From patchwork Sat Jan 25 08:23:36 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Levi Zim via B4 Relay X-Patchwork-Id: 13950246 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A39491EBFE8; Sat, 25 Jan 2025 08:24:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737793456; cv=none; b=ZQ2xy9xOAse8gcr56ieZ/ax4JzyZkoD43k1QoMwFh7u1Tgo5Uu5CC4qkRofP766rpvYxayGgz67KAqDMIZ/As8mrcyy6A9tt57oqJyPgQ+1UOFGodJXdr8G9uIcze+WL4yA9It9HamJ+txb/gWrBERMhWMnv7vZ+vGGb2IZBTCw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737793456; c=relaxed/simple; bh=ZtcDKBYvpGO+GJwMItu+xm+YQJmprDGI/QwBss5wxAA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=rQknL32xPtva4wKXEx8TN1WpgJerAZSP5h2JoKdBqOx8Xl7Rsw5FNNdJTqJ0cCQo/oHklMT81AQE4SnuaY2GugD6fn98pmJPlaHWKXK8GM1l0996SRCrS5iFl17NduOyREM/i1u7sl6IQG7inL8kkW0kR8wNq3g8QjWwTkX1RaQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=W/u64I0s; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="W/u64I0s" Received: by smtp.kernel.org (Postfix) with ESMTPS id EC6A8C4CEE0; Sat, 25 Jan 2025 08:24:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737793456; bh=ZtcDKBYvpGO+GJwMItu+xm+YQJmprDGI/QwBss5wxAA=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=W/u64I0szecxUFg0SZXHhVBHwF7DPDcT8lz9NpRS4t14PZayZ+RfuzlVK7tH0iwe8 q+9FFi1fWP4FXi9jr13GiKJEUOCZ4UXfSYlseMQcqmmF4m4YinUby7NUtEKnXlCKcD lpQCOlO3Bw5ctTJtrw+J8pJJgLzhnf4OMFVDRkRy4UTBRcBRvmhm8gKGNMMUnhwDrc mvylo8mIKT1t+HRBiGJG0U+QLsLNT4YvMbXVzkcpV1y6CXqdtOIzrHHPJotO8X/mx5 Z8+WxhEk8N8KwN8BYLt4TVbNimDt6J5hPy1ZWVZwbI9doz5ifgfI9uzC8oIxXuOpkg l4zTV7JTmqMyg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id D51E7C0218C; Sat, 25 Jan 2025 08:24:15 +0000 (UTC) From: Levi Zim via B4 Relay Date: Sat, 25 Jan 2025 16:23:36 +0800 Subject: [PATCH 1/7] bpf: Implement bpf_probe_read_kernel_dynptr helper Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250125-bpf_dynptr_probe-v1-1-c3cb121f6951@outlook.com> References: <20250125-bpf_dynptr_probe-v1-0-c3cb121f6951@outlook.com> In-Reply-To: <20250125-bpf_dynptr_probe-v1-0-c3cb121f6951@outlook.com> To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Matt Bobrowski , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Mykola Lysenko , Shuah Khan Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Andrii Nakryiko , Levi Zim X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=6356; i=rsworktech@outlook.com; h=from:subject:message-id; bh=A7uHiAoA3YZYbVOxcHt/y8HP3bfI8O7Zg6oKJ3y0uAs=; b=owEBbQKS/ZANAwAIAW87mNQvxsnYAcsmYgBnlJ+mqr8bV8bPsJXRYVZLG0rZ7T7ty/y176ahK t7RKvT0WKWJAjMEAAEIAB0WIQQolnD5HDY18KF0JEVvO5jUL8bJ2AUCZ5SfpgAKCRBvO5jUL8bJ 2NfMD/94TgHhtijqB3q4yHm6EDOXB5z081f8B38saB77wJFiAVemNdDSlrVDKngee8xZmbBsvIQ SUXq7BREHY39j+I15r9+17sUajBvS4pukDJysAD7m8v+UVx26Es9oaJuJGOkzGgXEpyzJHsSoAh 7oHvzsb9dAIXWitpeLEG6PGMN3XkfwjIxtQybmUd5kRM37U7s6eUftzEgQjKwrB2ddsl58TE9mS o6koqXB32s0S86Y+cjG/CdD3h+P20fADMMKge92mPHyYRTM0AY9deSjUrMqDRWgw9Nz9ldzZJ3c 9dklAeeJ62cbjZBBLYC40ahcGdKAwFnfARBP4yApXDE7OKzUb53T8qEFGbqGQhIdDxflT8QBsM7 eckeT7BxCojhXRIr+k2d6EgRrcxob3xTQSdbO1vdBYzs05FT5coId3xThV9TG3nvMVZ9yRdTpJC mKF/6Ofl9hxdKsbtG4gqvaZc6+ts1XpFLRa3nf323U/H7t2LqVwGbDPOqoB7xwMIu15W+5JcZql dAEVg8Dv75DRU3kccC/UJdTCFI3L/4TUTh5fwiXvDiTn701aMAH+BKrgoek8+14F2E1sYmpSwE0 2hXbdZ7jIcG3HSHROIPWEYBD3+n3hlk8HZKLItaB1ugf9F0MnFm+rAzzg2tcpJ2jqQEMQnZuhtV uvPJnJg0YHWxt2g== X-Developer-Key: i=rsworktech@outlook.com; a=openpgp; fpr=17AADD6726DDC58B8EE5881757670CCFA42CCF0A X-Endpoint-Received: by B4 Relay for rsworktech@outlook.com/default with auth_id=219 X-Original-From: Levi Zim Reply-To: rsworktech@outlook.com From: Levi Zim This patch add a helper function bpf_probe_read_kernel_dynptr: long bpf_probe_read_kernel_dynptr(const struct bpf_dynptr *dst, u32 offset, u32 size, const void *unsafe_ptr, u64 flags); It is useful for reading variable-length data from kernel memory into dynptr. Link: https://lore.kernel.org/bpf/MEYP282MB2312CFCE5F7712FDE313215AC64D2@MEYP282MB2312.AUSP282.PROD.OUTLOOK.COM/ Signed-off-by: Levi Zim --- include/linux/bpf.h | 2 ++ include/uapi/linux/bpf.h | 16 ++++++++++++++++ kernel/bpf/helpers.c | 8 ++++++-- kernel/trace/bpf_trace.