
 #include <kvm.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 #include "kvm_private.h"
 
+/* minidump must be the first item! */
 struct vmstate {
+	int minidump;		/* 1 = minidump mode */
 	pd_entry_t *l1pt;
 	void *mmapbase;
 	size_t mmapsize;
@@ -107,6 +110,8 @@ void
 _kvm_freevtop(kvm_t *kd)
 {
 	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);
@@ -117,13 +122,25 @@ _kvm_freevtop(kvm_t *kd)
 int
 _kvm_initvtop(kvm_t *kd)
 {
-	struct vmstate *vm = _kvm_malloc(kd, sizeof(*vm));
+	struct vmstate *vm;
 	struct nlist nlist[2];
 	u_long kernbase, physaddr, pa;
 	pd_entry_t *l1pt;
 	Elf32_Ehdr *ehdr;
 	size_t hdrsz;
-	
+	char minihdr[8];
+
+	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);
+		}
+	}
+
+	vm = _kvm_malloc(kd, sizeof(*vm));
 	if (vm == 0) {
 		_kvm_err(kd, kd->program, "cannot allocate vm");
 		return (-1);
@@ -193,6 +210,9 @@ _kvm_kvatop(kvm_t *kd, u_long va, off_t *pa)
 	pt_entry_t pte;
 	u_long pte_pa;
 
+	if (kd->vmst->minidump)
+		return (_kvm_minidump_kvatop(kd, va, pa));
+
 	if (vm->l1pt == NULL)
 		return (_kvm_pa2off(kd, va, pa, PAGE_SIZE));
 	pd = vm->l1pt[L1_IDX(va)];
diff --git a/lib/libkvm/kvm_minidump_arm.c b/lib/libkvm/kvm_minidump_arm.c
new file mode 100644
index 0000000..d48c1bc
--- /dev/null
+++ b/lib/libkvm/kvm_minidump_arm.c
@@ -0,0 +1,262 @@
+/*-
+ * Copyright (c) 2008 Semihalf, Grzegorz Bernacki
+ * 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_i386.c,v 1.2 2006/06/05 08:51:14
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * ARM 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/minidump.h>
+
+#include <limits.h>
+
+#include "kvm_private.h"
+
+struct hpte {
+	struct hpte	*next;
+	uint64_t	pa;
+	int64_t		off;
+};
+
+#define HPT_SIZE 1024
+
+/* minidump must be the first field */
+struct vmstate {
+	int		minidump;		/* 1 = minidump mode */
+	struct		minidumphdr hdr;
+	void		*hpt_head[HPT_SIZE];
+	uint32_t	*bitmap;
+	void		*ptemap;
+};
+
+static void
+hpt_insert(kvm_t *kd, uint64_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, uint64_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, uint32_t *base, int len, off_t off)
+{
+	uint64_t idx, pa;
+	uint32_t bit, bits;
+
+	for (idx = 0; idx < len / sizeof(*base); idx++) {
+		bits = base[idx];
+		while (bits) {
+			bit = ffs(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;
+
+	if (vm->bitmap)
+		free(vm->bitmap);
+	if (vm->ptemap)
+		free(vm->ptemap);
+	free(vm);
+	kd->vmst = NULL;
+}
+
+int
+_kvm_minidump_initvtop(kvm_t *kd)
+{
+	u_long pa;
+	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) {
+		_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->ptemap = _kvm_malloc(kd, vmst->hdr.ptesize);
+	if (vmst->ptemap == NULL) {
+		_kvm_err(kd, kd->program, "cannot allocate %d bytes for "
+		    "ptemap", vmst->hdr.ptesize);
+		return (-1);
+	}
+
+	if (pread(kd->pmfd, vmst->ptemap, vmst->hdr.ptesize, off) !=
+	    vmst->hdr.ptesize) {
+		_kvm_err(kd, kd->program, "cannot read %d bytes for ptemap",
+		    vmst->hdr.ptesize);
+		return (-1);
+	}
+
+	off += vmst->hdr.ptesize;
+
+	/* Build physical address hash table for sparse pages */
+	inithash(kd, vmst->bitmap, vmst->hdr.bitmapsize, off);
+
+	return (0);
+}
+
+int
+_kvm_minidump_kvatop(kvm_t *kd, u_long va, off_t *pa)
+{
+	struct vmstate *vm;
+	pt_entry_t pte;
+	u_long offset, pteindex, a;
+	off_t ofs;
+	uint32_t *ptemap;
+	int i;
+
+	if (ISALIVE(kd)) {
+		_kvm_err(kd, 0, "kvm_kvatop called in live kernel!");
+		return (0);
+	}
+
+	vm = kd->vmst;
+	ptemap = vm->ptemap;
+
+	if (va >= vm->hdr.kernbase) {
+		pteindex = (va - vm->hdr.kernbase) >> PAGE_SHIFT;
+		pte = ptemap[pteindex];
+		if (!pte) {
+			_kvm_err(kd, kd->program, "_kvm_vatop: pte not valid");
+			goto invalid;
+		}
+		if ((pte & L2_TYPE_MASK) == L2_TYPE_L) {
+			offset = va & L2_L_OFFSET;
+			a = pte & L2_L_FRAME;
+		} else if ((pte & L2_TYPE_MASK) == L2_TYPE_S) {
+			offset = va & L2_S_OFFSET;
+			a = pte & L2_S_FRAME;
+		} else
+			goto invalid;
+
+		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);
+
+invalid:
+	_kvm_err(kd, 0, "invalid address (0x%lx)", va);
+	return (0);
+}
diff --git a/lib/libkvm/kvm_private.h b/lib/libkvm/kvm_private.h
index e791b41..88ff716 100644
--- a/lib/libkvm/kvm_private.h
+++ b/lib/libkvm/kvm_private.h
@@ -79,7 +79,7 @@ void	 _kvm_syserr (kvm_t *kd, const char *program, const char *fmt, ...)
 	    __printflike(3, 4);
 int	 _kvm_uvatop(kvm_t *, const struct proc *, u_long, u_long *);
 
-#if defined(__amd64__) || defined(__i386__)
+#if defined(__amd64__) || defined(__i386__) || defined(__arm__)
 void	 _kvm_minidump_freevtop(kvm_t *);
 int	 _kvm_minidump_initvtop(kvm_t *);
 int	 _kvm_minidump_kvatop(kvm_t *, u_long, off_t *);