Add support to libkvm for reading vmcores from other architectures.

- Add a kvaddr_type to represent kernel virtual addresses instead of
  unsigned long.
- Add a struct kvm_nlist which is a stripped down version of struct nlist
  that uses kvaddr_t for n_value.
- Add a kvm_native() routine that returns true if an open kvm descriptor
  is for a native kernel and memory image.
- Add a kvm_open2() function similar to kvm_openfiles().  It drops the
  unused 'swapfile' argument and adds a new function pointer argument for
  a symbol resolving function.  Native kernels still use _fdnlist() from
  libc to resolve symbols if a resolver function is not supplied, but cross
  kernels require a resolver.
- Add a kvm_nlist2() function similar to kvm_nlist() except that it uses
  struct kvm_nlist instead of struct nlist.
- Add a kvm_read2() function similar to kvm_read() except that it uses
  kvaddr_t instead of unsigned long for the kernel virtual address.
- Add a new kvm_arch switch of routines needed by a vmcore backend.
  Each backend is responsible for implementing kvm_read2() for a given
  vmcore format.
- Use libelf to read headers from ELF kernels and cores (except for
  powerpc cores).
- Add internal helper routines for the common page offset hash table used
  by the minidump backends.
- Port all of the existing kvm backends to implement a kvm_arch switch and
  to be cross-friendly by using private constants instead of ones that
  vary by platform (e.g. PAGE_SIZE).  Static assertions are present when
  a given backend is compiled natively to ensure the private constants
  match the real ones.
- Enable all of the existing vmcore backends on all platforms.  This means
  that libkvm on any platform should be able to perform KVA translation
  and read data from a vmcore of any platform.

Tested on:	amd64, i386, sparc64 (marius)
Differential Revision:	https://reviews.freebsd.org/D3341

1 files changed, 69 insertions, 113 deletions

diff --git a/lib/libkvm/kvm_minidump_arm.c b/lib/libkvm/kvm_minidump_arm.c
index f4ba6044e4ea..9e9cd6726804 100644
--- a/lib/libkvm/kvm_minidump_arm.c
+++ b/lib/libkvm/kvm_minidump_arm.c
@@ -33,120 +33,54 @@ __FBSDID("$FreeBSD$");
  * ARM machine dependent routines for kvm and minidumps.
  */
 
+#include <sys/endian.h>
 #include <sys/param.h>
-#ifndef CROSS_LIBKVM
-#include <sys/user.h>
-#endif
-#include <sys/proc.h>
-#include <sys/stat.h>
-#include <sys/mman.h>
-#include <sys/fnv_hash.h>
+#include <kvm.h>
+#include <limits.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-#include <nlist.h>
-#include <kvm.h>
-
-#ifndef CROSS_LIBKVM
-#include <vm/vm.h>
-#include <vm/vm_param.h>
 
-#include <machine/elf.h>
-#include <machine/cpufunc.h>
-#include <machine/minidump.h>
-#else
-#include "../../sys/arm/include/pte.h"
-#include "../../sys/arm/include/vmparam.h"
 #include "../../sys/arm/include/minidump.h"
-#endif
-
-#include <limits.h>
 
 #include "kvm_private.h"
+#include "kvm_arm.h"
 
-struct hpte {
-	struct hpte	*next;
-	uint64_t	pa;
-	int64_t		off;
-};
+#define	arm_round_page(x)	roundup2((kvaddr_t)(x), ARM_PAGE_SIZE)
 
-#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;
+	struct		hpt hpt;
 	void		*ptemap;
+	unsigned char	ei_data;
 };
 
-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)
+_arm_minidump_probe(kvm_t *kd)
 {
-	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);
+
+	return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_ARM) &&
+	    _kvm_is_minidump(kd));
 }
 
-void
-_kvm_minidump_freevtop(kvm_t *kd)
+static void
+_arm_minidump_freevtop(kvm_t *kd)
 {
 	struct vmstate *vm = kd->vmst;
 
-	if (vm->bitmap)
-		free(vm->bitmap);
+	_kvm_hpt_free(&vm->hpt);
 	if (vm->ptemap)
 		free(vm->ptemap);
 	free(vm);
 	kd->vmst = NULL;
 }
 
-int
-_kvm_minidump_initvtop(kvm_t *kd)
+static int
+_arm_minidump_initvtop(kvm_t *kd)
 {
 	struct vmstate *vmst;
+	uint32_t *bitmap;
 	off_t off;
 
 	vmst = _kvm_malloc(kd, sizeof(*vmst));
@@ -156,7 +90,6 @@ _kvm_minidump_initvtop(kvm_t *kd)
 	}
 
 	kd->vmst = vmst;
-	vmst->minidump = 1;
 
 	if (pread(kd->pmfd, &vmst->hdr,
 	    sizeof(vmst->hdr), 0) != sizeof(vmst->hdr)) {
@@ -169,34 +102,41 @@ _kvm_minidump_initvtop(kvm_t *kd)
 		_kvm_err(kd, kd->program, "not a minidump for this platform");
 		return (-1);
 	}
+	vmst->hdr.version = _kvm32toh(kd, vmst->hdr.version);
 	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);
 	}
+	vmst->hdr.msgbufsize = _kvm32toh(kd, vmst->hdr.msgbufsize);
+	vmst->hdr.bitmapsize = _kvm32toh(kd, vmst->hdr.bitmapsize);
+	vmst->hdr.ptesize = _kvm32toh(kd, vmst->hdr.ptesize);
+	vmst->hdr.kernbase = _kvm32toh(kd, vmst->hdr.kernbase);
 
