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2023-01-23libbpf: Define powerpc syscall regs spec in bpf_tracing.hAndrii Nakryiko
Define explicit table of registers used for syscall argument passing. Note that 7th arg is supported on 32-bit powerpc architecture, by not on powerpc64. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230120200914.3008030-20-andrii@kernel.org
2023-01-23libbpf: Define mips syscall regs spec in bpf_tracing.hAndrii Nakryiko
Define explicit table of registers used for syscall argument passing. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230120200914.3008030-19-andrii@kernel.org
2023-01-23libbpf: Define arm64 syscall regs spec in bpf_tracing.hAndrii Nakryiko
Define explicit table of registers used for syscall argument passing. We need PT_REGS_PARM1_[CORE_]SYSCALL macros overrides, similarly to s390x, due to orig_x0 not being present in UAPI's pt_regs, so we need to utilize BPF CO-RE and custom pt_regs___arm64 definition. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Alan Maguire <alan.maguire@oracle.com> # arm64 Link: https://lore.kernel.org/bpf/20230120200914.3008030-18-andrii@kernel.org
2023-01-23libbpf: Define arm syscall regs spec in bpf_tracing.hAndrii Nakryiko
Define explicit table of registers used for syscall argument passing. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230120200914.3008030-17-andrii@kernel.org
2023-01-23libbpf: Define s390x syscall regs spec in bpf_tracing.hAndrii Nakryiko
Define explicit table of registers used for syscall argument passing. Note that we need custom overrides for PT_REGS_PARM1_[CORE_]SYSCALL macros due to the need to use BPF CO-RE and custom local pt_regs definitions to fetch orig_gpr2, storing 1st argument. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> # s390x Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/bpf/20230120200914.3008030-16-andrii@kernel.org
2023-01-23libbpf: Define i386 syscall regs spec in bpf_tracing.hAndrii Nakryiko
Define explicit table of registers used for syscall argument passing. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230120200914.3008030-15-andrii@kernel.org
2023-01-23libbpf: Define x86-64 syscall regs spec in bpf_tracing.hAndrii Nakryiko
Define explicit table of registers used for syscall argument passing. Remove now unnecessary overrides of PT_REGS_PARM5_[CORE_]SYSCALL macros. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230120200914.3008030-14-andrii@kernel.org
2023-01-23libbpf: Improve syscall tracing support in bpf_tracing.hAndrii Nakryiko
Set up generic support in bpf_tracing.h for up to 7 syscall arguments tracing with BPF_KSYSCALL, which seems to be the limit according to syscall(2) manpage. Also change the way that syscall convention is specified to be more explicit. Subsequent patches will adjust and define proper per-architecture syscall conventions. __PT_PARM1_SYSCALL_REG through __PT_PARM6_SYSCALL_REG is added temporarily to keep everything working before each architecture has syscall reg tables defined. They will be removed afterwards. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Alan Maguire <alan.maguire@oracle.com> # arm64 Link: https://lore.kernel.org/bpf/20230120200914.3008030-13-andrii@kernel.org
2023-01-23libbpf: Add BPF_UPROBE and BPF_URETPROBE macro aliasesAndrii Nakryiko
Add BPF_UPROBE and BPF_URETPROBE macros, aliased to BPF_KPROBE and BPF_KRETPROBE, respectively. This makes uprobe-based BPF program code much less confusing, especially to people new to tracing, at no cost in terms of maintainability. We'll use this macro in selftests in subsequent patch. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230120200914.3008030-11-andrii@kernel.org
2023-01-23libbpf: Complete LoongArch (loongarch) spec in bpf_tracing.hAndrii Nakryiko
Add PARM6 through PARM8 definitions. Add kernel docs link describing ABI for LoongArch. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230120200914.3008030-10-andrii@kernel.org
2023-01-23libbpf: Fix and complete ARC spec in bpf_tracing.hAndrii Nakryiko
Add PARM6 through PARM8 definitions. Also fix frame pointer (FP) register definition. Also leave a link to where to find ABI spec. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230120200914.3008030-9-andrii@kernel.org
2023-01-23libbpf: Complete riscv arch spec in bpf_tracing.hAndrii Nakryiko
Add PARM6 through PARM8 definitions for RISC V (riscv) arch. Leave the link for ABI doc for future reference. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Pu Lehui <pulehui@huawei.com> # RISC-V Link: https://lore.kernel.org/bpf/20230120200914.3008030-8-andrii@kernel.org
2023-01-23libbpf: Complete sparc spec in bpf_tracing.hAndrii Nakryiko
