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2022-10-21libbpf: Fix overrun in netlink attribute iterationXin Liu1-1/+1
[ Upstream commit 51e05a8cf8eb34da7473823b7f236a77adfef0b4 ] I accidentally found that a change in commit 1045b03e07d8 ("netlink: fix overrun in attribute iteration") was not synchronized to the function `nla_ok` in tools/lib/bpf/nlattr.c, I think it is necessary to modify, this patch will do it. Signed-off-by: Xin Liu <liuxin350@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220930090708.62394-1-liuxin350@huawei.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-21libbpf: Do not require executable permission for shared librariesHengqi Chen1-3/+5
[ Upstream commit 9e32084ef1c33a87a736d6ce3fcb95b60dac9aa1 ] Currently, resolve_full_path() requires executable permission for both programs and shared libraries. This causes failures on distos like Debian since the shared libraries are not installed executable and Linux is not requiring shared libraries to have executable permissions. Let's remove executable permission check for shared libraries. Reported-by: Goro Fuji <goro@fastly.com> Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220806102021.3867130-1-hengqi.chen@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-21libbpf: Ensure functions with always_inline attribute are inlineJames Hilliard2-9/+9
[ Upstream commit d25f40ff68aa61c838947bb9adee6c6b36e77453 ] GCC expects the always_inline attribute to only be set on inline functions, as such we should make all functions with this attribute use the __always_inline macro which makes the function inline and sets the attribute. Fixes errors like: /home/buildroot/bpf-next/tools/testing/selftests/bpf/tools/include/bpf/bpf_tracing.h:439:1: error: ‘always_inline’ function might not be inlinable [-Werror=attributes] 439 | ____##name(unsigned long long *ctx, ##args) | ^~~~ Signed-off-by: James Hilliard <james.hilliard1@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20220803151403.793024-1-james.hilliard1@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-21libbpf: Don't require full struct enum64 in UAPI headersAndrii Nakryiko1-1/+24
[ Upstream commit 87dbdc230d162bf9ee1ac77c8ade178b6b1e199e ] Drop the requirement for system-wide kernel UAPI headers to provide full struct btf_enum64 definition. This is an unexpected requirement that slipped in libbpf 1.0 and put unnecessary pressure ([0]) on users to have a bleeding-edge kernel UAPI header from unreleased Linux 6.0. To achieve this, we forward declare struct btf_enum64. But that's not enough as there is btf_enum64_value() helper that expects to know the layout of struct btf_enum64. So we get a bit creative with reinterpreting memory layout as array of __u32 and accesing lo32/hi32 fields as array elements. Alternative way would be to have a local pointer variable for anonymous struct with exactly the same layout as struct btf_enum64, but that gets us into C++ compiler errors complaining about invalid type casts. So play it safe, if ugly. [0] Closes: https://github.com/libbpf/libbpf/issues/562 Fixes: d90ec262b35b ("libbpf: Add enum64 support for btf_dump") Reported-by: Toke Høiland-Jørgensen <toke@toke.dk> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> Link: https://lore.kernel.org/bpf/20220927042940.147185-1-andrii@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-21libbpf: restore memory layout of bpf_object_open_optsAndrii Nakryiko1-1/+3
[ Upstream commit dbdea9b36fb61da3b9a1be0dd63542e2bfd3e5d7 ] When attach_prog_fd field was removed in libbpf 1.0 and replaced with `long: 0` placeholder, it actually shifted all the subsequent fields by 8 byte. This is due to `long: 0` promising to adjust next field's offset to long-aligned offset. But in this case we were already long-aligned as pin_root_path is a pointer. So `long: 0` had no effect, and thus didn't feel the gap created by removed attach_prog_fd. Non-zero bitfield should have been used instead. I validated using pahole. Originally kconfig field was at offset 40. With `long: 0` it's at offset 32, which is wrong. With this change it's back at offset 40. While technically libbpf 1.0 is allowed to break backwards compatibility and applications should have been recompiled against libbpf 1.0 headers, but given how trivial it is to preserve memory layout, let's fix this. Reported-by: Grant Seltzer Richman <grantseltzer@gmail.com> Fixes: 146bf811f5ac ("libbpf: remove most other deprecated high-level APIs") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220923230559.666608-1-andrii@kernel.org Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-21libbpf: Fix NULL pointer exception in API btf_dump__dump_type_dataXin Liu1-1/+1
