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authorPeter Wemm <peter@FreeBSD.org>1996-10-07 20:17:50 +0000
committerPeter Wemm <peter@FreeBSD.org>1996-10-07 20:17:50 +0000
commit2f85bf6e8e11f5cdf2402ee30e9ff07342422fa2 (patch)
treed9f48885838396b6e212770768038b9e4ee6299c
parent5893891624c59e77e62d882aa66e2dff3ec757b7 (diff)
downloadsrc-2f85bf6e8e11f5cdf2402ee30e9ff07342422fa2.tar.gz
src-2f85bf6e8e11f5cdf2402ee30e9ff07342422fa2.zip
Implement virtual-to-physical address mapping for the kvm library on
dead kernel debugging. The previous code was a "do nothing". The most obvious side effect of this is that you can now do things like this and reasonably expect them to work: dmesg -M /var/crash/vmcore.3 -N /var/crash/kernel.3 ps -axl -M /var/crash/vmcore.3 -N /var/crash/kernel.3 A good deal of this was lifted from the gdb code to do this, as well as from NetBSD's libkvm (which has completely different VM macros)
Notes
Notes: svn path=/head/; revision=18798
-rw-r--r--lib/libkvm/kvm_amd64.c85
-rw-r--r--lib/libkvm/kvm_i386.c85
2 files changed, 130 insertions, 40 deletions
diff --git a/lib/libkvm/kvm_amd64.c b/lib/libkvm/kvm_amd64.c
index efb4a53c9520..c32fd5305a1d 100644
--- a/lib/libkvm/kvm_amd64.c
+++ b/lib/libkvm/kvm_amd64.c
@@ -67,27 +67,27 @@ static char sccsid[] = "@(#)kvm_hp300.c 8.1 (Berkeley) 6/4/93";
#endif
struct vmstate {
- struct pde **IdlePTD;
- struct pde *PTD;
+ pd_entry_t *PTD;
};
-#define KREAD(kd, addr, p)\
- (kvm_read(kd, addr, (char *)(p), sizeof(*(p))) != sizeof(*(p)))
-
void
-_kvm_freevtop(kvm_t *kd) {
- if (kd->vmst->PTD) {
- free(kd->vmst->PTD);
- }
+_kvm_freevtop(kvm_t *kd)
+{
if (kd->vmst != 0) {
+ if (kd->vmst->PTD) {
+ free(kd->vmst->PTD);
+ }
free(kd->vmst);
}
}
int
-_kvm_initvtop(kvm_t *kd) {
+_kvm_initvtop(kvm_t *kd)
+{
struct vmstate *vm;
struct nlist nlist[2];
+ u_long pa;
+ pd_entry_t *PTD;
vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm));
if (vm == 0) {
@@ -95,6 +95,7 @@ _kvm_initvtop(kvm_t *kd) {
return (-1);
}
kd->vmst = vm;
+ vm->PTD = 0;
nlist[0].n_name = "_IdlePTD";
nlist[1].n_name = 0;
@@ -103,34 +104,78 @@ _kvm_initvtop(kvm_t *kd) {
_kvm_err(kd, kd->program, "bad namelist");
return (-1);
}
- vm->PTD = 0;
- vm->IdlePTD = 0;
- if (KREAD(kd, (u_long)nlist[0].n_value, &vm->IdlePTD)) {
+ if (kvm_read(kd, (nlist[0].n_value - KERNBASE), &pa, sizeof(pa)) != sizeof(pa)) {
_kvm_err(kd, kd->program, "cannot read IdlePTD");
return (-1);
}
- if ((vm->PTD = _kvm_malloc(kd, PAGE_SIZE /*sizeof(struct pde)*/)) != 0) {
- _kvm_err(kd, kd->program, "cannot allocate vm->PTD");
- }
- if (KREAD(kd, (u_long)nlist[1].n_value, &vm->PTD)) {
+ PTD = _kvm_malloc(kd, PAGE_SIZE);
+ if (kvm_read(kd, pa, PTD, PAGE_SIZE) != PAGE_SIZE) {
_kvm_err(kd, kd->program, "cannot read PTD");
return (-1);
}
+ vm->PTD = PTD;
return (0);
}
static int
-_kvm_vatop(kvm_t *kd, u_long va, u_long *pa) {
+_kvm_vatop(kvm_t *kd, u_long va, u_long *pa)
+{
+ struct vmstate *vm;
+ u_long offset;
+ u_long pte_pa;
+ pd_entry_t pde;
+ pt_entry_t pte;
+ u_long pdeindex;
+ u_long pteindex;
+ int i;
if (ISALIVE(kd)) {
_kvm_err(kd, 0, "vatop called in live kernel!");
return((off_t)0);
}
+
+ vm = kd->vmst;
+ offset = va & (PAGE_SIZE - 1);
+
+ /*
+ * If we are initializing (kernel page table descriptor pointer
+ * not yet set) then return pa == va to avoid infinite recursion.
