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2022-04-07Merge tag 'net-5.18-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from bpf and netfilter. Current release - new code bugs: - mctp: correct mctp_i2c_header_create result - eth: fungible: fix reference to __udivdi3 on 32b builds - eth: micrel: remove latencies support lan8814 Previous releases - regressions: - bpf: resolve to prog->aux->dst_prog->type only for BPF_PROG_TYPE_EXT - vrf: fix packet sniffing for traffic originating from ip tunnels - rxrpc: fix a race in rxrpc_exit_net() - dsa: revert "net: dsa: stop updating master MTU from master.c" - eth: ice: fix MAC address setting Previous releases - always broken: - tls: fix slab-out-of-bounds bug in decrypt_internal - bpf: support dual-stack sockets in bpf_tcp_check_syncookie - xdp: fix coalescing for page_pool fragment recycling - ovs: fix leak of nested actions - eth: sfc: - add missing xdp queue reinitialization - fix using uninitialized xdp tx_queue - eth: ice: - clear default forwarding VSI during VSI release - fix broken IFF_ALLMULTI handling - synchronize_rcu() when terminating rings - eth: qede: confirm skb is allocated before using - eth: aqc111: fix out-of-bounds accesses in RX fixup - eth: slip: fix NPD bug in sl_tx_timeout()" * tag 'net-5.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (61 commits) drivers: net: slip: fix NPD bug in sl_tx_timeout() bpf: Adjust bpf_tcp_check_syncookie selftest to test dual-stack sockets bpf: Support dual-stack sockets in bpf_tcp_check_syncookie myri10ge: fix an incorrect free for skb in myri10ge_sw_tso net: usb: aqc111: Fix out-of-bounds accesses in RX fixup qede: confirm skb is allocated before using net: ipv6mr: fix unused variable warning with CONFIG_IPV6_PIMSM_V2=n net: phy: mscc-miim: reject clause 45 register accesses net: axiemac: use a phandle to reference pcs_phy dt-bindings: net: add pcs-handle attribute net: axienet: factor out phy_node in struct axienet_local net: axienet: setup mdio unconditionally net: sfc: fix using uninitialized xdp tx_queue rxrpc: fix a race in rxrpc_exit_net() net: openvswitch: fix leak of nested actions net: ethernet: mv643xx: Fix over zealous checking of_get_mac_address() net: openvswitch: don't send internal clone attribute to the userspace. net: micrel: Fix KS8851 Kconfig ice: clear cmd_type_offset_bsz for TX rings ice: xsk: fix VSI state check in ice_xsk_wakeup() ...
2022-04-07libbpf: Make BPF-side of USDT support work on big-endian machinesIlya Leoshkevich
BPF_USDT_ARG_REG_DEREF handling always reads 8 bytes, regardless of the actual argument size. On little-endian the relevant argument bits end up in the lower bits of val, and later on the code that handles all the argument types expects them to be there. On big-endian they end up in the upper bits of val, breaking that expectation. Fix by right-shifting val on big-endian. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220407214411.257260-3-iii@linux.ibm.com
2022-04-07libbpf: Minor style improvements in USDT codeIlya Leoshkevich
Fix several typos and references to non-existing headers. Also use __BYTE_ORDER__ instead of __BYTE_ORDER for consistency with the rest of the bpf code - see commit 45f2bebc8079 ("libbpf: Fix endianness detection in BPF_CORE_READ_BITFIELD_PROBED()") for rationale). Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220407214411.257260-2-iii@linux.ibm.com
2022-04-07libbpf: Fix use #ifdef instead of #if to avoid compiler warningAndrii Nakryiko
As reported by Naresh: perf build errors on i386 [1] on Linux next-20220407 [2] usdt.c:1181:5: error: "__x86_64__" is not defined, evaluates to 0 [-Werror=undef] 1181 | #if __x86_64__ | ^~~~~~~~~~ usdt.c:1196:5: error: "__x86_64__" is not defined, evaluates to 0 [-Werror=undef] 1196 | #if __x86_64__ | ^~~~~~~~~~ cc1: all warnings being treated as errors Use #ifdef instead of #if to avoid this. Fixes: 4c59e584d158 ("libbpf: Add x86-specific USDT arg spec parsing logic") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220407203842.3019904-1-andrii@kernel.org
2022-04-07libbpf: Potential NULL dereference in usdt_manager_attach_usdt()Haowen Bai
link could be null but still dereference bpf_link__destroy(&link->link) and it will lead to a null pointer access. Signed-off-by: Haowen Bai <baihaowen@meizu.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1649299098-2069-1-git-send-email-baihaowen@meizu.com
2022-04-07selftests/bpf: Uprobe tests should verify param/return valuesAlan Maguire
uprobe/uretprobe tests don't do any validation of arguments/return values, and without this we can't be sure we are attached to the right function, or that we are indeed attached to a uprobe or uretprobe. To fix this record argument and return value for auto-attached functions and ensure these match expectations. Also need to filter by pid to ensure we do not pick up stray malloc()s since auto-attach traces libc system-wide. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1649245431-29956-4-git-send-email-alan.maguire@oracle.com
2022-04-07libbpf: Improve string parsing for uprobe auto-attachAlan Maguire