Add PARM6 definition for sparc architecture. Leave a link to calling convention documentation. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230120200914.3008030-7-andrii@kernel.org
2023-01-23libbpf: Complete powerpc spec in bpf_tracing.hAndrii Nakryiko
Add definitions of PARM6 through PARM8 for powerpc architecture. Add also a link to a functiona call sequence documentation for future reference. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230120200914.3008030-6-andrii@kernel.org
2023-01-23libbpf: Complete mips spec in bpf_tracing.hAndrii Nakryiko
Add registers for PARM6 through PARM8. Add a link to an ABI. We don't distinguish between O32, N32, and N64, so document that we assume N64 right now. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230120200914.3008030-5-andrii@kernel.org
2023-01-23libbpf: Fix arm and arm64 specs in bpf_tracing.hAndrii Nakryiko
Remove invalid support for PARM5 on 32-bit arm, as per ABI. Add three more argument registers for arm64. Also leave links to ABI specs for future reference. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Alan Maguire <alan.maguire@oracle.com> # arm64 Link: https://lore.kernel.org/bpf/20230120200914.3008030-4-andrii@kernel.org
2023-01-23libbpf: Add 6th argument support for x86-64 in bpf_tracing.hAndrii Nakryiko
Add r9 as register containing 6th argument on x86-64 architecture, as per its ABI. Add also a link to a page describing ABI for easier future reference. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230120200914.3008030-3-andrii@kernel.org
2023-01-23libbpf: Add support for fetching up to 8 arguments in kprobesAndrii Nakryiko
Add BPF_KPROBE() and PT_REGS_PARMx() support for up to 8 arguments, if target architecture supports this. Currently all architectures are limited to only 5 register-placed arguments, which is limiting even on x86-64. This patch adds generic macro machinery to support up to 8 arguments both when explicitly fetching it from pt_regs through PT_REGS_PARMx() macros, as well as more ergonomic access in BPF_KPROBE(). Also, for i386 architecture we now don't have to define fake PARM4 and PARM5 definitions, they will be generically substituted, just like for PARM6 through PARM8. Subsequent patches will fill out architecture-specific definitions, where appropriate. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Alan Maguire <alan.maguire@oracle.com> # arm64 Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> # s390x Link: https://lore.kernel.org/bpf/20230120200914.3008030-2-andrii@kernel.org
2023-01-13libbpf: Replace '.' with '_' in legacy kprobe event nameMenglong Dong
'.' is not allowed in the event name of kprobe. Therefore, we will get a EINVAL if the kernel function name has a '.' in legacy kprobe attach case, such as 'icmp_reply.constprop.0'. In order to adapt this case, we need to replace the '.' with other char in gen_kprobe_legacy_event_name(). And I use '_' for this propose. Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Link: https://lore.kernel.org/bpf/20230113093427.1666466-1-imagedong@tencent.com
2023-01-10libbpf: Fix map creation flags sanitizationLudovic L'Hours
As BPF_F_MMAPABLE flag is now conditionnaly set (by map_is_mmapable), it should not be toggled but disabled if not supported by kernel. Fixes: 4fcac46c7e10 ("libbpf: only add BPF_F_MMAPABLE flag for data maps with global vars") Signed-off-by: Ludovic L'Hours <ludovic.lhours@gmail.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230108182018.24433-1-ludovic.lhours@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-01-06libbpf: Poison strlcpy()Rong Tao
Since commit 9fc205b413b3("libbpf: Add sane strncpy alternative and use it internally") introduce libbpf_strlcpy(), thus add strlcpy() to a poison list to prevent accidental use of it. Signed-off-by: Rong Tao <rongtao@cestc.cn> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/tencent_5695A257C4D16B4413036BA1DAACDECB0B07@qq.com