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 66 insertions(+), 2 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index f3f50e29d63929acaf12c81f8356173f1f5e154b..9d5ae8b4b7d82c4523bf0ab041d4b76bf134a106 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1323,6 +1323,8 @@ u32 __bpf_dynptr_size(const struct bpf_dynptr_kern *ptr); const void *__bpf_dynptr_data(const struct bpf_dynptr_kern *ptr, u32 len); void *__bpf_dynptr_data_rw(const struct bpf_dynptr_kern *ptr, u32 len); bool __bpf_dynptr_is_rdonly(const struct bpf_dynptr_kern *ptr); +int bpf_dynptr_check_off_len(const struct bpf_dynptr_kern *ptr, u32 offset, u32 len); +enum bpf_dynptr_type bpf_dynptr_get_type(const struct bpf_dynptr_kern *ptr); #ifdef CONFIG_BPF_JIT int bpf_trampoline_link_prog(struct bpf_tramp_link *link, diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 2acf9b33637174bd16b1d12ccc6410c5f55a7ea9..2e08a59527ecf56732ea14ac34446b5eb25b5690 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5805,6 +5805,21 @@ union bpf_attr { * 0 on success. * * **-ENOENT** if the bpf_local_storage cannot be found. + * + * long bpf_probe_read_kernel_dynptr(const struct bpf_dynptr *dst, u32 offset, u32 size, const void *unsafe_ptr, u64 flags) + * Description + * Safely attempt to read *size* bytes from kernel space address + * *unsafe_ptr* and store the data in *dst* starting from *offset*. + * *flags* is currently unused. + * Return + * 0 on success. + * + * **-E2BIG** if *offset* + *len* exceeds the length of *src*'s data + * + * **-EINVAL** if *src* is an invalid dynptr or doesn't support this + * support this helper, or if *flags* is not 0. + * + * Or other negative errors on failure reading kernel memory. */ #define ___BPF_FUNC_MAPPER(FN, ctx...) \ FN(unspec, 0, ##ctx) \ @@ -6019,6 +6034,7 @@ union bpf_attr { FN(user_ringbuf_drain, 209, ##ctx) \ FN(cgrp_storage_get, 210, ##ctx) \ FN(cgrp_storage_delete, 211, ##ctx) \ + FN(probe_read_kernel_dynptr, 212, ##ctx) \ /* */ /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index f27ce162427ab4040d2e2d2eb84a883fe57de59e..a736dc9e7be98571103ba404420be0da4dac4fbe 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -1678,7 +1678,7 @@ static void bpf_dynptr_set_type(struct bpf_dynptr_kern *ptr, enum bpf_dynptr_typ ptr->size |= type << DYNPTR_TYPE_SHIFT; } -static enum bpf_dynptr_type bpf_dynptr_get_type(const struct bpf_dynptr_kern *ptr) +enum bpf_dynptr_type bpf_dynptr_get_type(const struct bpf_dynptr_kern *ptr) { return (ptr->size & ~(DYNPTR_RDONLY_BIT)) >> DYNPTR_TYPE_SHIFT; } @@ -1714,7 +1714,7 @@ void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr) memset(ptr, 0, sizeof(*ptr)); } -static int bpf_dynptr_check_off_len(const struct bpf_dynptr_kern *ptr, u32 offset, u32 len) +int bpf_dynptr_check_off_len(const struct bpf_dynptr_kern *ptr, u32 offset, u32 len) { u32 size = __bpf_dynptr_size(ptr); @@ -1900,6 +1900,7 @@ const struct bpf_func_proto bpf_probe_read_user_proto __weak; const struct bpf_func_proto bpf_probe_read_user_str_proto __weak; const struct bpf_func_proto bpf_probe_read_kernel_proto __weak; const struct bpf_func_proto bpf_probe_read_kernel_str_proto __weak; +const struct bpf_func_proto bpf_probe_read_kernel_dynptr_proto __weak; const struct bpf_func_proto bpf_task_pt_regs_proto __weak; const struct bpf_func_proto * @@ -2031,6 +2032,9 @@ bpf_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_probe_read_kernel: return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? NULL : &bpf_probe_read_kernel_proto; + case BPF_FUNC_probe_read_kernel_dynptr: + return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? + NULL : &bpf_probe_read_kernel_dynptr_proto; case BPF_FUNC_probe_read_user_str: return &bpf_probe_read_user_str_proto; case BPF_FUNC_probe_read_kernel_str: diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index adc947587eb8132ebbd54778d2db937b3b8861de..75c9d1e8d04c3b8930ae81345f5586756ce8b5ec 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -248,6 +248,48 @@ const struct bpf_func_proto bpf_probe_read_kernel_proto = { .arg3_type = ARG_ANYTHING, }; +BPF_CALL_5(bpf_probe_read_kernel_dynptr, const struct bpf_dynptr_kern *, dst, + u32, offset, u32, size, void *, unsafe_ptr, u64, flags) +{ + enum bpf_dynptr_type type; + int err; + + if (!dst->data || __bpf_dynptr_is_rdonly(dst)) + return -EINVAL; + + err = bpf_dynptr_check_off_len(dst, offset, size); + if (err) + return err; + + type = bpf_dynptr_get_type(dst); + + switch (type) { + case BPF_DYNPTR_TYPE_LOCAL: + case BPF_DYNPTR_TYPE_RINGBUF: + if (flags) + return -EINVAL; + return bpf_probe_read_kernel_common(dst->data + dst->offset + offset, + size, unsafe_ptr); + case BPF_DYNPTR_TYPE_SKB: + case BPF_DYNPTR_TYPE_XDP: + return -EINVAL; + default: + WARN_ONCE(true, "%s: unknown dynptr type %d\n", __func__, type); + return -EFAULT; + } +} + +const struct bpf_func_proto bpf_probe_read_kernel_dynptr_proto = { + .func = bpf_probe_read_kernel_dynptr, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_ANYTHING, + .arg5_type = ARG_ANYTHING, +}; + static __always_inline int bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) { From patchwork Sat Jan 25 08:23:37 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Levi Zim via B4 Relay X-Patchwork-Id: 13950247 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A3A182066D4; 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a=openpgp; fpr=17AADD6726DDC58B8EE5881757670CCFA42CCF0A X-Endpoint-Received: by B4 Relay for rsworktech@outlook.com/default with auth_id=219 X-Original-From: Levi Zim Reply-To: rsworktech@outlook.com From: Levi Zim This patch add a helper function bpf_probe_read_user_dynptr: long bpf_probe_read_user_dynptr(const struct bpf_dynptr *dst, u32 offset, u32 size, const void *unsafe_ptr, u64 flags); It is useful for reading variable-length data from user memory into dynptr. Signed-off-by: Levi Zim --- include/uapi/linux/bpf.h | 16 ++++++++++ kernel/bpf/helpers.c | 3 ++ kernel/trace/bpf_trace.c | 76 +++++++++++++++++++++++++++++++++--------------- 3 files changed, 71 insertions(+), 24 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 2e08a59527ecf56732ea14ac34446b5eb25b5690..d7d7a9ddd5dca07ba89d81ba77101a704af3163b 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5820,6 +5820,21 @@ union bpf_attr { * support this helper, or if *flags* is not 0. * * Or other negative errors on failure reading kernel memory. + * + * long bpf_probe_read_user_dynptr(const struct bpf_dynptr *dst, u32 offset, u32 size, const void *unsafe_ptr, u64 flags) + * Description + * Safely attempt to read *size* bytes from user space address + * *unsafe_ptr* and store the data in *dst* starting from *offset*. + * *flags* is currently unused. + * Return + * 0 on success. + * + * **-E2BIG** if *offset* + *len* exceeds the length of *src*'s data + * + * **-EINVAL** if *src* is an invalid dynptr or doesn't support this + * support this helper, or if *flags* is not 0. + * + * Or other negative errors on failure reading user space memory. */ #define ___BPF_FUNC_MAPPER(FN, ctx...) \ FN(unspec, 0, ##ctx) \ @@ -6035,6 +6050,7 @@ union bpf_attr { FN(cgrp_storage_get, 210, ##ctx) \ FN(cgrp_storage_delete, 211, ##ctx) \ FN(probe_read_kernel_dynptr, 212, ##ctx) \ + FN(probe_read_user_dynptr, 213, ##ctx) \ /* */ /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index a736dc9e7be98571103ba404420be0da4dac4fbe..ac563d09082e7c721999d7de035aabc000206a29 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -1898,6 +1898,7 @@ const struct bpf_func_proto bpf_get_current_task_proto __weak; const struct bpf_func_proto bpf_get_current_task_btf_proto __weak; const struct bpf_func_proto bpf_probe_read_user_proto __weak; const struct bpf_func_proto bpf_probe_read_user_str_proto __weak; +const struct bpf_func_proto bpf_probe_read_user_dynptr_proto __weak; const struct bpf_func_proto bpf_probe_read_kernel_proto __weak; const struct bpf_func_proto bpf_probe_read_kernel_str_proto __weak; const struct bpf_func_proto bpf_probe_read_kernel_dynptr_proto __weak; @@ -2029,6 +2030,8 @@ bpf_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_current_task_btf_proto; case BPF_FUNC_probe_read_user: return &bpf_probe_read_user_proto; + case BPF_FUNC_probe_read_user_dynptr: + return &bpf_probe_read_user_dynptr_proto; case BPF_FUNC_probe_read_kernel: return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? NULL : &bpf_probe_read_kernel_proto; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 75c9d1e8d04c3b8930ae81345f5586756ce8b5ec..d9f704c1342773c74b2414be4adfc8271d6d364d 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -181,6 +181,36 @@ bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) return ret; } +static int bpf_probe_read_check_dynptr(const struct bpf_dynptr_kern *dst, + u32 offset, u32 size, u64 flags) +{ + enum bpf_dynptr_type type; + int err; + + if (!dst->data || __bpf_dynptr_is_rdonly(dst)) + return -EINVAL; + + err = bpf_dynptr_check_off_len(dst, offset, size); + if (err) + return err; + + type = bpf_dynptr_get_type(dst); + + switch (type) { + case BPF_DYNPTR_TYPE_LOCAL: + case BPF_DYNPTR_TYPE_RINGBUF: + if (flags) + return -EINVAL; + return 0; + case BPF_DYNPTR_TYPE_SKB: + case BPF_DYNPTR_TYPE_XDP: + return -EINVAL; + default: + WARN_ONCE(true, "%s: unknown dynptr type %d\n", __func__, type); + return -EFAULT; + } +} + BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, const void __user *, unsafe_ptr) { @@ -196,6 +226,26 @@ const struct bpf_func_proto bpf_probe_read_user_proto = { .arg3_type = ARG_ANYTHING, }; +BPF_CALL_5(bpf_probe_read_user_dynptr, const struct bpf_dynptr_kern *, dst, + u32, offset, u32, size, void *, unsafe_ptr, u64, flags) +{ + int ret = bpf_probe_read_check_dynptr(dst, offset, size, flags); + + return ret ?: bpf_probe_read_user_common(dst->data + dst->offset + offset, + size, unsafe_ptr); +} + +const struct bpf_func_proto bpf_probe_read_user_dynptr_proto = { + .func = bpf_probe_read_user_dynptr, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_ANYTHING, + .arg5_type = ARG_ANYTHING, +}; + static __always_inline int bpf_probe_read_user_str_common(void *dst, u32 size, const void __user *unsafe_ptr) @@ -251,32 +301,10 @@ const struct bpf_func_proto bpf_probe_read_kernel_proto = { BPF_CALL_5(bpf_probe_read_kernel_dynptr, const struct bpf_dynptr_kern *, dst, u32, offset, u32, size, void *, unsafe_ptr, u64, flags) { - enum bpf_dynptr_type type; - int err; - - if (!dst->data || __bpf_dynptr_is_rdonly(dst)) - return -EINVAL; + int ret = bpf_probe_read_check_dynptr(dst, offset, size, flags); - err = bpf_dynptr_check_off_len(dst, offset, size); - if (err) - return err; - - type = bpf_dynptr_get_type(dst); - - switch (type) { - case BPF_DYNPTR_TYPE_LOCAL: - case BPF_DYNPTR_TYPE_RINGBUF: - if (flags) - return -EINVAL; - return bpf_probe_read_kernel_common(dst->data + dst->offset + offset, + return ret ?: bpf_probe_read_kernel_common(dst->data + dst->offset + offset, size, unsafe_ptr); - case BPF_DYNPTR_TYPE_SKB: - case BPF_DYNPTR_TYPE_XDP: - return -EINVAL; - default: - WARN_ONCE(true, "%s: unknown dynptr type %d\n", __func__, type); - return -EFAULT; - } } const struct bpf_func_proto bpf_probe_read_kernel_dynptr_proto = { From patchwork Sat Jan 25 08:23:38 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Levi Zim via B4 Relay X-Patchwork-Id: 13950245 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A39B12046AF; 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dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AsVwsjdV" Received: by smtp.kernel.org (Postfix) with ESMTPS id 169D2C4CEE3; Sat, 25 Jan 2025 08:24:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737793456; bh=PyRhaQiSnZLjeNlZTzgwUCTGU9Zv+fo1gZ0pY6cwY5A=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=AsVwsjdVP5/hfcvpE7Wkl6leiNVDtFC8w02N3KWNM19jmm7oA6YCosy2fMHxVkE8L ssR0K/tful33ls2WKBpynPVwjpyXTe6T3+Nm5u8nU5d49YdHyQLxgJzY7sgIE7j4Lw N3kqgccXnL4xsQvO5oKqwu/EuHQtPJDWssfa2vtAwnbnD9FntGrdYzJ8WGj0Zo/ETS inP/7q4jXbIDdk1rcvi8r26rGJUt7DJDRIjLzx8m2oueb9C7uzcb391xxVggHEc7+x dGpaofh7jA5+aNsV86KZbu9WJwaDHVJH1eAspAnLsBBbLHxxu85k3Ujece0tsap5uj 7IOF9J3vVC85Q== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 043CCC0218F; Sat, 25 Jan 2025 08:24:16 +0000 (UTC) From: Levi Zim via B4 Relay Date: Sat, 25 Jan 2025 16:23:38 +0800 Subject: [PATCH 3/7] bpf: Implement bpf_copy_from_user_dynptr helper Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250125-bpf_dynptr_probe-v1-3-c3cb121f6951@outlook.com> References: <20250125-bpf_dynptr_probe-v1-0-c3cb121f6951@outlook.com> In-Reply-To: <20250125-bpf_dynptr_probe-v1-0-c3cb121f6951@outlook.com> To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Matt Bobrowski , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Mykola Lysenko , Shuah Khan Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Andrii Nakryiko , Levi Zim X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; 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a=openpgp; fpr=17AADD6726DDC58B8EE5881757670CCFA42CCF0A X-Endpoint-Received: by B4 Relay for rsworktech@outlook.com/default with auth_id=219 X-Original-From: Levi Zim Reply-To: rsworktech@outlook.com From: Levi Zim This patch add a helper function bpf_copy_from_user_dynptr: bpf_copy_from_user_dynptr(const struct bpf_dynptr *dst, u32 offset, u32 size, const void *user_ptr, u64 