+ */
+ if (vm->PTD == 0) {
+ *pa = va;
+ return (PAGE_SIZE - offset);
+ }
+
+ pdeindex = va >> PDRSHIFT;
+ pde = vm->PTD[pdeindex];
+ if (((u_long)pde & PG_V) == 0)
+ goto invalid;
+
+ pteindex = (va >> PAGE_SHIFT) & (NPTEPG-1);
+ pte_pa = ((u_long)pde & PG_FRAME) + (pteindex * sizeof(pt_entry_t));
+
+ /* XXX This has to be a physical address read, kvm_read is virtual */
+ if (lseek(kd->pmfd, pte_pa, 0) == -1) {
+ _kvm_syserr(kd, kd->program, "_kvm_vatop: lseek");
+ goto invalid;
+ }
+ if (read(kd->pmfd, &pte, sizeof pte) != sizeof pte) {
+ _kvm_syserr(kd, kd->program, "_kvm_vatop: read");
+ goto invalid;
+ }
+ if (((u_long)pte & PG_V) == 0)
+ goto invalid;
+
+ *pa = ((u_long)pte & PG_FRAME) + offset;
+ return (PAGE_SIZE - offset);
+
+invalid:
_kvm_err(kd, 0, "invalid address (%x)", va);
- return ((off_t)0);
+ return (0);
}
int
-_kvm_kvatop(kvm_t *kd, u_long va, u_long *pa) {
+_kvm_kvatop(kvm_t *kd, u_long va, u_long *pa)
+{
return (_kvm_vatop(kd, va, pa));
}
diff --git a/lib/libkvm/kvm_i386.c b/lib/libkvm/kvm_i386.c
index efb4a53c9520..c32fd5305a1d 100644
--- a/lib/libkvm/kvm_i386.c
+++ b/lib/libkvm/kvm_i386.c
@@ -67,27 +67,27 @@ static char sccsid[] = "@(#)kvm_hp300.c 8.1 (Berkeley) 6/4/93";
#endif
struct vmstate {
- struct pde **IdlePTD;
- struct pde *PTD;
+ pd_entry_t *PTD;
};
-#define KREAD(kd, addr, p)\
- (kvm_read(kd, addr, (char *)(p), sizeof(*(p))) != sizeof(*(p)))
-
void
-_kvm_freevtop(kvm_t *kd) {
- if (kd->vmst->PTD) {
- free(kd->vmst->PTD);
- }
+_kvm_freevtop(kvm_t *kd)
+{
if (kd->vmst != 0) {
+ if (kd->vmst->PTD) {
+ free(kd->vmst->PTD);
+ }
free(kd->vmst);
}
}
int
-_kvm_initvtop(kvm_t *kd) {
+_kvm_initvtop(kvm_t *kd)
+{
struct vmstate *vm;
struct nlist nlist[2];
+ u_long pa;
+ pd_entry_t *PTD;
vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm));
if (vm == 0) {
@@ -95,6 +95,7 @@ _kvm_initvtop(kvm_t *kd) {
return (-1);
}
kd->vmst = vm;
+ vm->PTD = 0;
nlist[0].n_name = "_IdlePTD";
nlist[1].n_name = 0;
@@ -103,34 +104,78 @@ _kvm_initvtop(kvm_t *kd) {
_kvm_err(kd, kd->program, "bad namelist");
return (-1);
}
- vm->PTD = 0;
- vm->IdlePTD = 0;
