Always use 64-bit physical addresses for dump_avail[] in minidumps

As of r365978, minidumps include a copy of dump_avail[].  This is an
array of vm_paddr_t ranges.  libkvm walks the array assuming that
sizeof(vm_paddr_t) is equal to the platform "word size", but that's not
correct on some platforms.  For instance, i386 uses a 64-bit vm_paddr_t.

Fix the problem by always dumping 64-bit addresses.  On platforms where
vm_paddr_t is 32 bits wide, namely arm and mips (sometimes), translate
dump_avail[] to an array of uint64_t ranges.  With this change, libkvm
no longer needs to maintain a notion of the target word size, so get rid
of it.

This is a no-op on platforms where sizeof(vm_paddr_t) == 8.

Reviewed by:	alc, kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D27082

lib/libkvm/kvm_minidump_aarch64.c

@@ -127,8 +127,7 @@ _aarch64_minidump_initvtop(kvm_t *kd)
 	sparse_off = off + aarch64_round_page(vmst->hdr.bitmapsize) +
 	    aarch64_round_page(vmst->hdr.pmapsize);
 	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
-	    vmst->hdr.bitmapsize, off, sparse_off, AARCH64_PAGE_SIZE,
+	    vmst->hdr.bitmapsize, off, sparse_off, AARCH64_PAGE_SIZE) == -1) {
-	    sizeof(uint64_t)) == -1) {
 		return (-1);
 	}
 	off += aarch64_round_page(vmst->hdr.bitmapsize);

lib/libkvm/kvm_minidump_amd64.c

@@ -169,8 +169,7 @@ _amd64_minidump_initvtop(kvm_t *kd)
 	sparse_off = off + amd64_round_page(vmst->hdr.bitmapsize) +
 	    amd64_round_page(vmst->hdr.pmapsize);
 	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
-	    vmst->hdr.bitmapsize, off, sparse_off, AMD64_PAGE_SIZE,
+	    vmst->hdr.bitmapsize, off, sparse_off, AMD64_PAGE_SIZE) == -1) {
-	    sizeof(uint64_t)) == -1) {
 		return (-1);
 	}
 	off += amd64_round_page(vmst->hdr.bitmapsize);

lib/libkvm/kvm_minidump_arm.c

@@ -135,8 +135,7 @@ _arm_minidump_initvtop(kvm_t *kd)
 	sparse_off = off + arm_round_page(vmst->hdr.bitmapsize) +
 	    arm_round_page(vmst->hdr.ptesize);
 	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
-	    vmst->hdr.bitmapsize, off, sparse_off, ARM_PAGE_SIZE,
+	    vmst->hdr.bitmapsize, off, sparse_off, ARM_PAGE_SIZE) == -1) {
-	    sizeof(uint32_t)) == -1) {
 		return (-1);
 	}
 	off += arm_round_page(vmst->hdr.bitmapsize);

lib/libkvm/kvm_minidump_i386.c

@@ -131,8 +131,7 @@ _i386_minidump_initvtop(kvm_t *kd)
 	sparse_off = off + i386_round_page(vmst->hdr.bitmapsize) +
 	    i386_round_page(vmst->hdr.ptesize);
 	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
-	    vmst->hdr.bitmapsize, off, sparse_off, I386_PAGE_SIZE,
+	    vmst->hdr.bitmapsize, off, sparse_off, I386_PAGE_SIZE) == -1) {
-	    sizeof(uint32_t)) == -1) {
 		return (-1);
 	}
 	off += i386_round_page(vmst->hdr.bitmapsize);

lib/libkvm/kvm_minidump_mips.c

@@ -136,8 +136,7 @@ _mips_minidump_initvtop(kvm_t *kd)
 	sparse_off = off + mips_round_page(vmst->hdr.bitmapsize) +
 	    mips_round_page(vmst->hdr.ptesize);
 	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
-	    vmst->hdr.bitmapsize, off, sparse_off, MIPS_PAGE_SIZE,
+	    vmst->hdr.bitmapsize, off, sparse_off, MIPS_PAGE_SIZE) == -1) {
-	    sizeof(uint32_t)) == -1) {
 		return (-1);
 	}
 	off += mips_round_page(vmst->hdr.bitmapsize);

lib/libkvm/kvm_minidump_powerpc64.c

@@ -155,8 +155,7 @@ _powerpc64_minidump_initvtop(kvm_t *kd)
 
