BMC/Intel-BMC/linux.git/tools/lib, branch dev-5.14-intel

libbpf: Fix segfault in static linker for objects without BTF

2021-10-07T05:53:13+00:00

[ Upstream commit bcfd367c2839f2126c048fe59700ec1b538e2b06 ] When a BPF object is compiled without BTF info (without -g), trying to link such objects using bpftool causes a SIGSEGV due to btf__get_nr_types accessing obj->btf which is NULL. Fix this by checking for the NULL pointer, and return error. Reproducer: $ cat a.bpf.c extern int foo(void); int bar(void) { return foo(); } $ cat b.bpf.c int foo(void) { return 0; } $ clang -O2 -target bpf -c a.bpf.c $ clang -O2 -target bpf -c b.bpf.c $ bpftool gen obj out a.bpf.o b.bpf.o Segmentation fault (core dumped) After fix: $ bpftool gen obj out a.bpf.o b.bpf.o libbpf: failed to find BTF info for object 'a.bpf.o' Error: failed to link 'a.bpf.o': Unknown error -22 (-22) Fixes: a46349227cd8 (libbpf: Add linker extern resolution support for functions and global variables) Signed-off-by: Kumar Kartikeya Dwivedi Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20210924023725.70228-1-memxor@gmail.com Signed-off-by: Sasha Levin

libperf evsel: Make use of FD robust.

2021-09-30T08:13:07+00:00

[ Upstream commit aba5daeb645181ee5a046bc00c231fd045882aaa ] FD uses xyarray__entry that may return NULL if an index is out of bounds. If NULL is returned then a segv happens as FD unconditionally dereferences the pointer. This was happening in a case of with perf iostat as shown below. The fix is to make FD an "int*" rather than an int and handle the NULL case as either invalid input or a closed fd. $ sudo gdb --args perf stat --iostat list ... Breakpoint 1, perf_evsel__alloc_fd (evsel=0x5555560951a0, ncpus=1, nthreads=1) at evsel.c:50 50 { (gdb) bt #0 perf_evsel__alloc_fd (evsel=0x5555560951a0, ncpus=1, nthreads=1) at evsel.c:50 #1 0x000055555585c188 in evsel__open_cpu (evsel=0x5555560951a0, cpus=0x555556093410, threads=0x555556086fb0, start_cpu=0, end_cpu=1) at util/evsel.c:1792 #2 0x000055555585cfb2 in evsel__open (evsel=0x5555560951a0, cpus=0x0, threads=0x555556086fb0) at util/evsel.c:2045 #3 0x000055555585d0db in evsel__open_per_thread (evsel=0x5555560951a0, threads=0x555556086fb0) at util/evsel.c:2065 #4 0x00005555558ece64 in create_perf_stat_counter (evsel=0x5555560951a0, config=0x555555c34700 , target=0x555555c2f1c0 , cpu=0) at util/stat.c:590 #5 0x000055555578e927 in __run_perf_stat (argc=1, argv=0x7fffffffe4a0, run_idx=0) at builtin-stat.c:833 #6 0x000055555578f3c6 in run_perf_stat (argc=1, argv=0x7fffffffe4a0, run_idx=0) at builtin-stat.c:1048 #7 0x0000555555792ee5 in cmd_stat (argc=1, argv=0x7fffffffe4a0) at builtin-stat.c:2534 #8 0x0000555555835ed3 in run_builtin (p=0x555555c3f540 , argc=3, argv=0x7fffffffe4a0) at perf.c:313 #9 0x0000555555836154 in handle_internal_command (argc=3, argv=0x7fffffffe4a0) at perf.c:365 #10 0x000055555583629f in run_argv (argcp=0x7fffffffe2ec, argv=0x7fffffffe2e0) at perf.c:409 #11 0x0000555555836692 in main (argc=3, argv=0x7fffffffe4a0) at perf.c:539 ... (gdb) c Continuing. Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (uncore_iio_0/event=0x83,umask=0x04,ch_mask=0xF,fc_mask=0x07/). /bin/dmesg | grep -i perf may provide additional information. Program received signal SIGSEGV, Segmentation fault. 0x00005555559b03ea in perf_evsel__close_fd_cpu (evsel=0x5555560951a0, cpu=1) at evsel.c:166 166 if (FD(evsel, cpu, thread) >= 0) v3. fixes a bug in perf_evsel__run_ioctl where the sense of a branch was backward. Signed-off-by: Ian Rogers Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20210918054440.2350466-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

libbpf: Fix race when pinning maps in parallel

2021-09-18T11:43:43+00:00

[ Upstream commit 043c5bb3c4f43670ab4fea0b847373ab42d25f3e ] When loading in parallel multiple programs which use the same to-be pinned map, it is possible that two instances of the loader will call bpf_object__create_maps() at the same time. If the map doesn't exist when both instances call bpf_object__reuse_map(), then one of the instances will fail with EEXIST when calling bpf_map__pin(). Fix the race by retrying reusing a map if bpf_map__pin() returns EEXIST. The fix is similar to the one in iproute2: e4c4685fd6e4 ("bpf: Fix race condition with map pinning"). Before retrying the pinning, we don't do any special cleaning of an internal map state. The closer code inspection revealed that it's not required: - bpf_object__create_map(): map->inner_map is destroyed after a successful call, map->fd is closed if pinning fails. - bpf_object__populate_internal_map(): created map elements is destroyed upon close(map->fd). - init_map_slots(): slots are freed after their initialization. Signed-off-by: Martynas Pumputis Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210726152001.34845-1-m@lambda.lt Signed-off-by: Sasha Levin

