[PATCH] coccinelle: Add devm_kmalloc_objs conversion script

[PATCH] coccinelle: Add devm_kmalloc_objs conversion script

[Joe Perches]

Like commit bdc5071d7f7b ("coccinelle: Add kmalloc_objs conversion script")
with commit 1c7bbaeed110 ("coccinelle: kmalloc_obj: Remove default GFP_KERNEL arg")

Finds and converts sized devm_kmalloc-family of allocations into the typed
devm_kmalloc_obj-family of allocations.

Signed-off-by: Joe Perches <joe@perches.com>
---

Maybe this might be useful to run and apply just prior to some -rc1

Lightly tested but directly copied and modified to update the devm_ uses

 .../coccinelle/api/devm_kmalloc_objs.cocci    | 136 ++++++++++++++++++
 1 file changed, 136 insertions(+)
 create mode 100644 scripts/coccinelle/api/devm_kmalloc_objs.cocci

diff --git a/scripts/coccinelle/api/devm_kmalloc_objs.cocci b/scripts/coccinelle/api/devm_kmalloc_objs.cocci
new file mode 100644
index 0000000000000..322f79a2d9654
--- /dev/null
+++ b/scripts/coccinelle/api/devm_kmalloc_objs.cocci
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/// Use devm_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 == "devm_kmalloc_array":
+		func = "devm_kmalloc_objs"
+	elif name == "devm_kvmalloc_array":
+		func = "devm_kvmalloc_objs"
+	elif name == "devm_kcalloc":
+		func = "devm_kzalloc_objs"
+	elif name == "devm_kvcalloc":
+		func = "devm_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 uchar, ushort, uint, ulong;
+typedef __le16, __le32, __le64;
+typedef __be16, __be32, __be64;
+typedef wchar_t;
+type INTEGRAL = {u8,__u8,uint8_t,char,unsigned char,uchar,wchar_t,
+		 u16,__u16,uint16_t,unsigned short,ushort,
+		 u32,__u32,uint32_t,unsigned int,uint,
+		 u64,__u64,uint64_t,unsigned long,ulong,
+		 __le16,__le32,__le64,__be16,__be32,__be64};
+char [] STRING;
+INTEGRAL *BYTES;
+INTEGRAL **BYTES_PTRS;
+type TYPE;
+expression VAR;
+expression GFP;
+expression COUNT;
+expression FLEX;
+expression E;
+expression DEV;
+identifier ALLOC =~ "^devm_kv?[mz]alloc$";
+fresh identifier ALLOC_OBJ = ALLOC ## "_obj";
+fresh identifier ALLOC_FLEX = ALLOC ## "_flex";
+identifier ALLOC_ARRAY = {devm_kmalloc_array,devm_kvmalloc_array,devm_kcalloc,devm_kvcalloc};
+fresh identifier ALLOC_OBJS = script:python(ALLOC_ARRAY) { alloc_array(ALLOC_ARRAY) };