2023-01-04Merge tag 'for-netdev' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== bpf-next 2023-01-04 We've added 45 non-merge commits during the last 21 day(s) which contain a total of 50 files changed, 1454 insertions(+), 375 deletions(-). The main changes are: 1) Fixes, improvements and refactoring of parts of BPF verifier's state equivalence checks, from Andrii Nakryiko. 2) Fix a few corner cases in libbpf's BTF-to-C converter in particular around padding handling and enums, also from Andrii Nakryiko. 3) Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata, from Christian Ehrig. 4) Improve x86 JIT's codegen for PROBE_MEM runtime error checks, from Dave Marchevsky. 5) Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers, from Jiri Olsa. 6) Add proper documentation for BPF_MAP_TYPE_SOCK{MAP,HASH} maps, from Maryam Tahhan. 7) Improvements in libbpf's btf_parse_elf error handling, from Changbin Du. 8) Bigger batch of improvements to BPF tracing code samples, from Daniel T. Lee. 9) Add LoongArch support to libbpf's bpf_tracing helper header, from Hengqi Chen. 10) Fix a libbpf compiler warning in perf_event_open_probe on arm32, from Khem Raj. 11) Optimize bpf_local_storage_elem by removing 56 bytes of padding, from Martin KaFai Lau. 12) Use pkg-config to locate libelf for resolve_btfids build, from Shen Jiamin. 13) Various libbpf improvements around API documentation and errno handling, from Xin Liu. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (45 commits) libbpf: Return -ENODATA for missing btf section libbpf: Add LoongArch support to bpf_tracing.h libbpf: Restore errno after pr_warn. libbpf: Added the description of some API functions libbpf: Fix invalid return address register in s390 samples/bpf: Use BPF_KSYSCALL macro in syscall tracing programs samples/bpf: Fix tracex2 by using BPF_KSYSCALL macro samples/bpf: Change _kern suffix to .bpf with syscall tracing program samples/bpf: Use vmlinux.h instead of implicit headers in syscall tracing program samples/bpf: Use kyscall instead of kprobe in syscall tracing program bpf: rename list_head -> graph_root in field info types libbpf: fix errno is overwritten after being closed. bpf: fix regs_exact() logic in regsafe() to remap IDs correctly bpf: perform byte-by-byte comparison only when necessary in regsafe() bpf: reject non-exact register type matches in regsafe() bpf: generalize MAYBE_NULL vs non-MAYBE_NULL rule bpf: reorganize struct bpf_reg_state fields bpf: teach refsafe() to take into account ID remapping bpf: Remove unused field initialization in bpf's ctl_table selftests/bpf: Add jit probe_mem corner case tests to s390x denylist ... ==================== Link: https://lore.kernel.org/r/20230105000926.31350-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-01-03libbpf: Return -ENODATA for missing btf sectionChangbin Du
As discussed before, return -ENODATA (No data available) would be more meaningful than ENOENT (No such file or directory). Suggested-by: Leo Yan <leo.yan@linaro.org> Signed-off-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221231151436.6541-1-changbin.du@gmail.com
2023-01-03libbpf: Add LoongArch support to bpf_tracing.hHengqi Chen
Add PT_REGS macros for LoongArch ([0]). [0]: https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Huacai Chen <chenhuacai@loongson.cn> Link: https://lore.kernel.org/bpf/20221231100757.3177034-1-hengqi.chen@gmail.com
2022-12-29libbpf: Restore errno after pr_warn.Alexei Starovoitov
pr_warn calls into user-provided callback, which can clobber errno, so `errno = saved_errno` should happen after pr_warn. Fixes: 07453245620c ("libbpf: fix errno is overwritten after being closed.") Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-12-29libbpf: Added the description of some API functionsXin Liu
Currently, many API functions are not described in the document. Add add API description of the following four API functions: - libbpf_set_print; - bpf_object__open; - bpf_object__load; - bpf_object__close. Signed-off-by: Xin Liu <liuxin350@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221224112058.12038-1-liuxin350@huawei.com
2022-12-29libbpf: Fix invalid return address register in s390Daniel T. Lee
There is currently an invalid register mapping in the s390 return address register. As the manual[1] states, the return address can be found at r14. In bpf_tracing.h, the s390 registers were named gprs(general purpose registers). This commit fixes the problem by correcting the mistyped mapping. [1]: https://uclibc.org/docs/psABI-s390x.pdf#page=14 Fixes: 3cc31d794097 ("libbpf: Normalize PT_REGS_xxx() macro definitions") Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221224071527.2292-7-danieltimlee@gmail.com
2022-12-28libbpf: fix errno is overwritten after being closed.Xin Liu
In the ensure_good_fd function, if the fcntl function succeeds but the close function fails, ensure_good_fd returns a normal fd and sets errno, which may cause users to misunderstand. The close failure is not a serious problem, and the correct FD has been handed over to the upper-layer application. Let's restore errno here. Signed-off-by: Xin Liu <liuxin350@huawei.com> Link: https://lore.kernel.org/r/20221223133618.10323-1-liuxin350@huawei.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-12-21libbpf: start v1.2 development cycleAndrii Nakryiko