For uprobe auto-attach, the parsing can be simplified for the SEC() name to a single sscanf(); the return value of the sscanf can then be used to distinguish between sections that simply specify "u[ret]probe" (and thus cannot auto-attach), those that specify "u[ret]probe/binary_path:function+offset" etc. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1649245431-29956-3-git-send-email-alan.maguire@oracle.com
2022-04-07libbpf: Improve library identification for uprobe binary path resolutionAlan Maguire
In the process of doing path resolution for uprobe attach, libraries are identified by matching a ".so" substring in the binary_path. This matches a lot of patterns that do not conform to library.so[.version] format, so instead match a ".so" _suffix_, and if that fails match a ".so." substring for the versioned library case. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1649245431-29956-2-git-send-email-alan.maguire@oracle.com
2022-04-07selftests: KVM: Free the GIC FD when cleaning up in arch_timerOliver Upton
In order to correctly destroy a VM, all references to the VM must be freed. The arch_timer selftest creates a VGIC for the guest, which itself holds a reference to the VM. Close the GIC FD when cleaning up a VM. Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220406235615.1447180-4-oupton@google.com
2022-04-07selftests: KVM: Don't leak GIC FD across dirty log test iterationsOliver Upton
dirty_log_perf_test instantiates a VGICv3 for the guest (if supported by hardware) to reduce the overhead of guest exits. However, the test does not actually close the GIC fd when cleaning up the VM between test iterations, meaning that the VM is never actually destroyed in the kernel. While this is generally a bad idea, the bug was detected from the kernel spewing about duplicate debugfs entries as subsequent VMs happen to reuse the same FD even though the debugfs directory is still present. Abstract away the notion of setup/cleanup of the GIC FD from the test by creating arch-specific helpers for test setup/cleanup. Close the GIC FD on VM cleanup and do nothing for the other architectures. Fixes: c340f7899af6 ("KVM: selftests: Add vgic initialization for dirty log perf test for ARM") Reviewed-by: Jing Zhang <jingzhangos@google.com> Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220406235615.1447180-3-oupton@google.com
2022-04-07KVM: selftests: get-reg-list: Add KVM_REG_ARM_FW_REG(3)Andrew Jones
When testing a kernel with commit a5905d6af492 ("KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated") get-reg-list output vregs: Number blessed registers: 234 vregs: Number registers: 238 vregs: There are 1 new registers. Consider adding them to the blessed reg list with the following lines: KVM_REG_ARM_FW_REG(3), vregs: PASS ... That output inspired two changes: 1) add the new register to the blessed list and 2) explain why "Number registers" is actually four larger than "Number blessed registers" (on the system used for testing), even though only one register is being stated as new. The reason is that some registers are host dependent and they get filtered out when comparing with the blessed list. The system used for the test apparently had three filtered registers. Signed-off-by: Andrew Jones <drjones@redhat.com> Acked-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220316125129.392128-1-drjones@redhat.com
2022-04-06Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfJakub Kicinski
Alexei Starovoitov says: ==================== pull-request: bpf 2022-04-06 We've added 8 non-merge commits during the last 8 day(s) which contain a total of 9 files changed, 139 insertions(+), 36 deletions(-). The main changes are: 1) rethook related fixes, from Jiri and Masami. 2) Fix the case when tracing bpf prog is attached to struct_ops, from Martin. 3) Support dual-stack sockets in bpf_tcp_check_syncookie, from Maxim. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf: Adjust bpf_tcp_check_syncookie selftest to test dual-stack sockets bpf: Support dual-stack sockets in bpf_tcp_check_syncookie bpf: selftests: Test fentry tracing a struct_ops program bpf: Resolve to prog->aux->dst_prog->type only for BPF_PROG_TYPE_EXT rethook: Fix to use WRITE_ONCE() for rethook:: Handler selftests/bpf: Fix warning comparing pointer to 0 bpf: Fix sparse warnings in kprobe_multi_resolve_syms bpftool: Explicit errno handling in skeletons ==================== Link: https://lore.kernel.org/r/20220407031245.73026-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-06selftests/bpf: Test for writes to map key from BPF helpersKumar Kartikeya Dwivedi
When invoking bpf_for_each_map_elem callback, we are passed a PTR_TO_MAP_KEY, previously writes to this through helper may be allowed, but the fix in previous patches is meant to prevent that case. The test case tries to pass it as writable memory to helper, and fails test if it succeeds to pass the verifier. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20220319080827.73251-6-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-04-06selftests/bpf: Test passing rdonly mem to global funcKumar Kartikeya Dwivedi
Add two test cases, one pass read only map value pointer to global func, which should be rejected. The same code checks it for kfunc, so that is covered as well. Second one tries to use the missing check for PTR_TO_MEM's MEM_RDONLY flag and tries to write to a read only memory pointer. Without prior patches, both of these tests fail. Reviewed-by: Hao Luo <haoluo@google.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20220319080827.73251-5-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-04-06selftests/bpf: Use bpf_num_possible_cpus() in per-cpu map allocationsArtem Savkov
