Hi, This diff adjust the manpage of mem(4) to be more accurate. You can open(2) mem(4) in securelevel 1 in readonly mode, but not writable.
kern/spec_vnops.c: if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) { ... /* * When running in secure mode, do not allow opens * for writing of /dev/mem, /dev/kmem, or character * devices whose corresponding block devices are * currently mounted. */ if (securelevel >= 1) { ... if (iskmemdev(dev)) return (EPERM); } } OK? bye, Jan Index: man4.alpha/mem.4 =================================================================== RCS file: /cvs/src/share/man/man4/man4.alpha/mem.4,v retrieving revision 1.6 diff -u -p -r1.6 mem.4 --- man4.alpha/mem.4 12 Jan 2018 04:36:44 -0000 1.6 +++ man4.alpha/mem.4 17 Jan 2023 18:51:10 -0000 @@ -62,7 +62,7 @@ kernel virtual memory begins at .Li 0xfffffc0000230000 . .Pp Even with sufficient file system permissions, -these devices can only be opened when the +these devices can only be opened writable when the .Xr securelevel 7 is insecure or when the .Va kern.allowkmem Index: man4.amd64/mem.4 =================================================================== RCS file: /cvs/src/share/man/man4/man4.amd64/mem.4,v retrieving revision 1.6 diff -u -p -r1.6 mem.4 --- man4.amd64/mem.4 12 Jan 2018 04:36:44 -0000 1.6 +++ man4.amd64/mem.4 17 Jan 2023 18:48:23 -0000 @@ -63,7 +63,7 @@ The kernel virtual memory begins at addr .Li 0xffffffff80000000 . .Pp Even with sufficient file system permissions, -these devices can only be opened when the +these devices can only be opened writable when the .Xr securelevel 7 is insecure or when the .Va kern.allowkmem Index: man4.hppa/mem.4 =================================================================== RCS file: /cvs/src/share/man/man4/man4.hppa/mem.4,v retrieving revision 1.4 diff -u -p -r1.4 mem.4 --- man4.hppa/mem.4 12 Jan 2018 04:36:44 -0000 1.4 +++ man4.hppa/mem.4 17 Jan 2023 18:52:28 -0000 @@ -51,7 +51,7 @@ On hppa, the physical memory range is al address 0; kernel virtual memory begins at address 0 as well. .Pp Even with sufficient file system permissions, -these devices can only be opened when the +these devices can only be opened writable when the .Xr securelevel 7 is insecure or when the .Va kern.allowkmem Index: man4.i386/mem.4 =================================================================== RCS file: /cvs/src/share/man/man4/man4.i386/mem.4,v retrieving revision 1.12 diff -u -p -r1.12 mem.4 --- man4.i386/mem.4 12 Jan 2018 04:36:44 -0000 1.12 +++ man4.i386/mem.4 17 Jan 2023 18:53:00 -0000 @@ -63,7 +63,7 @@ long, and ends at virtual address .Li 0xfe000000 . .Pp Even with sufficient file system permissions, -these devices can only be opened when the +these devices can only be opened writable when the .Xr securelevel 7 is insecure or when the .Va kern.allowkmem Index: man4.landisk/mem.4 =================================================================== RCS file: /cvs/src/share/man/man4/man4.landisk/mem.4,v retrieving revision 1.4 diff -u -p -r1.4 mem.4 --- man4.landisk/mem.4 12 Jan 2018 04:36:44 -0000 1.4 +++ man4.landisk/mem.4 17 Jan 2023 18:53:54 -0000 @@ -58,7 +58,7 @@ The kernel virtual memory begins at addr .Li 0xc0000000 . .Pp Even with sufficient file system permissions, -these devices can only be opened when the +these devices can only be opened writable when the .Xr securelevel 7 is insecure or when the .Va kern.allowkmem Index: man4.loongson/mem.4 =================================================================== RCS file: /cvs/src/share/man/man4/man4.loongson/mem.4,v retrieving revision 1.4 diff -u -p -r1.4 mem.4 --- man4.loongson/mem.4 12 Jan 2018 04:36:44 -0000 1.4 +++ man4.loongson/mem.4 17 Jan 2023 18:54:33 -0000 @@ -88,7 +88,7 @@ The kernel virtual memory begins at addr .Ad 0xc000000000000000 . .Pp Even with sufficient file system permissions, -these devices can only be opened when the +these devices can only be opened writable when the .Xr securelevel 7 is insecure or when the .Va kern.allowkmem Index: man4.luna88k/mem.4 =================================================================== RCS file: /cvs/src/share/man/man4/man4.luna88k/mem.4,v retrieving revision 1.4 diff -u -p -r1.4 mem.4 --- man4.luna88k/mem.4 12 Jan 2018 04:36:44 -0000 1.4 +++ man4.luna88k/mem.4 17 Jan 2023 18:54:47 -0000 @@ -62,7 +62,7 @@ kernel virtual memory begins at .Ad 0x00000000 . .Pp Even with sufficient file system permissions, -these devices can only be opened when the +these devices can only be opened writable when the .Xr securelevel 7 is insecure or when the .Va kern.allowkmem Index: man4.macppc/mem.4 =================================================================== RCS file: /cvs/src/share/man/man4/man4.macppc/mem.4,v retrieving revision 1.7 diff -u -p -r1.7 mem.4 --- man4.macppc/mem.4 12 Jan 2018 04:36:44 -0000 1.7 +++ man4.macppc/mem.4 17 Jan 2023 18:55:18 -0000 @@ -62,7 +62,7 @@ kernel virtual memory begins at .Ad 0x00000000 . .Pp Even with sufficient file system permissions, -these devices can only be opened when the +these devices can only be opened writable when the .Xr securelevel 7 is insecure or when the .Va kern.allowkmem Index: man4.sparc64/mem.4 =================================================================== RCS file: /cvs/src/share/man/man4/man4.sparc64/mem.4,v retrieving revision 1.6 diff -u -p -r1.6 mem.4 --- man4.sparc64/mem.4 12 Jan 2018 04:36:44 -0000 1.6 +++ man4.sparc64/mem.4 17 Jan 2023 18:55:36 -0000 @@ -64,7 +64,7 @@ kernel virtual memory begins at .Li 0x001000000 . .Pp Even with sufficient file system permissions, -these devices can only be opened when the +these devices can only be opened writable when the .Xr securelevel 7 is insecure or when the .Va kern.allowkmem