kmem_cache_create_usercopy(9)

💖 kmem_cache_create_usercopy(9) 💖

okay bestie, welcome to the Kernel API Manual entry for kmem_cache_create_usercopy — it's literally about making a kmem cache with a region suitable for copying to userspace. lowkey essential, highkey iconic ✨

🌸 NAME 🌸

kmem_cache_create_usercopy — create a kmem cache with a region suitable for copying to userspace. periodt 💅

✨ SYNOPSIS ✨

struct kmem_cache * kmem_cache_create_usercopy (const char *name ,
unsigned int size , unsigned int align , slab_flags_t flags , unsigned
int useroffset , unsigned int usersize , void (*ctor)(void *) );

🎀 ARGUMENTS 🎀

• name — a string which is used in /proc/slabinfo to identify this cache. it's giving little name tag for your cache 🏷️
• size — the size of objects to be created in this cache.
• align — the required alignment for the objects.
• flags — SLAB flags.
• useroffset — Usercopy region offset.
• usersize — Usercopy region size.
• ctor — a constructor for the objects, or NULL.

🦋 DESCRIPTION 🦋

okay so real talk: this is a legacy wrapper, bestie. new code should use either KMEM_CACHE_USERCOPY if whitelisting a single field is sufficient, or kmem_cache_create with the necessary parameters passed via the args parameter (see struct kmem_cache_args). it's giving "old faithful but not the new hotness" 😭

🔥 RETURN 🔥

a pointer to the cache on success, NULL on failure. that's it, that's the tea ☕

🌈 SEE ALSO 🌈

the kernel file ./include/linux/slab.h is like the home base, and the whole squad is:

• SLAB_HWCACHE_ALIGN(9)
• SLAB_TYPESAFE_BY_RCU(9)
• SLAB_ACCOUNT(9)
• SLAB_RECLAIM_ACCOUNT(9)
• struct kmem_cache_args(9)
• kmem_cache_create(9)
• krealloc_node_align(9)
• kmem_cache_alloc(9)
• kmem_cache_charge(9)
• kmalloc(9)
• kmalloc_nolock(9)
• __alloc_objs(9)
• __alloc_flex(9)
• kmalloc_obj(9)
• kmalloc_objs(9)
• kmalloc_flex(9)
• kmalloc_array(9)
• krealloc_array(9)
• kcalloc(9)
• kzalloc(9)
• kvmalloc_node(9)
• kvrealloc_node_align(9)
• kmalloc_size_roundup(9)

mwah 💋 this page's source is ./include/linux, it's dated October 2026, and it's the kmem_cache_create_usercopy(9) manual page. bye bestie, go build something iconic 🫶