[ Upstream commit 7620bffbf72cd66a5d18e444a143b5b5989efa87 ] We found that function btf_dump__dump_type_data can be called by the user as an API, but in this function, the `opts` parameter may be used as a null pointer.This causes `opts->indent_str` to trigger a NULL pointer exception. Fixes: 2ce8450ef5a3 ("libbpf: add bpf_object__open_{file, mem} w/ extensible opts") Signed-off-by: Xin Liu <liuxin350@huawei.com> Signed-off-by: Weibin Kong <kongweibin2@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220917084809.30770-1-liuxin350@huawei.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-21libbpf: Fix crash if SEC("freplace") programs don't have attach_prog_fd setAndrii Nakryiko1-4/+9
[ Upstream commit 749c202cb6ea40f4d7ac95c4a1217a7b506f43a8 ] Fix SIGSEGV caused by libbpf trying to find attach type in vmlinux BTF for freplace programs. It's wrong to search in vmlinux BTF and libbpf doesn't even mark vmlinux BTF as required for freplace programs. So trying to search anything in obj->vmlinux_btf might cause NULL dereference if nothing else in BPF object requires vmlinux BTF. Instead, error out if freplace (EXT) program doesn't specify attach_prog_fd during at the load time. Fixes: 91abb4a6d79d ("libbpf: Support attachment of BPF tracing programs to kernel modules") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220909193053.577111-3-andrii@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-21libbpf: Initialize err in probe_map_createFlorian Fainelli1-1/+1
[ Upstream commit 3045f42a64324d339125a8a1a1763bb9e1e08300 ] GCC-11 warns about the possibly unitialized err variable in probe_map_create: libbpf_probes.c: In function 'probe_map_create': libbpf_probes.c:361:38: error: 'err' may be used uninitialized in this function [-Werror=maybe-uninitialized] 361 | return fd < 0 && err == exp_err ? 1 : 0; | ~~~~^~~~~~~~~~ Fixes: 878d8def0603 ("libbpf: Rework feature-probing APIs") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20220801025109.1206633-1-f.fainelli@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-10bpf: Disallow bpf programs call prog_run command.Alexei Starovoitov1-2/+2
The verifier cannot perform sufficient validation of bpf_attr->test.ctx_in pointer, therefore bpf programs should not be allowed to call BPF_PROG_RUN command from within the program. To fix this issue split bpf_sys_bpf() bpf helper into normal kern_sys_bpf() kernel function that can only be used by the kernel light skeleton directly. Reported-by: YiFei Zhu <zhuyifei@google.com> Fixes: b1d18a7574d0 ("bpf: Extend sys_bpf commands for bpf_syscall programs.") Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-30libbpf: Add bpf_obj_get_opts()Joe Burton3-0/+21
Add an extensible variant of bpf_obj_get() capable of setting the `file_flags` parameter. This parameter is needed to enable unprivileged access to BPF maps. Without a method like this, users must manually make the syscall. Signed-off-by: Joe Burton <jevburton@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220729202727.3311806-1-jevburton.kernel@gmail.com
2022-07-29libbpf: Support PPC in arch_specific_syscall_pfxDaniel Müller1-1/+10
Commit 708ac5bea0ce ("libbpf: add ksyscall/kretsyscall sections support for syscall kprobes") added the arch_specific_syscall_pfx() function, which returns a string representing the architecture in use. As it turns out this function is currently not aware of Power PC, where NULL is returned. That's being flagged by the libbpf CI system, which builds for ppc64le and the compiler sees a NULL pointer being passed in to a %s format string. With this change we add representations for two more architectures, for Power PC and Power PC 64, and also adjust the string format logic to handle NULL pointers gracefully, in an attempt to prevent similar issues with other architectures in the future. Fixes: 708ac5bea0ce ("libbpf: add ksyscall/kretsyscall sections support for syscall kprobes") Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220728222345.3125975-1-deso@posteo.net
2022-07-26libbpf: Extend BPF_KSYSCALL documentationIlya Leoshkevich1-4/+11
