[PATCH] checkpatch: forbid filesystem accesses from within the kernel

[PATCH] checkpatch: forbid filesystem accesses from within the kernel

[Prakruthi Deepak Heragu]

As use of sys_open/close/read/write system calls from within the kernel 
code is inappropriate, an error is triggered if used.

Signed-off-by: Prakruthi Deepak Heragu <pheragu@codeaurora.org>
---
 scripts/checkpatch.pl | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index a9c0550..e6e7e09 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -5372,6 +5372,13 @@ sub process {
 			     "Avoid line continuations in quoted strings\n" . $herecurr);
 		}
 
+# sys_open/read/write/close are not allowed in the kernel
+		if ($line =~ /\b(sys_(?:open|read|write|close))\b/) {
+			ERROR("FILE_OPS",
+			      "$1 is inappropriate in kernel code.\n" .
+			      $herecurr);
+		}
+
 # warn about #if 0
 		if ($line =~ /^.\s*\#\s*if\s+0\b/) {
 			CHK("REDUNDANT_CODE",
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH] checkpatch: forbid filesystem accesses from within the kernel

[Joe Perches]

On Thu, 2018-07-05 at 14:47 -0700, Prakruthi Deepak Heragu wrote:
> As use of sys_open/close/read/write system calls from within the kernel 
> code is inappropriate, an error is triggered if used.
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -5372,6 +5372,13 @@ sub process {
>  			     "Avoid line continuations in quoted strings\n" . $herecurr);
>  		}
>  
> +# sys_open/read/write/close are not allowed in the kernel
> +		if ($line =~ /\b(sys_(?:open|read|write|close))\b/) {
> +			ERROR("FILE_OPS",
> +			      "$1 is inappropriate in kernel code.\n" .
> +			      $herecurr);
> +		}
> +

Is this really useful?

As far as I can tell, this would only give
false positives on all existing kernel code.