bpf_map_value_size() uses num_possible_cpus() to determine map size, but some of the tests only allocate enough memory for online cpus. This results in out-of-bound writes in userspace during bpf(BPF_MAP_LOOKUP_ELEM) syscalls in cases when number of online cpus is lower than the number of possible cpus. Fix by switching from get_nprocs_conf() to bpf_num_possible_cpus() when determining the number of processors in these tests (test_progs/netcnt and test_cgroup_storage). Signed-off-by: Artem Savkov <asavkov@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220406085408.339336-1-asavkov@redhat.com
2022-04-06libbpf: Fix spelling mistake "libaries" -> "libraries"Colin Ian King
There is a spelling mistake in a pr_warn message. Fix it. Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220406080835.14879-1-colin.i.king@gmail.com
2022-04-06selftests/bpf: Fix issues in parse_num_list()Yuntao Wang
The function does not check that parsing_end is false after parsing argument. Thus, if the final part of the argument is something like '4-', which is invalid, parse_num_list() will discard it instead of returning -EINVAL. Before: $ ./test_progs -n 2,4- #2 atomic_bounds:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED After: $ ./test_progs -n 2,4- Failed to parse test numbers. Signed-off-by: Yuntao Wang <ytcoode@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220406003622.73539-1-ytcoode@gmail.com
2022-04-06bpf: Adjust bpf_tcp_check_syncookie selftest to test dual-stack socketsMaxim Mikityanskiy
The previous commit fixed support for dual-stack sockets in bpf_tcp_check_syncookie. This commit adjusts the selftest to verify the fixed functionality. Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Arthur Fabre <afabre@cloudflare.com> Link: https://lore.kernel.org/bpf/20220406124113.2795730-2-maximmi@nvidia.com
2022-04-06KVM: arm64: selftests: Introduce vcpu_width_configReiji Watanabe
Introduce a test for aarch64 that ensures non-mixed-width vCPUs (all 64bit vCPUs or all 32bit vcPUs) can be configured, and mixed-width vCPUs cannot be configured. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Reiji Watanabe <reijiw@google.com> Reviewed-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220329031924.619453-3-reijiw@google.com
2022-04-05selftests/bpf: Fix file descriptor leak in load_kallsyms()Yuntao Wang
Currently, if sym_cnt > 0, it just returns and does not close file, fix it. Signed-off-by: Yuntao Wang <ytcoode@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220405145711.49543-1-ytcoode@gmail.com
2022-04-05selftests/bpf: Add urandom_read shared lib and USDTsAndrii Nakryiko
Extend urandom_read helper binary to include USDTs of 4 combinations: semaphore/semaphoreless (refcounted and non-refcounted) and based in executable or shared library. We also extend urandom_read with ability to report it's own PID to parent process and wait for parent process to ready itself up for tracing urandom_read. We utilize popen() and underlying pipe properties for proper signaling. Once urandom_read is ready, we add few tests to validate that libbpf's USDT attachment handles all the above combinations of semaphore (or lack of it) and static or shared library USDTs. Also, we validate that libbpf handles shared libraries both with PID filter and without one (i.e., -1 for PID argument). Having the shared library case tested with and without PID is important because internal logic differs on kernels that don't support BPF cookies. On such older kernels, attaching to USDTs in shared libraries without specifying concrete PID doesn't work in principle, because it's impossible to determine shared library's load address to derive absolute IPs for uprobe attachments. Without absolute IPs, it's impossible to perform correct look up of USDT spec based on uprobe's absolute IP (the only kind available from BPF at runtime). This is not the problem on newer kernels with BPF cookie as we don't need IP-to-ID lookup because BPF cookie value *is* spec ID. So having those two situations as separate subtests is good because libbpf CI is able to test latest selftests against old kernels (e.g., 4.9 and 5.5), so we'll be able to disable PID-less shared lib attachment for old kernels, but will still leave PID-specific one enabled to validate this legacy logic is working correctly. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20220404234202.331384-8-andrii@kernel.org
2022-04-05selftests/bpf: Add basic USDT selftestsAndrii Nakryiko
