From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by mail.toke.dk (Postfix) with ESMTPS id E2A009C2241 for ; Tue, 15 Nov 2022 04:02:17 +0100 (CET) Authentication-Results: mail.toke.dk; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20210112 header.b=WJ+Gmv5/ Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-367f94b9b16so123369687b3.11 for ; Mon, 14 Nov 2022 19:02:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=E+8IjXRgxBNITPsOwIQKMXDKqWa80/z37oUBtUuQVa0=; b=WJ+Gmv5/4g5yFbrp5IctO/4xjTqfAnV73tfMi/F7yI3/SCZP1J+a2RMInH/6OsyyIe Rdh8XJsAMlXQJjWlonNRg0k7V+GccC8NlXTIEmWG3jf56Pt3ZbbxrzHH0YcvjzHJkREM kLMNnb+jiEbjPOkbR6ScJ5b2r80deVxSNTiYuKnzEu+PY/cPtUaNNQM5ZfOp+b9v+xX5 i/CVxyDT7vB9DCXEp/+Yj5ZkI1gjNKMs/mx3nxe7+J5CT7OCcwheY1XTKmVgMyOw21Ml MeHMnSYXDAO7WoztOY0aKuxmltR6B8pm3cqNEc9eqdd1+Wvtzy5Sj2XfOF6P2kyBi2VL TXUw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=E+8IjXRgxBNITPsOwIQKMXDKqWa80/z37oUBtUuQVa0=; b=JnwxtrFZN+KCzMEJUSAy2+MPiY98jMTUxclvPi3Pcf33MOLrc3vPWlpaMHzu8r+Pua l4s99it/DY6vf2v3xOFJeOBeTr3qyptpusGE8pYoN0qU0yXraAVsD6ilgrHERQqaE0YM omzS+Md21AJ7mSNiNxerGjQtazlKT6/NC4YSY1yitgJjTaxD3Gg6DmmmSnHPatF0BMVn glezKbV8eWwn94aVmrtKITXHSgEfT0TmhGl5Sk/fj2JezfYFAbpTsGEkN/MqbLUVOr5W /pD2qbmaGMDZxNoKlLfuS5bufuIC8HgYTuwgWpin643lwRZUrxA+l65iLiioNGibIpVC MOrw== X-Gm-Message-State: ANoB5pn/Wdi19J0P/X2tNIDS+6LcHzpMI19iyFfzqyhmGGNc0VM3ZGUn MTjSHWYmOR19J9mFJW6ar1tfnMM= X-Google-Smtp-Source: AA0mqf49JR+xywOcvNrrM2mX6vAJ2aTg+01p+IZYDcOS32Yl5zwEF1L6Kv8p/1IcRroXqOIzIsYPkrk= X-Received: from sdf.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5935]) (user=sdf job=sendgmr) by 2002:a25:3801:0:b0:6cf:ef46:e780 with SMTP id f1-20020a253801000000b006cfef46e780mr15073287yba.644.1668481335532; Mon, 14 Nov 2022 19:02:15 -0800 (PST) Date: Mon, 14 Nov 2022 19:02:01 -0800 In-Reply-To: <20221115030210.3159213-1-sdf@google.com> Mime-Version: 1.0 References: <20221115030210.3159213-1-sdf@google.com> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog Message-ID: <20221115030210.3159213-3-sdf@google.com> From: Stanislav Fomichev To: bpf@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Message-ID-Hash: SYQE25HZK6FXKREBS33MWKXJJEE4HBRD X-Message-ID-Hash: SYQE25HZK6FXKREBS33MWKXJJEE4HBRD X-MailFrom: 3NwFzYwMKCSgWHJKSSKPI.GSQbHT-LMRXWbHT-TVSNIGX.RIX@flex--sdf.bounces.google.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, David Ahern , Jakub Kicinski , Willem de Bruijn , Jesper Dangaard Brouer , Anatoly Burakov , Alexander Lobakin , Magnus Karlsson , Maryam Tahhan , xdp-hints@xdp-project.net, netdev@vger.kernel.org X-Mailman-Version: 3.3.6 Precedence: list Subject: [xdp-hints] [PATCH bpf-next 02/11] bpf: Introduce bpf_patch List-Id: XDP hardware hints design discussion Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: A simple abstraction around a series of instructions that transparently handles resizing. Currently, we have insn_buf[16] in convert_ctx_accesses which might not be enough for xdp kfuncs. If we find this abstraction helpful, we might convert existing insn_buf[16] to it in the future. Cc: John Fastabend Cc: David Ahern Cc: Martin KaFai Lau Cc: Jakub Kicinski Cc: Willem de Bruijn Cc: Jesper Dangaard Brouer Cc: Anatoly Burakov Cc: Alexander Lobakin Cc: Magnus Karlsson Cc: Maryam Tahhan Cc: xdp-hints@xdp-project.net Cc: netdev@vger.kernel.org Signed-off-by: Stanislav Fomichev --- include/linux/bpf_patch.h | 29 +++++++++++++++ kernel/bpf/Makefile | 2 +- kernel/bpf/bpf_patch.c | 77 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 107 insertions(+), 1 deletion(-) create mode 100644 include/linux/bpf_patch.h create mode 100644 kernel/bpf/bpf_patch.c diff --git a/include/linux/bpf_patch.h b/include/linux/bpf_patch.h new file mode 100644 index 000000000000..359c165ad68b --- /dev/null +++ b/include/linux/bpf_patch.