- if (KREAD(kd, (u_long)nlist[0].n_value, &vm->IdlePTD)) {
+ if (kvm_read(kd, (nlist[0].n_value - KERNBASE), &pa, sizeof(pa)) != sizeof(pa)) {
_kvm_err(kd, kd->program, "cannot read IdlePTD");
return (-1);
}
- if ((vm->PTD = _kvm_malloc(kd, PAGE_SIZE /*sizeof(struct pde)*/)) != 0) {
- _kvm_err(kd, kd->program, "cannot allocate vm->PTD");
- }
- if (KREAD(kd, (u_long)nlist[1].n_value, &vm->PTD)) {
+ PTD = _kvm_malloc(kd, PAGE_SIZE);
+ if (kvm_read(kd, pa, PTD, PAGE_SIZE) != PAGE_SIZE) {
_kvm_err(kd, kd->program, "cannot read PTD");
return (-1);
}
+ vm->PTD = PTD;
return (0);
}
static int
-_kvm_vatop(kvm_t *kd, u_long va, u_long *pa) {
+_kvm_vatop(kvm_t *kd, u_long va, u_long *pa)
+{
+ struct vmstate *vm;
+ u_long offset;
+ u_long pte_pa;
+ pd_entry_t pde;
+ pt_entry_t pte;
+ u_long pdeindex;
+ u_long pteindex;
+ int i;
if (ISALIVE(kd)) {
_kvm_err(kd, 0, "vatop called in live kernel!");
return((off_t)0);
}
+
+ vm = kd->vmst;
+ offset = va & (PAGE_SIZE - 1);
+
+ /*
+ * If we are initializing (kernel page table descriptor pointer
+ * not yet set) then return pa == va to avoid infinite recursion.
+ */
+ if (vm->PTD == 0) {
+ *pa = va;
+ return (PAGE_SIZE - offset);
+ }
+
+ pdeindex = va >> PDRSHIFT;
+ pde = vm->PTD[pdeindex];
+ if (((u_long)pde & PG_V) == 0)
+ goto invalid;
+
+ pteindex = (va >> PAGE_SHIFT) & (NPTEPG-1);
+ pte_pa = ((u_long)pde & PG_FRAME) + (pteindex * sizeof(pt_entry_t));
+
+ /* XXX This has to be a physical address read, kvm_read is virtual */
+ if (lseek(kd->pmfd, pte_pa, 0) == -1) {
+ _kvm_syserr(kd, kd->program, "_kvm_vatop: lseek");
+ goto invalid;
+ }
+ if (read(kd->pmfd, &pte, sizeof pte) != sizeof pte) {
+ _kvm_syserr(kd, kd->program, "_kvm_vatop: read");
+ goto invalid;
+ }
+ if (((u_long)pte & PG_V) == 0)
+ goto invalid;
+
+ *pa = ((u_long)pte & PG_FRAME) + offset;
+ return (PAGE_SIZE - offset);
+
+invalid:
_kvm_err(kd, 0, "invalid address (%x)", va);
- return ((off_t)0);
+ return (0);
}
int
-_kvm_kvatop(kvm_t *kd, u_long va, u_long *pa) {
+_kvm_kvatop(kvm_t *kd, u_long va, u_long *pa)
+{
return (_kvm_vatop(kd, va, pa));
}