From nobody Tue Sep 9 00:02:22 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22690C6FD1D for ; Fri, 7 Apr 2023 17:19:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229638AbjDGRTE (ORCPT ); Fri, 7 Apr 2023 13:19:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53582 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230039AbjDGRSz (ORCPT ); Fri, 7 Apr 2023 13:18:55 -0400 Received: from mail-ot1-x341.google.com (mail-ot1-x341.google.com [IPv6:2607:f8b0:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EBF4440FB; Fri, 7 Apr 2023 10:18:45 -0700 (PDT) Received: by mail-ot1-x341.google.com with SMTP id f19-20020a9d5f13000000b00693ce5a2f3eso22363632oti.8; Fri, 07 Apr 2023 10:18:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680887925; x=1683479925; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=sLteJQ8c+SN8oNJjCjxoIRPKFzLnI8skpOxBYxbnER4=; b=LVmzZcc4ItOFp3vZDq/gdzosshgwAr0ww023QcO3qkGDF6IeynqiyGwg7ts2NY5tox 76VACvntsuvoCYA4nLD8by+CStm6RuBjW9vjyeaipcoX5Qv3EtCuqDjOikiI9rCRWrdo RMRNxSiMqqOvWvP/gpCwBRYGwWTWpNi+pwfXJyp1vS3GEWf2sRRLz9cuyTz4VDlisEkN 0xz74QfUwmwtKygBH3eMGPDk8oyZzw3loY59ChPX51cOQZu4hGwNbK+q8RPisSSuR0Gb nrBOyqnKTMjmDFH2Q10OkRiUQ/ezc/iFG31UbVxY03eMy5rIWqlfDH+GztnizOEporb/ BX+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680887925; x=1683479925; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=sLteJQ8c+SN8oNJjCjxoIRPKFzLnI8skpOxBYxbnER4=; b=5WlC5F7qlR+atCK/RqYS4nx3DpUQSeNfHSUEFhOxdjawFDRYpQEolN6M1CaywnyDgh einqw9qLa/dpp6AvxRg3XPXgeDjYxfWyqdF66nrE0nT/PfC4pHFnBJjaJzu1GskF8Eeu zhvIxVZ+6ovhVEKDO2WXdh45yqYWyTZIp5u3jcFjh9I1nNcP98zI7/FCwYRurbVvZ620 fzjSO/JO4xi+l3rP17EitJ7E6Isr9kzaDm41QkEuHSYy2x4F2ZuwNhmxS9sTheh4G7kh UrsmjUY8rgpQ6bzEg0fLmJIqA6cciokKSm1uuQSFSnyy03ZvNxmj/npGtqQlWR1Dfiqg KSCA== X-Gm-Message-State: AAQBX9eoOb/HTni+9DZN7gVCVAP2+M9bN1HlaJLGvbBSlRIV4DpHezu3 Uow36F5YCBpTi3hy4ko+CiLO5cgrXBb2kU4= X-Google-Smtp-Source: AKy350Y/gKRvyuVHJithHouBOyeSoXFbnST168BAY2wAAOZ4E/7+p+xV2fEEc9gqgJuQo5C4vVAiQw== X-Received: by 2002:a05:6830:13d8:b0:6a1:373d:b0a6 with SMTP id e24-20020a05683013d800b006a1373db0a6mr1212595otq.23.1680887925115; Fri, 07 Apr 2023 10:18:45 -0700 (PDT) Received: from fedora.mshome.net ([104.184.156.161]) by smtp.gmail.com with ESMTPSA id l9-20020a9d7349000000b006a2ddc13c46sm1816730otk.78.2023.04.07.10.18.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Apr 2023 10:18:44 -0700 (PDT) From: Gregory Price X-Google-Original-From: Gregory Price To: linux-kernel@vger.kernel.org Cc: linux-doc@vger.kernel.org, linux-arch@vger.kernel.org, oleg@redhat.com, avagin@gmail.com, peterz@infradead.org, luto@kernel.org, krisman@collabora.com, tglx@linutronix.de, corbet@lwn.net, shuah@kernel.org, catalin.marinas@arm.com, arnd@arndb.de, Gregory Price Subject: [PATCH v16 1/4] syscall_user_dispatch: helper function to operate on given task Date: Fri, 7 Apr 2023 13:18:31 -0400 Message-Id: <20230407171834.3558-2-gregory.price@memverge.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230407171834.3558-1-gregory.price@memverge.com> References: <20230407171834.3558-1-gregory.price@memverge.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Preparatory patch ahead of set/get interfaces which will allow a ptrace to get/set the syscall user dispatch configuration of a task. This will simplify the set interface and consolidates error paths. Signed-off-by: Gregory Price Reviewed-by: Oleg Nesterov --- kernel/entry/syscall_user_dispatch.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/kernel/entry/syscall_user_dispatch.c b/kernel/entry/syscall_us= er_dispatch.c index 0b6379adff6b..22396b234854 100644 --- a/kernel/entry/syscall_user_dispatch.c +++ b/kernel/entry/syscall_user_dispatch.c @@ -68,8 +68,9 @@ bool syscall_user_dispatch(struct pt_regs *regs) return true; } =20 -int set_syscall_user_dispatch(unsigned long mode, unsigned long offset, - unsigned long len, char __user *selector) +static int task_set_syscall_user_dispatch(struct task_struct *task, unsign= ed long mode, + unsigned long offset, unsigned long len, + char __user *selector) { switch (mode) { case PR_SYS_DISPATCH_OFF: @@ -94,15 +95,21 @@ int set_syscall_user_dispatch(unsigned long mode, unsig= ned long offset, return -EINVAL; } =20 - current->syscall_dispatch.selector =3D selector; - current->syscall_dispatch.offset =3D offset; - current->syscall_dispatch.len =3D len; - current->syscall_dispatch.on_dispatch =3D false; + task->syscall_dispatch.selector =3D selector; + task->syscall_dispatch.offset =3D offset; + task->syscall_dispatch.len =3D len; + task->syscall_dispatch.on_dispatch =3D false; =20 if (mode =3D=3D PR_SYS_DISPATCH_ON) - set_syscall_work(SYSCALL_USER_DISPATCH); + set_task_syscall_work(task, SYSCALL_USER_DISPATCH); else - clear_syscall_work(SYSCALL_USER_DISPATCH); + clear_task_syscall_work(task, SYSCALL_USER_DISPATCH); =20 return 0; } + +int set_syscall_user_dispatch(unsigned long mode, unsigned long offset, + unsigned long len, char __user *selector) +{ + return task_set_syscall_user_dispatch(current, mode, offset, len, selecto= r); +} --=20 2.39.1 From nobody Tue Sep 9 00:02:22 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 336F4C6FD1D for ; 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Fri, 07 Apr 2023 10:18:48 -0700 (PDT) Received: from fedora.mshome.net ([104.184.156.161]) by smtp.gmail.com with ESMTPSA id l9-20020a9d7349000000b006a2ddc13c46sm1816730otk.78.2023.04.07.10.18.