Explicitly list known quirks. Mention that socket-related syscalls can be invoked via socketcall(). Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20220726134008.256968-2-iii@linux.ibm.com
2022-07-21libbpf: Fix str_has_sfx()'s return valueDan Carpenter1-3/+3
The return from strcmp() is inverted so it wrongly returns true instead of false and vice versa. Fixes: a1c9d61b19cb ("libbpf: Improve library identification for uprobe binary path resolution") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Cc: Alan Maguire <alan.maguire@oracle.com> Link: https://lore.kernel.org/bpf/YtZ+/dAA195d99ak@kili
2022-07-21libbpf: Fix sign expansion bug in btf_dump_get_enum_value()Dan Carpenter1-1/+1
The code here is supposed to take a signed int and store it in a signed long long. Unfortunately, the way that the type promotion works with this conditional statement is that it takes a signed int, type promotes it to a __u32, and then stores that as a signed long long. The result is never negative. This is from static analysis, but I made a little test program just to test it before I sent the patch: #include <stdio.h> int main(void) { unsigned long long src = -1ULL; signed long long dst1, dst2; int is_signed = 1; dst1 = is_signed ? *(int *)&src : *(unsigned int *)0; dst2 = is_signed ? (signed long long)*(int *)&src : *(unsigned int *)0; printf("%lld\n", dst1); printf("%lld\n", dst2); return 0; } Fixes: d90ec262b35b ("libbpf: Add enum64 support for btf_dump") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/YtZ+LpgPADm7BeEd@kili
2022-07-19libbpf: fix an snprintf() overflow checkDan Carpenter1-1/+1
The snprintf() function returns the number of bytes it *would* have copied if there were enough space. So it can return > the sizeof(gen->attach_target). Fixes: 67234743736a ("libbpf: Generate loader program out of BPF ELF file.") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/r/YtZ+oAySqIhFl6/J@kili Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-19libbpf: make RINGBUF map size adjustments more eagerlyAndrii Nakryiko1-35/+42
Make libbpf adjust RINGBUF map size (rounding it up to closest power-of-2 of page_size) more eagerly: during open phase when initializing the map and on explicit calls to bpf_map__set_max_entries(). Such approach allows user to check actual size of BPF ringbuf even before it's created in the kernel, but also it prevents various edge case scenarios where BPF ringbuf size can get out of sync with what it would be in kernel. One of them (reported in [0]) is during an attempt to pin/reuse BPF ringbuf. Move adjust_ringbuf_sz() helper closer to its first actual use. The implementation of the helper is unchanged. Also make detection of whether bpf_object is already loaded more robust by checking obj->loaded explicitly, given that map->fd can be < 0 even if bpf_object is already loaded due to ability to disable map creation with bpf_map__set_autocreate(map, false). [0] Closes: https://github.com/libbpf/libbpf/pull/530 Fixes: 0087a681fa8c ("libbpf: Automatically fix up BPF_MAP_TYPE_RINGBUF size, if necessary") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220715230952.2219271-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-19libbpf: fallback to tracefs mount point if debugfs is not mountedAndrii Nakryiko1-21/+40
Teach libbpf to fallback to tracefs mount point (/sys/kernel/tracing) if debugfs (/sys/kernel/debug/tracing) isn't mounted. Acked-by: Yonghong Song <yhs@fb.com> Suggested-by: Connor O'Brien <connoro@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220715185736.898848-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-19libbpf: add ksyscall/kretsyscall sections support for syscall kprobesAndrii Nakryiko4-9/+157
Add SEC("ksyscall")/SEC("ksyscall/<syscall_name>") and corresponding kretsyscall variants (for return kprobes) to allow users to kprobe syscall functions in kernel. These special sections allow to ignore complexities and differences between kernel versions and host architectures when it comes to syscall wrapper and corresponding __<arch>_sys_<syscall> vs __se_sys_<syscall> differences, depending on whether host kernel has CONFIG_ARCH_HAS_SYSCALL_WRAPPER (though libbpf itself doesn't rely on /proc/config.gz for detecting this, see BPF_KSYSCALL patch for how it's done internally). Combined with the use of BPF_KSYSCALL() macro, this allows to just specify intended syscall name and expected input arguments and leave dealing with all the variations to libbpf. In addition to SEC("ksyscall+") and