[PATCH v4 01/15] devres: provide devm_kmemdup_const()
From: Bartosz Golaszewski <hidden>
Date: 2025-08-12 08:27:11
Also in:
imx, linux-arm-msm, linux-gpio, linux-hardening, linux-mediatek, linux-mips, linux-mm, linux-omap, linux-renesas-soc, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds
From: Bartosz Golaszewski <redacted> Provide a function similar to devm_strdup_const() but for copying blocks of memory that are likely to be placed in .rodata. Signed-off-by: Bartosz Golaszewski <redacted> --- drivers/base/devres.c | 21 +++++++++++++++++++++ include/linux/device/devres.h | 2 ++ 2 files changed, 23 insertions(+)
diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index ff55e1bcfa30057849a352c577bd32f1aa196532..c948c88d395607ff511ffa6eb0a75b7847ab9239 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c@@ -1117,6 +1117,27 @@ void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp) } EXPORT_SYMBOL_GPL(devm_kmemdup); +/** + * devm_kmemdup_const - conditionally duplicate and manage a region of memory + * + * @dev: Device this memory belongs to + * @src: memory region to duplicate + * @len: memory region length, + * @gfp: GFP mask to use + * + * Return: source address if it is in .rodata or the return value of kmemdup() + * to which the function falls back otherwise. + */ +const void * +devm_kmemdup_const(struct device *dev, const void *src, size_t len, gfp_t gfp) +{ + if (is_kernel_rodata((unsigned long)src)) + return src; + + return devm_kmemdup(dev, src, len, gfp); +} +EXPORT_SYMBOL_GPL(devm_kmemdup_const); + struct pages_devres { unsigned long addr; unsigned int order;
diff --git a/include/linux/device/devres.h b/include/linux/device/devres.h
index ae696d10faff4468a41f37b5d5fd679d4ff11997..8c5f57e0d613492fd0b2ec97dd384181608192fc 100644
--- a/include/linux/device/devres.h
+++ b/include/linux/device/devres.h@@ -80,6 +80,8 @@ void devm_kfree(struct device *dev, const void *p); void * __realloc_size(3) devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp); +const void * +devm_kmemdup_const(struct device *dev, const void *src, size_t len, gfp_t gfp); static inline void *devm_kmemdup_array(struct device *dev, const void *src, size_t n, size_t size, gfp_t flags) {
--
2.48.1