scripts/gdb: add mm introspection utils

This command provides a way to traverse the entire page hierarchy by a
given virtual address on x86.  In addition to qemu's commands info
tlb/info mem it provides the complete information about the paging
structure for an arbitrary virtual address.  It supports 4KB/2MB/1GB and 5
level paging.

Here is an example output for 2MB success translation:

(gdb) translate-vm address
cr3:
    cr3 binary data                0x1085be003
    next entry physical address   0x1085be000
    ---
    bit  3          page level write through       False
    bit  4          page level cache disabled      False
level 4:
    entry address                  0xffff8881085be7f8
    page entry binary data         0x800000010ac83067
    next entry physical address   0x10ac83000
    ---
    bit  0          entry present                  True
    bit  1          read/write access allowed      True
    bit  2          user access allowed            True
    bit  3          page level write through       False
    bit  4          page level cache disabled      False
    bit  5          entry has been accessed        True
    bit  7          page size                      False
    bit  11         restart to ordinary            False
    bit  63         execute disable                True
level 3:
    entry address                  0xffff88810ac83a48
    page entry binary data         0x101af7067
    next entry physical address   0x101af7000
    ---
    bit  0          entry present                  True
    bit  1          read/write access allowed      True
    bit  2          user access allowed            True
    bit  3          page level write through       False
    bit  4          page level cache disabled      False
    bit  5          entry has been accessed        True
    bit  7          page size                      False
    bit  11         restart to ordinary            False
    bit  63         execute disable                False
level 2:
    entry address                  0xffff888101af7368
    page entry binary data         0x80000001634008e7
    page size                      2MB
    page physical address         0x163400000
    ---
    bit  0          entry present                  True
    bit  1          read/write access allowed      True
    bit  2          user access allowed            True
    bit  3          page level write through       False
    bit  4          page level cache disabled      False
    bit  5          entry has been accessed        True
    bit  7          page size                      True
    bit  6          page dirty                     True
    bit  8          global translation             False
    bit  11         restart to ordinary            True
    bit  12         pat                            False
    bits (59, 62)   protection key                 0
    bit  63         execute disable                True

[[email protected]: add SPDX line, other tweaks]
  Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: s/physicall/physical/]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Dmitrii Bundin <[email protected]>
Acked by: Mike Rapoport (IBM) <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jan Kiszka <[email protected]>
Cc: Kieran Bingham <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py
index 3e8d3669f0ce..3a5b44cd6bfe 100644
--- a/scripts/gdb/vmlinux-gdb.py
+++ b/scripts/gdb/vmlinux-gdb.py
@@ -37,3 +37,4 @@ else:
     import linux.clk
     import linux.genpd
     import linux.device
+    import linux.mm