* [PATCH] coccinelle: misc: Check for hard-coded constants
@ 2020-08-12 23:35 Mohammed Billoo
0 siblings, 0 replies; 3+ messages in thread
From: Mohammed Billoo @ 2020-08-12 23:35 UTC (permalink / raw)
To: linux-safety; +Cc: Mohammed Billoo
This semantic patch looks for variables that are initialized to
constants, arrays that are both declared and indexed with constants.
A false positive will occur when a variable is initialized to 0, which
must happen for auto variables. This will be resolved in a future patch.
The patch was tested against the following snippet:
int main()
{
int iarr[54]; /* instance 1 */
int j = 0; /* instance 2 */
int i = 1; /* instance 3 */
iarr[0] = 3; /* instance 4 */
return 0;
}
and it correctly identified instances 1, 3, and 4. It incorrectly
identified instance 2, which will be addressed in a future patch.
---
scripts/coccinelle/misc/magic_numbers.cocci | 45 +++++++++++++++++++++
1 file changed, 45 insertions(+)
create mode 100644 scripts/coccinelle/misc/magic_numbers.cocci
diff --git a/scripts/coccinelle/misc/magic_numbers.cocci b/scripts/coccinelle/misc/magic_numbers.cocci
new file mode 100644
index 000000000000..be6df33d28e4
--- /dev/null
+++ b/scripts/coccinelle/misc/magic_numbers.cocci
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/// Capture and instances of CWE-547 (https://cwe.mitre.org/data/definitions/547.html)
+///
+//# This attempts to capture instances of magic numbers and report them
+
+virtual report
+
+@r1 depends on report@
+type T;
+constant C;
+identifier var;
+position p;
+@@
+* T var@p = C;
+
+@script:python depends on report@
+p << r1.p;
+@@
+coccilib.report.print_report(p[0], "Hard-coded constant, consider using #define")
+
+@r2 depends on report@
+type T;
+identifier var;
+constant C;
+position p;
+@@
+* T var[C];
+
+@script:python depends on report@
+p << r2.p;
+@@
+coccilib.report.print_report(p[0], "Hard-coded constant, consider using #define")
+
+@r3 depends on report@
+type T;
+constant C;
+position p;
+T[] E;
+@@
+* E[C]@p = ... ;
+
+@script:python depends on report@
+p << r3.p;
+@@
+coccilib.report.print_report(p[0], "Hard-coded constant, consider using #define")
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH] coccinelle: misc: Check for hard-coded constants
@ 2020-08-12 23:43 Mohammed Billoo
0 siblings, 0 replies; 3+ messages in thread
From: Mohammed Billoo @ 2020-08-12 23:43 UTC (permalink / raw)
To: linux-safety; +Cc: Mohammed Billoo
This semantic patch looks for variables that are initialized to
constants, arrays that are both declared and indexed with constants.
A false positive will occur when a variable is initialized to 0, which
must happen for auto variables. This will be resolved in a future patch.
The patch was tested against the following snippet:
int main()
{
int iarr[54]; /* instance 1 */
int j = 0; /* instance 2 */
int i = 1; /* instance 3 */
iarr[0] = 3; /* instance 4 */
return 0;
}
and it correctly identified instances 1, 3, and 4. It incorrectly
identified instance 2, which will be addressed in a future patch.
Signed-off-by: Mohammed Billoo <mab@mab-labs.com>
---
scripts/coccinelle/misc/magic_numbers.cocci | 45 +++++++++++++++++++++
1 file changed, 45 insertions(+)
create mode 100644 scripts/coccinelle/misc/magic_numbers.cocci
diff --git a/scripts/coccinelle/misc/magic_numbers.cocci b/scripts/coccinelle/misc/magic_numbers.cocci
new file mode 100644
index 000000000000..be6df33d28e4
--- /dev/null
+++ b/scripts/coccinelle/misc/magic_numbers.cocci
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/// Capture and instances of CWE-547 (https://cwe.mitre.org/data/definitions/547.html)
+///
+//# This attempts to capture instances of magic numbers and report them
+
+virtual report
+
+@r1 depends on report@
+type T;
+constant C;
+identifier var;
+position p;
+@@
+* T var@p = C;
+
+@script:python depends on report@
+p << r1.p;
+@@
+coccilib.report.print_report(p[0], "Hard-coded constant, consider using #define")
+
+@r2 depends on report@
+type T;
+identifier var;
+constant C;
+position p;
+@@
+* T var[C];
+
+@script:python depends on report@
+p << r2.p;
+@@
+coccilib.report.print_report(p[0], "Hard-coded constant, consider using #define")
+
+@r3 depends on report@
+type T;
+constant C;
+position p;
+T[] E;
+@@
+* E[C]@p = ... ;
+
+@script:python depends on report@
+p << r3.p;
+@@
+coccilib.report.print_report(p[0], "Hard-coded constant, consider using #define")
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH] coccinelle: misc: Check for hard-coded constants
@ 2020-08-12 23:41 Mohammed Billoo
0 siblings, 0 replies; 3+ messages in thread
From: Mohammed Billoo @ 2020-08-12 23:41 UTC (permalink / raw)
To: linux-safety; +Cc: Mohammed Billoo
This semantic patch looks for variables that are initialized to
constants, arrays that are both declared and indexed with constants.
A false positive will occur when a variable is initialized to 0, which
must happen for auto variables. This will be resolved in a future patch.
The patch was tested against the following snippet:
int main()
{
int iarr[54]; /* instance 1 */
int j = 0; /* instance 2 */
int i = 1; /* instance 3 */
iarr[0] = 3; /* instance 4 */
return 0;
}
and it correctly identified instances 1, 3, and 4. It incorrectly
identified instance 2, which will be addressed in a future patch.
---
scripts/coccinelle/misc/magic_numbers.cocci | 45 +++++++++++++++++++++
1 file changed, 45 insertions(+)
create mode 100644 scripts/coccinelle/misc/magic_numbers.cocci
diff --git a/scripts/coccinelle/misc/magic_numbers.cocci b/scripts/coccinelle/misc/magic_numbers.cocci
new file mode 100644
index 000000000000..be6df33d28e4
--- /dev/null
+++ b/scripts/coccinelle/misc/magic_numbers.cocci
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/// Capture and instances of CWE-547 (https://cwe.mitre.org/data/definitions/547.html)
+///
+//# This attempts to capture instances of magic numbers and report them
+
+virtual report
+
+@r1 depends on report@
+type T;
+constant C;
+identifier var;
+position p;
+@@
+* T var@p = C;
+
+@script:python depends on report@
+p << r1.p;
+@@
+coccilib.report.print_report(p[0], "Hard-coded constant, consider using #define")
+
+@r2 depends on report@
+type T;
+identifier var;
+constant C;
+position p;
+@@
+* T var[C];
+
+@script:python depends on report@
+p << r2.p;
+@@
+coccilib.report.print_report(p[0], "Hard-coded constant, consider using #define")
+
+@r3 depends on report@
+type T;
+constant C;
+position p;
+T[] E;
+@@
+* E[C]@p = ... ;
+
+@script:python depends on report@
+p << r3.p;
+@@
+coccilib.report.print_report(p[0], "Hard-coded constant, consider using #define")
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
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