 	/* build physical address lookup table for sparse pages */
 	if (_kvm_pt_init(kd, hdr->dumpavailsize, dump_avail_off,
-	    hdr->bitmapsize, bitmap_off, sparse_off, PPC64_PAGE_SIZE,
+	    hdr->bitmapsize, bitmap_off, sparse_off, PPC64_PAGE_SIZE) == -1)
-	    sizeof(uint64_t)) == -1)
 		goto failed;
 
 	if (_kvm_pmap_init(kd, hdr->pmapsize, pmap_off) == -1)

lib/libkvm/kvm_minidump_riscv.c

@@ -128,8 +128,7 @@ _riscv_minidump_initvtop(kvm_t *kd)
 	sparse_off = off + riscv_round_page(vmst->hdr.bitmapsize) +
 	    riscv_round_page(vmst->hdr.pmapsize);
 	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
-	    vmst->hdr.bitmapsize, off, sparse_off, RISCV_PAGE_SIZE,
+	    vmst->hdr.bitmapsize, off, sparse_off, RISCV_PAGE_SIZE) == -1) {
-	    sizeof(uint64_t)) == -1) {
 		return (-1);
 	}
 	off += riscv_round_page(vmst->hdr.bitmapsize);

lib/libkvm/kvm_private.c

@@ -291,8 +291,7 @@ _kvm_map_get(kvm_t *kd, u_long pa, unsigned int page_size)
 
 int
 _kvm_pt_init(kvm_t *kd, size_t dump_avail_size, off_t dump_avail_off,
-    size_t map_len, off_t map_off, off_t sparse_off, int page_size,
+    size_t map_len, off_t map_off, off_t sparse_off, int page_size)
-    int word_size)
 {
 	uint64_t *addr;
 	uint32_t *popcount_bin;
@@ -311,14 +310,8 @@ _kvm_pt_init(kvm_t *kd, size_t dump_avail_size, off_t dump_avail_off,
 		 * last_pa. Create an implied dump_avail that
 		 * expresses this.
 		 */
-		kd->dump_avail = calloc(4, word_size);
+		kd->dump_avail = calloc(4, sizeof(uint64_t));
-		if (word_size == sizeof(uint32_t)) {
+		kd->dump_avail[1] = _kvm64toh(kd, map_len * 8 * page_size);
-			((uint32_t *)kd->dump_avail)[1] = _kvm32toh(kd,
-			    map_len * 8 * page_size);
-		} else {
-			kd->dump_avail[1] = _kvm64toh(kd,
-			    map_len * 8 * page_size);
-		}
 	}
 
 	/*
@@ -375,7 +368,6 @@ _kvm_pt_init(kvm_t *kd, size_t dump_avail_size, off_t dump_avail_off,
 	kd->pt_sparse_off = sparse_off;
 	kd->pt_sparse_size = (uint64_t)*popcount_bin * page_size;
 	kd->pt_page_size = page_size;
-	kd->pt_word_size = word_size;
 
 	/*
 	 * Map the sparse page array.  This is useful for performing point
@@ -419,13 +411,7 @@ _kvm_pmap_init(kvm_t *kd, uint32_t pmap_size, off_t pmap_off)
 static inline uint64_t
 dump_avail_n(kvm_t *kd, long i)
 {
-	uint32_t *d32;
+	return (_kvm64toh(kd, kd->dump_avail[i]));
-
-	if (kd->pt_word_size == sizeof(uint32_t)) {
-		d32 = (uint32_t *)kd->dump_avail;
-		return (_kvm32toh(kd, d32[i]));
-	} else
-		return (_kvm64toh(kd, kd->dump_avail[i]));
 }
 
 uint64_t

lib/libkvm/kvm_private.h

@@ -112,7 +112,6 @@ struct __kvm {
 	uint64_t	pt_sparse_size;
 	uint32_t	*pt_popcounts;
 	unsigned int	pt_page_size;
-	unsigned int	pt_word_size;
 
