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* libbpf: Fixes incorrect rx_ring_setup_doneKev Jackson2021-06-231-1/+1
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 11fc79fc9f2e395aa39fa5baccae62767c5d8280 ] When calling xsk_socket__create_shared(), the logic at line 1097 marks a boolean flag true within the xsk_umem structure to track setup progress in order to support multiple calls to the function. However, instead of marking umem->tx_ring_setup_done, the code incorrectly sets umem->rx_ring_setup_done. This leads to improper behaviour when creating and destroying xsk and umem structures. Multiple calls to this function is documented as supported. Fixes: ca7a83e2487a ("libbpf: Only create rx and tx XDP rings when necessary") Signed-off-by: Kev Jackson <foamdino@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/YL4aU4f3Aaik7CN0@linux-dev Signed-off-by: Sasha Levin <sashal@kernel.org>
* libbpf: Fix signed overflow in ringbuf_process_ringBrendan Jackman2021-05-191-9/+21
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 2a30f9440640c418bcfbea9b2b344d268b58e0a2 ] One of our benchmarks running in (Google-internal) CI pushes data through the ringbuf faster htan than userspace is able to consume it. In this case it seems we're actually able to get >INT_MAX entries in a single ring_buffer__consume() call. ASAN detected that cnt overflows in this case. Fix by using 64-bit counter internally and then capping the result to INT_MAX before converting to the int return type. Do the same for the ring_buffer__poll(). Fixes: bf99c936f947 (libbpf: Add BPF ring buffer support) Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210429130510.1621665-1-jackmanb@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* selftests/bpf: Fix BPF_CORE_READ_BITFIELD() macroAndrii Nakryiko2021-05-141-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 0f20615d64ee2ad5e2a133a812382d0c4071589b ] Fix BPF_CORE_READ_BITFIELD() macro used for reading CO-RE-relocatable bitfields. Missing breaks in a switch caused 8-byte reads always. This can confuse libbpf because it does strict checks that memory load size corresponds to the original size of the field, which in this case quite often would be wrong. After fixing that, we run into another problem, which quite subtle, so worth documenting here. The issue is in Clang optimization and CO-RE relocation interactions. Without that asm volatile construct (also known as barrier_var()), Clang will re-order BYTE_OFFSET and BYTE_SIZE relocations and will apply BYTE_OFFSET 4 times for each switch case arm. This will result in the same error from libbpf about mismatch of memory load size and original field size. I.e., if we were reading u32, we'd still have *(u8 *), *(u16 *), *(u32 *), and *(u64 *) memory loads, three of which will fail. Using barrier_var() forces Clang to apply BYTE_OFFSET relocation first (and once) to calculate p, after which value of p is used without relocation in each of switch case arms, doing appropiately-sized memory load. Here's the list of relevant relocations and pieces of generated BPF code before and after this patch for test_core_reloc_bitfields_direct selftests. BEFORE ===== #45: core_reloc: insn #160 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32 #46: core_reloc: insn #167 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #47: core_reloc: insn #174 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #48: core_reloc: insn #178 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #49: core_reloc: insn #182 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 157: 18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll 159: 7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1 160: b7 02 00 00 04 00 00 00 r2 = 4 ; BYTE_SIZE relocation here ^^^ 161: 66 02 07 00 03 00 00 00 if w2 s> 3 goto +7 <LBB0_63> 162: 16 02 0d 00 01 00 00 00 if w2 == 1 goto +13 <LBB0_65> 163: 16 02 01 00 02 00 00 00 if w2 == 2 goto +1 <LBB0_66> 164: 05 00 12 00 00 00 00 00 goto +18 <LBB0_69> 0000000000000528 <LBB0_66>: 165: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 167: 69 11 08 00 00 00 00 00 r1 = *(u16 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 168: 05 00 0e 00 00 00 00 00 goto +14 <LBB0_69> 0000000000000548 <LBB0_63>: 169: 16 02 0a 00 04 00 00 00 if w2 == 4 goto +10 <LBB0_67> 170: 16 02 01 00 08 00 00 00 if w2 == 8 goto +1 <LBB0_68> 171: 05 00 0b 00 00 00 00 00 goto +11 <LBB0_69> 0000000000000560 <LBB0_68>: 172: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 174: 79 11 08 00 00 00 00 00 r1 = *(u64 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 175: 05 00 07 00 00 00 00 00 goto +7 <LBB0_69> 0000000000000580 <LBB0_65>: 176: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 178: 71 11 08 00 00 00 00 00 r1 = *(u8 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 179: 05 00 03 00 00 00 00 00 goto +3 <LBB0_69> 00000000000005a0 <LBB0_67>: 180: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 182: 61 11 08 00 00 00 00 00 r1 = *(u32 *)(r1 + 8) ; BYTE_OFFSET relo here w/ RIGHT size ^^^^^^^^^^^^^^^^ 00000000000005b8 <LBB0_69>: 183: 67 01 00 00 20 00 00 00 r1 <<= 32 184: b7 02 00 00 00 00 00 00 r2 = 0 185: 16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71> 186: c7 01 00 00 20 00 00 00 r1 s>>= 32 187: 05 00 01 00 00 00 00 00 goto +1 <LBB0_72> 00000000000005e0 <LBB0_71>: 188: 77 01 00 00 20 00 00 00 r1 >>= 32 AFTER ===== #30: core_reloc: insn #132 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #31: core_reloc: insn #134 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32 129: 18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll 131: 7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1 132: b7 01 00 00 08 00 00 00 r1 = 8 ; BYTE_OFFSET relo here ^^^ ; no size check for non-memory dereferencing instructions 133: 0f 12 00 00 00 00 00 00 r2 += r1 134: b7 03 00 00 04 00 00 00 r3 = 4 ; BYTE_SIZE relocation here ^^^ 135: 66 03 05 00 03 00 00 00 if w3 s> 3 goto +5 <LBB0_63> 136: 16 03 09 00 01 00 00 00 if w3 == 1 goto +9 <LBB0_65> 137: 16 03 01 00 02 00 00 00 if