Commit 1beb9b72 authored by Pratyush Yadav (Google)'s avatar Pratyush Yadav (Google) Committed by Andrew Morton
Browse files

memfd: export memfd_{add,get}_seals() 

Patch series "mm: memfd_luo: preserve file seals", v2.

This series adds support for preserving file seals when preserving a memfd
using LUO.  Patch 1 exports some memfd seal manipulation functions and
patch 2 adds support for preserving them.  Since it makes changes to the
serialized data structure for memfd, it also bumps the version number.


This patch (of 2):

Support for preserving file seals will be added to memfd preservation
using the Live Update Orchestrator (LUO).  Export memfd_{add,get}_seals)()
so memfd_luo can use them to manipulate the seals.

Link: https://lkml.kernel.org/r/20260216185946.1215770-1-pratyush@kernel.org
Link: https://lkml.kernel.org/r/20260216185946.1215770-2-pratyush@kernel.org


Signed-off-by: default avatarPratyush Yadav (Google) <pratyush@kernel.org>
Acked-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Tested-by: default avatarSamiullah Khawaja <skhawaja@google.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 1df1a1b9

include/linux/memfd.h

+12 −0
Original line number Diff line number Diff line
@@ -18,6 +18,8 @@ struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx); 
 */

int memfd_check_seals_mmap(struct file *file, vm_flags_t *vm_flags_ptr);

struct file *memfd_alloc_file(const char *name, unsigned int flags);

int memfd_get_seals(struct file *file);

int memfd_add_seals(struct file *file, unsigned int seals);

#else

static inline long memfd_fcntl(struct file *f, unsigned int c, unsigned int a)

{
@@ -37,6 +39,16 @@ static inline struct file *memfd_alloc_file(const char *name, unsigned int flags 
{

	return ERR_PTR(-EINVAL);

}



static inline int memfd_get_seals(struct file *file)

{

	return -EINVAL;

}



static inline int memfd_add_seals(struct file *file, unsigned int seals)

{

	return -EINVAL;

}

#endif



#endif /* __LINUX_MEMFD_H */

mm/memfd.c

+2 −2
Original line number Diff line number Diff line
@@ -227,7 +227,7 @@ static unsigned int *memfd_file_seals_ptr(struct file *file) 
		     F_SEAL_WRITE | \

		     F_SEAL_FUTURE_WRITE)



static int memfd_add_seals(struct file *file, unsigned int seals)

int memfd_add_seals(struct file *file, unsigned int seals)

{

	struct inode *inode = file_inode(file);

	unsigned int *file_seals;
@@ -309,7 +309,7 @@ static int memfd_add_seals(struct file *file, unsigned int seals) 
	return error;

}



static int memfd_get_seals(struct file *file)

int memfd_get_seals(struct file *file)

{

	unsigned int *seals = memfd_file_seals_ptr(file);