 	/* Page & sparse map structures. */
 	void		*page_map;
@@ -190,7 +189,7 @@ kvaddr_t _kvm_dpcpu_validaddr(kvm_t *, kvaddr_t);
 int	 _kvm_probe_elf_kernel(kvm_t *, int, int);
 int	 _kvm_is_minidump(kvm_t *);
 int	 _kvm_read_core_phdrs(kvm_t *, size_t *, GElf_Phdr **);
-int	 _kvm_pt_init(kvm_t *, size_t, off_t, size_t, off_t, off_t, int, int);
+int	 _kvm_pt_init(kvm_t *, size_t, off_t, size_t, off_t, off_t, int);
 off_t	 _kvm_pt_find(kvm_t *, uint64_t, unsigned int);
 int	 _kvm_visit_cb(kvm_t *, kvm_walk_pages_cb_t *, void *, u_long,
 	    u_long, u_long, vm_prot_t, size_t, unsigned int);

sys/arm/arm/minidump_machdep.c

@@ -169,18 +169,18 @@ blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t pa, size_t sz)
 }
 
 /* A buffer for general use. Its size must be one page at least. */
-static char dumpbuf[PAGE_SIZE];
+static char dumpbuf[PAGE_SIZE] __aligned(sizeof(uint64_t));
 CTASSERT(sizeof(dumpbuf) % sizeof(pt2_entry_t) == 0);
 
 int
 minidumpsys(struct dumperinfo *di)
 {
 	struct minidumphdr mdhdr;
-	uint64_t dumpsize;
+	uint64_t dumpsize, *dump_avail_buf;
 	uint32_t ptesize;
 	uint32_t pa, prev_pa = 0, count = 0;
 	vm_offset_t va;
-	int error;
+	int error, i;
 	char *addr;
 
 	/*
@@ -207,7 +207,7 @@ minidumpsys(struct dumperinfo *di)
 	/* Calculate dump size. */
 	dumpsize = ptesize;
 	dumpsize += round_page(msgbufp->msg_size);
-	dumpsize += round_page(sizeof(dump_avail));
+	dumpsize += round_page(nitems(dump_avail) * sizeof(uint64_t));
 	dumpsize += round_page(BITSET_SIZE(vm_page_dump_pages));
 	VM_PAGE_DUMP_FOREACH(pa) {
 		/* Clear out undumpable pages now if needed */
@@ -230,7 +230,8 @@ minidumpsys(struct dumperinfo *di)
 	mdhdr.kernbase = KERNBASE;
 	mdhdr.arch = __ARM_ARCH;
 	mdhdr.mmuformat = MINIDUMP_MMU_FORMAT_V6;
-	mdhdr.dumpavailsize = round_page(sizeof(dump_avail));
+	mdhdr.dumpavailsize = round_page(nitems(dump_avail) * sizeof(uint64_t));
+
 	dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_ARM_VERSION,
 	    dumpsize);
 
@@ -254,11 +255,15 @@ minidumpsys(struct dumperinfo *di)
 	if (error)
 		goto fail;
 
-	/* Dump dump_avail */
+	/* Dump dump_avail.  Make a copy using 64-bit physical addresses. */
-	_Static_assert(sizeof(dump_avail) <= sizeof(dumpbuf),
+	_Static_assert(nitems(dump_avail) * sizeof(uint64_t) <= sizeof(dumpbuf),
 	    "Large dump_avail not handled");
 	bzero(dumpbuf, sizeof(dumpbuf));
-	memcpy(dumpbuf, dump_avail, sizeof(dump_avail));
+	dump_avail_buf = (uint64_t *)dumpbuf;
+	for (i = 0; dump_avail[i] != 0 || dump_avail[i + 1] != 0; i += 2) {
+		dump_avail_buf[i] = dump_avail[i];
+		dump_avail_buf[i + 1] = dump_avail[i + 1];
+	}
 	error = blk_write(di, dumpbuf, 0, PAGE_SIZE);
 	if (error)
 		goto fail;

sys/kern/kern_dump.c

@@ -290,7 +290,7 @@ dumpsys_generic(struct dumperinfo *di)
 	size_t hdrsz;
 	int error;
 