w3 == 2 goto +1 <LBB0_66> 138: 05 00 0a 00 00 00 00 00 goto +10 <LBB0_69> 0000000000000458 <LBB0_66>: 139: 69 21 00 00 00 00 00 00 r1 = *(u16 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 140: 05 00 08 00 00 00 00 00 goto +8 <LBB0_69> 0000000000000468 <LBB0_63>: 141: 16 03 06 00 04 00 00 00 if w3 == 4 goto +6 <LBB0_67> 142: 16 03 01 00 08 00 00 00 if w3 == 8 goto +1 <LBB0_68> 143: 05 00 05 00 00 00 00 00 goto +5 <LBB0_69> 0000000000000480 <LBB0_68>: 144: 79 21 00 00 00 00 00 00 r1 = *(u64 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 145: 05 00 03 00 00 00 00 00 goto +3 <LBB0_69> 0000000000000490 <LBB0_65>: 146: 71 21 00 00 00 00 00 00 r1 = *(u8 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 147: 05 00 01 00 00 00 00 00 goto +1 <LBB0_69> 00000000000004a0 <LBB0_67>: 148: 61 21 00 00 00 00 00 00 r1 = *(u32 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 00000000000004a8 <LBB0_69>: 149: 67 01 00 00 20 00 00 00 r1 <<= 32 150: b7 02 00 00 00 00 00 00 r2 = 0 151: 16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71> 152: c7 01 00 00 20 00 00 00 r1 s>>= 32 153: 05 00 01 00 00 00 00 00 goto +1 <LBB0_72> 00000000000004d0 <LBB0_71>: 154: 77 01 00 00 20 00 00 00 r1 >>= 323 Fixes: ee26dade0e3b ("libbpf: Add support for relocatable bitfields") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Lorenz Bauer <lmb@cloudflare.com> Link: https://lore.kernel.org/bpf/20210426192949.416837-4-andrii@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
* libbpf: Initialize the bpf_seq_printf parameters array field by fieldFlorent Revest2021-05-141-11/+29
| | | | | | | | | | | | | | | | [ Upstream commit 83cd92b46484aa8f64cdc0bff8ac6940d1f78519 ] When initializing the __param array with a one liner, if all args are const, the initial array value will be placed in the rodata section but because libbpf does not support relocation in the rodata section, any pointer in this array will stay NULL. Fixes: c09add2fbc5a ("tools/libbpf: Add bpf_iter support") Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210419155243.1632274-5-revest@chromium.org Signed-off-by: Sasha Levin <sashal@kernel.org>
* libbpf: Add explicit padding to btf_dump_emit_type_decl_optsKP Singh2021-05-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit ea24b19562fe5f72c78319dbb347b701818956d9 ] Similar to https://lore.kernel.org/bpf/20210313210920.1959628-2-andrii@kernel.org/ When DECLARE_LIBBPF_OPTS is used with inline field initialization, e.g: DECLARE_LIBBPF_OPTS(btf_dump_emit_type_decl_opts, opts, .field_name = var_ident, .indent_level = 2, .strip_mods = strip_mods, ); and compiled in debug mode, the compiler generates code which leaves the padding uninitialized and triggers errors within libbpf APIs which require strict zero initialization of OPTS structs. Adding anonymous padding field fixes the issue. Fixes: 9f81654eebe8 ("libbpf: Expose BTF-to-C type declaration emitting API") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: KP Singh <kpsingh@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210319192117.2310658-1-kpsingh@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
* libbpf: Add explicit padding to bpf_xdp_set_link_optsAndrii Nakryiko2021-05-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | [ Upstream commit dde7b3f5f2f458297aeccfd4783e53ab8ca046db ] Adding such anonymous padding fixes the issue with uninitialized portions of bpf_xdp_set_link_opts when using LIBBPF_DECLARE_OPTS macro with inline field initialization: DECLARE_LIBBPF_OPTS(bpf_xdp_set_link_opts, opts, .old_fd = -1); When such code is compiled in debug mode, compiler is generating code that leaves padding bytes uninitialized, which triggers error inside libbpf APIs that do strict zero initialization checks for OPTS structs. Adding anonymous padding field fixes the issue. Fixes: bd5ca3ef93cd ("libbpf: Add function to set link XDP fd while specifying old program") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210313210920.1959628-2-andrii@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
* libbpf: Fix potential NULL pointer dereferenceCiara Loftus2021-04-211-2/+3
| | | | | | | | | | | | commit afd0be7299533bb2e2b09104399d8a467ecbd2c5 upstream. Wait until after the UMEM is checked for null to dereference it. Fixes: 43f1bc1efff1 ("libbpf: Restore umem state after socket create failure") Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210408052009.7844-1-ciara.loftus@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* libbpf: Only create rx and tx XDP rings when necessaryCiara Loftus2021-04-141-2/+11
| | | | | | | | | | | | | | | | | | | | | commit ca7a83e2487ad0bc9a3e0e7a8645354aa1782f13 upstream. Prior to this commit xsk_socket__create(_shared) always attempted to create the rx and tx rings for the socket. However this causes an issue when the socket being setup is that which shares the fd with the UMEM. If a previous call to this function failed with this socket after the rings were set up, a subsequent call would always fail because the rings are not torn down after the first call and when we try to set them up again we encounter an error because they already exist. Solve this by remembering whether the rings were set up by introducing new bools to struct xsk_umem which represent the ring setup status and using them to determine whether or not to set up the rings. Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210331061218.1647-4-ciara.loftus@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* libbpf: Restore umem state after socket create failureCiara Loftus2021-04-141-18/+23
| | | | | | | | | | | | | | | | | | | commit 43f1bc1efff16f553dd573d02eb7a15750925568 upstream. If the call to xsk_socket__create fails, the user may want to retry the socket creation using the same umem. Ensure that the umem is in the same state on exit if the call fails by: 1. ensuring the umem _save pointers are unmodified. 2. not unmapping the set of umem rings that were set up with the umem during xsk_umem__create, since those maps existed before the call to xsk_socket__create and should remain in tact even in the event of failure. Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices") Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210331061218.1647-3-ciara.loftus@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* libbpf: Ensure umem pointer is non-NULL before dereferencingCiara Loftus2021-04-141-0/+3