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _LINUX_BPF_PATCH_H +#define _LINUX_BPF_PATCH_H 1 + +#include + +struct bpf_patch { + struct bpf_insn *insn; + size_t capacity; + size_t len; + int err; +}; + +void bpf_patch_free(struct bpf_patch *patch); +size_t bpf_patch_len(const struct bpf_patch *patch); +int bpf_patch_err(const struct bpf_patch *patch); +void __bpf_patch_append(struct bpf_patch *patch, struct bpf_insn insn); +struct bpf_insn *bpf_patch_data(const struct bpf_patch *patch); +void bpf_patch_resolve_jmp(struct bpf_patch *patch); +u32 bpf_patch_magles_registers(const struct bpf_patch *patch); + +#define bpf_patch_append(patch, ...) ({ \ + struct bpf_insn insn[] = { __VA_ARGS__ }; \ + int i; \ + for (i = 0; i < ARRAY_SIZE(insn); i++) \ + __bpf_patch_append(patch, insn[i]); \ +}) + +#endif diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index 3a12e6b400a2..5724f36292a5 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -13,7 +13,7 @@ obj-$(CONFIG_BPF_SYSCALL) += bpf_local_storage.o bpf_task_storage.o obj-${CONFIG_BPF_LSM} += bpf_inode_storage.o obj-$(CONFIG_BPF_SYSCALL) += disasm.o obj-$(CONFIG_BPF_JIT) += trampoline.o -obj-$(CONFIG_BPF_SYSCALL) += btf.o memalloc.o +obj-$(CONFIG_BPF_SYSCALL) += btf.o memalloc.o bpf_patch.o obj-$(CONFIG_BPF_JIT) += dispatcher.o ifeq ($(CONFIG_NET),y) obj-$(CONFIG_BPF_SYSCALL) += devmap.o diff --git a/kernel/bpf/bpf_patch.c b/kernel/bpf/bpf_patch.c new file mode 100644 index 000000000000..eb768398fd8f --- /dev/null +++ b/kernel/bpf/bpf_patch.c @@ -0,0 +1,77 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include + +void bpf_patch_free(struct bpf_patch *patch) +{ + kfree(patch->insn); +} + +size_t bpf_patch_len(const struct bpf_patch *patch) +{ + return patch->len; +} + +int bpf_patch_err(const struct bpf_patch *patch) +{ + return patch->err; +} + +void __bpf_patch_append(struct bpf_patch *patch, struct bpf_insn insn) +{ + void *arr; + + if (patch->err) + return; + + if (patch->len + 1 > patch->capacity) { + if (!patch->capacity) + patch->capacity = 16; + else + patch->capacity *= 2; + + arr = krealloc_array(patch->insn, patch->capacity, sizeof(insn), GFP_KERNEL); + if (!arr) { + patch->err = -ENOMEM; + kfree(patch->insn); + return; + } + + patch->insn = arr; + patch->capacity *= 2; + } + + patch->insn[patch->len++] = insn; +} +EXPORT_SYMBOL(__bpf_patch_append); + +struct bpf_insn *bpf_patch_data(const struct bpf_patch *patch) +{ + return patch->insn; +} + +void bpf_patch_resolve_jmp(struct bpf_patch *patch) +{ + int i; + + for (i = 0; i < patch->len; i++) { + if (BPF_CLASS(patch->insn[i].code) != BPF_JMP) + continue; + + if (patch->insn[i].off != S16_MAX) + continue; + + patch->insn[i].off = patch->len - i - 1; + } +} + +u32 bpf_patch_magles_registers(const struct bpf_patch *patch) +{ + u32 mask = 0; + int i; + + for (i = 0; i < patch->len; i++) + mask |= 1 << patch->insn[i].dst_reg; + + return mask; +} -- 2.38.1.431.g37b22c650d-goog