-#if !defined(__powerpc__) || defined(__powerpc64__)
+#if MINIDUMP_PAGE_TRACKING == 1
 	if (do_minidump)
 		return (minidumpsys(di));
 #endif

sys/mips/mips/minidump_machdep.c

@@ -60,7 +60,7 @@ static struct kerneldumpheader kdh;
 /* Handle chunked writes. */
 static uint64_t counter, progress, dumpsize;
 /* Just auxiliary bufffer */
-static char tmpbuffer[PAGE_SIZE];
+static char tmpbuffer[PAGE_SIZE] __aligned(sizeof(uint64_t));
 
 extern pd_entry_t *kernel_segmap;
 
@@ -165,6 +165,7 @@ int
 minidumpsys(struct dumperinfo *di)
 {
 	struct minidumphdr mdhdr;
+	uint64_t *dump_avail_buf;
 	uint32_t ptesize;
 	vm_paddr_t pa;
 	vm_offset_t prev_pte = 0;
@@ -206,7 +207,7 @@ minidumpsys(struct dumperinfo *di)
 	/* Calculate dump size. */
 	dumpsize = ptesize;
 	dumpsize += round_page(msgbufp->msg_size);
-	dumpsize += round_page(sizeof(dump_avail));
+	dumpsize += round_page(nitems(dump_avail) * sizeof(uint64_t));
 	dumpsize += round_page(BITSET_SIZE(vm_page_dump_pages));
 	VM_PAGE_DUMP_FOREACH(pa) {
 		/* Clear out undumpable pages now if needed */
@@ -227,7 +228,7 @@ minidumpsys(struct dumperinfo *di)
 	mdhdr.bitmapsize = round_page(BITSET_SIZE(vm_page_dump_pages));
 	mdhdr.ptesize = ptesize;
 	mdhdr.kernbase = VM_MIN_KERNEL_ADDRESS;
-	mdhdr.dumpavailsize = round_page(sizeof(dump_avail));
+	mdhdr.dumpavailsize = round_page(nitems(dump_avail) * sizeof(uint64_t));
 
 	dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_MIPS_VERSION,
 	    dumpsize);
@@ -252,11 +253,19 @@ minidumpsys(struct dumperinfo *di)
 	if (error)
 		goto fail;
 
-	/* Dump dump_avail */
+	/* Dump dump_avail.  Make a copy using 64-bit physical addresses. */
-	_Static_assert(sizeof(dump_avail) <= sizeof(tmpbuffer),
+	_Static_assert(nitems(dump_avail) * sizeof(uint64_t) <=
-	    "Large dump_avail not handled");
+	    sizeof(tmpbuffer), "Large dump_avail not handled");
 	bzero(tmpbuffer, sizeof(tmpbuffer));
-	memcpy(tmpbuffer, dump_avail, sizeof(dump_avail));
+	if (sizeof(dump_avail[0]) != sizeof(uint64_t)) {
+		dump_avail_buf = (uint64_t *)tmpbuffer;
+		for (i = 0; dump_avail[i] != 0 || dump_avail[i + 1] != 0; i++) {
+			dump_avail_buf[i] = dump_avail[i];
+			dump_avail_buf[i + 1] = dump_avail[i + 1];
+		}
+	} else {
+		memcpy(tmpbuffer, dump_avail, sizeof(dump_avail));
+	}
 	error = write_buffer(di, tmpbuffer, PAGE_SIZE);
 	if (error)
 		goto fail;