Add semaphore-based USDT to test_progs itself and write basic tests to valicate both auto-attachment and manual attachment logic, as well as BPF-side functionality. Also add subtests to validate that libbpf properly deduplicates USDT specs and handles spec overflow situations correctly, as well as proper "rollback" of partially-attached multi-spec USDT. BPF-side of selftest intentionally consists of two files to validate that usdt.bpf.h header can be included from multiple source code files that are subsequently linked into final BPF object file without causing any symbol duplication or other issues. We are validating that __weak maps and bpf_usdt_xxx() API functions defined in usdt.bpf.h do work as intended. USDT selftests utilize sys/sdt.h header that on Ubuntu systems comes from systemtap-sdt-devel package. But to simplify everyone's life, including CI but especially casual contributors to bpf/bpf-next that are trying to build selftests, I've checked in sys/sdt.h header from [0] directly. This way it will work on all architectures and distros without having to figure it out for every relevant combination and adding any extra implicit package dependencies. [0] https://sourceware.org/git?p=systemtap.git;a=blob_plain;f=includes/sys/sdt.h;h=ca0162b4dc57520b96638c8ae79ad547eb1dd3a1;hb=HEAD Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20220404234202.331384-7-andrii@kernel.org
2022-04-05libbpf: Add x86-specific USDT arg spec parsing logicAndrii Nakryiko
Add x86/x86_64-specific USDT argument specification parsing. Each architecture will require their own logic, as all this is arch-specific assembly-based notation. Architectures that libbpf doesn't support for USDTs will pr_warn() with specific error and return -ENOTSUP. We use sscanf() as a very powerful and easy to use string parser. Those spaces in sscanf's format string mean "skip any whitespaces", which is pretty nifty (and somewhat little known) feature. All this was tested on little-endian architecture, so bit shifts are probably off on big-endian, which our CI will hopefully prove. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Reviewed-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20220404234202.331384-6-andrii@kernel.org
2022-04-05libbpf: Wire up spec management and other arch-independent USDT logicAndrii Nakryiko
Last part of architecture-agnostic user-space USDT handling logic is to set up BPF spec and, optionally, IP-to-ID maps from user-space. usdt_manager performs a compact spec ID allocation to utilize fixed-sized BPF maps as efficiently as possible. We also use hashmap to deduplicate USDT arg spec strings and map identical strings to single USDT spec, minimizing the necessary BPF map size. usdt_manager supports arbitrary sequences of attachment and detachment, both of the same USDT and multiple different USDTs and internally maintains a free list of unused spec IDs. bpf_link_usdt's logic is extended with proper setup and teardown of this spec ID free list and supporting BPF maps. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Reviewed-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20220404234202.331384-5-andrii@kernel.org
2022-04-05libbpf: Add USDT notes parsing and resolution logicAndrii Nakryiko
Implement architecture-agnostic parts of USDT parsing logic. The code is the documentation in this case, it's futile to try to succinctly describe how USDT parsing is done in any sort of concreteness. But still, USDTs are recorded in special ELF notes section (.note.stapsdt), where each USDT call site is described separately. Along with USDT provider and USDT name, each such note contains USDT argument specification, which uses assembly-like syntax to describe how to fetch value of USDT argument. USDT arg spec could be just a constant, or a register, or a register dereference (most common cases in x86_64), but it technically can be much more complicated cases, like offset relative to global symbol and stuff like that. One of the later patches will implement most common subset of this for x86 and x86-64 architectures, which seems to handle a lot of real-world production application. USDT arg spec contains a compact encoding allowing usdt.bpf.h from previous patch to handle the above 3 cases. Instead of recording which register might be needed, we encode register's offset within struct pt_regs to simplify BPF-side implementation. USDT argument can be of different byte sizes (1, 2, 4, and 8) and signed or unsigned. To handle this, libbpf pre-calculates necessary bit shifts to do proper casting and sign-extension in a short sequences of left and right shifts. The rest is in the code with sometimes extensive comments and references to external "documentation" for USDTs. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Reviewed-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20220404234202.331384-4-andrii@kernel.org
2022-04-05libbpf: Wire up USDT API and bpf_link integrationAndrii Nakryiko
Wire up libbpf USDT support APIs without yet implementing all the nitty-gritty details of USDT discovery, spec parsing, and BPF map initialization. User-visible user-space API is simple and is conceptually very similar to uprobe API. bpf_program__attach_usdt() API allows to programmatically attach given BPF program to a USDT, specified through binary path (executable or shared lib), USDT provider and name. Also, just like in uprobe case, PID filter is specified (0 - self, -1 - any process, or specific PID). Optionally, USDT cookie value can be specified. Such single API invocation will try to discover given USDT in specified binary and will use (potentially many) BPF uprobes to attach this program in correct locations. Just like any bpf_program__attach_xxx() APIs, bpf_link is returned that represents this attachment. It