SEC("kretsyscall+") add bpf_program__attach_ksyscall() API which allows to specify syscall name at runtime and provide associated BPF cookie value. At the moment SEC("ksyscall") and bpf_program__attach_ksyscall() do not handle all the calling convention quirks for mmap(), clone() and compat syscalls. It also only attaches to "native" syscall interfaces. If host system supports compat syscalls or defines 32-bit syscalls in 64-bit kernel, such syscall interfaces won't be attached to by libbpf. These limitations may or may not change in the future. Therefore it is recommended to use SEC("kprobe") for these syscalls or if working with compat and 32-bit interfaces is required. Tested-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220714070755.3235561-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-19libbpf: improve BPF_KPROBE_SYSCALL macro and rename it to BPF_KSYSCALLAndrii Nakryiko2-13/+40
Improve BPF_KPROBE_SYSCALL (and rename it to shorter BPF_KSYSCALL to match libbpf's SEC("ksyscall") section name, added in next patch) to use __kconfig variable to determine how to properly fetch syscall arguments. Instead of relying on hard-coded knowledge of whether kernel's architecture uses syscall wrapper or not (which only reflects the latest kernel versions, but is not necessarily true for older kernels and won't necessarily hold for later kernel versions on some particular host architecture), determine this at runtime by attempting to create perf_event (with fallback to kprobe event creation through tracefs on legacy kernels, just like kprobe attachment code is doing) for kernel function that would correspond to bpf() syscall on a system that has CONFIG_ARCH_HAS_SYSCALL_WRAPPER set (e.g., for x86-64 it would try '__x64_sys_bpf'). If host kernel uses syscall wrapper, syscall kernel function's first argument is a pointer to struct pt_regs that then contains syscall arguments. In such case we need to use bpf_probe_read_kernel() to fetch actual arguments (which we do through BPF_CORE_READ() macro) from inner pt_regs. But if the kernel doesn't use syscall wrapper approach, input arguments can be read from struct pt_regs directly with no probe reading. All this feature detection is done without requiring /proc/config.gz existence and parsing, and BPF-side helper code uses newly added LINUX_HAS_SYSCALL_WRAPPER virtual __kconfig extern to keep in sync with user-side feature detection of libbpf. BPF_KSYSCALL() macro can be used both with SEC("kprobe") programs that define syscall function explicitly (e.g., SEC("kprobe/__x64_sys_bpf")) and SEC("ksyscall") program added in the next patch (which are the same kprobe program with added benefit of libbpf determining correct kernel function name automatically). Kretprobe and kretsyscall (added in next patch) programs don't need BPF_KSYSCALL as they don't provide access to input arguments. Normal BPF_KRETPROBE is completely sufficient and is recommended. Tested-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220714070755.3235561-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-19libbpf: generalize virtual __kconfig externs and use it for USDTAndrii Nakryiko2-45/+66
Libbpf supports single virtual __kconfig extern currently: LINUX_KERNEL_VERSION. LINUX_KERNEL_VERSION isn't coming from /proc/kconfig.gz and is intead customly filled out by libbpf. This patch generalizes this approach to support more such virtual __kconfig externs. One such extern added in this patch is LINUX_HAS_BPF_COOKIE which is used for BPF-side USDT supporting code in usdt.bpf.h instead of using CO-RE-based enum detection approach for detecting bpf_get_attach_cookie() BPF helper. This allows to remove otherwise not needed CO-RE dependency and keeps user-space and BPF-side parts of libbpf's USDT support strictly in sync in terms of their feature detection. We'll use similar approach for syscall wrapper detection for BPF_KSYSCALL() BPF-side macro in follow up patch. Generally, currently libbpf reserves CONFIG_ prefix for Kconfig values and LINUX_ for virtual libbpf-backed externs. In the future we might extend the set of prefixes that are supported. This can be done without any breaking changes, as currently any __kconfig extern with unrecognized name is rejected. For LINUX_xxx externs we support the normal "weak rule": if libbpf doesn't recognize given LINUX_xxx extern but such extern is marked as __weak, it is not rejected and defaults to zero. This follows CONFIG_xxx handling logic and will allow BPF applications to opportunistically use newer libbpf virtual externs without breaking on older libbpf versions unnecessarily. Tested-by: Alan Maguire <alan.maguire@oracle.com> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220714070755.3235561-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-15libbpf: perfbuf: Add API to get the ring bufferJon Doron3-0/+33