Bump current version for new development cycle to v1.2. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20221221180049.853365-1-andrii@kernel.org Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-12-20libbpf: Show error info about missing ".BTF" sectionChangbin Du
Show the real problem instead of just saying "No such file or directory". Now will print below info: libbpf: failed to find '.BTF' ELF section in /home/changbin/work/linux/vmlinux Error: failed to load BTF from /home/changbin/work/linux/vmlinux: No such file or directory Signed-off-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221217223509.88254-2-changbin.du@gmail.com
2022-12-20libbpf: Fix build warning on ref_ctr_off for 32-bit architecturesKhem Raj
Clang warns on 32-bit ARM on this comparision: libbpf.c:10497:18: error: result of comparison of constant 4294967296 with expression of type 'size_t' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare] if (ref_ctr_off >= (1ULL << PERF_UPROBE_REF_CTR_OFFSET_BITS)) ~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Typecast ref_ctr_off to __u64 in the check conditional, it is false on 32bit anyways. Signed-off-by: Khem Raj <raj.khem@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221219191526.296264-1-raj.khem@gmail.com
2022-12-16Merge remote-tracking branch 'torvalds/master' into perf/coreArnaldo Carvalho de Melo
To resolve a trivial merge conflict with c302378bc157f6a7 ("libbpf: Hashmap interface update to allow both long and void* keys/values"), where a function present upstream was removed in the perf tools development tree. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-12-15libbpf: Fix btf_dump's packed struct determinationAndrii Nakryiko
Fix bug in btf_dump's logic of determining if a given struct type is packed or not. The notion of "natural alignment" is not needed and is even harmful in this case, so drop it altogether. The biggest difference in btf_is_struct_packed() compared to its original implementation is that we don't really use btf__align_of() to determine overall alignment of a struct type (because it could be 1 for both packed and non-packed struct, depending on specifci field definitions), and just use field's actual alignment to calculate whether any field is requiring packing or struct's size overall necessitates packing. Add two simple test cases that demonstrate the difference this change would make. Fixes: ea2ce1ba99aa ("libbpf: Fix BTF-to-C converter's padding logic") Reported-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20221215183605.4149488-1-andrii@kernel.org
2022-12-15libbpf: Fix BTF-to-C converter's padding logicAndrii Nakryiko
Turns out that btf_dump API doesn't handle a bunch of tricky corner cases, as reported by Per, and further discovered using his testing Python script ([0]). This patch revamps btf_dump's padding logic significantly, making it more correct and also avoiding unnecessary explicit padding, where compiler would pad naturally. This overall topic turned out to be very tricky and subtle, there are lots of subtle corner cases. The comments in the code tries to give some clues, but comments themselves are supposed to be paired with good understanding of C alignment and padding rules. Plus some experimentation to figure out subtle things like whether `long :0;` means that struct is now forced to be long-aligned (no, it's not, turns out). Anyways, Per's script, while not completely correct in some known situations, doesn't show any obvious cases where this logic breaks, so this is a nice improvement over the previous state of this logic. Some selftests had to be adjusted to accommodate better use of natural alignment rules, eliminating some unnecessary padding, or changing it to `type: 0;` alignment markers. Note also that for when we are in between bitfields, we emit explicit bit size, while otherwise we use `: 0`, this feels much more natural in practice. Next patch will add few more test cases, found through randomized Per's script. [0] https://lore.kernel.org/bpf/85f83c333f5355c8ac026f835b18d15060725fcb.camel@ericsson.com/ Reported-by: Per Sundström XP <per.xp.sundstrom@ericsson.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20221212211505.558851-6-andrii@kernel.org
2022-12-15libbpf: Fix btf__align_of() by taking into account field offsetsAndrii Nakryiko
