Commit cf2c2e4a authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Martin KaFai Lau
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bpf: Plumb get_unmapped_area() callback into bpf_map_ops 



Subsequent patches introduce bpf_arena that imposes special alignment
requirements on address selection.

Acked-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20240307031228.42896-4-alexei.starovoitov@gmail.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent 8d94f135

include/linux/bpf.h

+3 −0
Original line number Diff line number Diff line
@@ -139,6 +139,9 @@ struct bpf_map_ops { 
	int (*map_mmap)(struct bpf_map *map, struct vm_area_struct *vma);

	__poll_t (*map_poll)(struct bpf_map *map, struct file *filp,

			     struct poll_table_struct *pts);

	unsigned long (*map_get_unmapped_area)(struct file *filep, unsigned long addr,

					       unsigned long len, unsigned long pgoff,

					       unsigned long flags);



	/* Functions called by bpf_local_storage maps */

	int (*map_local_storage_charge)(struct bpf_local_storage_map *smap,

kernel/bpf/syscall.c

+16 −0
Original line number Diff line number Diff line
@@ -937,6 +937,21 @@ static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts) 
	return EPOLLERR;

}



static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr,

					   unsigned long len, unsigned long pgoff,

					   unsigned long flags)

{

	struct bpf_map *map = filp->private_data;



	if (map->ops->map_get_unmapped_area)

		return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags);

#ifdef CONFIG_MMU

	return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags);

#else

	return addr;

#endif

}



const struct file_operations bpf_map_fops = {

#ifdef CONFIG_PROC_FS

	.show_fdinfo	= bpf_map_show_fdinfo,
@@ -946,6 +961,7 @@ const struct file_operations bpf_map_fops = { 
	.write		= bpf_dummy_write,

	.mmap		= bpf_map_mmap,

	.poll		= bpf_map_poll,

	.get_unmapped_area = bpf_get_unmapped_area,

};



int bpf_map_new_fd(struct bpf_map *map, int flags)