Add support for writing a custom event reader, by exposing the ring buffer. With the new API perf_buffer__buffer() you will get access to the raw mmaped()'ed per-cpu underlying memory of the ring buffer. This region contains both the perf buffer data and header (struct perf_event_mmap_page), which manages the ring buffer state (head/tail positions, when accessing the head/tail position it's important to take into consideration SMP). With this type of low level access one can implement different types of consumers here are few simple examples where this API helps with: 1. perf_event_read_simple is allocating using malloc, perhaps you want to handle the wrap-around in some other way. 2. Since perf buf is per-cpu then the order of the events is not guarnteed, for example: Given 3 events where each event has a timestamp t0 < t1 < t2, and the events are spread on more than 1 CPU, then we can end up with the following state in the ring buf: CPU[0] => [t0, t2] CPU[1] => [t1] When you consume the events from CPU[0], you could know there is a t1 missing, (assuming there are no drops, and your event data contains a sequential index). So now one can simply do the following, for CPU[0], you can store the address of t0 and t2 in an array (without moving the tail, so there data is not perished) then move on the CPU[1] and set the address of t1 in the same array. So you end up with something like: void **arr[] = [&t0, &t1, &t2], now you can consume it orderely and move the tails as you process in order. 3. Assuming there are multiple CPUs and we want to start draining the messages from them, then we can "pick" with which one to start with according to the remaining free space in the ring buffer. Signed-off-by: Jon Doron <jond@wiz.io> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220715181122.149224-1-arilou@gmail.com
2022-07-14libbpf: Fix the name of a reused mapAnquan Wu1-2/+7
BPF map name is limited to BPF_OBJ_NAME_LEN. A map name is defined as being longer than BPF_OBJ_NAME_LEN, it will be truncated to BPF_OBJ_NAME_LEN when a userspace program calls libbpf to create the map. A pinned map also generates a path in the /sys. If the previous program wanted to reuse the map, it can not get bpf_map by name, because the name of the map is only partially the same as the name which get from pinned path. The syscall information below show that map name "process_pinned_map" is truncated to "process_pinned_". bpf(BPF_OBJ_GET, {pathname="/sys/fs/bpf/process_pinned_map", bpf_fd=0, file_flags=0}, 144) = -1 ENOENT (No such file or directory) bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_HASH, key_size=4, value_size=4,max_entries=1024, map_flags=0, inner_map_fd=0, map_name="process_pinned_",map_ifindex=0, btf_fd=3, btf_key_type_id=6, btf_value_type_id=10,btf_vmlinux_value_type_id=0}, 72) = 4 This patch check that if the name of pinned map are the same as the actual name for the first (BPF_OBJ_NAME_LEN - 1), bpf map still uses the name which is included in bpf object. Fixes: 26736eb9a483 ("tools: libbpf: allow map reuse") Signed-off-by: Anquan Wu <leiqi96@hotmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/OSZP286MB1725CEA1C95C5CB8E7CCC53FB8869@OSZP286MB1725.JPNP286.PROD.OUTLOOK.COM
2022-07-13libbpf: Error out when binary_path is NULL for uprobe and USDTHengqi Chen1-6/+7
binary_path is a required non-null parameter for bpf_program__attach_usdt and bpf_program__attach_uprobe_opts. Check it against NULL to prevent coredump on strchr. Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220712025745.2703995-1-hengqi.chen@gmail.com
2022-07-09bpf: Correctly propagate errors up from bpf_core_composites_matchDaniel Müller1-1/+8
