linux/tools/lib/bpf, branch v5.2

bpf, libbpf: enable recvmsg attach types

2019-06-06T23:53:12Z

Another trivial patch to libbpf in order to enable identifying and attaching programs to BPF_CGROUP_UDP{4,6}_RECVMSG by section name. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov

libbpf: Return btf_fd for load_sk_storage_btf

2019-06-01T00:03:39Z

Before this change, function load_sk_storage_btf expected that libbpf__probe_raw_btf was returning a BTF descriptor, but in fact it was returning an information about whether the probe was successful (0 or 1). load_sk_storage_btf was using that value as an argument of the close function, which was resulting in closing stdout and thus terminating the process which called that function. That bug was visible in bpftool. `bpftool feature` subcommand was always exiting too early (because of closed stdout) and it didn't display all requested probes. `bpftool -j feature` or `bpftool -p feature` were not returning a valid json object. This change renames the libbpf__probe_raw_btf function to libbpf__load_raw_btf, which now returns a BTF descriptor, as expected in load_sk_storage_btf. v2: - Fix typo in the commit message. v3: - Simplify BTF descriptor handling in bpf_object__probe_btf_* functions. - Rename libbpf__probe_raw_btf function to libbpf__load_raw_btf and return a BTF descriptor. v4: - Fix typo in the commit message. Fixes: d7c4b3980c18 ("libbpf: detect supported kernel BTF features and sanitize BTF") Signed-off-by: Michal Rostecki Acked-by: Andrii Nakryiko Acked-by: Song Liu Signed-off-by: Alexei Starovoitov

libbpf: move logging helpers into libbpf_internal.h

2019-05-16T19:47:47Z

libbpf_util.h header was recently exposed as public as a dependency of xsk.h. In addition to memory barriers, it contained logging helpers, which are not supposed to be exposed. This patch moves those into libbpf_internal.h, which is kept as an internal header. Cc: Stanislav Fomichev Cc: Daniel Borkmann Fixes: 7080da890984 ("libbpf: add libbpf_util.h to header install.") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov

libbpf: don't fail when feature probing fails

2019-05-15T23:32:19Z

Otherwise libbpf is unusable from unprivileged process with kernel.kernel.unprivileged_bpf_disabled=1. All I get is EPERM from the probes, even if I just want to open an ELF object and look at what progs/maps it has. Instead of dying on probes, let's just pr_debug the error and try to continue. Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann

libbpf: detect supported kernel BTF features and sanitize BTF

2019-05-12T23:31:20Z

Depending on used versions of libbpf, Clang, and kernel, it's possible to have valid BPF object files with valid BTF information, that still won't load successfully due to Clang emitting newer BTF features (e.g., BTF_KIND_FUNC, .BTF.ext's line_info/func_info, BTF_KIND_DATASEC, etc), that are not yet supported by older kernel. This patch adds detection of BTF features and sanitizes BPF object's BTF by substituting various supported BTF kinds, which have compatible layout: - BTF_KIND_FUNC -> BTF_KIND_TYPEDEF - BTF_KIND_FUNC_PROTO -> BTF_KIND_ENUM - BTF_KIND_VAR -> BTF_KIND_INT - BTF_KIND_DATASEC -> BTF_KIND_STRUCT Replacement is done in such a way as to preserve as much information as possible (names, sizes, etc) where possible without violating kernel's validation rules. v2->v3: - remove duplicate #defines from libbpf_util.h v1->v2: - add internal libbpf_internal.h w/ common stuff - switch SK storage BTF to use new libbpf__probe_raw_btf() Reported-by: Alexei Starovoitov Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann

libbpf: remove unnecessary cast-to-void

2019-05-06T09:35:17Z

The patches with fixes tags added a cast-to-void in the places when the return value of a function was ignored. This is not common practice in the kernel, and is therefore removed in this patch. Reported-by: Daniel Borkmann Fixes: 5750902a6e9b ("libbpf: proper XSKMAP cleanup") Fixes: 0e6741f09297 ("libbpf: fix invalid munmap call") Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann

libbpf: add libbpf_util.h to header install.

2019-05-05T07:06:59Z

The libbpf_util.h is used by xsk.h, so add it to the install headers. Reported-by: Ben Pfaff Signed-off-by: William Tu Acked-by: Yonghong Song Signed-off-by: Alexei Starovoitov

tools/bpf: fix perf build error with uClibc (seen on ARC)

2019-05-05T07:04:01Z

When build perf for ARC recently, there was a build failure due to lack of __NR_bpf. | Auto-detecting system features: | | ... get_cpuid: [ OFF ] | ... bpf: [ on ] | | # error __NR_bpf not defined. libbpf does not support your arch. ^~~~~ | bpf.c: In function 'sys_bpf': | bpf.c:66:17: error: '__NR_bpf' undeclared (first use in this function) | return syscall(__NR_bpf, cmd, attr, size); | ^~~~~~~~ | sys_bpf Signed-off-by: Vineet Gupta Acked-by: Yonghong Song Signed-off-by: Alexei Starovoitov

libbpf: proper XSKMAP cleanup

2019-05-05T06:26:22Z

The bpf_map_update_elem() function, when used on an XSKMAP, will fail if not a valid AF_XDP socket is passed as value. Therefore, this is function cannot be used to clear the XSKMAP. Instead, the bpf_map_delete_elem() function should be used for that. This patch also simplifies the code by breaking up xsk_update_bpf_maps() into three smaller functions. Reported-by: William Tu Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Signed-off-by: Björn Töpel Tested-by: William Tu Signed-off-by: Alexei Starovoitov

libbpf: fix invalid munmap call

2019-05-05T06:26:22Z

When unmapping the AF_XDP memory regions used for the rings, an invalid address was passed to the munmap() calls. Instead of passing the beginning of the memory region, the descriptor region was passed to munmap. When the userspace application tried to tear down an AF_XDP socket, the operation failed and the application would still have a reference to socket it wished to get rid of. Reported-by: William Tu Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Signed-off-by: Björn Töpel Tested-by: William Tu Signed-off-by: Alexei Starovoitov