The branch main has been updated by vexeduxr:
URL:
https://cgit.FreeBSD.org/src/commit/?id=2e91875bc2d861ce3b8f3e893dca999d139f590e
commit 2e91875bc2d861ce3b8f3e893dca999d139f590e
Author: Ahmad Khalifa <vexed...@freebsd.org>
AuthorDate: 2025-05-22 12:44:57 +0000
Commit: Ahmad Khalifa <vexed...@freebsd.org>
CommitDate: 2025-06-22 03:49:32 +0000
libkvm/kvm_open.3: document broken full dumps
Starting 13.1 the amd64 kernel was made relocatable, but the kernel
didn't provide enough information for libkvm to figure out where it was
loaded.
Reviewed by: markj
Approved by: imp (mentor)
Pull Request: https://github.com/freebsd/freebsd-src/pull/1706
Closes: https://github.com/freebsd/freebsd-src/pull/1706
---
lib/libkvm/kvm_open.3 | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
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 ,
