diff options
Diffstat (limited to 'lib/libkvm')
| -rw-r--r-- | lib/libkvm/kvm_amd64.c | 46 | ||||
| -rw-r--r-- | lib/libkvm/kvm_open.3 | 15 |
2 files changed, 51 insertions, 10 deletions
diff --git a/lib/libkvm/kvm_amd64.c b/lib/libkvm/kvm_amd64.c index e3640cf12243..acc7ac017a3c 100644 --- a/lib/libkvm/kvm_amd64.c +++ b/lib/libkvm/kvm_amd64.c @@ -109,8 +109,9 @@ _amd64_initvtop(kvm_t *kd) { struct kvm_nlist nl[2]; amd64_physaddr_t pa; - kvaddr_t kernbase; + kvaddr_t kernbase, kernphys; amd64_pml4e_t *PML4; + int found = 0; kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst)); if (kd->vmst == NULL) { @@ -123,16 +124,43 @@ _amd64_initvtop(kvm_t *kd) if (_kvm_read_core_phdrs(kd, &kd->vmst->phnum, &kd->vmst->phdr) == -1) return (-1); + + for (size_t i = 0; i < kd->vmst->phnum; i++) { + if (kd->vmst->phdr[i].p_type == PT_DUMP_DELTA) { + /* Account for the 2M hole at KERNBASE. */ + kernphys = kd->vmst->phdr[i].p_paddr - + kd->vmst->phdr[i].p_align; + kernbase = kd->vmst->phdr[i].p_vaddr; + + found = 1; + break; + } + } } - nl[0].n_name = "kernbase"; - nl[1].n_name = 0; + if (found == 0) { + nl[0].n_name = "kernbase"; + nl[1].n_name = 0; - if (kvm_nlist2(kd, nl) != 0) { - _kvm_err(kd, kd->program, "bad namelist - no kernbase"); - return (-1); + if (kvm_nlist2(kd, nl) != 0) { + _kvm_err(kd, kd->program, "bad namelist - no kernbase"); + return (-1); + } + + nl[0].n_name = "kernphys"; + nl[1].n_name = 0; + + /* XXX + * Relocatable kernels can still be loaded at 2M. + */ + if (kvm_nlist2(kd, nl) != 1) { + _kvm_err(kd, kd->program, "cannot determine kernphys"); + return (-1); + } + + kernphys = 0; + kernbase = nl[0].n_value; } - kernbase = nl[0].n_value; nl[0].n_name = "KPML4phys"; nl[1].n_name = 0; @@ -141,8 +169,8 @@ _amd64_initvtop(kvm_t *kd) _kvm_err(kd, kd->program, "bad namelist - no KPML4phys"); return (-1); } - if (kvm_read2(kd, (nl[0].n_value - kernbase), &pa, sizeof(pa)) != - sizeof(pa)) { + if (kvm_read2(kd, (nl[0].n_value - kernbase + kernphys), &pa, + sizeof(pa)) != sizeof(pa)) { _kvm_err(kd, kd->program, "cannot read KPML4phys"); return (-1); } diff --git a/lib/libkvm/kvm_open.3 b/lib/libkvm/kvm_open.3 index a7e428748215..9a32719d537b 100644 --- a/lib/libkvm/kvm_open.3 +++ b/lib/libkvm/kvm_open.3 @@ -29,7 +29,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.Dd March 20, 2017 +.Dd June 22, 2025 .Dt KVM_OPEN 3 .Os .Sh NAME @@ -245,7 +245,20 @@ The value passed via was .Dv NULL . .El +.Sh NOTE +Full memory dumps taken on 13.x (excluding 13.0) and 14.x amd64 kernels +will cause both +.Fn kvm_open +and +.Fn kvm_open2 +to fail since they do not provide sufficient information to figure out +where in physical memory the kernel was loaded. +Full memory dumps have to be explicitly enabled by setting the +.Va debug.minidump +.Xr sysctl 8 +to 0. .Sh SEE ALSO +.Xr dumpon 8 , .Xr close 2 , .Xr open 2 , .Xr kvm 3 , |