Commit 57c49d23 authored by Gal Pressman's avatar Gal Pressman Committed by Jakub Kicinski
Browse files

scripts/coccinelle: Find PTR_ERR() to %pe candidates 



Add a new Coccinelle script to identify places where PTR_ERR() is used
in print functions and suggest using the %pe format specifier instead.

For printing error pointers (i.e., a pointer for which IS_ERR() is true)
%pe will print a symbolic error name (e.g,. -EINVAL), opposed to the raw
errno (e.g,. -22) produced by PTR_ERR().
It also makes the code cleaner by saving a redundant call to PTR_ERR().

The script supports context, report, and org modes.

Example transformation:
    printk("Error: %ld\n", PTR_ERR(ptr));  // Before
    printk("Error: %pe\n", ptr);          // After

Signed-off-by: default avatarGal Pressman <gal@nvidia.com>
Reviewed-by: default avatarAlexei Lazar <alazar@nvidia.com>
Signed-off-by: default avatarTariq Toukan <tariqt@nvidia.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/1758192227-701925-2-git-send-email-tariqt@nvidia.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 203e3beb

scripts/coccinelle/misc/ptr_err_to_pe.cocci

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// SPDX-License-Identifier: GPL-2.0-only

/// Use %pe format specifier instead of PTR_ERR() for printing error pointers.

///

/// For printing error pointers (i.e., a pointer for which IS_ERR() is true)

/// %pe will print a symbolic error name (e.g., -EINVAL), opposed to the raw

/// errno (e.g., -22) produced by PTR_ERR().

/// It also makes the code cleaner by saving a redundant call to PTR_ERR().

///

// Confidence: High

// Copyright: (C) 2025 NVIDIA CORPORATION & AFFILIATES.

// URL: https://coccinelle.gitlabpages.inria.fr/website

// Options: --no-includes --include-headers



virtual context

virtual org

virtual report



@r@

expression ptr;

constant fmt;

position p;

identifier print_func;

@@

* print_func(..., fmt, ..., PTR_ERR@p(ptr), ...)



@script:python depends on r && report@

p << r.p;

@@

coccilib.report.print_report(p[0], "WARNING: Consider using %pe to print PTR_ERR()")



@script:python depends on r && org@

p << r.p;

@@

coccilib.org.print_todo(p[0], "WARNING: Consider using %pe to print PTR_ERR()")