linux/samples/bpf, branch v5.8

bpf, xdp, samples: Fix null pointer dereference in *_user code

2020-06-16T12:55:35Z

Memset on the pointer right after malloc can cause a NULL pointer deference if it failed to allocate memory. A simple fix is to replace malloc()/memset() pair with a simple call to calloc(). Fixes: 0fca931a6f21 ("samples/bpf: program demonstrating access to xdp_rxq_info") Signed-off-by: Gaurav Singh Signed-off-by: Daniel Borkmann Acked-by: Jesper Dangaard Brouer Acked-by: John Fastabend

samples, bpf: Refactor kprobe, tail call kern progs map definition

2020-05-19T15:13:03Z

Because the previous two commit replaced the bpf_load implementation of the user program with libbpf, the corresponding kernel program's MAP definition can be replaced with new BTF-defined map syntax. This commit only updates the samples which uses libbpf API for loading bpf program not with bpf_load. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200516040608.1377876-6-danieltimlee@gmail.com

samples, bpf: Add tracex7 test file to .gitignore

2020-05-19T15:13:00Z

This commit adds tracex7 test file (testfile.img) to .gitignore which comes from test_override_return.sh. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200516040608.1377876-5-danieltimlee@gmail.com

samples, bpf: Refactor tail call user progs with libbpf

2020-05-19T15:12:56Z

BPF tail call uses the BPF_MAP_TYPE_PROG_ARRAY type map for calling into other BPF programs and this PROG_ARRAY should be filled prior to use. Currently, samples with the PROG_ARRAY type MAP fill this program array with bpf_load. For bpf_load to fill this map, kernel BPF program must specify the section with specific format of / (e.g. SEC("socket/0")) But by using libbpf instead of bpf_load, user program can specify which programs should be added to PROG_ARRAY. The advantage of this approach is that you can selectively add only the programs you want, rather than adding all of them to PROG_ARRAY, and it's much more intuitive than the traditional approach. This commit refactors user programs with the PROG_ARRAY type MAP with libbpf instead of using bpf_load. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200516040608.1377876-4-danieltimlee@gmail.com

samples, bpf: Refactor kprobe tracing user progs with libbpf

2020-05-19T15:12:53Z

Currently, the kprobe BPF program attachment method for bpf_load is quite old. The implementation of bpf_load "directly" controls and manages(create, delete) the kprobe events of DEBUGFS. On the other hand, using using the libbpf automatically manages the kprobe event. (under bpf_link interface) By calling bpf_program__attach(_kprobe) in libbpf, the corresponding kprobe is created and the BPF program will be attached to this kprobe. To remove this, by simply invoking bpf_link__destroy will clean up the event. This commit refactors kprobe tracing programs (tracex{1~7}_user.c) with libbpf using bpf_link interface and bpf_program__attach. tracex2_kern.c, which tracks system calls (sys_*), has been modified to append prefix depending on architecture. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200516040608.1377876-3-danieltimlee@gmail.com

samples, bpf: Refactor pointer error check with libbpf

2020-05-19T15:12:49Z

Current method of checking pointer error is not user friendly. Especially the __must_check define makes this less intuitive. Since, libbpf has an API libbpf_get_error() which checks pointer error, this commit refactors existing pointer error check logic with libbpf. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200516040608.1377876-2-danieltimlee@gmail.com

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-05-15T20:48:59Z

Move the bpf verifier trace check into the new switch statement in HEAD. Resolve the overlapping changes in hinic, where bug fixes overlap the addition of VF support. Signed-off-by: David S. Miller

samples/bpf: xdp_redirect_cpu: Set MAX_CPUS according to NR_CPUS

2020-05-15T01:27:00Z

xdp_redirect_cpu is currently failing in bpf_prog_load_xattr() allocating cpu_map map if CONFIG_NR_CPUS is less than 64 since cpu_map_alloc() requires max_entries to be less than NR_CPUS. Set cpu_map max_entries according to NR_CPUS in xdp_redirect_cpu_kern.c and get currently running cpus in xdp_redirect_cpu_user.c Signed-off-by: Lorenzo Bianconi Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/374472755001c260158c4e4b22f193bdd3c56fb7.1589300442.git.lorenzo@kernel.org

samples: bpf: Fix build error

2020-05-14T19:37:39Z

GCC 10 is very strict about symbol clash, and lwt_len_hist_user contains a symbol which clashes with libbpf: /usr/bin/ld: samples/bpf/lwt_len_hist_user.o:(.bss+0x0): multiple definition of `bpf_log_buf'; samples/bpf/bpf_load.o:(.bss+0x8c0): first defined here collect2: error: ld returned 1 exit status bpf_log_buf here seems to be a leftover, so removing it. Signed-off-by: Matteo Croce Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200511113234.80722-1-mcroce@redhat.com

samples/bpf: Remove compiler warnings

2020-05-13T19:30:50Z

Commit 5fbc220862fc ("tools/libpf: Add offsetof/container_of macro in bpf_helpers.h") added macros offsetof/container_of to bpf_helpers.h. Unfortunately, it caused compilation warnings below for a few samples/bpf programs: In file included from /data/users/yhs/work/net-next/samples/bpf/sockex2_kern.c:4: In file included from /data/users/yhs/work/net-next/include/uapi/linux/in.h:24: In file included from /data/users/yhs/work/net-next/include/linux/socket.h:8: In file included from /data/users/yhs/work/net-next/include/linux/uio.h:8: /data/users/yhs/work/net-next/include/linux/kernel.h:992:9: warning: 'container_of' macro redefined [-Wmacro-redefined] ^ /data/users/yhs/work/net-next/tools/lib/bpf/bpf_helpers.h:46:9: note: previous definition is here ^ 1 warning generated. CLANG-bpf samples/bpf/sockex3_kern.o In all these cases, bpf_helpers.h is included first, followed by other standard headers. The macro container_of is defined unconditionally in kernel.h, causing the compiler warning. The fix is to move bpf_helpers.h after standard headers. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200513180223.2949987-1-yhs@fb.com