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[PATCH v6 5/5] coccinelle: Add kmalloc_objs conversion script

Kees Cook posted 5 patches 2 weeks, 1 day ago
[PATCH v6 5/5] coccinelle: Add kmalloc_objs conversion script
Posted by Kees Cook 2 weeks, 1 day ago 
Finds and converts sized kmalloc-family of allocations into the
typed kmalloc_obj-family of allocations.

Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Cc: Nicolas Palix <nicolas.palix@imag.fr>
Cc: cocci@inria.fr
---
 scripts/coccinelle/api/kmalloc_objs.cocci | 109 ++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 scripts/coccinelle/api/kmalloc_objs.cocci

diff --git a/scripts/coccinelle/api/kmalloc_objs.cocci b/scripts/coccinelle/api/kmalloc_objs.cocci
new file mode 100644
index 000000000000..916cc3a661b9
--- /dev/null
+++ b/scripts/coccinelle/api/kmalloc_objs.cocci
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/// Use kmalloc_obj family of macros for allocations
+///
+// Confidence: High
+// Options: --include-headers-for-types --all-includes --include-headers --keep-comments
+
+virtual patch
+
+@initialize:python@
+@@
+import sys
+
+def alloc_array(name):
+	func = "FAILED_RENAME"
+	if name == "kmalloc_array":
+		func = "kmalloc_objs"
+	elif name == "kvmalloc_array":
+		func = "kvmalloc_objs"
+	elif name == "kcalloc":
+		func = "kzalloc_objs"
+	elif name == "kvcalloc":
+		func = "kvzalloc_objs"
+	else:
+		print(f"Unknown transform for {name}", file=sys.stderr)
+	return func
+
+// This excludes anything that is assigning to or from integral types or
+// string literals. Everything else gets the sizeof() extracted for the
+// kmalloc_obj() type/var argument. sizeof(void *) is also excluded because
+// it will need case-by-case double-checking to make sure the right type is
+// being assigned.
+@direct depends on patch && !(file in "tools") && !(file in "samples")@
+typedef u8, u16, u32, u64;
+typedef __u8, __u16, __u32, __u64;
+typedef uint8_t, uint16_t, uint32_t, uint64_t;
+typedef __le16, __le32, __le64;
+typedef __be16, __be32, __be64;
+type INTEGRAL = {u8,__u8,uint8_t,char,unsigned char,
+		 u16,__u16,uint16_t,unsigned short,
+		 u32,__u32,uint32_t,unsigned int,
+		 u64,__u64,uint64_t,unsigned long,
+		 __le16,__le32,__le64,__be16,__be32,__be64};
+char [] STRING;
+INTEGRAL *BYTES;
+type TYPE;
+expression VAR;
+expression GFP;
+expression COUNT;
+expression FLEX;
+expression E;
+identifier ALLOC =~ "^kv?[mz]alloc$";
+fresh identifier ALLOC_OBJ = ALLOC ## "_obj";
+fresh identifier ALLOC_FLEX = ALLOC ## "_flex";
+identifier ALLOC_ARRAY = {kmalloc_array,kvmalloc_array,kcalloc,kvcalloc};
+fresh identifier ALLOC_OBJS = script:python(ALLOC_ARRAY) { alloc_array(ALLOC_ARRAY) };
+@@
+
+(
+-	VAR = ALLOC((sizeof(*VAR)), GFP)
++	VAR = ALLOC_OBJ(*VAR, GFP)
+|
+	ALLOC((\(sizeof(STRING)\|sizeof(INTEGRAL)\|sizeof(INTEGRAL *)\)), GFP)
+|
+	BYTES = ALLOC((sizeof(E)), GFP)
+|
+	BYTES = ALLOC((sizeof(TYPE)), GFP)
+|
+	ALLOC((sizeof(void *)), GFP)
+|
+-	ALLOC((sizeof(E)), GFP)
++	ALLOC_OBJ(E, GFP)
+|
+-	ALLOC((sizeof(TYPE)), GFP)
++	ALLOC_OBJ(TYPE, GFP)
+|
+	ALLOC_ARRAY(COUNT, (\(sizeof(STRING)\|sizeof(INTEGRAL)\|sizeof(INTEGRAL *)\)), GFP)
+|
+	BYTES = ALLOC_ARRAY(COUNT, (sizeof(E)), GFP)
+|
+	BYTES = ALLOC_ARRAY(COUNT, (sizeof(TYPE)), GFP)
+|
+	ALLOC_ARRAY((\(sizeof(STRING)\|sizeof(INTEGRAL)\|sizeof(INTEGRAL *)\)), COUNT, GFP)
+|
+	BYTES = ALLOC_ARRAY((sizeof(E)), COUNT, GFP)
+|
+	BYTES = ALLOC_ARRAY((sizeof(TYPE)), COUNT, GFP)
+|
+	ALLOC_ARRAY(COUNT, (sizeof(void *)), GFP)
+|
+	ALLOC_ARRAY((sizeof(void *)), COUNT, GFP)
+|
+-	ALLOC_ARRAY(COUNT, (sizeof(E)), GFP)
++	ALLOC_OBJS(E, COUNT, GFP)
+|
+-	ALLOC_ARRAY(COUNT, (sizeof(TYPE)), GFP)
++	ALLOC_OBJS(TYPE, COUNT, GFP)
+|
+-	ALLOC_ARRAY((sizeof(E)), COUNT, GFP)
++	ALLOC_OBJS(E, COUNT, GFP)
+|
+-	ALLOC_ARRAY((sizeof(TYPE)), COUNT, GFP)
++	ALLOC_OBJS(TYPE, COUNT, GFP)
+|
+-	ALLOC(struct_size(VAR, FLEX, COUNT), GFP)
++	ALLOC_FLEX(*VAR, FLEX, COUNT, GFP)
+|
+-	ALLOC(struct_size_t(TYPE, FLEX, COUNT), GFP)
++	ALLOC_FLEX(TYPE, FLEX, COUNT, GFP)
+)
-- 
2.34.1
Re: [cocci] [PATCH v6 5/5] coccinelle: Add kmalloc_objs conversion script
Posted by Julia Lawall 2 days, 22 hours ago 

