libkvm bits for arm.

1 files changed, 162 insertions, 18 deletions

diff --git a/lib/libkvm/kvm_arm.c b/lib/libkvm/kvm_arm.c
index 70d8354..0bde0bf 100644
--- a/lib/libkvm/kvm_arm.c
+++ b/lib/libkvm/kvm_arm.c
@@ -39,8 +39,14 @@
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
+#include <sys/elf32.h>
+#include <sys/mman.h>
 
 #include <vm/vm.h>
+#include <vm/vm_param.h>
+#include <vm/pmap.h>
+
+#include <machine/pmap.h>
 
 #include <db.h>
 #include <limits.h>
@@ -49,37 +55,175 @@ __FBSDID("$FreeBSD$");
 
 #include "kvm_private.h"
 
+struct vmstate {
+	pd_entry_t *l1pt;
+	void *mmapbase;
+	size_t mmapsize;
+};
+
+static int
+_kvm_maphdrs(kvm_t *kd, size_t sz)
+{
+	struct vmstate *vm = kd->vmst;
+
+	/* munmap() previous mmap(). */
+	if (vm->mmapbase != NULL) {
+		munmap(vm->mmapbase, vm->mmapsize);
+		vm->mmapbase = NULL;
+	}
+
+	vm->mmapsize = sz;
+	vm->mmapbase = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0);
+	if (vm->mmapbase == MAP_FAILED) {
+		_kvm_err(kd, kd->program, "cannot mmap corefile");
+		return (-1);
+	}
+
+	return (0);
+}
+
+/*
+ * Translate a physical memory address to a file-offset in the crash-dump.
+ */
+static size_t
+_kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs, size_t pgsz)
+{
+	Elf32_Ehdr *e = kd->vmst->mmapbase;
+	Elf32_Phdr *p = (Elf32_Phdr*)((char*)e + e->e_phoff);
+	int n = e->e_phnum;
+
+	while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
+		p++, n--;
+	if (n == 0)
+		return (0);
+
+	*ofs = (pa - p->p_paddr) + p->p_offset;
+	if (pgsz == 0)
+		return (p->p_memsz - (pa - p->p_paddr));
+	return (pgsz - ((size_t)pa & (pgsz - 1)));
+}
+
 void
-_kvm_freevtop(kd)
-	kvm_t *kd;
+_kvm_freevtop(kvm_t *kd)
 {
-	if (kd->vmst != 0)
+	if (kd->vmst != 0) {
+		if (kd->vmst->mmapbase != NULL)
+			munmap(kd->vmst->mmapbase, kd->vmst->mmapsize);
 		free(kd->vmst);
+		kd->vmst = NULL;
+	}
 }
 
 int
-_kvm_initvtop(kd)
-	kvm_t *kd;
+_kvm_initvtop(kvm_t *kd)
 {
+	struct vmstate *vm = _kvm_malloc(kd, sizeof(*vm));
+	struct nlist nlist[2];
+	u_long kernbase, physaddr, pa;
+	pd_entry_t *l1pt;
+	Elf32_Ehdr *ehdr;
+	size_t hdrsz;
+	
+	if (vm == 0) {
+		_kvm_err(kd, kd->program, "cannot allocate vm");
+		return (-1);
+	}
+	kd->vmst = vm;
+	vm->l1pt = NULL;
+	if (_kvm_maphdrs(kd, sizeof(Elf32_Ehdr)) == -1)
+		return (-1);
+	ehdr = kd->vmst->mmapbase;
+	hdrsz = ehdr->e_phoff + ehdr->e_phentsize * ehdr->e_phnum;
+	if (_kvm_maphdrs(kd, hdrsz) == -1)
+		return (-1);
+	nlist[0].n_name = "kernbase";
+	nlist[1].n_name = NULL;
+	if (kvm_nlist(kd, nlist) != 0)
+		kernbase = KERNBASE;
+	else
+		kernbase = nlist[0].n_value;
+
+	nlist[0].n_name = "physaddr";
+	if (kvm_nlist(kd, nlist) != 0) {
+		_kvm_err(kd, kd->program, "couldn't get phys addr");
+		return (-1);
+	}
+	physaddr = nlist[0].n_value;
+	nlist[0].n_name = "kernel_l1pa";
+	if (kvm_nlist(kd, nlist) != 0) {
+		_kvm_err(kd, kd->program, "bad namelist");
+		return (-1);
+	}
+	if (kvm_read(kd, (nlist[0].n_value - kernbase + physaddr), &pa,
+	    sizeof(pa)) != sizeof(pa)) {
+		_kvm_err(kd, kd->program, "cannot read kernel_l1pa");
+		return (-1);
+	}
+	l1pt = _kvm_malloc(kd, L1_TABLE_SIZE);
+	if (kvm_read(kd, pa, l1pt, L1_TABLE_SIZE) != L1_TABLE_SIZE) {
+		_kvm_err(kd, kd->program, "cannot read l1pt");
+		free(l1pt);
+		return (-1);
+	}
+	vm->l1pt = l1pt;
 	return 0;
 }
 
