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linux/kernel/bpf/preload/bpf_preload_kern.c

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bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
// SPDX-License-Identifier: GPL-2.0
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/module.h>
#include "bpf_preload.h"
bpf: iterators: Split iterators.lskel.h into little- and big- endian versions iterators.lskel.h is little-endian, therefore bpf iterator is currently broken on big-endian systems. Introduce a big-endian version and add instructions regarding its generation. Unfortunately bpftool's cross-endianness capabilities are limited to BTF right now, so the procedure requires access to a big-endian machine or a configured emulator. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/r/20230128000650.1516334-25-iii@linux.ibm.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-27 17:06:43 -07:00
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
#include "iterators/iterators.lskel-little-endian.h"
#else
#include "iterators/iterators.lskel-big-endian.h"
#endif
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
static struct bpf_link *maps_link, *progs_link;
static struct iterators_bpf *skel;
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
static void free_links_and_skel(void)
{
if (!IS_ERR_OR_NULL(maps_link))
bpf_link_put(maps_link);
if (!IS_ERR_OR_NULL(progs_link))
bpf_link_put(progs_link);
iterators_bpf__destroy(skel);
}
static int preload(struct bpf_preload_info *obj)
{
bpf: Replace all non-returning strlcpy with strscpy strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. This is not the case here, however, in an effort to remove strlcpy() completely [2], lets replace strlcpy() here with strscpy(). No return values were used, so a direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/bpf/20230530155659.309657-1-azeemshaikh38@gmail.com
2023-05-30 08:56:59 -07:00
strscpy(obj[0].link_name, "maps.debug", sizeof(obj[0].link_name));
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
obj[0].link = maps_link;
bpf: Replace all non-returning strlcpy with strscpy strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. This is not the case here, however, in an effort to remove strlcpy() completely [2], lets replace strlcpy() here with strscpy(). No return values were used, so a direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/bpf/20230530155659.309657-1-azeemshaikh38@gmail.com
2023-05-30 08:56:59 -07:00
strscpy(obj[1].link_name, "progs.debug", sizeof(obj[1].link_name));
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
obj[1].link = progs_link;
return 0;
}
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
static struct bpf_preload_ops ops = {
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
.preload = preload,
.owner = THIS_MODULE,
};
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
static int load_skel(void)
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
{
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
int err;
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
skel = iterators_bpf__open();
if (!skel)
return -ENOMEM;
err = iterators_bpf__load(skel);
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
if (err)
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
goto out;
err = iterators_bpf__attach(skel);
if (err)
goto out;
maps_link = bpf_link_get_from_fd(skel->links.dump_bpf_map_fd);
if (IS_ERR(maps_link)) {
err = PTR_ERR(maps_link);
goto out;
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
}
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
progs_link = bpf_link_get_from_fd(skel->links.dump_bpf_prog_fd);
if (IS_ERR(progs_link)) {
err = PTR_ERR(progs_link);
goto out;
bpf: Fix umd memory leak in copy_process() The syzbot reported a memleak as follows: BUG: memory leak unreferenced object 0xffff888101b41d00 (size 120): comm "kworker/u4:0", pid 8, jiffies 4294944270 (age 12.780s) backtrace: [<ffffffff8125dc56>] alloc_pid+0x66/0x560 [<ffffffff81226405>] copy_process+0x1465/0x25e0 [<ffffffff81227943>] kernel_clone+0xf3/0x670 [<ffffffff812281a1>] kernel_thread+0x61/0x80 [<ffffffff81253464>] call_usermodehelper_exec_work [<ffffffff81253464>] call_usermodehelper_exec_work+0xc4/0x120 [<ffffffff812591c9>] process_one_work+0x2c9/0x600 [<ffffffff81259ab9>] worker_thread+0x59/0x5d0 [<ffffffff812611c8>] kthread+0x178/0x1b0 [<ffffffff8100227f>] ret_from_fork+0x1f/0x30 unreferenced object 0xffff888110ef5c00 (size 232): comm "kworker/u4:0", pid 8414, jiffies 4294944270 (age 12.780s) backtrace: [<ffffffff8154a0cf>] kmem_cache_zalloc [<ffffffff8154a0cf>] __alloc_file+0x1f/0xf0 [<ffffffff8154a809>] alloc_empty_file+0x69/0x120 [<ffffffff8154a8f3>] alloc_file+0x33/0x1b0 [<ffffffff8154ab22>] alloc_file_pseudo+0xb2/0x140 [<ffffffff81559218>] create_pipe_files+0x138/0x2e0 [<ffffffff8126c793>] umd_setup+0x33/0x220 [<ffffffff81253574>] call_usermodehelper_exec_async+0xb4/0x1b0 [<ffffffff8100227f>] ret_from_fork+0x1f/0x30 After the UMD process exits, the pipe_to_umh/pipe_from_umh and tgid need to be released. Fixes: d71fa5c9763c ("bpf: Add kernel module with user mode driver that populates bpffs.") Reported-by: syzbot+44908bb56d2bfe56b28e@syzkaller.appspotmail.com Signed-off-by: Zqiang <qiang.zhang@windriver.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210317030915.2865-1-qiang.zhang@windriver.com
2021-03-16 20:09:15 -07:00
}