is a virtual BPF link that doesn't have direct kernel object, as it can consist of multiple underlying BPF uprobe links. As such, attachment is not atomic operation and there can be brief moment when some USDT call sites are attached while others are still in the process of attaching. This should be taken into consideration by user. But bpf_program__attach_usdt() guarantees that in the case of success all USDT call sites are successfully attached, or all the successfuly attachments will be detached as soon as some USDT call sites failed to be attached. So, in theory, there could be cases of failed bpf_program__attach_usdt() call which did trigger few USDT program invocations. This is unavoidable due to multi-uprobe nature of USDT and has to be handled by user, if it's important to create an illusion of atomicity. USDT BPF programs themselves are marked in BPF source code as either SEC("usdt"), in which case they won't be auto-attached through skeleton's <skel>__attach() method, or it can have a full definition, which follows the spirit of fully-specified uprobes: SEC("usdt/<path>:<provider>:<name>"). In the latter case skeleton's attach method will attempt auto-attachment. Similarly, generic bpf_program__attach() will have enought information to go off of for parameterless attachment. USDT BPF programs are actually uprobes, and as such for kernel they are marked as BPF_PROG_TYPE_KPROBE. Another part of this patch is USDT-related feature probing: - BPF cookie support detection from user-space; - detection of kernel support for auto-refcounting of USDT semaphore. The latter is optional. If kernel doesn't support such feature and USDT doesn't rely on USDT semaphores, no error is returned. But if libbpf detects that USDT requires setting semaphores and kernel doesn't support this, libbpf errors out with explicit pr_warn() message. Libbpf doesn't support poking process's memory directly to increment semaphore value, like BCC does on legacy kernels, due to inherent raciness and danger of such process memory manipulation. Libbpf let's kernel take care of this properly or gives up. Logistically, all the extra USDT-related infrastructure of libbpf is put into a separate usdt.c file and abstracted behind struct usdt_manager. Each bpf_object has lazily-initialized usdt_manager pointer, which is only instantiated if USDT programs are attempted to be attached. Closing BPF object frees up usdt_manager resources. usdt_manager keeps track of USDT spec ID assignment and few other small things. Subsequent patches will fill out remaining missing pieces of USDT initialization and setup logic. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Link: https://lore.kernel.org/bpf/20220404234202.331384-3-andrii@kernel.org
2022-04-05libbpf: Add BPF-side of USDT supportAndrii Nakryiko
Add BPF-side implementation of libbpf-provided USDT support. This consists of single header library, usdt.bpf.h, which is meant to be used from user's BPF-side source code. This header is added to the list of installed libbpf header, along bpf_helpers.h and others. BPF-side implementation consists of two BPF maps: - spec map, which contains "a USDT spec" which encodes information necessary to be able to fetch USDT arguments and other information (argument count, user-provided cookie value, etc) at runtime; - IP-to-spec-ID map, which is only used on kernels that don't support BPF cookie feature. It allows to lookup spec ID based on the place in user application that triggers USDT program. These maps have default sizes, 256 and 1024, which are chosen conservatively to not waste a lot of space, but handling a lot of common cases. But there could be cases when user application needs to either trace a lot of different USDTs, or USDTs are heavily inlined and their arguments are located in a lot of differing locations. For such cases it might be necessary to size those maps up, which libbpf allows to do by overriding BPF_USDT_MAX_SPEC_CNT and BPF_USDT_MAX_IP_CNT macros. It is an important aspect to keep in mind. Single USDT (user-space equivalent of kernel tracepoint) can have multiple USDT "call sites". That is, single logical USDT is triggered from multiple places in user application. This can happen due to function inlining. Each such inlined instance of USDT invocation can have its own unique USDT argument specification (instructions about the location of the value of each of USDT arguments). So while USDT looks very similar to usual uprobe or kernel tracepoint, under the hood it's actually a collection of uprobes, each potentially needing different spec to know how to fetch arguments. User-visible API consists of three helper functions: - bpf_usdt_arg_cnt(), which returns number of arguments of current USDT; - bpf_usdt_arg(), which reads value of specified USDT argument (by it's zero-indexed position) and returns it as 64-bit value; - bpf_usdt_cookie(), which functions like BPF cookie for USDT programs; this is necessary as libbpf doesn't allow specifying actual BPF cookie and utilizes it internally for USDT support implementation. Each bpf_usdt_xxx() APIs expect struct pt_regs * context, passed into BPF program. On kernels that don't support BPF cookie it is used to fetch absolute IP address of the underlying uprobe. usdt.bpf.h