kernel/linux.git/include/linux/filter.h, branch v6.6.14

bpf: fix inconsistent return types of bpf_xdp_copy_buf().

2023-08-04T21:38:31+00:00

Fix inconsistent return types in two implementations of bpf_xdp_copy_buf(). There are two implementations: one is an empty implementation whose return type does not match the actual implementation. Suggested-by: Alexei Starovoitov Signed-off-by: Kui-Feng Lee Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20230804005101.1534505-1-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau

net: invert the netdevice.h vs xdp.h dependency

2023-08-03T15:38:07+00:00

xdp.h is far more specific and is included in only 67 other files vs netdevice.h's 1538 include sites. Make xdp.h include netdevice.h, instead of the other way around. This decreases the incremental allmodconfig builds size when xdp.h is touched from 5947 to 662 objects. Move bpf_prog_run_xdp() to xdp.h, seems appropriate and filter.h is a mega-header in its own right so it's nice to avoid xdp.h getting included there as well. The only unfortunate part is that the typedef for xdp_features_t has to move to netdevice.h, since its embedded in struct netdevice. Signed-off-by: Jakub Kicinski Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/r/20230803010230.1755386-4-kuba@kernel.org Signed-off-by: Martin KaFai Lau

bpf: Fix jit blinding with new sdiv/smov insns

2023-07-28T01:52:33+00:00

Handle new insns properly in bpf_jit_blind_insn() function. Acked-by: Eduard Zingerman Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20230728011225.3715812-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov

bpf: Support new sign-extension load insns

2023-07-28T01:52:33+00:00

Add interpreter/jit support for new sign-extension load insns which adds a new mode (BPF_MEMSX). Also add verifier support to recognize these insns and to do proper verification with new insns. In verifier, besides to deduce proper bounds for the dst_reg, probed memory access is also properly handled. Acked-by: Eduard Zingerman Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20230728011156.3711870-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov

bpf: Cleanup unused function declaration

2023-06-06T15:05:21+00:00

All usage and the definition of `bpf_prog_free_linfo()` has been removed in commit e16301fbe183 ("bpf: Simplify freeing logic in linfo and jited_linfo"). Clean up its declaration in the header file. Signed-off-by: Ruiqi Gong Signed-off-by: Daniel Borkmann Acked-by: Stanislav Fomichev Link: https://lore.kernel.org/all/20230602030842.279262-1-gongruiqi@huaweicloud.com/ Link: https://lore.kernel.org/bpf/20230606021047.170667-1-gongruiqi@huaweicloud.com

bpf: Support 64-bit pointers to kfuncs

2023-04-14T04:36:41+00:00

test_ksyms_module fails to emit a kfunc call targeting a module on s390x, because the verifier stores the difference between kfunc address and __bpf_call_base in bpf_insn.imm, which is s32, and modules are roughly (1 << 42) bytes away from the kernel on s390x. Fix by keeping BTF id in bpf_insn.imm for BPF_PSEUDO_KFUNC_CALLs, and storing the absolute address in bpf_kfunc_desc. Introduce bpf_jit_supports_far_kfunc_call() in order to limit this new behavior to the s390x JIT. Otherwise other JITs need to be modified, which is not desired. Introduce bpf_get_kfunc_addr() instead of exposing both find_kfunc_desc() and struct bpf_kfunc_desc. In addition to sorting kfuncs by imm, also sort them by offset, in order to handle conflicting imms from different modules. Do this on all architectures in order to simplify code. Factor out resolving specialized kfuncs (XPD and dynptr) from fixup_kfunc_call(). This was required in the first place, because fixup_kfunc_call() uses find_kfunc_desc(), which returns a const pointer, so it's not possible to modify kfunc addr without stripping const, which is not nice. It also removes repetition of code like: if (bpf_jit_supports_far_kfunc_call()) desc->addr = func; else insn->imm = BPF_CALL_IMM(func); and separates kfunc_desc_tab fixups from kfunc_call fixups. Suggested-by: Jiri Olsa Signed-off-by: Ilya Leoshkevich Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20230412230632.885985-1-iii@linux.ibm.com Signed-off-by: Alexei Starovoitov

bpf: Remove unused arguments from btf_struct_access().