| | | | | | | | | | | | | | | commit df662016310aa4475d7986fd726af45c8fe4f362 upstream. Calls to xsk_socket__create dereference the umem to access the fill_save and comp_save pointers. Make sure the umem is non-NULL before doing this. Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices") Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20210331061218.1647-2-ciara.loftus@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* libbpf: Fix bail out from 'ringbuf_process_ring()' on errorPedro Tammela2021-04-141-1/+1
| | | | | | | | | | | | | | | | | commit 6032ebb54c60cae24329f6aba3ce0c1ca8ad6abe upstream. The current code bails out with negative and positive returns. If the callback returns a positive return code, 'ring_buffer__consume()' and 'ring_buffer__poll()' will return a spurious number of records consumed, but mostly important will continue the processing loop. This patch makes positive returns from the callback a no-op. Fixes: bf99c936f947 ("libbpf: Add BPF ring buffer support") Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210325150115.138750-1-pctammela@mojatatu.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* libbpf: Fix BTF dump of pointer-to-array-of-structJean-Philippe Brucker2021-03-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 901ee1d750f29a335423eeb9463c3ca461ca18c2 ] The vmlinux.h generated from BTF is invalid when building drivers/phy/ti/phy-gmii-sel.c with clang: vmlinux.h:61702:27: error: array type has incomplete element type ‘struct reg_field’ 61702 | const struct reg_field (*regfields)[3]; | ^~~~~~~~~ bpftool generates a forward declaration for this struct regfield, which compilers aren't happy about. Here's a simplified reproducer: struct inner { int val; }; struct outer { struct inner (*ptr_to_array)[2]; } A; After build with clang -> bpftool btf dump c -> clang/gcc: ./def-clang.h:11:23: error: array has incomplete element type 'struct inner' struct inner (*ptr_to_array)[2]; Member ptr_to_array of struct outer is a pointer to an array of struct inner. In the DWARF generated by clang, struct outer appears before struct inner, so when converting BTF of struct outer into C, bpftool issues a forward declaration to struct inner. With GCC the DWARF info is reversed so struct inner gets fully defined. That forward declaration is not sufficient when compilers handle an array of the struct, even when it's only used through a pointer. Note that we can trigger the same issue with an intermediate typedef: struct inner { int val; }; typedef struct inner inner2_t[2]; struct outer { inner2_t *ptr_to_array; } A; Becomes: struct inner; typedef struct inner inner2_t[2]; And causes: ./def-clang.h:10:30: error: array has incomplete element type 'struct inner' typedef struct inner inner2_t[2]; To fix this, clear through_ptr whenever we encounter an intermediate array, to make the inner struct part of a strong link and force full declaration. Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion") Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210319112554.794552-2-jean-philippe@linaro.org Signed-off-by: Sasha Levin <sashal@kernel.org>
* libbpf: Use SOCK_CLOEXEC when opening the netlink socketKumar Kartikeya Dwivedi2021-03-301-1/+1
| | | | | | | | | | | | | | | [ Upstream commit 58bfd95b554f1a23d01228672f86bb489bdbf4ba ] Otherwise, there exists a small window between the opening and closing of the socket fd where it may leak into processes launched by some other thread. Fixes: 949abbe88436 ("libbpf: add function to setup XDP") Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20210317115857.6536-1-memxor@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* libbpf: Fix error path in bpf_object__elf_init()Namhyung Kim2021-03-301-1/+2
| | | | | | | | | | | | | [ Upstream commit 8f3f5792f2940c16ab63c614b26494c8689c9c1e ] When it failed to get section names, it should call into bpf_object__elf_finish() like others. Fixes: 88a82120282b ("libbpf: Factor out common ELF operations and improve logging") Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210317145414.884817-1-namhyung@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
* libbpf: Fix INSTALL flag orderGeorgi Valkov2021-03-301-1/+1
| | | | | | | | | | | | | | | | | [ Upstream commit e7fb6465d4c8e767e39cbee72464e0060ab3d20c ] It was reported ([0]) that having optional -m flag between source and destination arguments in install command breaks bpftools cross-build on MacOS. Move -m to the front to fix this issue. [0] https://github.com/openwrt/openwrt/pull/3959 Fixes: 7110d80d53f4 ("libbpf: Makefile set specified permission mode") Signed-off-by: Georgi Valkov <gvalkov@abv.bg> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210308183038.613432-1-andrii@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
* libbpf: Clear map_info before each bpf_obj_get_info_by_fdMaciej Fijalkowski2021-03-171-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 2b2aedabc44e9660f90ccf7ba1ca2706d75f411f upstream. xsk_lookup_bpf_maps, based on prog_fd, looks whether current prog has a reference to XSKMAP. BPF prog can include insns that work on various BPF maps and this is covered by iterating through map_ids. The bpf_map_info that is passed to bpf_obj_get_info_by_fd for filling needs to be cleared at each iteration, so that it doesn't contain any outdated fields and that is currently missing in the function of interest. To fix that, zero-init map_info via memset before each bpf_obj_get_info_by_fd call. Also, since the area of this code is touched, in general strcmp is considered harmful, so let's convert it to strncmp and provide the size of the array name for current map_info. While at it, do s/continue/break/ once we have found the xsks_map to