also provides BPF_USDT() macro, which functions like BPF_PROG() and BPF_KPROBE() and allows much more user-friendly way to get access to USDT arguments, if USDT definition is static and known to the user. It is expected that majority of use cases won't have to use bpf_usdt_arg_cnt() and bpf_usdt_arg() directly and BPF_USDT() will cover all their needs. Last, usdt.bpf.h is utilizing BPF CO-RE for one single purpose: to detect kernel support for BPF cookie. If BPF CO-RE dependency is undesirable, user application can redefine BPF_USDT_HAS_BPF_COOKIE to either a boolean constant (or equivalently zero and non-zero), or even point it to its own .rodata variable that can be specified from user's application user-space code. It is important that BPF_USDT_HAS_BPF_COOKIE is known to BPF verifier as static value (thus .rodata and not just .data), as otherwise BPF code will still contain bpf_get_attach_cookie() BPF helper call and will fail validation at runtime, if not dead-code eliminated. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Link: https://lore.kernel.org/bpf/20220404234202.331384-2-andrii@kernel.org
2022-04-05objtool: Fix SLS validation for kcov tail-call replacementPeter Zijlstra
Since not all compilers have a function attribute to disable KCOV instrumentation, objtool can rewrite KCOV instrumentation in noinstr functions as per commit: f56dae88a81f ("objtool: Handle __sanitize_cov*() tail calls") However, this has subtle interaction with the SLS validation from commit: 1cc1e4c8aab4 ("objtool: Add straight-line-speculation validation") In that when a tail-call instrucion is replaced with a RET an additional INT3 instruction is also written, but is not represented in the decoded instruction stream. This then leads to false positive missing INT3 objtool warnings in noinstr code. Instead of adding additional struct instruction objects, mark the RET instruction with retpoline_safe to suppress the warning (since we know there really is an INT3). Fixes: 1cc1e4c8aab4 ("objtool: Add straight-line-speculation validation") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220323230712.GA8939@worktop.programming.kicks-ass.net
2022-04-05objtool: Fix IBT tail-call detectionPeter Zijlstra
Objtool reports: arch/x86/crypto/poly1305-x86_64.o: warning: objtool: poly1305_blocks_avx() falls through to next function poly1305_blocks_x86_64() arch/x86/crypto/poly1305-x86_64.o: warning: objtool: poly1305_emit_avx() falls through to next function poly1305_emit_x86_64() arch/x86/crypto/poly1305-x86_64.o: warning: objtool: poly1305_blocks_avx2() falls through to next function poly1305_blocks_x86_64() Which reads like: 0000000000000040 <poly1305_blocks_x86_64>: 40: f3 0f 1e fa endbr64 ... 0000000000000400 <poly1305_blocks_avx>: 400: f3 0f 1e fa endbr64 404: 44 8b 47 14 mov 0x14(%rdi),%r8d 408: 48 81 fa 80 00 00 00 cmp $0x80,%rdx 40f: 73 09 jae 41a <poly1305_blocks_avx+0x1a> 411: 45 85 c0 test %r8d,%r8d 414: 0f 84 2a fc ff ff je 44 <poly1305_blocks_x86_64+0x4> ... These are simple conditional tail-calls and *should* be recognised as such by objtool, however due to a mistake in commit 08f87a93c8ec ("objtool: Validate IBT assumptions") this is failing. Specifically, the jump_dest is +4, this means the instruction pointed at will not be ENDBR and as such it will fail the second clause of is_first_func_insn() that was supposed to capture this exact case. Instead, have is_first_func_insn() look at the previous instruction. Fixes: 08f87a93c8ec ("objtool: Validate IBT assumptions") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220322115125.811582125@infradead.org
2022-04-04libbpf: Support Debian in resolve_full_path()Ilya Leoshkevich
attach_probe selftest fails on Debian-based distros with `failed to resolve full path for 'libc.so.6'`. The reason is that these distros embraced multiarch to the point where even for the "main" architecture they store libc in /lib/<triple>. This is configured in /etc/ld.so.conf and in theory it's possible to replicate the loader's parsing and processing logic in libbpf, however a much simpler solution is to just enumerate the known library paths. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220404225020.51029-1-iii@linux.ibm.com
2022-04-04selftests/bpf: Define SYS_NANOSLEEP_KPROBE_NAME for aarch64Ilya Leoshkevich
attach_probe selftest fails on aarch64 with `failed to create kprobe 'sys_nanosleep+0x0' perf event: No such file or directory`. This is because, like on several other architectures, nanosleep has a prefix. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Alan Maguire <alan.maguire@oracle.com> Link: https://lore.kernel.org/bpf/20220404142101.27900-1-iii@linux.ibm.com
2022-04-04bpftool: Handle libbpf_probe_prog_type errorsMilan Landaverde
Previously [1], we were using bpf_probe_prog_type which returned a bool, but the new libbpf_probe_bpf_prog_type can return a negative error code on failure. This change decides for bpftool to declare a program type is not available on probe failure. [1] https://lore.kernel.org/bpf/20220202225916.3313522-3-andrii@kernel.org/ Signed-off-by: Milan Landaverde <milan@mdaverde.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20220331154555.422506-4-milan@mdaverde.com
2022-04-04bpftool: Add missing link typesMilan Landaverde
