From cf2c2e4a3d910270903d50462aaa75140cdb2c96 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Wed, 6 Mar 2024 19:12:25 -0800 Subject: [PATCH] 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: Kumar Kartikeya Dwivedi Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/r/20240307031228.42896-4-alexei.starovoitov@gmail.com Signed-off-by: Martin KaFai Lau --- include/linux/bpf.h | 3 +++ kernel/bpf/syscall.c | 16 ++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 785660810e6a7..95e07673cdc1a 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -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, diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index b2750b79ac805..f63f4da4db5ea 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -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) -- 2.49.0