bpf: Fix issue with bpf preload module taking over stdout/stdin of kernel. In cb80ddc67152 ("bpf: Convert bpf_preload.ko to use light skeleton.") BPF preload was switched from user mode process to use in-kernel light skeleton instead. However, in the kernel context, early in the boot sequence, the first available FD can start from 0, instead of normally 3 for user mode process. So FDs 0 and 1 are then used for loaded BPF programs and prevent init process from setting up stdin/stdout/stderr on FD 0, 1, and 2 as expected. Before the fix: ls -lah /proc/1/fd/* lrwx------1 root root 64 Feb 23 17:20 /proc/1/fd/0 -> /dev/null lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/1 -> /dev/null lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/2 -> /dev/console lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/6 -> /dev/console lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/7 -> /dev/console After the fix: ls -lah /proc/1/fd/* lrwx------ 1 root root 64 Feb 24 21:23 /proc/1/fd/0 -> /dev/console lrwx------ 1 root root 64 Feb 24 21:23 /proc/1/fd/1 -> /dev/console lrwx------ 1 root root 64 Feb 24 21:23 /proc/1/fd/2 -> /dev/console Fix by closing prog FDs after initialization. struct bpf_prog's themselves are kept alive through direct kernel references taken with bpf_link_get_from_fd(). Fixes: cb80ddc67152 ("bpf: Convert bpf_preload.ko to use light skeleton.") Signed-off-by: Yucong Sun <fallentree@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220225185923.2535519-1-fallentree@fb.com
2022-02-25 11:59:24 -07:00
/* Avoid taking over stdin/stdout/stderr of init process. Zeroing out
* makes skel_closenz() a no-op later in iterators_bpf__destroy().
*/
close_fd(skel->links.dump_bpf_map_fd);
skel->links.dump_bpf_map_fd = 0;
close_fd(skel->links.dump_bpf_prog_fd);
skel->links.dump_bpf_prog_fd = 0;
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
return 0;
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
out:
free_links_and_skel();
return err;
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
}
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
static int __init load(void)
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
{
int err;
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
err = load_skel();
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
if (err)
return err;
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
bpf_preload_ops = &ops;
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
return err;
}
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
static void __exit fini(void)
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
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{
bpf_preload_ops = NULL;
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
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free_links_and_skel();
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
2020-08-18 21:27:58 -07:00
}
bpf: Convert bpf_preload.ko to use light skeleton. The main change is a move of the single line #include "iterators.lskel.h" from iterators/iterators.c to bpf_preload_kern.c. Which means that generated light skeleton can be used from user space or user mode driver like iterators.c or from the kernel module or the kernel itself. The direct use of light skeleton from the kernel module simplifies the code, since UMD is no longer necessary. The libbpf.a required user space and UMD. The CO-RE in the kernel and generated "loader bpf program" used by the light skeleton are capable to perform complex loading operations traditionally provided by libbpf. In addition UMD approach was launching UMD process every time bpffs has to be mounted. With light skeleton in the kernel the bpf_preload kernel module loads bpf iterators once and pins them multiple times into different bpffs mounts. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-6-alexei.starovoitov@gmail.com
2022-02-09 16:20:01 -07:00
late_initcall(load);
module_exit(fini);
bpf: Add kernel module with user mode driver that populates bpffs. Add kernel module with user mode driver that populates bpffs with BPF iterators. $ mount bpffs /my/bpffs/ -t bpf $ ls -la /my/bpffs/ total 4 drwxrwxrwt 2 root root 0 Jul 2 00:27 . drwxr-xr-x 19 root root 4096 Jul 2 00:09 .. -rw------- 1 root root 0 Jul 2 00:27 maps.debug -rw------- 1 root root 0 Jul 2 00:27 progs.debug The user mode driver will load BPF Type Formats, create BPF maps, populate BPF maps, load two BPF programs, attach them to BPF iterators, and finally send two bpf_link IDs back to the kernel. The kernel will pin two bpf_links into newly mounted bpffs instance under names "progs.debug" and "maps.debug". These two files become human readable. $ cat /my/bpffs/progs.debug id name attached 11 dump_bpf_map bpf_iter_bpf_map 12 dump_bpf_prog bpf_iter_bpf_prog 27 test_pkt_access 32 test_main test_pkt_access test_pkt_access 33 test_subprog1 test_pkt_access_subprog1 test_pkt_access 34 test_subprog2 test_pkt_access_subprog2 test_pkt_access 35 test_subprog3 test_pkt_access_subprog3 test_pkt_access 36 new_get_skb_len get_skb_len test_pkt_access 37 new_get_skb_ifindex get_skb_ifindex test_pkt_access 38 new_get_constant get_constant test_pkt_access The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about all BPF programs currently loaded in the system. This information is unstable and will change from kernel to kernel as ".debug" suffix conveys. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
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MODULE_LICENSE("GPL");
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