+@@
+
+(
+-	VAR = ALLOC(DEV,(sizeof(*VAR)), GFP)
++	VAR = ALLOC_OBJ(DEV,*VAR, GFP)
+|
+	ALLOC(DEV,(\(sizeof(STRING)\|sizeof(INTEGRAL)\|sizeof(INTEGRAL *)\)), GFP)
+|
+	BYTES = ALLOC(DEV,(sizeof(E)), GFP)
+|
+	BYTES = ALLOC(DEV,(sizeof(TYPE)), GFP)
+|
+	BYTES_PTRS = ALLOC(DEV,(sizeof(E)), GFP)
+|
+	BYTES_PTRS = ALLOC(DEV,(sizeof(TYPE)), GFP)
+|
+	ALLOC(DEV,(sizeof(void *)), GFP)
+|
+-	ALLOC(DEV,(sizeof(E)), GFP)
++	ALLOC_OBJ(DEV, E, GFP)
+|
+-	ALLOC(DEV,(sizeof(TYPE)), GFP)
++	ALLOC_OBJ(DEV,TYPE, GFP)
+|
+	ALLOC_ARRAY(DEV,COUNT, (\(sizeof(STRING)\|sizeof(INTEGRAL)\|sizeof(INTEGRAL *)\)), GFP)
+|
+	BYTES = ALLOC_ARRAY(DEV, COUNT, (sizeof(E)), GFP)
+|
+	BYTES = ALLOC_ARRAY(DEV,COUNT, (sizeof(TYPE)), GFP)
+|
+	BYTES_PTRS = ALLOC_ARRAY(DEV, COUNT, (sizeof(E)), GFP)
+|
+	BYTES_PTRS = ALLOC_ARRAY(DEV, COUNT, (sizeof(TYPE)), GFP)
+|
+	ALLOC_ARRAY(DEV, (\(sizeof(STRING)\|sizeof(INTEGRAL)\|sizeof(INTEGRAL *)\)), COUNT, GFP)
+|
+	BYTES = ALLOC_ARRAY(DEV, (sizeof(E)), COUNT, GFP)
+|
+	BYTES = ALLOC_ARRAY(DEV, (sizeof(TYPE)), COUNT, GFP)
+|
+	BYTES_PTRS = ALLOC_ARRAY(DEV, (sizeof(E)), COUNT, GFP)
+|
+	BYTES_PTRS = ALLOC_ARRAY(DEV, (sizeof(TYPE)), COUNT, GFP)
+|
+	ALLOC_ARRAY(DEV, COUNT, (sizeof(void *)), GFP)
+|
+	ALLOC_ARRAY(DEV, (sizeof(void *)), COUNT, GFP)
+|
+-	ALLOC_ARRAY(DEV, COUNT, (sizeof(E)), GFP)
++	ALLOC_OBJS(DEV, E, COUNT, GFP)
+|
+-	ALLOC_ARRAY(DEV, COUNT, (sizeof(TYPE)), GFP)
++	ALLOC_OBJS(DEV, TYPE, COUNT, GFP)
+|
+-	ALLOC_ARRAY(DEV, (sizeof(E)), COUNT, GFP)
++	ALLOC_OBJS(DEV, E, COUNT, GFP)
+|
+-	ALLOC_ARRAY(DEV, (sizeof(TYPE)), COUNT, GFP)
++	ALLOC_OBJS(DEV, TYPE, COUNT, GFP)
+|
+-	ALLOC(DEV, struct_size(VAR, FLEX, COUNT), GFP)
++	ALLOC_FLEX(DEV, *VAR, FLEX, COUNT, GFP)
+|
+-	ALLOC(DEV, struct_size_t(TYPE, FLEX, COUNT), GFP)
++	ALLOC_FLEX(DEV, TYPE, FLEX, COUNT, GFP)
+)
+
+@drop_gfp_kernel depends on patch && !(file in "tools") && !(file in "samples")@
+identifier ALLOC = {devm_kmalloc_obj,devm_kmalloc_objs,devm_kmalloc_flex,
+		    devm_kzalloc_obj,devm_kzalloc_objs,devm_kzalloc_flex,
+		    devm_kvmalloc_obj,devm_kvmalloc_objs,devm_kvmalloc_flex,
+		    devm_kvzalloc_obj,devm_kvzalloc_objs,devm_kvzalloc_flex};
+@@
+
+	ALLOC(...
+-		 , GFP_KERNEL
+	     )
-- 
2.54.0