flags) It is useful for reading variable-length data from kernel memory into dynptr. Signed-off-by: Levi Zim --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 17 +++++++++++++++++ kernel/bpf/helpers.c | 42 ++++++++++++++++++++++++++++++++++++++++++ kernel/trace/bpf_trace.c | 2 ++ 4 files changed, 62 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 9d5ae8b4b7d82c4523bf0ab041d4b76bf134a106..d0412eaf63d69c0e437575c77008548edc692335 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -3357,6 +3357,7 @@ extern const struct bpf_func_proto bpf_get_retval_proto; extern const struct bpf_func_proto bpf_user_ringbuf_drain_proto; extern const struct bpf_func_proto bpf_cgrp_storage_get_proto; extern const struct bpf_func_proto bpf_cgrp_storage_delete_proto; +extern const struct bpf_func_proto bpf_copy_from_user_dynptr_proto; const struct bpf_func_proto *tracing_prog_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index d7d7a9ddd5dca07ba89d81ba77101a704af3163b..f92cf809b50bc393d54eb0e8de2e1ce2a39e95d0 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5835,6 +5835,22 @@ union bpf_attr { * support this helper, or if *flags* is not 0. * * Or other negative errors on failure reading user space memory. + * + * long bpf_copy_from_user_dynptr(const struct bpf_dynptr *dst, u32 offset, u32 size, const void *user_ptr, u64 flags) + * Description + * Read *size* bytes from user space address *user_ptr* and store + * the data in *dst* starting from *offset*. + * This is a wrapper of **copy_from_user**\ (). + * *flags* is currently unused. + * Return + * 0 on success. + * + * **-E2BIG** if *offset* + *len* exceeds the length of *src*'s data + * + * **-EINVAL** if *src* is an invalid dynptr or doesn't support this + * support this helper, or if *flags* is not 0. + * + * Or other negative errors on failure reading user space memory. */ #define ___BPF_FUNC_MAPPER(FN, ctx...) \ FN(unspec, 0, ##ctx) \ @@ -6051,6 +6067,7 @@ union bpf_attr { FN(cgrp_storage_delete, 211, ##ctx) \ FN(probe_read_kernel_dynptr, 212, ##ctx) \ FN(probe_read_user_dynptr, 213, ##ctx) \ + FN(copy_from_user_dynptr, 214, ##ctx) \ /* */ /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index ac563d09082e7c721999d7de035aabc000206a29..d756c80596315bd07fe6e71885b61efc8cb2ef4f 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -676,6 +676,48 @@ const struct bpf_func_proto bpf_copy_from_user_proto = { .arg3_type = ARG_ANYTHING, }; +BPF_CALL_5(bpf_copy_from_user_dynptr, const struct bpf_dynptr_kern *, dst, + u32, offset, u32, size, const void __user *, user_ptr, u32, flags) +{ + enum bpf_dynptr_type type; + int err; + + if (!dst->data || __bpf_dynptr_is_rdonly(dst)) + return -EINVAL; + + err = bpf_dynptr_check_off_len(dst, offset, size); + if (err) + return err; + + type = bpf_dynptr_get_type(dst); + + switch (type) { + case BPF_DYNPTR_TYPE_LOCAL: + case BPF_DYNPTR_TYPE_RINGBUF: + if (flags) + return -EINVAL; + return ____bpf_copy_from_user(dst->data + dst->offset + offset, size, user_ptr); + case BPF_DYNPTR_TYPE_SKB: + case BPF_DYNPTR_TYPE_XDP: + return -EINVAL; + default: + WARN_ONCE(true, "%s: unknown dynptr type %d\n", __func__, type); + return -EFAULT; + } +} + +const struct bpf_func_proto bpf_copy_from_user_dynptr_proto = { + .func = bpf_copy_from_user_dynptr, + .gpl_only = false, + .might_sleep = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_ANYTHING, + .arg5_type = ARG_ANYTHING, +}; + BPF_CALL_5(bpf_copy_from_user_task, void *, dst, u32, size, const void __user *, user_ptr, struct task_struct *, tsk, u64, flags) { diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index d9f704c1342773c74b2414be4adfc8271d6d364d..424931925fe3b02db083bc19cc64e19918b40c5a 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1598,6 +1598,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_copy_from_user_proto; case BPF_FUNC_copy_from_user_task: return &bpf_copy_from_user_task_proto; + case BPF_FUNC_copy_from_user_dynptr: + return &bpf_copy_from_user_dynptr_proto; case BPF_FUNC_snprintf_btf: return &bpf_snprintf_btf_proto; case BPF_FUNC_per_cpu_ptr: From patchwork Sat Jan 25 08:23:39 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Levi Zim via B4 Relay X-Patchwork-Id: 13950243 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A38941547F3; 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a=openpgp; fpr=17AADD6726DDC58B8EE5881757670CCFA42CCF0A