Will display the link type names in bpftool link show output Signed-off-by: Milan Landaverde <milan@mdaverde.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220331154555.422506-3-milan@mdaverde.com
2022-04-04bpftool: Add syscall prog typeMilan Landaverde
In addition to displaying the program type in bpftool prog show this enables us to be able to query bpf_prog_type_syscall availability through feature probe as well as see which helpers are available in those programs (such as bpf_sys_bpf and bpf_sys_close) Signed-off-by: Milan Landaverde <milan@mdaverde.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20220331154555.422506-2-milan@mdaverde.com
2022-04-04selftests/bpf: Fix parsing of prog types in UAPI hdr for bpftool syncQuentin Monnet
The script for checking that various lists of types in bpftool remain in sync with the UAPI BPF header uses a regex to parse enum bpf_prog_type. If this enum contains a set of values different from the list of program types in bpftool, it complains. This script should have reported the addition, some time ago, of the new BPF_PROG_TYPE_SYSCALL, which was not reported to bpftool's program types list. It failed to do so, because it failed to parse that new type from the enum. This is because the new value, in the BPF header, has an explicative comment on the same line, and the regex does not support that. Let's update the script to support parsing enum values when they have comments on the same line. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220404140944.64744-1-quentin@isovalent.com
2022-04-04selftests/harness: Pass variant to teardownWillem de Bruijn
FIXTURE_VARIANT data is passed to FIXTURE_SETUP and TEST_F as "variant". In some cases, the variant will change the setup, such that expectations also change on teardown. Also pass variant to FIXTURE_TEARDOWN. The new FIXTURE_TEARDOWN logic is identical to that in FIXTURE_SETUP, right above. Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201210231010.420298-1-willemdebruijn.kernel@gmail.com Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-04-04selftests/harness: Run TEARDOWN for ASSERT failuresKees Cook
The kselftest test harness has traditionally not run the registered TEARDOWN handler when a test encountered an ASSERT. This creates unexpected situations and tests need to be very careful about using ASSERT, which seems a needless hurdle for test writers. Because of the harness's design for optional failure handlers, the original implementation of ASSERT used an abort() to immediately stop execution, but that meant the context for running teardown was lost. Instead, use setjmp/longjmp so that teardown can be done. Failed SETUP routines continue to not be followed by TEARDOWN, though. Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: Shuah Khan <shuah@kernel.org> Cc: linux-kselftest@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-04-04selftests: fix an unused variable warning in pidfd selftestAxel Rasmussen
I fixed a few warnings like this in commit e2aa5e650b07 ("selftests: fixup build warnings in pidfd / clone3 tests"), but I missed this one by mistake. Since this variable is unused, remove it. Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-04-04selftests: fix header dependency for pid_namespace selftestsAxel Rasmussen
The way the test target was defined before, when building with clang we get a command line like this: clang -Wall -Werror -g -I../../../../usr/include/ \ regression_enomem.c ../pidfd/pidfd.h -o regression_enomem This yields an error, because clang thinks we want to produce both a *.o file, as well as a precompiled header: clang: error: cannot specify -o when generating multiple output files gcc, for whatever reason, doesn't exhibit the same behavior which I suspect is why the problem wasn't noticed before. This can be fixed simply by using the LOCAL_HDRS infrastructure the selftests lib.mk provides. It does the right think and marks the target as depending on the header (so if the header changes, we rebuild), but it filters the header out of the compiler command line, so we don't get the error described above. Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-04-04selftests: x86: add 32bit build warnings for SUSEGeliang Tang
In order to successfully build all these 32bit tests, these 32bit gcc and glibc packages, named gcc-32bit and glibc-devel-static-32bit on SUSE, need to be installed. This patch added this information in warn_32bit_failure. Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-04-04selftests/proc: fix array_size.cocci warningGuo Zhengkui
Fix the following coccicheck warning: tools/testing/selftests/proc/proc-pid-vm.c:371:26-27: WARNING: Use ARRAY_SIZE tools/testing/selftests/proc/proc-pid-vm.c:420:26-27: WARNING: Use ARRAY_SIZE It has been tested with gcc (Debian 8.3.0-6) 8.3.0 on x86_64. Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-04-04selftests/vDSO: fix array_size.cocci warningGuo Zhengkui
Fix the following coccicheck warning: tools/testing/selftests/vDSO/vdso_test_correctness.c:309:46-47: WARNING: Use ARRAY_SIZE tools/testing/selftests/vDSO/vdso_test_correctness.c:373:46-47: WARNING: Use ARRAY_SIZE It has been tested with gcc (Debian 8.3.0-6) 8.3.0 on x86_64. Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-04-03libbpf: Don't return -EINVAL if hdr_len < offsetofend(core_relo_len)Yuntao Wang