btf__align_of() is supposed to be return alignment requirement of a requested BTF type. For STRUCT/UNION it doesn't always return correct value, because it calculates alignment only based on field types. But for packed structs this is not enough, we need to also check field offsets and struct size. If field offset isn't aligned according to field type's natural alignment, then struct must be packed. Similarly, if struct size is not a multiple of struct's natural alignment, then struct must be packed as well. This patch fixes this issue precisely by additionally checking these conditions. Fixes: 3d208f4ca111 ("libbpf: Expose btf__align_of() API") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20221212211505.558851-5-andrii@kernel.org
2022-12-15libbpf: Handle non-standardly sized enums better in BTF-to-C dumperAndrii Nakryiko
Turns out C allows to force enum to be 1-byte or 8-byte explicitly using mode(byte) or mode(word), respecticely. Linux sources are using this in some cases. This is imporant to handle correctly, as enum size determines corresponding fields in a struct that use that enum type. And if enum size is incorrect, this will lead to invalid struct layout. So add mode(byte) and mode(word) attribute support to btf_dump APIs. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20221212211505.558851-3-andrii@kernel.org
2022-12-15libbpf: Fix single-line struct definition output in btf_dumpAndrii Nakryiko
btf_dump APIs emit unnecessary tabs when emitting struct/union definition that fits on the single line. Before this patch we'd get: struct blah {<tab>}; This patch fixes this and makes sure that we get more natural: struct blah {}; Fixes: 44a726c3f23c ("bpftool: Print newline before '}' for struct with padding only fields") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20221212211505.558851-2-andrii@kernel.org
2022-12-14libbpf: Optimized return value in libbpf_strerror when errno is libbpf errnoXin Liu
This is a small improvement in libbpf_strerror. When libbpf_strerror is used to obtain the system error description, if the length of the buf is insufficient, libbpf_sterror returns ERANGE and sets errno to ERANGE. However, this processing is not performed when the error code customized by libbpf is obtained. Make some minor improvements here, return -ERANGE and set errno to ERANGE when buf is not enough for custom description. Signed-off-by: Xin Liu <liuxin350@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20221210082045.233697-1-liuxin350@huawei.com
2022-12-06libbpf: Parse usdt args without offset on x86 (e.g. 8@(%rsp))Timo Hunziker
Parse USDT arguments like "8@(%rsp)" on x86. These are emmited by SystemTap. The argument syntax is similar to the existing "memory dereference case" but the offset left out as it's zero (i.e. read the value from the address in the register). We treat it the same as the the "memory dereference case", but set the offset to 0. I've tested that this fixes the "unrecognized arg #N spec: 8@(%rsp).." error I've run into when attaching to a probe with such an argument. Attaching and reading the correct argument values works. Something similar might be needed for the other supported architectures. [0] Closes: https://github.com/libbpf/libbpf/issues/559 Signed-off-by: Timo Hunziker <timo.hunziker@gmx.ch> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221203123746.2160-1-timo.hunziker@eclipso.ch
2022-12-02libbpf: Improve usability of libbpf MakefileXin Liu
Current libbpf Makefile does not contain the help command, which is inconvenient to use. Similar to the Makefile help command of the perf, a help command is provided to list the commands supported by libbpf make and the functions of the commands. Signed-off-by: Xin Liu <liuxin350@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221202081738.128513-1-liuxin350@huawei.com
2022-11-30libbpf: Avoid enum forward-declarations in public API in C++ modeAndrii Nakryiko
C++ enum forward declarations are fundamentally not compatible with pure C enum definitions, and so libbpf's use of `enum bpf_stats_type;` forward declaration in libbpf/bpf.h public API header is causing C++ compilation issues. More details can be found in [0], but it comes down to C++ supporting enum forward declaration only with explicitly specified backing type: enum bpf_stats_type: int; In C (and I believe it's a GCC extension also), such forward declaration is simply: enum bpf_stats_type; Further, in Linux UAPI this enum is defined in pure C way: enum bpf_stats_type { BPF_STATS_RUN_TIME = 0; } And even though in both cases backing type is int, which can be confirmed by looking at DWARF information, for C++ compiler actual enum definition and forward declaration are incompatible. To eliminate this problem, for C++ mode define input argument as int, which makes enum unnecessary in libbpf public header. This solves the issue and as demonstrated by next patch doesn't cause any unwanted compiler warnings, at least with default warnings setting. [0] https://stackoverflow.com/questions/42766839/c11-enum-forward-causes-underlying-type-mismatch [1] Closes: https://github.com/libbpf/libbpf/issues/249 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20221130200013.2997831-1-andrii@kernel.org