X-Endpoint-Received: by B4 Relay for rsworktech@outlook.com/default with auth_id=219 X-Original-From: Levi Zim Reply-To: rsworktech@outlook.com From: Levi Zim This update brings the new bpf_probe_read_{kernel,user} helpers Signed-off-by: Levi Zim --- tools/include/uapi/linux/bpf.h | 49 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 2acf9b33637174bd16b1d12ccc6410c5f55a7ea9..f92cf809b50bc393d54eb0e8de2e1ce2a39e95d0 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5805,6 +5805,52 @@ union bpf_attr { * 0 on success. * * **-ENOENT** if the bpf_local_storage cannot be found. + * + * long bpf_probe_read_kernel_dynptr(const struct bpf_dynptr *dst, u32 offset, u32 size, const void *unsafe_ptr, u64 flags) + * Description + * Safely attempt to read *size* bytes from kernel space address + * *unsafe_ptr* and store the data in *dst* starting from *offset*. + * *flags* is currently unused. + * Return + * 0 on success. + * + * **-E2BIG** if *offset* + *len* exceeds the length of *src*'s data + * + * **-EINVAL** if *src* is an invalid dynptr or doesn't support this + * support this helper, or if *flags* is not 0. + * + * Or other negative errors on failure reading kernel memory. + * + * long bpf_probe_read_user_dynptr(const struct bpf_dynptr *dst, u32 offset, u32 size, const void *unsafe_ptr, u64 flags) + * Description + * Safely attempt to read *size* bytes from user space address + * *unsafe_ptr* and store the data in *dst* starting from *offset*. + * *flags* is currently unused. + * Return + * 0 on success. + * + * **-E2BIG** if *offset* + *len* exceeds the length of *src*'s data + * + * **-EINVAL** if *src* is an invalid dynptr or doesn't support this + * support this helper, or if *flags* is not 0. + * + * Or other negative errors on failure reading user space memory. + * + * long bpf_copy_from_user_dynptr(const struct bpf_dynptr *dst, u32 offset, u32 size, const void *user_ptr, u64 flags) + * Description + * Read *size* bytes from user space address *user_ptr* and store + * the data in *dst* starting from *offset*. + * This is a wrapper of **copy_from_user**\ (). + * *flags* is currently unused. + * Return + * 0 on success. + * + * **-E2BIG** if *offset* + *len* exceeds the length of *src*'s data + * + * **-EINVAL** if *src* is an invalid dynptr or doesn't support this + * support this helper, or if *flags* is not 0. + * + * Or other negative errors on failure reading user space memory. */ #define ___BPF_FUNC_MAPPER(FN, ctx...) \ FN(unspec, 0, ##ctx) \ @@ -6019,6 +6065,9 @@ union bpf_attr { FN(user_ringbuf_drain, 209, ##ctx) \ FN(cgrp_storage_get, 210, ##ctx) \ FN(cgrp_storage_delete, 211, ##ctx) \ + FN(probe_read_kernel_dynptr, 212, ##ctx) \ + FN(probe_read_user_dynptr, 213, ##ctx) \ + FN(copy_from_user_dynptr, 214, ##ctx) \ /* */ /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't From patchwork Sat Jan 25 08:23:40 2025 Content-Type: text/plain; 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Sat, 25 Jan 2025 08:24:16 +0000 (UTC) From: Levi Zim via B4 Relay Date: Sat, 25 Jan 2025 16:23:40 +0800 Subject: [PATCH 5/7] selftests/bpf: probe_read_kernel_dynptr test Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250125-bpf_dynptr_probe-v1-5-c3cb121f6951@outlook.com> References: <20250125-bpf_dynptr_probe-v1-0-c3cb121f6951@outlook.com> In-Reply-To: <20250125-bpf_dynptr_probe-v1-0-c3cb121f6951@outlook.com> To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Matt Bobrowski , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Mykola Lysenko , Shuah Khan Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Andrii Nakryiko , Levi Zim X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; 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a=openpgp; fpr=17AADD6726DDC58B8EE5881757670CCFA42CCF0A X-Endpoint-Received: by B4 Relay for rsworktech@outlook.com/default with auth_id=219 X-Original-From: Levi Zim Reply-To: rsworktech@outlook.com From: Levi Zim This patch adds a test for probe_read_kernel_dynptr helper, which tests reading variable length of kernel memory into a ringbuf backed dynptr. Signed-off-by: Levi Zim --- tools/testing/selftests/bpf/prog_tests/dynptr.c | 40 +++++++++++++++++++++- tools/testing/selftests/bpf/progs/dynptr_success.c | 38 ++++++++++++++++++++ 2 files changed, 77 