On Wed, 3 Dec 2025, Kees Cook wrote:

> Finds and converts sized kmalloc-family of allocations into the
> typed kmalloc_obj-family of allocations.

The combination of the use of a regular expression to find the function
names and the big disjunction makes this unnecessarily slow.  I will try
to propose something shortly.

julia

>
> Signed-off-by: Kees Cook <kees@kernel.org>
> ---
> Cc: Julia Lawall <Julia.Lawall@inria.fr>
> Cc: Nicolas Palix <nicolas.palix@imag.fr>
> Cc: cocci@inria.fr
> ---
>  scripts/coccinelle/api/kmalloc_objs.cocci | 109 ++++++++++++++++++++++
>  1 file changed, 109 insertions(+)
>  create mode 100644 scripts/coccinelle/api/kmalloc_objs.cocci
>
> diff --git a/scripts/coccinelle/api/kmalloc_objs.cocci b/scripts/coccinelle/api/kmalloc_objs.cocci
> new file mode 100644
> index 000000000000..916cc3a661b9
> --- /dev/null
> +++ b/scripts/coccinelle/api/kmalloc_objs.cocci
> @@ -0,0 +1,109 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/// Use kmalloc_obj family of macros for allocations
> +///
> +// Confidence: High
> +// Options: --include-headers-for-types --all-includes --include-headers --keep-comments
> +
> +virtual patch
> +
> +@initialize:python@
> +@@
> +import sys
> +
> +def alloc_array(name):
> +	func = "FAILED_RENAME"
> +	if name == "kmalloc_array":
> +		func = "kmalloc_objs"
> +	elif name == "kvmalloc_array":
> +		func = "kvmalloc_objs"
> +	elif name == "kcalloc":
> +		func = "kzalloc_objs"
> +	elif name == "kvcalloc":
> +		func = "kvzalloc_objs"
> +	else:
> +		print(f"Unknown transform for {name}", file=sys.stderr)
> +	return func
> +
> +// This excludes anything that is assigning to or from integral types or
> +// string literals. Everything else gets the sizeof() extracted for the
> +// kmalloc_obj() type/var argument. sizeof(void *) is also excluded because
> +// it will need case-by-case double-checking to make sure the right type is
> +// being assigned.
> +@direct depends on patch && !(file in "tools") && !(file in "samples")@
> +typedef u8, u16, u32, u64;
> +typedef __u8, __u16, __u32, __u64;
> +typedef uint8_t, uint16_t, uint32_t, uint64_t;
> +typedef __le16, __le32, __le64;
> +typedef __be16, __be32, __be64;
> +type INTEGRAL = {u8,__u8,uint8_t,char,unsigned char,
> +		 u16,__u16,uint16_t,unsigned short,
> +		 u32,__u32,uint32_t,unsigned int,
> +		 u64,__u64,uint64_t,unsigned long,
> +		 __le16,__le32,__le64,__be16,__be32,__be64};
> +char [] STRING;
> +INTEGRAL *BYTES;
> +type TYPE;
> +expression VAR;
> +expression GFP;
> +expression COUNT;
> +expression FLEX;
> +expression E;
> +identifier ALLOC =~ "^kv?[mz]alloc$";
> +fresh identifier ALLOC_OBJ = ALLOC ## "_obj";
> +fresh identifier ALLOC_FLEX = ALLOC ## "_flex";
> +identifier ALLOC_ARRAY = {kmalloc_array,kvmalloc_array,kcalloc,kvcalloc};
