Commit graph

3 commits

Author SHA1 Message Date
Kieran Bingham
b7235d6bb5 scripts/gdb: add a Radix Tree Parser
Linux makes use of the Radix Tree data structure to store pointers indexed
by integer values.  This structure is utilised across many structures in
the kernel including the IRQ descriptor tables, and several filesystems.

This module provides a method to lookup values from a structure given its
head node.

Usage:

The function lx_radix_tree_lookup, must be given a symbol of type struct
radix_tree_root, and an index into that tree.

The object returned is a generic integer value, and must be cast correctly
to the type based on the storage in the data structure.

For example, to print the irq descriptor in the sparse irq_desc_tree at
index 18, try the following:

(gdb) print (struct irq_desc)$lx_radix_tree_lookup(irq_desc_tree, 18)

This script previously existed under commit
e127a73d41 ("scripts/gdb: add a Radix Tree
Parser") and was later reverted with
b447e02548a3304c47b78b5e2d75a4312a8f17e1i (Revert "scripts/gdb: add a
Radix Tree Parser").

This version expects the XArray based radix tree implementation and has
been verified using QEMU/x86 on Linux 6.3-rc5.

[f.fainelli@gmail.com: revive and update for xarray implementation]
[f.fainelli@gmail.com: guard against a NULL node in the while loop]
  Link: https://lkml.kernel.org/r/20230405222743.1191674-1-f.fainelli@gmail.com
Link: https://lkml.kernel.org/r/20230404214049.1016811-1-f.fainelli@gmail.com
Signed-off-by: Kieran Bingham <kieran.bingham@linaro.org>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:39:33 -07:00
Kieran Bingham
b447e02548 Revert "scripts/gdb: add a Radix Tree Parser"
This reverts commit e127a73d41 ("scripts/gdb: add a Radix Tree
Parser")

The python implementation of radix-tree was merged at the same time as
the radix-tree system was heavily reworked from commit e9256efcc8
("radix-tree: introduce radix_tree_empty") to 3bcadd6fa6 ("radix-tree:
free up the bottom bit of exceptional entries for reuse") and no longer
functions, but also prevents other gdb scripts from loading.

This functionality has not yet hit a release, so simply remove it for
now

Link: http://lkml.kernel.org/r/1467127337-11135-6-git-send-email-kieran@bingham.xyz
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-15 14:54:27 +09:00
Kieran Bingham
e127a73d41 scripts/gdb: add a Radix Tree Parser
Linux makes use of the Radix Tree data structure to store pointers
indexed by integer values.  This structure is utilised across many
structures in the kernel including the IRQ descriptor tables, and
several filesystems.

This module provides a method to lookup values from a structure given
its head node.

Usage:

The function lx_radix_tree_lookup, must be given a symbol of type struct
radix_tree_root, and an index into that tree.

The object returned is a generic integer value, and must be cast
correctly to the type based on the storage in the data structure.

For example, to print the irq descriptor in the sparse irq_desc_tree at
index 18, try the following:

 (gdb) print (struct irq_desc)$lx_radix_tree_lookup(irq_desc_tree, 18)

Link: http://lkml.kernel.org/r/d2028c55e50cf95a9b7f8ca0d11885174b0cc709.1462865983.git.jan.kiszka@siemens.com
Signed-off-by: Kieran Bingham <kieran.bingham@linaro.org>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00