terminate the search. Fixes: 5750902a6e9b ("libbpf: proper XSKMAP cleanup") Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/20210303185636.18070-4-maciej.fijalkowski@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* libbpf: Ignore non function pointer member in struct_opsMartin KaFai Lau2021-03-041-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit d2836dddc95d5dd82c7cb23726c97d8c9147f050 ] When libbpf initializes the kernel's struct_ops in "bpf_map__init_kern_struct_ops()", it enforces all pointer types must be a function pointer and rejects others. It turns out to be too strict. For example, when directly using "struct tcp_congestion_ops" from vmlinux.h, it has a "struct module *owner" member and it is set to NULL in a bpf_tcp_cc.o. Instead, it only needs to ensure the member is a function pointer if it has been set (relocated) to a bpf-prog. This patch moves the "btf_is_func_proto(kern_mtype)" check after the existing "if (!prog) { continue; }". The original debug message in "if (!prog) { continue; }" is also removed since it is no longer valid. Beside, there is a later debug message to tell which function pointer is set. The "btf_is_func_proto(mtype)" has already been guaranteed in "bpf_object__collect_st_ops_relos()" which has been run before "bpf_map__init_kern_struct_ops()". Thus, this check is removed. v2: - Remove outdated debug message (Andrii) Remove because there is a later debug message to tell which function pointer is set. - Following mtype->type is no longer needed. Remove: "skip_mods_and_typedefs(btf, mtype->type, &mtype_id)" - Do "if (!prog)" test before skip_mods_and_typedefs. Fixes: 590a00888250 ("bpf: libbpf: Add STRUCT_OPS support") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210212021030.266932-1-kafai@fb.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* libbpf: Sanitise map names before pinningToke Høiland-Jørgensen2020-12-301-0/+12
| | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 9cf309c56f7910a81fbe053b6f11c3b1f0987b12 ] When we added sanitising of map names before loading programs to libbpf, we still allowed periods in the name. While the kernel will accept these for the map names themselves, they are not allowed in file names when pinning maps. This means that bpf_object__pin_maps() will fail if called on an object that contains internal maps (such as sections .rodata). Fix this by replacing periods with underscores when constructing map pin paths. This only affects the paths generated by libbpf when bpf_object__pin_maps() is called with a path argument. Any pin paths set by bpf_map__set_pin_path() are unaffected, and it will still be up to the caller to avoid invalid characters in those. Fixes: 113e6b7e15e2 ("libbpf: Sanitise internal map names so they are not rejected by the kernel") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20201203093306.107676-1-toke@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* libbpf: Fix ring_buffer__poll() to return number of consumed samplesAndrii Nakryiko2020-12-011-1/+1
| | | | | | | | | | | | Fix ring_buffer__poll() to return the number of non-discarded records consumed, just like its documentation states. It's also consistent with ring_buffer__consume() return. Fix up selftests with wrong expected results. Fixes: bf99c936f947 ("libbpf: Add BPF ring buffer support") Fixes: cb1c9ddd5525 ("selftests/bpf: Add BPF ringbuf selftests") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201130223336.904192-1-andrii@kernel.org
* libbpf: Fix VERSIONED_SYM_COUNT number parsingJiri Olsa2020-11-191-0/+2
| | | | | | | | | | | | | | | | | | | | | | | We remove "other info" from "readelf -s --wide" output when parsing GLOBAL_SYM_COUNT variable, which was added in [1]. But we don't do that for VERSIONED_SYM_COUNT and it's failing the check_abi target on powerpc Fedora 33. The extra "other info" wasn't problem for VERSIONED_SYM_COUNT parsing until commit [2] added awk in the pipe, which assumes that the last column is symbol, but it can be "other info". Adding "other info" removal for VERSIONED_SYM_COUNT the same way as we did for GLOBAL_SYM_COUNT parsing. [1] aa915931ac3e ("libbpf: Fix readelf output parsing for Fedora") [2] 746f534a4809 ("tools/libbpf: Avoid counting local symbols in ABI check") Fixes: 746f534a4809 ("tools/libbpf: Avoid counting local symbols in ABI check") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20201118211350.1493421-1-jolsa@kernel.org
* libbpf: Don't attempt to load unused subprog as an entry-point BPF programAndrii Nakryiko2020-11-091-10/+13
| | | | | | | | | | | | | | | | | | If BPF code contains unused BPF subprogram and there are no other subprogram calls (which can realistically happen in real-world applications given sufficiently smart Clang code optimizations), libbpf will erroneously assume that subprograms are entry-point programs and will attempt to load them with UNSPEC program type. Fix by not relying on subcall instructions and rather detect it based on the structure of BPF object's sections. Fixes: 9a94f277c4fb ("tools: libbpf: restore the ability to load programs from .text section") Reported-by: Dmitrii Banshchikov <dbanschikov@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20201107000251.256821-1-andrii@kernel.org
* libbpf: Fix possible use after free in xsk_socket__deleteMagnus Karlsson2020-11-041-2/+4
| | | | | | | | | | | | Fix a possible use after free in xsk_socket__delete that will happen if xsk_put_ctx() frees the ctx. To fix, save the umem reference taken from the context and just use that instead. Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices") Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1604396490-12129-3-git-send-email-magnus.karlsson@gmail.com
* libbpf: Fix null dereference in xsk_socket__deleteMagnus Karlsson2020-11-041-1/+2
| | | | | | | | | | | | Fix a possible null pointer dereference in xsk_socket__delete that will occur if a null pointer is fed into the function. Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices") Reported-by: Andrii Nakryiko <andrii.nakryiko@gmail.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1604396490-12129-2-git-send-email-magnus.karlsson@gmail.com