2023-04-04T23:57:10+00:00

Remove unused arguments from btf_struct_access() callback. Signed-off-by: Alexei Starovoitov Signed-off-by: Andrii Nakryiko Acked-by: David Vernet Link: https://lore.kernel.org/bpf/20230404045029.82870-3-alexei.starovoitov@gmail.com

bpf: return long from bpf_map_ops funcs

2023-03-22T22:11:30+00:00

This patch changes the return types of bpf_map_ops functions to long, where previously int was returned. Using long allows for bpf programs to maintain the sign bit in the absence of sign extension during situations where inlined bpf helper funcs make calls to the bpf_map_ops funcs and a negative error is returned. The definitions of the helper funcs are generated from comments in the bpf uapi header at `include/uapi/linux/bpf.h`. The return type of these helpers was previously changed from int to long in commit bdb7b79b4ce8. For any case where one of the map helpers call the bpf_map_ops funcs that are still returning 32-bit int, a compiler might not include sign extension instructions to properly convert the 32-bit negative value a 64-bit negative value. For example: bpf assembly excerpt of an inlined helper calling a kernel function and checking for a specific error: ; err = bpf_map_update_elem(&mymap, &key, &val, BPF_NOEXIST); ... 46: call 0xffffffffe103291c ; htab_map_update_elem ; if (err && err != -EEXIST) { 4b: cmp $0xffffffffffffffef,%rax ; cmp -EEXIST,%rax kernel function assembly excerpt of return value from `htab_map_update_elem` returning 32-bit int: movl $0xffffffef, %r9d ... movl %r9d, %eax ...results in the comparison: cmp $0xffffffffffffffef, $0x00000000ffffffef Fixes: bdb7b79b4ce8 ("bpf: Switch most helper return values from 32-bit int to 64-bit long") Tested-by: Eduard Zingerman Signed-off-by: JP Kobryn Link: https://lore.kernel.org/r/20230322194754.185781-3-inwardvessel@gmail.com Signed-off-by: Alexei Starovoitov

bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr

2023-03-01T17:55:24+00:00

Two new kfuncs are added, bpf_dynptr_slice and bpf_dynptr_slice_rdwr. The user must pass in a buffer to store the contents of the data slice if a direct pointer to the data cannot be obtained. For skb and xdp type dynptrs, these two APIs are the only way to obtain a data slice. However, for other types of dynptrs, there is no difference between bpf_dynptr_slice(_rdwr) and bpf_dynptr_data. For skb type dynptrs, the data is copied into the user provided buffer if any of the data is not in the linear portion of the skb. For xdp type dynptrs, the data is copied into the user provided buffer if the data is between xdp frags. If the skb is cloned and a call to bpf_dynptr_data_rdwr is made, then the skb will be uncloned (see bpf_unclone_prologue()). Please note that any bpf_dynptr_write() automatically invalidates any prior data slices of the skb dynptr. This is because the skb may be cloned or may need to pull its paged buffer into the head. As such, any bpf_dynptr_write() will automatically have its prior data slices invalidated, even if the write is to data in the skb head of an uncloned skb. Please note as well that any other helper calls that change the underlying packet buffer (eg bpf_skb_pull_data()) invalidates any data slices of the skb dynptr as well, for the same reasons. Signed-off-by: Joanne Koong Link: https://lore.kernel.org/r/20230301154953.641654-10-joannelkoong@gmail.com Signed-off-by: Alexei Starovoitov

bpf: Add xdp dynptrs

2023-03-01T17:55:24+00:00

Add xdp dynptrs, which are dynptrs whose underlying pointer points to a xdp_buff. The dynptr acts on xdp data. xdp dynptrs have two main benefits. One is that they allow operations on sizes that are not statically known at compile-time (eg variable-sized accesses). Another is that parsing the packet data through dynptrs (instead of through direct access of xdp->data and xdp->data_end) can be more ergonomic and less brittle (eg does not need manual if checking for being within bounds of data_end). For reads and writes on the dynptr, this includes reading/writing from/to and across fragments. Data slices through the bpf_dynptr_data API are not supported; instead bpf_dynptr_slice() and bpf_dynptr_slice_rdwr() should be used. For examples of how xdp dynptrs can be used, please see the attached selftests. Signed-off-by: Joanne Koong Link: https://lore.kernel.org/r/20230301154953.641654-9-joannelkoong@gmail.com Signed-off-by: Alexei Starovoitov