libbpf: Fix reuse of pinned map on older kernel

2021-09-18T11:43:36+00:00

[ Upstream commit 97eb31384af943d6b97eb5947262cee4ef25cb87 ] When loading a BPF program with a pinned map, the loader checks whether the pinned map can be reused, i.e. their properties match. To derive such of the pinned map, the loader invokes BPF_OBJ_GET_INFO_BY_FD and then does the comparison. Unfortunately, on < 4.12 kernels the BPF_OBJ_GET_INFO_BY_FD is not available, so loading the program fails with the following error: libbpf: failed to get map info for map FD 5: Invalid argument libbpf: couldn't reuse pinned map at '/sys/fs/bpf/tc/globals/cilium_call_policy': parameter mismatch" libbpf: map 'cilium_call_policy': error reusing pinned map libbpf: map 'cilium_call_policy': failed to create: Invalid argument(-22) libbpf: failed to load object 'bpf_overlay.o' To fix this, fallback to derivation of the map properties via /proc/$PID/fdinfo/$MAP_FD if BPF_OBJ_GET_INFO_BY_FD fails with EINVAL, which can be used as an indicator that the kernel doesn't support the latter. Signed-off-by: Martynas Pumputis Signed-off-by: Andrii Nakryiko Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20210712125552.58705-1-m@lambda.lt Signed-off-by: Sasha Levin

libbpf: Re-build libbpf.so when libbpf.map changes

2021-09-15T08:02:23+00:00

[ Upstream commit 61c7aa5020e98ac2fdcf07d07eec1baf2e9f0a08 ] Ensure libbpf.so is re-built whenever libbpf.map is modified. Without this, changes to libbpf.map are not detected and versioned symbols mismatch error will be reported until `make clean && make` is used, which is a suboptimal developer experience. Fixes: 306b267cb3c4 ("libbpf: Verify versioned symbols") Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20210815070609.987780-8-andrii@kernel.org Signed-off-by: Sasha Levin

libbpf: Return non-null error on failures in libbpf_find_prog_btf_id()

2021-09-15T08:02:16+00:00

[ Upstream commit 6d2d73cdd673d493f9f3751188757129b1d23fb7 ] Variable "err" is initialised to -EINVAL so that this error code is returned when something goes wrong in libbpf_find_prog_btf_id(). However, a recent change in the function made use of the variable in such a way that it is set to 0 if retrieving linear information on the program is successful, and this 0 value remains if we error out on failures at later stages. Let's fix this by setting err to -EINVAL later in the function. Fixes: e9fc3ce99b34 ("libbpf: Streamline error reporting for high-level APIs") Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210729162028.29512-2-quentin@isovalent.com Signed-off-by: Sasha Levin

libbpf: Fix removal of inner map in bpf_object__create_map

2021-09-15T08:02:12+00:00

[ Upstream commit a21ab4c59e09c2a9994a6e393b7484e3b3f78a99 ] If creating an outer map of a BTF-defined map-in-map fails (via bpf_object__create_map()), then the previously created its inner map won't be destroyed. Fix this by ensuring that the destroy routines are not bypassed in the case of a failure. Fixes: 646f02ffdd49c ("libbpf: Add BTF-defined map-in-map support") Reported-by: Andrii Nakryiko Signed-off-by: Martynas Pumputis Signed-off-by: Andrii Nakryiko Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20210719173838.423148-2-m@lambda.lt Signed-off-by: Sasha Levin

libbpf: Fix the possible memory leak on error

2021-09-15T08:02:11+00:00

[ Upstream commit 18353c87e0e0440d4c7c746ed740738bbc1b538e ] If the strdup() fails then we need to call bpf_object__close(obj) to avoid a resource leak. Fixes: 166750bc1dd2 ("libbpf: Support libbpf-provided extern variables") Signed-off-by: Shuyi Cheng Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/1626180159-112996-3-git-send-email-chengshuyi@linux.alibaba.com Signed-off-by: Sasha Levin

libbpf: Do not close un-owned FD 0 on errors

2021-08-06T23:39:15+00:00

Before this patch, btf_new() was liable to close an arbitrary FD 0 if BTF parsing failed. This was because: * btf->fd was initialized to 0 through the calloc() * btf__free() (in the `done` label) closed any FDs >= 0 * btf->fd is left at 0 if parsing fails This issue was discovered on a system using libbpf v0.3 (without BTF_KIND_FLOAT support) but with a kernel that had BTF_KIND_FLOAT types in BTF. Thus, parsing fails. While this patch technically doesn't fix any issues b/c upstream libbpf has BTF_KIND_FLOAT support, it'll help prevent issues in the future if more BTF types are added. It also allow the fix to be backported to older libbpf's. Fixes: 3289959b97ca ("libbpf: Support BTF loading and raw data output in both endianness") Signed-off-by: Daniel Xu Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/5969bb991adedb03c6ae93e051fd2a00d293cf25.1627513670.git.dxu@dxuuu.xyz

libbpf: Fix probe for BPF_PROG_TYPE_CGROUP_SOCKOPT

2021-08-06T23:38:52+00:00

This patch fixes the probe for BPF_PROG_TYPE_CGROUP_SOCKOPT, so the probe reports accurate results when used by e.g. bpftool. Fixes: 4cdbfb59c44a ("libbpf: support sockopt hooks") Signed-off-by: Robin Gögge Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20210728225825.2357586-1-r.goegge@gmail.com