* libbpf, hashmap: Fix undefined behavior in hash_bitsIan Rogers2020-11-021-6/+9
| | | | | | | | | | | | | | | | | If bits is 0, the case when the map is empty, then the >> is the size of the register which is undefined behavior - on x86 it is the same as a shift by 0. Fix by handling the 0 case explicitly and guarding calls to hash_bits for empty maps in hashmap__for_each_key_entry and hashmap__for_each_entry_safe. Fixes: e3b924224028 ("libbpf: add resizable non-thread safe internal hashmap") Suggested-by: Andrii Nakryiko <andriin@fb.com>, Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20201029223707.494059-1-irogers@google.com
* bpf, libbpf: Guard bpf inline asm from bpf_tail_call_staticDaniel Borkmann2020-10-221-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Yaniv reported a compilation error after pulling latest libbpf: [...] ../libbpf/src/root/usr/include/bpf/bpf_helpers.h:99:10: error: unknown register name 'r0' in asm : "r0", "r1", "r2", "r3", "r4", "r5"); [...] The issue got triggered given Yaniv was compiling tracing programs with native target (e.g. x86) instead of BPF target, hence no BTF generated vmlinux.h nor CO-RE used, and later llc with -march=bpf was invoked to compile from LLVM IR to BPF object file. Given that clang was expecting x86 inline asm and not BPF one the error complained that these regs don't exist on the former. Guard bpf_tail_call_static() with defined(__bpf__) where BPF inline asm is valid to use. BPF tracing programs on more modern kernels use BPF target anyway and thus the bpf_tail_call_static() function will be available for them. BPF inline asm is supported since clang 7 (clang <= 6 otherwise throws same above error), and __bpf_unreachable() since clang 8, therefore include the latter condition in order to prevent compilation errors for older clang versions. Given even an old Ubuntu 18.04 LTS has official LLVM packages all the way up to llvm-10, I did not bother to special case the __bpf_unreachable() inside bpf_tail_call_static() further. Also, undo the sockex3_kern's use of bpf_tail_call_static() sample given they still have the old hacky way to even compile networking progs with native instead of BPF target so bpf_tail_call_static() won't be defined there anymore. Fixes: 0e9f6841f664 ("bpf, libbpf: Add bpf_tail_call_static helper for bpf programs") Reported-by: Yaniv Agman <yanivagman@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Tested-by: Yaniv Agman <yanivagman@gmail.com> Link: https://lore.kernel.org/bpf/CAMy7=ZUk08w5Gc2Z-EKi4JFtuUCaZYmE4yzhJjrExXpYKR4L8w@mail.gmail.com Link: https://lore.kernel.org/bpf/20201021203257.26223-1-daniel@iogearbox.net
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski2020-10-122-60/+295
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-10-12 The main changes are: 1) The BPF verifier improvements to track register allocation pattern, from Alexei and Yonghong. 2) libbpf relocation support for different size load/store, from Andrii. 3) bpf_redirect_peer() helper and support for inner map array with different max_entries, from Daniel. 4) BPF support for per-cpu variables, form Hao. 5) sockmap improvements, from John. ==================== Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * libbpf: Allow specifying both ELF and raw BTF for CO-RE BTF overrideAndrii Nakryiko2020-10-071-1/+1
| | | | | | | | | | | | | | | | | | | | Use generalized BTF parsing logic, making it possible to parse BTF both from ELF file, as well as a raw BTF dump. This makes it easier to write custom tests with manually generated BTFs. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201008001025.292064-4-andrii@kernel.org
| * libbpf: Support safe subset of load/store instruction resizing with CO-REAndrii Nakryiko2020-10-071-8/+136
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for patching instructions of the following form: - rX = *(T *)(rY + <off>); - *(T *)(rX + <off>) = rY; - *(T *)(rX + <off>) = <imm>, where T is one of {u8, u16, u32, u64}. For such instructions, if the actual kernel field recorded in CO-RE relocation has a different size than the one recorded locally (e.g., from vmlinux.h), then libbpf will adjust T to an appropriate 1-, 2-, 4-, or 8-byte loads. In general, such transformation is not always correct and could lead to invalid final value being loaded or stored. But two classes of cases are always safe: - if both local and target (kernel) types are unsigned integers, but of different sizes, then it's OK to adjust load/store instruction according to the necessary memory size. Zero-extending nature of such instructions and unsignedness make sure that the final value is always correct; - pointer size mismatch between BPF target architecture (which is always 64-bit) and 32-bit host kernel architecture can be similarly resolved automatically, because pointer is essentially an unsigned integer. Loading 32-bit pointer into 64-bit BPF register with zero extension will leave correct pointer in the register. Both cases are necessary to support CO-RE on 32-bit kernels, as `unsigned long` in vmlinux.h generated from 32-bit kernel is 32-bit, but when compiled with BPF program for BPF target it will be treated by compiler as 64-bit integer. Similarly, pointers in vmlinux.h are 32-bit for kernel, but treated as 64-bit values by compiler for BPF target. Both problems are now resolved by libbpf for direct memory reads. But similar transformations are useful in general when kernel fields are "resized" from, e.g., unsigned int to unsigned long (or vice versa). Now, similar transformations for signed integers are not safe to perform as they will result in incorrect sign extension of the value. If such situation is detected, libbpf will emit helpful message and will poison the instruction. Not failing immediately means that it's possible to guard the instruction based on kernel version (or other conditions) and make sure it's not reachable. If there is a need to read signed integers that change sizes between different kernels, it's possible to use BPF_CORE_READ_BITFIELD() macro, which works both with bitfields and non-bitfield integers of any signedness and handles sign-extension properly. Also, bpf_core_read() with proper size and/or use of bpf_core_field_size() relocation could allow to deal with such complicated situations explicitly, if not so conventiently as direct memory reads. Selftests added in a separate patch in progs/test_core_autosize.c demonstrate both direct memory and probed use cases. BPF_CORE_READ() is not changed and it won't deal with such situations as automatically as direct memory reads due to the signedness integer limitations, which are much harder to detect and control with compiler macro magic. So it's encouraged to utilize direct memory reads as much as possible. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201008001025.292064-3-andrii@kernel.org
| * libbpf: Skip CO-RE relocations for not loaded BPF programsAndrii Nakryiko2020-10-071-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | Bypass CO-RE relocations step for BPF programs that are not going to be loaded. This allows to have BPF programs compiled in and disabled dynamically if kernel is not supposed to provide enough relocation information. In such case, there won't be unnecessary warnings about failed relocations. Fixes: d929758101fc ("libbpf: Support disabling auto-loading BPF programs") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201008001025.292064-2-andrii@kernel.org
| * libbpf: Fix compatibility problem in xsk_socket__createMagnus Karlsson2020-10-071-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a compatibility problem when the old XDP_SHARED_UMEM mode is used together with the xsk_socket__create() call. In the old XDP_SHARED_UMEM mode, only sharing of the same device and queue id was allowed, and in this mode, the fill ring and completion ring were shared between the AF_XDP sockets. Therefore, it was perfectly fine to call the xsk_socket__create() API for each socket and not use the new xsk_socket__create_shared() API. This behavior was ruined by the commit introducing XDP_SHARED_UMEM support between different devices and/or queue ids. This patch restores the ability to use xsk_socket__create in these circumstances so that backward compatibility is not broken. Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices") Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/1602070946-11154-1-git-send-email-magnus.karlsson@gmail.com
| * bpf, libbpf: Use valid btf in bpf_program__set_attach_targetLuigi Rizzo2020-10-061-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bpf_program__set_attach_target(prog, fd, ...) will always fail when fd = 0 (attach to a kernel symbol) because obj->btf_vmlinux is NULL and there is no way to set it (at the moment btf_vmlinux is meant to be temporary storage for use in bpf_object__load_xattr()). Fix this by using libbpf_find_vmlinux_btf_id(). At some point we may want to opportunistically cache btf_vmlinux so it can be reused with multiple programs. Signed-off-by: Luigi Rizzo <lrizzo@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Petar Penkov <ppenkov@google.com> Link: https://lore.kernel.org/bpf/20201005224528.389097-1-lrizzo@google.com
| * libbpf: Check if pin_path was set even map fd existHangbin Liu2020-10-061-19/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Say a user reuse map fd after creating a map manually and set the pin_path, then load the object via libbpf. In libbpf bpf_object__create_maps(), bpf_object__reuse_map() will return 0 if there is no pinned map in map->pin_path. Then after checking if map fd exist, we should also check if pin_path was set and do bpf_map__pin() instead of continue the loop. Fix it by creating map if fd not exist and continue checking pin_path after that. Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20201006021345.3817033-3-liuhangbin@gmail.com
| * libbpf: Close map fd if init map slots failedHangbin Liu2020-10-061-21/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously we forgot to close the map fd if bpf_map_update_elem() failed during map slot init, which will leak map fd. Let's move map slot initialization to new function init_map_slots() to simplify the code. And close the map fd if init slot failed. Reported-by: Andrii Nakryiko <andrii.nakryiko@gmail.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20201006021345.3817033-2-liuhangbin@gmail.com
| * bpf/libbpf: BTF support for typed ksymsHao Luo2020-10-021-13/+99
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a ksym is defined with a type, libbpf will try to find the ksym's btf information from kernel btf. If a valid btf entry for the ksym is found, libbpf can pass in the found btf id to the verifier, which validates the ksym's type and value. Typeless ksyms (i.e. those defined as 'void') will not have such btf_id, but it has the symbol's address (read from kallsyms) and its value is treated as a raw pointer. Signed-off-by: Hao Luo <haoluo@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200929235049.2533242-3-haoluo@google.com
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller2020-10-051-1/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | Rejecting non-native endian BTF overlapped with the addition of support for it. The rest were more simple overlapping changes, except the renesas ravb binding update, which had to follow a file move as well as a YAML conversion. Signed-off-by: David S. Miller <davem@davemloft.net>
| * libbpf: Fix XDP program load regression for old kernelsAndrii Nakryiko2020-09-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix regression in libbpf, introduced by XDP link change, which causes XDP programs to fail to be loaded into kernel due to specified BPF_XDP expected_attach_type. While kernel doesn't enforce expected_attach_type for BPF_PROG_TYPE_XDP, some old kernels already support XDP program, but they don't yet recognize expected_attach_type field in bpf_attr, so setting it to non-zero value causes program load to fail. Luckily, libbpf already has a mechanism to deal with such cases, so just make expected_attach_type optional for XDP programs. Fixes: dc8698cac7aa ("libbpf: Add support for BPF XDP link") Reported-by: Nikita Shirokov <tehnerd@tehnerd.com> Reported-by: Udip Pant <udippant@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200924171705.3803628-1-andriin@fb.com