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/dynptr.c b/tools/testing/selftests/bpf/prog_tests/dynptr.c index b614a5272dfd6486e287181270a0bcf63f638344..d9a25c2873b6ed4219e063845b1caf978a7016fd 100644 --- a/tools/testing/selftests/bpf/prog_tests/dynptr.c +++ b/tools/testing/selftests/bpf/prog_tests/dynptr.c @@ -10,6 +10,7 @@ enum test_setup_type { SETUP_SYSCALL_SLEEP, SETUP_SKB_PROG, SETUP_SKB_PROG_TP, + SETUP_RINGBUF, }; static struct { @@ -30,20 +31,37 @@ static struct { {"test_dynptr_skb_no_buff", SETUP_SKB_PROG}, {"test_dynptr_skb_strcmp", SETUP_SKB_PROG}, {"test_dynptr_skb_tp_btf", SETUP_SKB_PROG_TP}, + {"test_probe_read_kernel_dynptr", SETUP_RINGBUF}, }; +static int ringbuf_cb(void *ctx, void *data, size_t len) +{ + struct dynptr_success *skel = ctx; + const char *buf = data; + + if (!ASSERT_EQ(len, skel->data->test_buf.length, "length")) + return -E2BIG; + + if (!ASSERT_MEMEQ(buf, skel->data->test_buf.buf, len, "ringbuf_cb")) + return -EINVAL; + + return 0; +} + static void verify_success(const char *prog_name, enum test_setup_type setup_type) { + struct ring_buffer *rb = NULL; struct dynptr_success *skel; struct bpf_program *prog; struct bpf_link *link; - int err; + int err, ret; skel = dynptr_success__open(); if (!ASSERT_OK_PTR(skel, "dynptr_success__open")) return; skel->bss->pid = getpid(); + skel->data->test_buf.length = 8; prog = bpf_object__find_program_by_name(skel->obj, prog_name); if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name")) @@ -63,6 +81,24 @@ static void verify_success(const char *prog_name, enum test_setup_type setup_typ usleep(1); + bpf_link__destroy(link); + break; + case SETUP_RINGBUF: + link = bpf_program__attach(prog); + if (!ASSERT_OK_PTR(link, "bpf_program__attach")) + goto cleanup; + + rb = ring_buffer__new(bpf_map__fd(skel->maps.ringbuf), ringbuf_cb, skel, NULL); + if (!ASSERT_OK_PTR(rb, "ring_buffer__new")) + goto cleanup; + + usleep(1); + + ret = ring_buffer__poll(rb, 5000); + + if (!ASSERT_EQ(ret, 1, "ring_buffer__poll")) + goto cleanup; + bpf_link__destroy(link); break; case SETUP_SKB_PROG: @@ -125,6 +161,8 @@ static void verify_success(const char *prog_name, enum test_setup_type setup_typ ASSERT_EQ(skel->bss->err, 0, "err"); cleanup: + if (rb != NULL) + ring_buffer__free(rb); dynptr_success__destroy(skel); } diff --git a/tools/testing/selftests/bpf/progs/dynptr_success.c b/tools/testing/selftests/bpf/progs/dynptr_success.c index bfcc85686cf046361b451f97f4cd310a6ccdb1ed..64c698f83a37bfe924db93d36982a0a1c8defe62 100644 --- a/tools/testing/selftests/bpf/progs/dynptr_success.c +++ b/tools/testing/selftests/bpf/progs/dynptr_success.c @@ -567,3 +567,41 @@ int BPF_PROG(test_dynptr_skb_tp_btf, void *skb, void *location) return 1; } + +#define MAX_BUFFER_LEN 20 + +struct { + __u32 length; + char buf[MAX_BUFFER_LEN]; +} test_buf = { + .length = 0, + .buf = "0123456789abcdef", +}; + +SEC("?tp/syscalls/sys_enter_nanosleep") +int test_probe_read_kernel_dynptr(void *ctx) +{ + int copy_len = test_buf.length; + struct bpf_dynptr ptr; + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + + if (test_buf.length > MAX_BUFFER_LEN) + copy_len = MAX_BUFFER_LEN; + + bpf_ringbuf_reserve_dynptr(&ringbuf, copy_len, 0, &ptr); + + if (-E2BIG != bpf_probe_read_kernel_dynptr(&ptr, 0, MAX_BUFFER_LEN + 1, + test_buf.buf, 0)) { + err = 1; + goto cleanup; + } + + err = bpf_probe_read_kernel_dynptr(&ptr, 0, copy_len, + test_buf.buf, 0); + +cleanup: + bpf_ringbuf_submit_dynptr(&ptr, 0); + return 0; +} From patchwork Sat Jan 25 08:23:41 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Levi Zim via B4 Relay X-Patchwork-Id: 13950248 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D6299207A35; 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a=openpgp; fpr=17AADD6726DDC58B8EE5881757670CCFA42CCF0A X-Endpoint-Received: by B4 Relay for rsworktech@outlook.com/default with auth_id=219 X-Original-From: Levi Zim Reply-To: rsworktech@outlook.com From: Levi Zim This patch adds a test for probe_read_user_dynptr helper, which tests reading variable length of user memory into a ringbuf backed dynptr. Signed-off-by: Levi Zim --- tools/testing/selftests/bpf/prog_tests/dynptr.c | 2 ++ tools/testing/selftests/bpf/progs/dynptr_success.c | 36 +++++++++++++++++++++- 2 files changed, 37 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/dynptr.c b/tools/testing/selftests/bpf/prog_tests/dynptr.c