2022-11-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
tools/lib/bpf/ringbuf.c 927cbb478adf ("libbpf: Handle size overflow for ringbuf mmap") b486d19a0ab0 ("libbpf: checkpatch: Fixed code alignments in ringbuf.c") https://lore.kernel.org/all/20221121122707.44d1446a@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-22selftests/bpf: Workaround for llvm nop-4 bugAlexei Starovoitov
Currently LLVM fails to recognize .data.* as data section and defaults to .text section. Later BPF backend tries to emit 4-byte NOP instruction which doesn't exist in BPF ISA and aborts. The fix for LLVM is pending: https://reviews.llvm.org/D138477 While waiting for the fix lets workaround the linked_list test case by using .bss.* prefix which is properly recognized by LLVM as BSS section. Fix libbpf to support .bss. prefix and adjust tests. Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-20tools lib bpf: Avoid install_headers make warningIan Rogers
The perf build makes the install_headers target, however, as there is no action for this target a warning is always produced of: make[3]: Nothing to be done for 'install_headers'. Solve this by adding a display of 'INSTALL libbpf_headers'. Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Hao Luo <haoluo@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Nicolas Schier <nicolas@fjasle.eu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: Stanislav Fomichev <sdf@google.com> Cc: Stephane Eranian <eranian@google.com> Cc: Yonghong Song <yhs@fb.com> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221117004356.279422-3-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-11-18libbpf: Ignore hashmap__find() result explicitly in btf_dumpAndrii Nakryiko
Coverity is reporting that btf_dump_name_dups() doesn't check return result of hashmap__find() call. This is intentional, so make it explicit with (void) cast. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20221117192824.4093553-1-andrii@kernel.org
2022-11-17libbpf: Check the validity of size in user_ring_buffer__reserve()Hou Tao
The top two bits of size are used as busy and discard flags, so reject the reservation that has any of these special bits in the size. With the addition of validity check, these is also no need to check whether or not total_size is overflowed. Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221116072351.1168938-5-houtao@huaweicloud.com
2022-11-17libbpf: Handle size overflow for user ringbuf mmapHou Tao
Similar with the overflow problem on ringbuf mmap, in user_ringbuf_map() 2 * max_entries may overflow u32 when mapping writeable region. Fixing it by casting the size of writable mmap region into a __u64 and checking whether or not there will be overflow during mmap. Fixes: b66ccae01f1d ("bpf: Add libbpf logic for user-space ring buffer") Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221116072351.1168938-4-houtao@huaweicloud.com
2022-11-17libbpf: Handle size overflow for ringbuf mmapHou Tao
The maximum size of ringbuf is 2GB on x86-64 host, so 2 * max_entries will overflow u32 when mapping producer page and data pages. Only casting max_entries to size_t is not enough, because for 32-bits application on 64-bits kernel the size of read-only mmap region also could overflow size_t. So fixing it by casting the size of read-only mmap region into a __u64 and checking whether or not there will be overflow during mmap. Fixes: bf99c936f947 ("libbpf: Add BPF ring buffer support") Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221116072351.1168938-3-houtao@huaweicloud.com
2022-11-17libbpf: Use page size as max_entries when probing ring buffer mapHou Tao
Using page size as max_entries when probing ring buffer map, else the probe may fail on host with 64KB page size (e.g., an ARM64 host). After the fix, the output of "bpftool feature" on above host will be correct. Before : eBPF map_type ringbuf is NOT available eBPF map_type user_ringbuf is NOT available After : eBPF map_type ringbuf is available eBPF map_type user_ringbuf is available Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221116072351.1168938-2-houtao@huaweicloud.com
2022-11-14libbpf: checkpatch: Fixed code alignments in ringbuf.cKang Minchul
Fixed some checkpatch issues in ringbuf.c Signed-off-by: Kang Minchul <tegongkang@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20221113190648.38556-4-tegongkang@gmail.com