This change addresses a comment made earlier [0] about a missing return of an error when __bpf_core_types_match is invoked from bpf_core_composites_match, which could have let to us erroneously ignoring errors. Regarding the typedef name check pointed out in the same context, it is not actually an issue, because callers of the function perform a name check for the root type anyway. To make that more obvious, let's add comments to the function (similar to what we have for bpf_core_types_are_compat, which is called in pretty much the same context). [0]: https://lore.kernel.org/bpf/165708121449.4919.13204634393477172905.git-patchwork-notify@kernel.org/T/#m55141e8f8cfd2e8d97e65328fa04852870d01af6 Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220707211931.3415440-1-deso@posteo.net
2022-07-09libbpf: Disable SEC pragma macro on GCCJames Hilliard1-0/+13
It seems the gcc preprocessor breaks with pragmas when surrounding __attribute__. Disable these pragmas on GCC due to upstream bugs see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55578 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90400 Fixes errors like: error: expected identifier or '(' before '#pragma' 106 | SEC("cgroup/bind6") | ^~~ error: expected '=', ',', ';', 'asm' or '__attribute__' before '#pragma' 114 | char _license[] SEC("license") = "GPL"; | ^~~ Signed-off-by: James Hilliard <james.hilliard1@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220706111839.1247911-1-james.hilliard1@gmail.com
2022-07-07libbpf, riscv: Use a0 for RC registerYixun Lan1-1/+1
According to the RISC-V calling convention register usage here [0], a0 is used as return value register, so rename it to make it consistent with the spec. [0] section 18.2, table 18.2 https://riscv.org/wp-content/uploads/2015/01/riscv-calling.pdf Fixes: 589fed479ba1 ("riscv, libbpf: Add RISC-V (RV64) support to bpf_tracing.h") Signed-off-by: Yixun Lan <dlan@gentoo.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn@kernel.org> Acked-by: Amjad OULED-AMEUR <ouledameur.amjad@gmail.com> Link: https://lore.kernel.org/bpf/20220706140204.47926-1-dlan@gentoo.org
2022-07-06libbpf: Remove unnecessary usdt_rel_ip assignmentsAndrii Nakryiko1-4/+2
Coverity detected that usdt_rel_ip is unconditionally overwritten anyways, so there is no need to unnecessarily initialize it with unused value. Clean this up. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20220705224818.4026623-4-andrii@kernel.org
2022-07-06libbpf: Cleanup the legacy uprobe_event on failed add/attach_event()Chuang Wang1-5/+14
A potential scenario, when an error is returned after add_uprobe_event_legacy() in perf_event_uprobe_open_legacy(), or bpf_program__attach_perf_event_opts() in bpf_program__attach_uprobe_opts() returns an error, the uprobe_event that was previously created is not cleaned. So, with this patch, when an error is returned, fix this by adding remove_uprobe_event_legacy() Signed-off-by: Chuang Wang <nashuiliang@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220629151848.65587-4-nashuiliang@gmail.com
2022-07-06libbpf: Fix wrong variable used in perf_event_uprobe_open_legacy()Chuang Wang1-1/+1
Use "type" as opposed to "err" in pr_warn() after determine_uprobe_perf_type_legacy() returns an error. Signed-off-by: Chuang Wang <nashuiliang@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220629151848.65587-3-nashuiliang@gmail.com
2022-07-06libbpf: Cleanup the legacy kprobe_event on failed add/attach_event()Chuang Wang1-4/+14
Before the 0bc11ed5ab60 commit ("kprobes: Allow kprobes coexist with livepatch"), in a scenario where livepatch and kprobe coexist on the same function entry, the creation of kprobe_event using add_kprobe_event_legacy() will be successful, at the same time as a trace event (e.g. /debugfs/tracing/events/kprobe/XXX) will exist, but perf_event_open() will return an error because both livepatch and kprobe use FTRACE_OPS_FL_IPMODIFY. As follows: 1) add a livepatch $ insmod livepatch-XXX.ko 2) add a kprobe using tracefs API (i.e. add_kprobe_event_legacy) $ echo 'p:mykprobe XXX' > /sys/kernel/debug/tracing/kprobe_events 3) enable this kprobe (i.e. sys_perf_event_open) This will return an error, -EBUSY. On Andrii Nakryiko's comment, few error paths in bpf_program__attach_kprobe_opts() that should need to call remove_kprobe_event_legacy(). With this patch, whenever an error is returned after add_kprobe_event_legacy() or bpf_program__attach_perf_event_opts(), this ensures that the created kprobe_event is cleaned. Signed-off-by: Chuang Wang <nashuiliang@gmail.com> Signed-off-by: Jingren Zhou <zhoujingren@didiglobal.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220629151848.65587-2-nashuiliang@gmail.com
2022-07-06libbpf: add bpf_core_type_matches() helper macroAndrii Nakryiko1-0/+10