> +fresh identifier ALLOC_OBJS = script:python(ALLOC_ARRAY) { alloc_array(ALLOC_ARRAY) };
> +@@
> +
> +(
> +-	VAR = ALLOC((sizeof(*VAR)), GFP)
> ++	VAR = ALLOC_OBJ(*VAR, GFP)
> +|
> +	ALLOC((\(sizeof(STRING)\|sizeof(INTEGRAL)\|sizeof(INTEGRAL *)\)), GFP)
> +|
> +	BYTES = ALLOC((sizeof(E)), GFP)
> +|
> +	BYTES = ALLOC((sizeof(TYPE)), GFP)
> +|
> +	ALLOC((sizeof(void *)), GFP)
> +|
> +-	ALLOC((sizeof(E)), GFP)
> ++	ALLOC_OBJ(E, GFP)
> +|
> +-	ALLOC((sizeof(TYPE)), GFP)
> ++	ALLOC_OBJ(TYPE, GFP)
> +|
> +	ALLOC_ARRAY(COUNT, (\(sizeof(STRING)\|sizeof(INTEGRAL)\|sizeof(INTEGRAL *)\)), GFP)
> +|
> +	BYTES = ALLOC_ARRAY(COUNT, (sizeof(E)), GFP)
> +|
> +	BYTES = ALLOC_ARRAY(COUNT, (sizeof(TYPE)), GFP)
> +|
> +	ALLOC_ARRAY((\(sizeof(STRING)\|sizeof(INTEGRAL)\|sizeof(INTEGRAL *)\)), COUNT, GFP)
> +|
> +	BYTES = ALLOC_ARRAY((sizeof(E)), COUNT, GFP)
> +|
> +	BYTES = ALLOC_ARRAY((sizeof(TYPE)), COUNT, GFP)
> +|
> +	ALLOC_ARRAY(COUNT, (sizeof(void *)), GFP)
> +|
> +	ALLOC_ARRAY((sizeof(void *)), COUNT, GFP)
> +|
> +-	ALLOC_ARRAY(COUNT, (sizeof(E)), GFP)
> ++	ALLOC_OBJS(E, COUNT, GFP)
> +|
> +-	ALLOC_ARRAY(COUNT, (sizeof(TYPE)), GFP)
> ++	ALLOC_OBJS(TYPE, COUNT, GFP)
> +|
> +-	ALLOC_ARRAY((sizeof(E)), COUNT, GFP)
> ++	ALLOC_OBJS(E, COUNT, GFP)
> +|
> +-	ALLOC_ARRAY((sizeof(TYPE)), COUNT, GFP)
> ++	ALLOC_OBJS(TYPE, COUNT, GFP)
> +|
> +-	ALLOC(struct_size(VAR, FLEX, COUNT), GFP)
> ++	ALLOC_FLEX(*VAR, FLEX, COUNT, GFP)
> +|
> +-	ALLOC(struct_size_t(TYPE, FLEX, COUNT), GFP)
> ++	ALLOC_FLEX(TYPE, FLEX, COUNT, GFP)
> +)
> --
> 2.34.1
>
>
Re: [PATCH v6 5/5] coccinelle: Add kmalloc_objs conversion script
Posted by Markus Elfring 1 week, 1 day ago 
> Finds and converts sized kmalloc-family of allocations into the
> typed kmalloc_obj-family of allocations.

Can previous patch review concerns get more development attention anyhow?
https://lore.kernel.org/cocci/71d406fb-9fb1-44a9-912a-7a0d270b9577@web.de/
https://sympa.inria.fr/sympa/arc/cocci/2025-11/msg00066.html

Regards,
Markus
Re: [PATCH v6 5/5] coccinelle: Add kmalloc_objs conversion script
Posted by Kees Cook 1 week ago 
On Thu, Dec 11, 2025 at 03:15:08PM +0100, Markus Elfring wrote:
> > Finds and converts sized kmalloc-family of allocations into the
> > typed kmalloc_obj-family of allocations.
> 
> Can previous patch review concerns get more development attention anyhow?
> https://lore.kernel.org/cocci/71d406fb-9fb1-44a9-912a-7a0d270b9577@web.de/
> https://sympa.inria.fr/sympa/arc/cocci/2025-11/msg00066.html

I've replied there now. tl;dr: I already dropped the empty Comments line
for this v5, and didn't want to make other changes to the .cocci without
a better rationale. I'm open to suggestions, though!

-Kees

-- 
Kees Cook

Patchew 2.1-devel-b67e4c2

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