linux/tools/lib/bpf, branch v5.8

libbpf: Fix libbpf hashmap on (I)LP32 architectures

2020-07-10T02:38:55Z

On ILP32, 64-bit result was shifted by value calculated for 32-bit long type and returned value was much outside hashmap capacity. As advised by Andrii Nakryiko, this patch uses different hashing variant for architectures with size_t shorter than long long. Fixes: e3b924224028 ("libbpf: add resizable non-thread safe internal hashmap") Signed-off-by: Jakub Bogusz Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200709225723.1069937-1-andriin@fb.com

libbpf: Adjust SEC short cut for expected attach type BPF_XDP_DEVMAP

2020-06-25T20:36:00Z

Adjust the SEC("xdp_devmap/") prog type prefix to contain a slash "/" for expected attach type BPF_XDP_DEVMAP. This is consistent with other prog types like tracing. Fixes: 2778797037a6 ("libbpf: Add SEC name for xdp programs attached to device map") Suggested-by: Andrii Nakryiko Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/159309521882.821855.6873145686353617509.stgit@firesoul

libbpf: Fix CO-RE relocs against .text section

2020-06-24T00:01:43Z

bpf_object__find_program_by_title(), used by CO-RE relocation code, doesn't return .text "BPF program", if it is a function storage for sub-programs. Because of that, any CO-RE relocation in helper non-inlined functions will fail. Fix this by searching for .text-corresponding BPF program manually. Adjust one of bpf_iter selftest to exhibit this pattern. Fixes: ddc7c3042614 ("libbpf: implement BPF CO-RE offset relocation algorithm") Reported-by: Yonghong Song Signed-off-by: Andrii Nakryiko Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200619230423.691274-1-andriin@fb.com

libbpf: Forward-declare bpf_stats_type for systems with outdated UAPI headers

2020-06-22T21:23:49Z

Systems that doesn't yet have the very latest linux/bpf.h header, enum bpf_stats_type will be undefined, causing compilation warnings. Prevents this by forward-declaring enum. Fixes: 0bee106716cf ("libbpf: Add support for command BPF_ENABLE_STATS") Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20200621031159.2279101-1-andriin@fb.com

libbpf: Support pre-initializing .bss global variables

2020-06-12T22:27:47Z

Remove invalid assumption in libbpf that .bss map doesn't have to be updated in kernel. With addition of skeleton and memory-mapped initialization image, .bss doesn't have to be all zeroes when BPF map is created, because user-code might have initialized those variables from user-space. Fixes: eba9c5f498a1 ("libbpf: Refactor global data map initialization") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200612194504.557844-1-andriin@fb.com

libbpf: Handle GCC noreturn-turned-volatile quirk

2020-06-10T11:37:02Z

Handle a GCC quirk of emitting extra volatile modifier in DWARF (and subsequently preserved in BTF by pahole) for function pointers marked as __attribute__((noreturn)). This was the way to mark such functions before GCC 2.5 added noreturn attribute. Drop such func_proto modifiers, similarly to how it's done for array (also to handle GCC quirk/bug). Such volatile attribute is emitted by GCC only, so existing selftests can't express such test. Simple repro is like this (compiled with GCC + BTF generated by pahole): struct my_struct { void __attribute__((noreturn)) (*fn)(int); }; struct my_struct a; Without this fix, output will be: struct my_struct { voidvolatile (*fn)(int); }; With the fix: struct my_struct { void (*fn)(int); }; Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion") Reported-by: Jean-Philippe Brucker Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Tested-by: Jean-Philippe Brucker Link: https://lore.kernel.org/bpf/20200610052335.2862559-1-andriin@fb.com

libbpf: Define __WORDSIZE if not available

2020-06-09T23:19:25Z

Some systems, such as Android, don't have a define for __WORDSIZE, do it in terms of __SIZEOF_LONG__, as done in perf since 2012: http://git.kernel.org/torvalds/c/3f34f6c0233ae055b5 For reference: https://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html I build tested it here and Andrii did some Travis CI build tests too. Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200608161150.GA3073@kernel.org

libbpf: Add support for bpf_link-based netns attachment

2020-06-01T22:21:03Z

Add bpf_program__attach_nets(), which uses LINK_CREATE subcommand to create an FD-based kernel bpf_link, for attach types tied to network namespace, that is BPF_FLOW_DISSECTOR for the moment. Signed-off-by: Jakub Sitnicki Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200531082846.2117903-7-jakub@cloudflare.com

libbpf: Add _GNU_SOURCE for reallocarray to ringbuf.c

2020-06-01T22:13:04Z

On systems with recent enough glibc, reallocarray compat won't kick in, so reallocarray() itself has to come from stdlib.h include. But _GNU_SOURCE is necessary to enable it. So add it. Fixes: bf99c936f947 ("libbpf: Add BPF ring buffer support") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20200601202601.2139477-1-andriin@fb.com

libbpf: Add SEC name for xdp programs attached to device map

2020-06-01T21:48:32Z

Support SEC("xdp_devmap*") as a short cut for loading the program with type BPF_PROG_TYPE_XDP and expected attach type BPF_XDP_DEVMAP. Signed-off-by: David Ahern Signed-off-by: Alexei Starovoitov Acked-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/bpf/20200529220716.75383-5-dsahern@kernel.org Signed-off-by: Alexei Starovoitov