index d9a25c2873b6ed4219e063845b1caf978a7016fd..a5a61a4c570d803bfca2af3f1a3b7d5eb0b8197f 100644 --- a/tools/testing/selftests/bpf/prog_tests/dynptr.c +++ b/tools/testing/selftests/bpf/prog_tests/dynptr.c @@ -32,6 +32,7 @@ static struct { {"test_dynptr_skb_strcmp", SETUP_SKB_PROG}, {"test_dynptr_skb_tp_btf", SETUP_SKB_PROG_TP}, {"test_probe_read_kernel_dynptr", SETUP_RINGBUF}, + {"test_probe_read_user_dynptr", SETUP_RINGBUF}, }; static int ringbuf_cb(void *ctx, void *data, size_t len) @@ -61,6 +62,7 @@ static void verify_success(const char *prog_name, enum test_setup_type setup_typ return; skel->bss->pid = getpid(); + skel->bss->user_ptr = (void *)&skel->data->test_buf; skel->data->test_buf.length = 8; prog = bpf_object__find_program_by_name(skel->obj, prog_name); diff --git a/tools/testing/selftests/bpf/progs/dynptr_success.c b/tools/testing/selftests/bpf/progs/dynptr_success.c index 64c698f83a37bfe924db93d36982a0a1c8defe62..5317860290dccb0862b6a0b94bb6f738c8d92835 100644 --- a/tools/testing/selftests/bpf/progs/dynptr_success.c +++ b/tools/testing/selftests/bpf/progs/dynptr_success.c @@ -576,7 +576,7 @@ struct { } test_buf = { .length = 0, .buf = "0123456789abcdef", -}; +}, *user_ptr; SEC("?tp/syscalls/sys_enter_nanosleep") int test_probe_read_kernel_dynptr(void *ctx) @@ -605,3 +605,37 @@ int test_probe_read_kernel_dynptr(void *ctx) bpf_ringbuf_submit_dynptr(&ptr, 0); return 0; } + +SEC("?tp/syscalls/sys_enter_nanosleep") +int test_probe_read_user_dynptr(void *ctx) +{ + struct bpf_dynptr ptr; + int copy_len; + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + + err = bpf_probe_read_user(©_len, sizeof(copy_len), &user_ptr->length); + if (err < 0 || copy_len < 0) { + err = 1; 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a=openpgp; fpr=17AADD6726DDC58B8EE5881757670CCFA42CCF0A X-Endpoint-Received: by B4 Relay for rsworktech@outlook.com/default with auth_id=219 X-Original-From: Levi Zim Reply-To: rsworktech@outlook.com From: Levi Zim This patch adds a test for copy_from_user_dynptr helper, which tests reading variable length of user memory into a ringbuf backed dynptr. Signed-off-by: Levi Zim --- tools/testing/selftests/bpf/prog_tests/dynptr.c | 3 ++ tools/testing/selftests/bpf/progs/dynptr_success.c | 34 ++++++++++++++++++++++ 2 files changed, 37 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/dynptr.c b/tools/testing/selftests/bpf/prog_tests/dynptr.c index a5a61a4c570d803bfca2af3f1a3b7d5eb0b8197f..a0095204609c710d49a6105ebf8be44723fb53d2 100644 --- a/tools/testing/selftests/bpf/prog_tests/dynptr.c +++ b/tools/testing/selftests/bpf/prog_tests/dynptr.c @@ -33,6 +33,7 @@ static struct { {"test_dynptr_skb_tp_btf", SETUP_SKB_PROG_TP}, {"test_probe_read_kernel_dynptr", SETUP_RINGBUF}, {"test_probe_read_user_dynptr", SETUP_RINGBUF}, + {"test_copy_from_user_dynptr", SETUP_RINGBUF}, }; static int ringbuf_cb(void *ctx, void *data, size_t len) @@ -43,6 +44,8 @@ static int ringbuf_cb(void *ctx, void *data, size_t len) if (!ASSERT_EQ(len, skel->data->test_buf.length, "length")) return -E2BIG; + ASSERT_EQ(skel->bss->err, 0, "err"); + if (!ASSERT_MEMEQ(buf, skel->data->test_buf.buf, len, "ringbuf_cb")) return -EINVAL; diff --git a/tools/testing/selftests/bpf/progs/dynptr_success.c b/tools/testing/selftests/bpf/progs/dynptr_success.c index 5317860290dccb0862b6a0b94bb6f738c8d92835..10dda58fed66a05ad1b08c8684784fddabe3f4ad 100644 --- a/tools/testing/selftests/bpf/progs/dynptr_success.c +++ b/tools/testing/selftests/bpf/progs/dynptr_success.c @@ -639,3 +639,37 @@ int test_probe_read_user_dynptr(void *ctx) bpf_ringbuf_submit_dynptr(&ptr, 0); return 0; } + +SEC("?fentry.s/" SYS_PREFIX "sys_nanosleep") +int test_copy_from_user_dynptr(void *ctx) +{ + struct bpf_dynptr ptr; + int copy_len; + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + + err = bpf_probe_read_user(©_len, sizeof(copy_len), &user_ptr->length); + if (err < 0 || copy_len < 0) { + err = 1; + return 0; + } + + if (copy_len > MAX_BUFFER_LEN) + copy_len = MAX_BUFFER_LEN; + + bpf_ringbuf_reserve_dynptr(&ringbuf, copy_len, 0, &ptr); + + if (-E2BIG != bpf_copy_from_user_dynptr(&ptr, 0, MAX_BUFFER_LEN + 1, + &user_ptr->buf, 0)) { + err = 2; + goto cleanup; + } + + err = bpf_copy_from_user_dynptr(&ptr, 0, copy_len, + &user_ptr->buf, 0); + +cleanup: + bpf_ringbuf_submit_dynptr(&ptr, 0); + return 0; +}