Re: [PATCH] coccinelle: Add devm_kmalloc_objs conversion script

[Joe Perches]

On Mon, 2026-06-15 at 19:10 -0700, Joe Perches wrote:
> Like commit bdc5071d7f7b ("coccinelle: Add kmalloc_objs conversion script")
> with commit 1c7bbaeed110 ("coccinelle: kmalloc_obj: Remove default GFP_KERNEL arg")
> 
> Finds and converts sized devm_kmalloc-family of allocations into the typed
> devm_kmalloc_obj-family of allocations.

Its been a bit.
Any comments or negatives about using or running this script?

This script would change more than 8000 instances in more than
5000 files in Linus' current master.

$ spatch -D patch --very-quiet --cocci-file ./scripts/coccinelle/api/devm_kmalloc_objs.cocci \
    --include-headers-for-types --all-includes --include-headers --keep-comments \
    -I ./arch/x86/include -I ./arch/x86/include/generated -I ./include \
    -I ./arch/x86/include/uapi -I ./arch/x86/include/generated/uapi -I ./include/uapi \
    -I ./include/generated/uapi --include ./include/linux/compiler-version.h \
    --include ./include/linux/kconfig.h .

Re: [PATCH] coccinelle: Add devm_kmalloc_objs conversion script

[Julia Lawall]

On Wed, 24 Jun 2026, Joe Perches wrote:

> On Mon, 2026-06-15 at 19:10 -0700, Joe Perches wrote:
> > Like commit bdc5071d7f7b ("coccinelle: Add kmalloc_objs conversion script")
> > with commit 1c7bbaeed110 ("coccinelle: kmalloc_obj: Remove default GFP_KERNEL arg")
> >
> > Finds and converts sized devm_kmalloc-family of allocations into the typed
> > devm_kmalloc_obj-family of allocations.
>
> Its been a bit.
> Any comments or negatives about using or running this script?
>
> This script would change more than 8000 instances in more than
> 5000 files in Linus' current master.

I was going to try it this evening.  Are you concerned that it is too
much?

julia

>
> $ spatch -D patch --very-quiet --cocci-file ./scripts/coccinelle/api/devm_kmalloc_objs.cocci \
>     --include-headers-for-types --all-includes --include-headers --keep-comments \
>     -I ./arch/x86/include -I ./arch/x86/include/generated -I ./include \
>     -I ./arch/x86/include/uapi -I ./arch/x86/include/generated/uapi -I ./include/uapi \
>     -I ./include/generated/uapi --include ./include/linux/compiler-version.h \
>     --include ./include/linux/kconfig.h .
>

Re: [PATCH] coccinelle: Add devm_kmalloc_objs conversion script

[Joe Perches]

On Wed, 2026-06-24 at 19:25 +0200, Julia Lawall wrote:
> On Wed, 24 Jun 2026, Joe Perches wrote:
> > On Mon, 2026-06-15 at 19:10 -0700, Joe Perches wrote:
> > > Like commit bdc5071d7f7b ("coccinelle: Add kmalloc_objs conversion script")
> > > with commit 1c7bbaeed110 ("coccinelle: kmalloc_obj: Remove default GFP_KERNEL arg")
> > > 
> > > Finds and converts sized devm_kmalloc-family of allocations into the typed
> > > devm_kmalloc_obj-family of allocations.
> > 
> > Its been a bit.
> > Any comments or negatives about using or running this script?
> > 
> > This script would change more than 8000 instances in more than
> > 5000 files in Linus' current master.
> 
> I was going to try it this evening.  Are you concerned that it is too
> much?

Not really.
There were no comments and it might have been overlooked.

Re: [cocci] [PATCH] coccinelle: Add devm_kmalloc_objs conversion script

[Markus Elfring]

> +virtual patch

Will additional operation modes become relevant after clarification of implementation details?


…
> +def alloc_array(name):
> +	func = "FAILED_RENAME"
> +	if name == "devm_kmalloc_array":
> +		func = "devm_kmalloc_objs"
…

* I suggest to avoid duplicate variable assignments.

* How do you think about to collaborate with the Python data structure “dictionary”?


…
> +expression VAR;
> +expression GFP;
> +expression COUNT;
…

Such repetition of SmPL key words can eventually be also avoided.


…
> +|
> +	BYTES_PTRS = ALLOC(DEV,(sizeof(E)), GFP)
> +|
> +	BYTES_PTRS = ALLOC(DEV,(sizeof(TYPE)), GFP)
> +|
…

I see possibilities to refine such an SmPL disjunction.


…
> +@drop_gfp_kernel depends on patch && !(file in "tools") && !(file in "samples")@
> +identifier ALLOC = {devm_kmalloc_obj,devm_kmalloc_objs,devm_kmalloc_flex,
> +		    devm_kzalloc_obj,devm_kzalloc_objs,devm_kzalloc_flex,
> +		    devm_kvmalloc_obj,devm_kvmalloc_objs,devm_kvmalloc_flex,
> +		    devm_kvzalloc_obj,devm_kvzalloc_objs,devm_kvzalloc_flex};
> +@@
…

Can development interests grow for more advanced management of such function names?

Regards,
Markus