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

From: Julia Lawall

Date: Sun Nov 01 2026 - 18:52:21 EST

On Sun, 1 Nov 2026, 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.

Applied

>
> Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
> ---
>
> Maybe this might be useful to run and apply just prior to some -rc1
>
> 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 .

I'm not sure that --include-headers-for-types is useful. That is useful
when there is an expression metavariable that is required to have a
particular type. I don't see that here. I also got around 5000 changes
in Linus's current master without using that argument. I didn't try it,
but I think --no-includes would thus be fine. --include-headers will get
the changes in the header files.

If the --keep comments argument is useful, it could be added to the
semantic patch, by putting #spatch --keep-comments at the top of the file.

julia

>
> Lightly tested but directly copied and modified to update the devm_ uses
>
> Its been a bit.
> Any comments or negatives about using or running this script?
>
> .../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
> + )
>