[PATCH v2] Documentation: checkpatch: Add SYMBOLIC_PERMS message

From: Utkarsh Verma
Date: Sat Sep 04 2021 - 04:24:05 EST

Add a new message type SYMBOLIC_PERMS under the 'Permissions'
subsection. Octal permission bits are easier to read and understand
instead of their symbolic macro names.

Suggested-by: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx>
Signed-off-by: Utkarsh Verma <utkarshverma294@xxxxxxxxx>
Acked-by: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx>
Reviewed-by: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx>
Documentation/dev-tools/checkpatch.rst | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/Documentation/dev-tools/checkpatch.rst b/Documentation/dev-tools/checkpatch.rst
index f0956e9ea2d8..41037594ec24 100644
--- a/Documentation/dev-tools/checkpatch.rst
+++ b/Documentation/dev-tools/checkpatch.rst
@@ -957,6 +957,17 @@ Permissions
Permission bits should use 4 digit octal permissions (like 0700 or 0444).
Avoid using any other base like decimal.

+ Permission bits in the octal form are more readable and easier to
+ understand than their symbolic counterparts because many command-line
+ tools use this notation only. Experienced kernel developers have been using
+ this traditional Unix permission bits for decades and so they find it
+ easier to understand the octal notation than the symbolic macros.
+ For example, it is harder to read S_IWUSR|S_IRUGO than 0644, which
+ obscures the developer's intent rather than clarifying it.
+ See: https://lore.kernel.org/lkml/CA+55aFw5v23T-zvDZp-MmD_EYxF8WbafwwB59934FV7g21uMGQ@xxxxxxxxxxxxxx/

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