This patch finalizes support for the proposed type match relation in libbpf by adding bpf_core_type_matches() macro which emits TYPE_MATCH relocation. Clang support for this relocation was added in [0]. [0] https://reviews.llvm.org/D126838 Signed-off-by: Daniel Müller <deso@posteo.net>¬ Signed-off-by: Andrii Nakryiko <andrii@kernel.org>¬ Link: https://lore.kernel.org/bpf/20220628160127.607834-7-deso@posteo.net¬
2022-07-06bpf, libbpf: Add type match supportDaniel Müller3-4/+285
This patch adds support for the proposed type match relation to relo_core where it is shared between userspace and kernel. It plumbs through both kernel-side and libbpf-side support. The matching relation is defined as follows (copy from source): - modifiers and typedefs are stripped (and, hence, effectively ignored) - generally speaking types need to be of same kind (struct vs. struct, union vs. union, etc.) - exceptions are struct/union behind a pointer which could also match a forward declaration of a struct or union, respectively, and enum vs. enum64 (see below) Then, depending on type: - integers: - match if size and signedness match - arrays & pointers: - target types are recursively matched - structs & unions: - local members need to exist in target with the same name - for each member we recursively check match unless it is already behind a pointer, in which case we only check matching names and compatible kind - enums: - local variants have to have a match in target by symbolic name (but not numeric value) - size has to match (but enum may match enum64 and vice versa) - function pointers: - number and position of arguments in local type has to match target - for each argument and the return value we recursively check match Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220628160127.607834-5-deso@posteo.net
2022-07-06bpf: Introduce TYPE_MATCH related constants/macrosDaniel Müller1-0/+1
In order to provide type match support we require a new type of relocation which, in turn, requires toolchain support. Recent LLVM/Clang versions support a new value for the last argument to the __builtin_preserve_type_info builtin, for example. With this change we introduce the necessary constants into relevant header files, mirroring what the compiler may support. Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220628160127.607834-2-deso@posteo.net
2022-06-29libbpf: implement bpf_prog_query_optsStanislav Fomichev3-7/+47
Implement bpf_prog_query_opts as a more expendable version of bpf_prog_query. Expose new prog_attach_flags and attach_btf_func_id as well: * prog_attach_flags is a per-program attach_type; relevant only for lsm cgroup program which might have different attach_flags per attach_btf_id * attach_btf_func_id is a new field expose for prog_query which specifies real btf function id for lsm cgroup attachments Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20220628174314.1216643-10-sdf@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-29libbpf: add lsm_cgoup_sock typeStanislav Fomichev1-0/+3
lsm_cgroup/ is the prefix for BPF_LSM_CGROUP. Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20220628174314.1216643-9-sdf@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: fix up few libbpf.map problemsAndrii Nakryiko2-3/+4
Seems like we missed to add 2 APIs to libbpf.map and another API was misspelled. Fix it in libbpf.map. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-16-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: enforce strict libbpf 1.0 behaviorsAndrii Nakryiko5-261/+37
Remove support for legacy features and behaviors that previously had to be disabled by calling libbpf_set_strict_mode(): - legacy BPF map definitions are not supported now; - RLIMIT_MEMLOCK auto-setting, if necessary, is always on (but see libbpf_set_memlock_rlim()); - program name is used for program pinning (instead of section name); - cleaned up error returning logic; - entry BPF programs should have SEC() always. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-15-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: clean up SEC() handlingAndrii Nakryiko1-72/+47
Get rid of sloppy prefix logic and remove deprecated xdp_{devmap,cpumap} sections. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-13-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: remove internal multi-instance prog supportAndrii Nakryiko1-283/+34