+/* from arm/pmap.c */
+#define	L1_IDX(va)		(((vm_offset_t)(va)) >> L1_S_SHIFT)
+/* from arm/pmap.h */
+#define	L1_TYPE_INV	0x00		/* Invalid (fault) */
+#define	L1_TYPE_C	0x01		/* Coarse L2 */
+#define	L1_TYPE_S	0x02		/* Section */
+#define	L1_TYPE_F	0x03		/* Fine L2 */
+#define	L1_TYPE_MASK	0x03		/* mask of type bits */
+
+#define	l1pte_section_p(pde)	(((pde) & L1_TYPE_MASK) == L1_TYPE_S)
+#define	l1pte_valid(pde)	((pde) != 0)
+#define	l2pte_valid(pte)	((pte) != 0)
+#define l2pte_index(v)		(((v) & L2_ADDR_BITS) >> L2_S_SHIFT)
+
+
 int
-_kvm_kvatop(kd, va, pa)
-	kvm_t *kd;
-	u_long va;
-	off_t *pa;
+_kvm_kvatop(kvm_t *kd, u_long va, off_t *pa)
 {
-	_kvm_err(kd, 0, "vatop not yet implemented!");
-	return 0;
-}
+	u_long offset = va & (PAGE_SIZE - 1);
+	struct vmstate *vm = kd->vmst;
+	pd_entry_t pd;
+	pt_entry_t pte;
+	u_long pte_pa;
 
-off_t
-_kvm_pa2off(kd, pa)
-	kvm_t *kd;
-	u_long pa;
-{
-	_kvm_err(kd, 0, "pa2off not yet implemented!");
+	if (vm->l1pt == NULL)
+		return (_kvm_pa2off(kd, va, pa, PAGE_SIZE));
+	pd = vm->l1pt[L1_IDX(va)];
+	if (!l1pte_valid(pd))
+		goto invalid;
+	if (l1pte_section_p(pd)) {
+		/* 1MB section mapping. */
+		*pa = ((u_long)pd & L1_S_ADDR_MASK) + (va & L1_S_OFFSET);
+		return  (_kvm_pa2off(kd, *pa, pa, L1_S_SIZE));
+	}
+	pte_pa = (pd & L1_ADDR_MASK) + l2pte_index(va) * sizeof(pte);
+	_kvm_pa2off(kd, pte_pa, (off_t *)&pte_pa, L1_S_SIZE);
+	if (lseek(kd->pmfd, pte_pa, 0) == -1) {
+		_kvm_syserr(kd, kd->program, "_kvm_kvatop: lseek");
+		goto invalid;
+	}
+	if (read(kd->pmfd, &pte, sizeof(pte)) != sizeof (pte)) {
+		_kvm_syserr(kd, kd->program, "_kvm_kvatop: read");
+		goto invalid;
+	}
+	if (!l2pte_valid(pte)) {
+		goto invalid;
+	}
+	if ((pte & L2_TYPE_MASK) == L2_TYPE_L) {
+		*pa = (pte & L2_L_FRAME) | (va & L2_L_OFFSET);
+		return (_kvm_pa2off(kd, *pa, pa, L2_L_SIZE));
+	}
+	*pa = (pte & L2_S_FRAME) | (va & L2_S_OFFSET);
+	return (_kvm_pa2off(kd, *pa, pa, PAGE_SIZE));
+invalid:
+	_kvm_err(kd, 0, "Invalid address (%x)", va);
 	return 0;
 }