| * libbpf: Fix native endian assumption when parsing BTFTony Ambardar2020-09-211-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Code in btf__parse_raw() fails to detect raw BTF of non-native endianness and assumes it must be ELF data, which then fails to parse as ELF and yields a misleading error message: root:/# bpftool btf dump file /sys/kernel/btf/vmlinux libbpf: failed to get EHDR from /sys/kernel/btf/vmlinux For example, this could occur after cross-compiling a BTF-enabled kernel for a target with non-native endianness, which is currently unsupported. Check for correct endianness and emit a clearer error message: root:/# bpftool btf dump file /sys/kernel/btf/vmlinux libbpf: non-native BTF endianness is not supported Fixes: 94a1fedd63ed ("libbpf: Add btf__parse_raw() and generic btf__parse() APIs") Signed-off-by: Tony Ambardar <Tony.Ambardar@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/90f81508ecc57bc0da318e0fe0f45cfe49b17ea7.1600417359.git.Tony.Ambardar@gmail.com
* | libbpf: Make btf_dump work with modifiable BTFAndrii Nakryiko2020-09-303-22/+65
| | | | | | | | | | | | | | | | | | | | | | | | Ensure that btf_dump can accommodate new BTF types being appended to BTF instance after struct btf_dump was created. This came up during attemp to use btf_dump for raw type dumping in selftests, but given changes are not excessive, it's good to not have any gotchas in API usage, so I decided to support such use case in general. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200929232843.1249318-2-andriin@fb.com
* | bpf, libbpf: Add bpf_tail_call_static helper for bpf programsDaniel Borkmann2020-09-301-0/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Port of tail_call_static() helper function from Cilium's BPF code base [0] to libbpf, so others can easily consume it as well. We've been using this in production code for some time now. The main idea is that we guarantee that the kernel's BPF infrastructure and JIT (here: x86_64) can patch the JITed BPF insns with direct jumps instead of having to fall back to using expensive retpolines. By using inline asm, we guarantee that the compiler won't merge the call from different paths with potentially different content of r2/r3. We're also using Cilium's __throw_build_bug() macro (here as: __bpf_unreachable()) in different places as a neat trick to trigger compilation errors when compiler does not remove code at compilation time. This works for the BPF back end as it does not implement the __builtin_trap(). [0] https://github.com/cilium/cilium/commit/f5537c26020d5297b70936c6b7d03a1e412a1035 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/1656a082e077552eb46642d513b4a6bde9a7dd01.1601477936.git.daniel@iogearbox.net
* | libbpf: Compile in PIC mode only for shared library caseAndrii Nakryiko2020-09-291-2/+1
| | | | | | | | | | | | | | | | | | | | Libbpf compiles .o's for static and shared library modes separately, so no need to specify -fPIC for both. Keep it only for shared library mode. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200929220604.833631-3-andriin@fb.com
* | libbpf: Compile libbpf under -O2 level by default and catch extra warningsAndrii Nakryiko2020-09-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | For some reason compiler doesn't complain about uninitialized variable, fixed in previous patch, if libbpf is compiled without -O2 optimization level. So do compile it with -O2 and never let similar issue slip by again. -Wall is added unconditionally, so no need to specify it again. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200929220604.833631-2-andriin@fb.com
* | libbpf: Fix uninitialized variable in btf_parse_type_secAndrii Nakryiko2020-09-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | Fix obvious unitialized variable use that wasn't reported by compiler. libbpf Makefile changes to catch such errors are added separately. Fixes: 3289959b97ca ("libbpf: Support BTF loading and raw data output in both endianness") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200929220604.833631-1-andriin@fb.com
* | libbpf: Add support for freplace attachment in bpf_link_createToke Høiland-Jørgensen2020-09-295-9/+60
| | | | | | | | | | | | | | | | | | | | | | This adds support for supplying a target btf ID for the bpf_link_create() operation, and adds a new bpf_program__attach_freplace() high-level API for attaching freplace functions with a target. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/160138355387.48470.18026176785351166890.stgit@toke.dk
* | libbpf: Support BTF loading and raw data output in both endiannessAndrii Nakryiko2020-09-293-64/+255
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Teach BTF to recognized wrong endianness and transparently convert it internally to host endianness. Original endianness of BTF will be preserved and used during btf__get_raw_data() to convert resulting raw data to the same endianness and a source raw_data. This means that little-endian host can parse big-endian BTF with no issues, all the type data will be presented to the client application in native endianness, but when it's time for emitting BTF to persist it in a file (e.g., after BTF deduplication), original non-native endianness will be preserved and stored. It's possible to query original endianness of BTF data with new btf__endianness() API. It's also possible to override desired output endianness with btf__set_endianness(), so that if application needs to load, say, big-endian BTF and store it as little-endian BTF, it's possible to manually override this. If btf__set_endianness() was used to change endianness, btf__endianness() will reflect overridden endianness. Given there are no known use cases for supporting cross-endianness for .BTF.ext, loading .BTF.ext in non-native endianness is not supported. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200929043046.1324350-3-andriin@fb.com