Clean up internals that had to deal with the possibility of multi-instance bpf_programs. Libbpf 1.0 doesn't support this, so all this is not necessary now and can be simplified. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-12-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: cleanup LIBBPF_DEPRECATED_SINCE supporting macros for v0.xAndrii Nakryiko1-13/+3
Keep the LIBBPF_DEPRECATED_SINCE macro "framework" for future deprecations, but clean up 0.x related helper macros. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-11-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: remove multi-instance and custom private data APIsAndrii Nakryiko3-212/+10
Remove all the public APIs that are related to creating multi-instance bpf_programs through custom preprocessing callback and generally working with them. Also remove all the bpf_{object,map,program}__[set_]priv() APIs. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-10-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: remove most other deprecated high-level APIsAndrii Nakryiko3-421/+26
Remove a bunch of high-level bpf_object/bpf_map/bpf_program related APIs. All the APIs related to private per-object/map/prog state, program preprocessing callback, and generally everything multi-instance related is removed in a separate patch. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-9-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: remove prog_info_linear APIsAndrii Nakryiko3-317/+0
Remove prog_info_linear-related APIs previously used by perf. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-8-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: clean up perfbuf APIsAndrii Nakryiko3-112/+18
Remove deprecated perfbuf APIs and clean up opts structs. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-7-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: remove deprecated BTF APIsAndrii Nakryiko5-325/+24
Get rid of deprecated BTF-related APIs. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-6-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: remove deprecated probing APIsAndrii Nakryiko3-132/+5
Get rid of deprecated feature-probing APIs. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: remove deprecated XDP APIsAndrii Nakryiko3-78/+8
Get rid of deprecated bpf_set_link*() and bpf_get_link*() APIs. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: remove deprecated low-level APIsAndrii Nakryiko5-374/+4
Drop low-level APIs as well as high-level (and very confusingly named) BPF object loading bpf_prog_load_xattr() and bpf_prog_load_deprecated() APIs. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: move xsk.{c,h} into selftests/bpfAndrii Nakryiko5-1610/+2
Remove deprecated xsk APIs from libbpf. But given we have selftests relying on this, move those files (with minimal adjustments to make them compilable) under selftests/bpf. We also remove all the removed APIs from libbpf.map, while overall keeping version inheritance chain, as most APIs are backwards compatible so there is no need to reassign them as LIBBPF_1.0.0 versions. Cc: Magnus Karlsson <magnus.karlsson@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-25bpf: Merge "types_are_compat" logic into relo_core.cDaniel Müller3-71/+83
BPF type compatibility checks (bpf_core_types_are_compat()) are currently duplicated between kernel and user space. That's a historical artifact more than intentional doing and can lead to subtle bugs where one implementation is adjusted but another is forgotten. That happened with the enum64 work, for example, where the libbpf side was changed (commit 23b2a3a8f63a ("libbpf: Add enum64 relocation support")) to use the btf_kind_core_compat() helper function but the kernel side was not (commit 6089fb325cf7 ("bpf: Add btf enum64 support")). This patch addresses both the duplication issue, by merging both implementations and moving them into relo_core.c, and fixes the alluded to kind check (by giving preference to libbpf's already adjusted logic). For discussion of the topic, please refer to: https://lore.kernel.org/bpf/CAADnVQKbWR7oarBdewgOBZUPzryhRYvEbkhyPJQHHuxq=0K1gw@mail.gmail.com/T/#mcc99f4a33ad9a322afaf1b9276fb1f0b7add9665 Changelog: v1 -> v2: - limited libbpf recursion limit to 32 - changed name to __bpf_core_types_are_compat - included warning previously present in libbpf version - merged kernel and user space changes into a single patch Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220623182934.2582827-1-deso@posteo.net