 	/* Skip header and msgbuf */
-	off = PAGE_SIZE + round_page(vmst->hdr.msgbufsize);
+	off = ARM_PAGE_SIZE + arm_round_page(vmst->hdr.msgbufsize);
 
-	vmst->bitmap = _kvm_malloc(kd, vmst->hdr.bitmapsize);
-	if (vmst->bitmap == NULL) {
+	bitmap = _kvm_malloc(kd, vmst->hdr.bitmapsize);
+	if (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) !=
+	if (pread(kd->pmfd, bitmap, vmst->hdr.bitmapsize, off) !=
 	    (ssize_t)vmst->hdr.bitmapsize) {
 		_kvm_err(kd, kd->program, "cannot read %d bytes for page bitmap",
 		    vmst->hdr.bitmapsize);
+		free(bitmap);
 		return (-1);
 	}
-	off += round_page(vmst->hdr.bitmapsize);
+	off += arm_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);
+		free(bitmap);
 		return (-1);
 	}
 
@@ -204,28 +144,32 @@ _kvm_minidump_initvtop(kvm_t *kd)
 	    (ssize_t)vmst->hdr.ptesize) {
 		_kvm_err(kd, kd->program, "cannot read %d bytes for ptemap",
 		    vmst->hdr.ptesize);
+		free(bitmap);
 		return (-1);
 	}
 
 	off += vmst->hdr.ptesize;
 
 	/* Build physical address hash table for sparse pages */
-	inithash(kd, vmst->bitmap, vmst->hdr.bitmapsize, off);
+	_kvm_hpt_init(kd, &vmst->hpt, bitmap, vmst->hdr.bitmapsize, off,
+	    ARM_PAGE_SIZE, sizeof(*bitmap));
+	free(bitmap);
 
 	return (0);
 }
 
-int
-_kvm_minidump_kvatop(kvm_t *kd, u_long va, off_t *pa)
+static int
+_arm_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
 {
 	struct vmstate *vm;
-	pt_entry_t pte;
-	u_long offset, pteindex, a;
+	arm_pt_entry_t pte;
+	arm_physaddr_t offset, a;
+	kvaddr_t pteindex;
 	off_t ofs;
-	uint32_t *ptemap;
+	arm_pt_entry_t *ptemap;
 
 	if (ISALIVE(kd)) {
-		_kvm_err(kd, 0, "kvm_kvatop called in live kernel!");
+		_kvm_err(kd, 0, "_arm_minidump_kvatop called in live kernel!");
 		return (0);
 	}
 
@@ -233,36 +177,48 @@ _kvm_minidump_kvatop(kvm_t *kd, u_long va, off_t *pa)
 	ptemap = vm->ptemap;
 
 	if (va >= vm->hdr.kernbase) {
-		pteindex = (va - vm->hdr.kernbase) >> PAGE_SHIFT;
-		pte = ptemap[pteindex];
+		pteindex = (va - vm->hdr.kernbase) >> ARM_PAGE_SHIFT;
+		pte = _kvm32toh(kd, ptemap[pteindex]);
 		if (!pte) {
-			_kvm_err(kd, kd->program, "_kvm_vatop: pte not valid");
+			_kvm_err(kd, kd->program,
+			    "_arm_minidump_kvatop: 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;
+		if ((pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_L) {
+			offset = va & ARM_L2_L_OFFSET;
+			a = pte & ARM_L2_L_FRAME;
+		} else if ((pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_S) {
+			offset = va & ARM_L2_S_OFFSET;
+			a = pte & ARM_L2_S_FRAME;
 		} else
 			goto invalid;
 
-		ofs = hpt_find(kd, a);
+		ofs = _kvm_hpt_find(&vm->hpt, a);
 		if (ofs == -1) {
-			_kvm_err(kd, kd->program, "_kvm_vatop: physical "
-			    "address 0x%lx not in minidump", a);
+			_kvm_err(kd, kd->program, "_arm_minidump_kvatop: "
+			    "physical address 0x%jx not in minidump",
+			    (uintmax_t)a);
 			goto invalid;
 		}
 
 		*pa = ofs + offset;
-		return (PAGE_SIZE - offset);
+		return (ARM_PAGE_SIZE - offset);
 
 	} else
-		_kvm_err(kd, kd->program, "_kvm_vatop: virtual address 0x%lx "
-		    "not minidumped", va);
+		_kvm_err(kd, kd->program, "_arm_minidump_kvatop: virtual "
+		    "address 0x%jx not minidumped", (uintmax_t)va);
 
 invalid:
-	_kvm_err(kd, 0, "invalid address (0x%lx)", va);
+	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
 	return (0);
 }
+
+struct kvm_arch kvm_arm_minidump = {
+	.ka_probe = _arm_minidump_probe,
+	.ka_initvtop = _arm_minidump_initvtop,
+	.ka_freevtop = _arm_minidump_freevtop,
+	.ka_kvatop = _arm_minidump_kvatop,
+	.ka_native = _arm_native,
+};
+
+KVM_ARCH(kvm_arm_minidump);