kernel/tools/lib, branch linux-6.9.y

libbpf: don't close(-1) in multi-uprobe feature detector

2024-07-11T10:51:24Z

commit 7d0b3953f6d832daec10a0d76e2d4db405768a8b upstream. Guard close(link_fd) with extra link_fd >= 0 check to prevent close(-1). Detected by Coverity static analysis. Fixes: 04d939a2ab22 ("libbpf: detect broken PID filtering logic for multi-uprobe") Signed-off-by: Andrii Nakryiko Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20240529231212.768828-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Greg Kroah-Hartman

libbpf: detect broken PID filtering logic for multi-uprobe

2024-07-11T10:51:22Z

[ Upstream commit 04d939a2ab229a3821f04fc81f7c027842f501f1 ] Libbpf is automatically (and transparently to user) detecting multi-uprobe support in the kernel, and, if supported, uses multi-uprobes to improve USDT attachment speed. USDTs can be attached system-wide or for the specific process by PID. In the latter case, we rely on correct kernel logic of not triggering USDT for unrelated processes. As such, on older kernels that do support multi-uprobes, but still have broken PID filtering logic, we need to fall back to singular uprobes. Unfortunately, whether user is using PID filtering or not is known at the attachment time, which happens after relevant BPF programs were loaded into the kernel. Also unfortunately, we need to make a call whether to use multi-uprobes or singular uprobe for SEC("usdt") programs during BPF object load time, at which point we have no information about possible PID filtering. The distinction between single and multi-uprobes is small, but important for the kernel. Multi-uprobes get BPF_TRACE_UPROBE_MULTI attach type, and kernel internally substitiute different implementation of some of BPF helpers (e.g., bpf_get_attach_cookie()) depending on whether uprobe is multi or singular. So, multi-uprobes and singular uprobes cannot be intermixed. All the above implies that we have to make an early and conservative call about the use of multi-uprobes. And so this patch modifies libbpf's existing feature detector for multi-uprobe support to also check correct PID filtering. If PID filtering is not yet fixed, we fall back to singular uprobes for USDTs. This extension to feature detection is simple thanks to kernel's -EINVAL addition for pid < 0. Acked-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20240521163401.3005045-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpf: Avoid uninitialized value in BPF_CORE_READ_BITFIELD

2024-07-11T10:51:04Z

[ Upstream commit 009367099eb61a4fc2af44d4eb06b6b4de7de6db ] [Changes from V1: - Use a default branch in the switch statement to initialize `val'.] GCC warns that `val' may be used uninitialized in the BPF_CRE_READ_BITFIELD macro, defined in bpf_core_read.h as: [...] unsigned long long val; \ [...] \ switch (__CORE_RELO(s, field, BYTE_SIZE)) { \ case 1: val = *(const unsigned char *)p; break; \ case 2: val = *(const unsigned short *)p; break; \ case 4: val = *(const unsigned int *)p; break; \ case 8: val = *(const unsigned long long *)p; break; \ } \ [...] val; \ } \ This patch adds a default entry in the switch statement that sets `val' to zero in order to avoid the warning, and random values to be used in case __builtin_preserve_field_info returns unexpected values for BPF_FIELD_BYTE_SIZE. Tested in bpf-next master. No regressions. Signed-off-by: Jose E. Marchesi Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240508101313.16662-1-jose.marchesi@oracle.com Signed-off-by: Sasha Levin

libsubcmd: Fix parse-options memory leak

2024-06-12T09:39:21Z

[ Upstream commit 230a7a71f92212e723fa435d4ca5922de33ec88a ] If a usage string is built in parse_options_subcommand, also free it. Fixes: 901421a5bdf605d2 ("perf tools: Remove subcmd dependencies on strbuf") Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Josh Poimboeuf Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20240509052015.1914670-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

libbpf: fix feature detectors when using token_fd

2024-05-30T07:45:02Z

[ Upstream commit 1de27bba6d50a909647f304eadc0f7c59a842a50 ] Adjust `union bpf_attr` size passed to kernel in two feature-detecting functions to take into account prog_token_fd field. Libbpf is avoiding memset()'ing entire `union bpf_attr` by only using minimal set of bpf_attr's fields. Two places have been missed when wiring BPF token support in libbpf's feature detection logic. Fix them trivially. Fixes: f3dcee938f48 ("libbpf: Wire up token_fd into feature probing logic") Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20240513180804.403775-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

libbpf: Fix error message in attach_kprobe_multi

2024-05-30T07:44:30Z

[ Upstream commit 7c13ef16e87ac2e44d16c0468b1191bceb06f95c ] We just failed to retrieve pattern, so we need to print spec instead. Fixes: ddc6b04989eb ("libbpf: Add bpf_program__attach_kprobe_multi_opts function") Reported-by: Andrii Nakryiko Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240502075541.1425761-2-jolsa@kernel.org Signed-off-by: Sasha Levin

libbpf: Prevent null-pointer dereference when prog to load has no BTF

2024-05-30T07:44:11Z

[ Upstream commit 9bf48fa19a4b1d186e08b20bf7e5de26a15644fb ] In bpf_objec_load_prog(), there's no guarantee that obj->btf is non-NULL when passing it to btf__fd(), and this function does not perform any check before dereferencing its argument (as bpf_object__btf_fd() used to do). As a consequence, we get segmentation fault errors in bpftool (for example) when trying to load programs that come without BTF information. v2: Keep btf__fd() in the fix instead of reverting to bpf_object__btf_fd(). Fixes: df7c3f7d3a3d ("libbpf: make uniform use of btf__fd() accessor inside libbpf") Suggested-by: Andrii Nakryiko Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240314150438.232462-1-qmo@kernel.org Signed-off-by: Sasha Levin

Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2024-03-26T11:55:18Z

Daniel Borkmann says: ==================== pull-request: bpf 2024-03-25 The following pull-request contains BPF updates for your *net* tree. We've added 17 non-merge commits during the last 12 day(s) which contain a total of 19 files changed, 184 insertions(+), 61 deletions(-). The main changes are: 1) Fix an arm64 BPF JIT bug in BPF_LDX_MEMSX implementation's offset handling found via test_bpf module, from Puranjay Mohan. 2) Various fixups to the BPF arena code in particular in the BPF verifier and around BPF selftests to match latest corresponding LLVM implementation, from Puranjay Mohan and Alexei Starovoitov. 3) Fix xsk to not assume that metadata is always requested in TX completion, from Stanislav Fomichev. 4) Fix riscv BPF JIT's kfunc parameter incompatibility between BPF and the riscv ABI which requires sign-extension on int/uint, from Pu Lehui. 5) Fix s390x BPF JIT's bpf_plt pointer arithmetic which triggered a crash when testing struct_ops, from Ilya Leoshkevich. 6) Fix libbpf's arena mmap handling which had incorrect u64-to-pointer cast on 32-bit architectures, from Andrii Nakryiko. 7) Fix libbpf to define MFD_CLOEXEC when not available, from Arnaldo Carvalho de Melo. 8) Fix arm64 BPF JIT implementation for 32bit unconditional bswap which resulted in an incorrect swap as indicated by test_bpf, from Artem Savkov. 9) Fix BPF man page build script to use silent mode, from Hangbin Liu. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: riscv, bpf: Fix kfunc parameters incompatibility between bpf and riscv abi bpf: verifier: reject addr_space_cast insn without arena selftests/bpf: verifier_arena: fix mmap address for arm64 bpf: verifier: fix addr_space_cast from as(1) to as(0) libbpf: Define MFD_CLOEXEC if not available arm64: bpf: fix 32bit unconditional bswap bpf, arm64: fix bug in BPF_LDX_MEMSX libbpf: fix u64-to-pointer cast on 32-bit arches s390/bpf: Fix bpf_plt pointer arithmetic xsk: Don't assume metadata is always requested in TX completion selftests/bpf: Add arena test case for 4Gbyte corner case selftests/bpf: Remove hard coded PAGE_SIZE macro. libbpf, selftests/bpf: Adjust libbpf, bpftool, selftests to match LLVM bpf: Clarify bpf_arena comments. MAINTAINERS: Update email address for Quentin Monnet scripts/bpf_doc: Use silent mode when exec make cmd bpf: Temporarily disable atomic operations in BPF arena ==================== Link: https://lore.kernel.org/r/20240325213520.26688-1-daniel@iogearbox.net Signed-off-by: Paolo Abeni

Merge tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2024-03-21T21:41:00Z

Pull Kbuild updates from Masahiro Yamada: - Generate a list of built DTB files (arch/*/boot/dts/dtbs-list) - Use more threads when building Debian packages in parallel - Fix warnings shown during the RPM kernel package uninstallation - Change OBJECT_FILES_NON_STANDARD_*.o etc. to take a relative path to Makefile - Support GCC's -fmin-function-alignment flag - Fix a null pointer dereference bug in modpost - Add the DTB support to the RPM package - Various fixes and cleanups in Kconfig * tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (67 commits) kconfig: tests: test dependency after shuffling choices kconfig: tests: add a test for randconfig with dependent choices kconfig: tests: support KCONFIG_SEED for the randconfig runner kbuild: rpm-pkg: add dtb files in kernel rpm kconfig: remove unneeded menu_is_visible() call in conf_write_defconfig() kconfig: check prompt for choice while parsing kconfig: lxdialog: remove unused dialog colors kconfig: lxdialog: fix button color for blackbg theme modpost: fix null pointer dereference kbuild: remove GCC's default -Wpacked-bitfield-compat flag kbuild: unexport abs_srctree and abs_objtree kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1 kconfig: remove named choice support kconfig: use linked list in get_symbol_str() to iterate over menus kconfig: link menus to a symbol kbuild: fix inconsistent indentation in top Makefile kbuild: Use -fmin-function-alignment when available alpha: merge two entries for CONFIG_ALPHA_GAMMA alpha: merge two entries for CONFIG_ALPHA_EV4 kbuild: change DTC_FLAGS_.o to take the path relative to $(obj) ...

libbpf: Define MFD_CLOEXEC if not available

2024-03-21T18:27:17Z

Since its going directly to the syscall to avoid not having memfd_create() available in some systems, do the same for its MFD_CLOEXEC flags, defining it if not available. This fixes the build in those systems, noticed while building perf on a set of build containers. Fixes: 9fa5e1a180aa639f ("libbpf: Call memfd_create() syscall directly") Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/ZfxZ9nCyKvwmpKkE@x1