Since core relos is an optional part of the .BTF.ext ELF section, we should skip parsing it instead of returning -EINVAL if header size is less than offsetofend(struct btf_ext_header, core_relo_len). Signed-off-by: Yuntao Wang <ytcoode@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220404005320.1723055-1-ytcoode@gmail.com
2022-04-03selftests/bpf: Add tests for uprobe auto-attach via skeletonAlan Maguire
tests that verify auto-attach works for function entry/return for local functions in program and library functions in a library. Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1648654000-21758-6-git-send-email-alan.maguire@oracle.com
2022-04-03selftests/bpf: Add tests for u[ret]probe attach by nameAlan Maguire
add tests that verify attaching by name for 1. local functions in a program 2. library functions in a shared object ...succeed for uprobe and uretprobes using new "func_name" option for bpf_program__attach_uprobe_opts(). Also verify auto-attach works where uprobe, path to binary and function name are specified, but fails with -EOPNOTSUPP with a SEC name that does not specify binary path/function. Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1648654000-21758-5-git-send-email-alan.maguire@oracle.com
2022-04-03libbpf: Add auto-attach for uprobes based on section nameAlan Maguire
Now that u[ret]probes can use name-based specification, it makes sense to add support for auto-attach based on SEC() definition. The format proposed is SEC("u[ret]probe/binary:[raw_offset|[function_name[+offset]]") For example, to trace malloc() in libc: SEC("uprobe/libc.so.6:malloc") ...or to trace function foo2 in /usr/bin/foo: SEC("uprobe//usr/bin/foo:foo2") Auto-attach is done for all tasks (pid -1). prog can be an absolute path or simply a program/library name; in the latter case, we use PATH/LD_LIBRARY_PATH to resolve the full path, falling back to standard locations (/usr/bin:/usr/sbin or /usr/lib64:/usr/lib) if the file is not found via environment-variable specified locations. Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1648654000-21758-4-git-send-email-alan.maguire@oracle.com
2022-04-03libbpf: Support function name-based attach uprobesAlan Maguire
kprobe attach is name-based, using lookups of kallsyms to translate a function name to an address. Currently uprobe attach is done via an offset value as described in [1]. Extend uprobe opts for attach to include a function name which can then be converted into a uprobe-friendly offset. The calcualation is done in several steps: 1. First, determine the symbol address using libelf; this gives us the offset as reported by objdump 2. If the function is a shared library function - and the binary provided is a shared library - no further work is required; the address found is the required address 3. Finally, if the function is local, subtract the base address associated with the object, retrieved from ELF program headers. The resultant value is then added to the func_offset value passed in to specify the uprobe attach address. So specifying a func_offset of 0 along with a function name "printf" will attach to printf entry. The modes of operation supported are then 1. to attach to a local function in a binary; function "foo1" in "/usr/bin/foo" 2. to attach to a shared library function in a shared library - function "malloc" in libc. [1] https://www.kernel.org/doc/html/latest/trace/uprobetracer.html Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1648654000-21758-3-git-send-email-alan.maguire@oracle.com
2022-04-03libbpf: auto-resolve programs/libraries when necessary for uprobesAlan Maguire
bpf_program__attach_uprobe_opts() requires a binary_path argument specifying binary to instrument. Supporting simply specifying "libc.so.6" or "foo" should be possible too. Library search checks LD_LIBRARY_PATH, then /usr/lib64, /usr/lib. This allows users to run BPF programs prefixed with LD_LIBRARY_PATH=/path2/lib while still searching standard locations. Similarly for non .so files, we check PATH and /usr/bin, /usr/sbin. Path determination will be useful for auto-attach of BPF uprobe programs using SEC() definition. Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1648654000-21758-2-git-send-email-alan.maguire@oracle.com
2022-04-03bpf: Correct the comment for BTF kind bitfieldHaiyue Wang
The commit 8fd886911a6a ("bpf: Add BTF_KIND_FLOAT to uapi") has extended the BTF kind bitfield from 4 to 5 bits, correct the comment. Signed-off-by: Haiyue Wang <haiyue.wang@intel.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220403115327.205964-1-haiyue.wang@intel.com
2022-04-03selftests/bpf: Fix cd_flavor_subdir() of test_progsYuntao Wang
Currently, when we run test_progs with just executable file name, for example 'PATH=. test_progs-no_alu32', cd_flavor_subdir() will not check if test_progs is running as a flavored test runner and switch into corresponding sub-directory. This will cause test_progs-no_alu32 executed by the 'PATH=. test_progs-no_alu32' command to run in the wrong directory and load the wrong BPF objects. Signed-off-by: Yuntao Wang <ytcoode@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220403135245.1713283-1-ytcoode@gmail.com