* | selftests/bpf: Test BTF writing APIsAndrii Nakryiko2020-09-281-4/+4
| | | | | | | | | | | | | | | | | | Add selftests for BTF writer APIs. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200929020533.711288-4-andriin@fb.com
* | libbpf: Add btf__str_by_offset() as a more generic variant of name_by_offsetAndrii Nakryiko2020-09-283-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | BTF strings are used not just for names, they can be arbitrary strings used for CO-RE relocations, line/func infos, etc. Thus "name_by_offset" terminology is too specific and might be misleading. Instead, introduce btf__str_by_offset() API which uses generic string terminology. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200929020533.711288-3-andriin@fb.com
* | libbpf: Add BTF writing APIsAndrii Nakryiko2020-09-283-0/+838
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add APIs for appending new BTF types at the end of BTF object. Each BTF kind has either one API of the form btf__add_<kind>(). For types that have variable amount of additional items (struct/union, enum, func_proto, datasec), additional API is provided to emit each such item. E.g., for emitting a struct, one would use the following sequence of API calls: btf__add_struct(...); btf__add_field(...); ... btf__add_field(...); Each btf__add_field() will ensure that the last BTF type is of STRUCT or UNION kind and will automatically increment that type's vlen field. All the strings are provided as C strings (const char *), not a string offset. This significantly improves usability of BTF writer APIs. All such strings will be automatically appended to string section or existing string will be re-used, if such string was already added previously. Each API attempts to do all the reasonable validations, like enforcing non-empty names for entities with required names, proper value bounds, various bit offset restrictions, etc. Type ID validation is minimal because it's possible to emit a type that refers to type that will be emitted later, so libbpf has no way to enforce such cases. User must be careful to properly emit all the necessary types and specify type IDs that will be valid in the finally generated BTF. Each of btf__add_<kind>() APIs return new type ID on success or negative value on error. APIs like btf__add_field() that emit additional items return zero on success and negative value on error. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200929020533.711288-2-andriin@fb.com
* | libbpf: Add btf__new_empty() to create an empty BTF objectAndrii Nakryiko2020-09-283-0/+32
| | | | | | | | | | | | | | | | | | | | | | Add an ability to create an empty BTF object from scratch. This is going to be used by pahole for BTF encoding. And also by selftest for convenient creation of BTF objects. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200926011357.2366158-7-andriin@fb.com
* | libbpf: Allow modification of BTF and add btf__add_str APIAndrii Nakryiko2020-09-283-8/+258
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow internal BTF representation to switch from default read-only mode, in which raw BTF data is a single non-modifiable block of memory with BTF header, types, and strings layed out sequentially and contiguously in memory, into a writable representation with types and strings data split out into separate memory regions, that can be dynamically expanded. Such writable internal representation is transparent to users of libbpf APIs, but allows to append new types and strings at the end of BTF, which is a typical use case when generating BTF programmatically. All the basic guarantees of BTF types and strings layout is preserved, i.e., user can get `struct btf_type *` pointer and read it directly. Such btf_type pointers might be invalidated if BTF is modified, so some care is required in such mixed read/write scenarios. Switch from read-only to writable configuration happens automatically the first time when user attempts to modify BTF by either adding a new type or new string. It is still possible to get raw BTF data, which is a single piece of memory that can be persisted in ELF section or into a file as raw BTF. Such raw data memory is also still owned by BTF and will be freed either when BTF object is freed or if another modification to BTF happens, as any modification invalidates BTF raw representation. This patch adds the first two BTF manipulation APIs: btf__add_str(), which allows to add arbitrary strings to BTF string section, and btf__find_str() which allows to find existing string offset, but not add it if it's missing. All the added strings are automatically deduplicated. This is achieved by maintaining an additional string lookup index for all unique strings. Such index is built when BTF is switched to modifiable mode. If at that time BTF strings section contained duplicate strings, they are not de-duplicated. This is done specifically to not modify the existing content of BTF (types, their string offsets, etc), which can cause confusion and is especially important property if there is struct btf_ext associated with struct btf. By following this "imperfect deduplication" process, btf_ext is kept consitent and correct. If deduplication of strings is necessary, it can be forced by doing BTF deduplication, at which point all the strings will be eagerly deduplicated and all string offsets both in struct btf and struct btf_ext will be updated. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200926011357.2366158-6-andriin@fb.com
* | libbpf: Extract generic string hashing function for reuseAndrii Nakryiko2020-09-282-8/+13
| | | | | | | | | | | | | | | | | | | | Calculating a hash of zero-terminated string is a common need when using hashmap, so extract it for reuse. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200926011357.2366158-5-andriin@fb.com