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Apr 2023 10:18:48 -0700 (PDT) From: Gregory Price X-Google-Original-From: Gregory Price To: linux-kernel@vger.kernel.org Cc: linux-doc@vger.kernel.org, linux-arch@vger.kernel.org, oleg@redhat.com, avagin@gmail.com, peterz@infradead.org, luto@kernel.org, krisman@collabora.com, tglx@linutronix.de, corbet@lwn.net, shuah@kernel.org, catalin.marinas@arm.com, arnd@arndb.de, Gregory Price Subject: [PATCH v16 2/4] syscall user dispatch: untag selector addresses before access_ok Date: Fri, 7 Apr 2023 13:18:32 -0400 Message-Id: <20230407171834.3558-3-gregory.price@memverge.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230407171834.3558-1-gregory.price@memverge.com> References: <20230407171834.3558-1-gregory.price@memverge.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This is a preparatory patch for enabling checkpoint/restart of tasks utilizing syscall user dispatch via ptrace. To support checkpoint/restart, ptrace must be able to set the selector of the tracee. The selector is a user pointer that may be subject to memory tagging extensions on some architectures (namely ARM MTE). access_ok will clear memory tags for tagged addresses on tasks where memory tagging is enabled. However, to allow ptrace to set a task's selector when tracer and tracee are not both tagged or untagged, the selector address must be untagged when calling access_ok. Since access_ok utilizes current to determine whether or not to untag an address, an untagged tracer will always fail to restore a tagged address in a tagged tracee. This patch will resolve this issue. The result of this is that a tagged tracer may be capable of setting an invalid address, which will cause the tracee to SIGSEGV on next syscall. This is equivalent to the tracee setting a bad selector address (such as selector=3D0x1). This is preferable to the alternative of creating a task_access_ok variant, and is consistent with other operations which change tracee pointers via ptrace. For more information, see: https://lore.kernel.org/all/ZCWXE04nLZ4pXEtM@arm.com/ Signed-off-by: Gregory Price Acked-by: Oleg Nesterov Suggested-by: Catalin Marinas Reviewed-by: Catalin Marinas --- kernel/entry/syscall_user_dispatch.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/kernel/entry/syscall_user_dispatch.c b/kernel/entry/syscall_us= er_dispatch.c index 22396b234854..424f24350f8b 100644 --- a/kernel/entry/syscall_user_dispatch.c +++ b/kernel/entry/syscall_user_dispatch.c @@ -87,7 +87,14 @@ static int task_set_syscall_user_dispatch(struct task_st= ruct *task, unsigned lon if (offset && offset + len <=3D offset) return -EINVAL; =20 - if (selector && !access_ok(selector, sizeof(*selector))) + /* + * access_ok will clear memory tags for tagged addresses on tasks where + * memory tagging is enabled. To enable a tracer to set a tracee's + * selector not in the same tagging state, the selector address must be + * untagged for access_ok, otherwise an untagged tracer will always fail + * to set a tagged tracee's selector. + */ + if (selector && !access_ok(untagged_addr(selector), sizeof(*selector))) return -EFAULT; =20 break; --=20 2.39.1 From nobody Tue Sep 9 00:02:22 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C22A3C6FD1D for ; Fri, 7 Apr 2023 17:19:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230253AbjDGRTL (ORCPT ); Fri, 7 Apr 2023 13:19:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53618 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229840AbjDGRS4 (ORCPT ); Fri, 7 Apr 2023 13:18:56 -0400 Received: from mail-oa1-x43.google.com (mail-oa1-x43.google.com [IPv6:2001:4860:4864:20::43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A068A4ED0; Fri, 7 Apr 2023 10:18:52 -0700 (PDT) Received: by mail-oa1-x43.google.com with SMTP id 586e51a60fabf-18412684c50so2166950fac.5; Fri, 07 Apr 2023 10:18:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680887932; x=1683479932; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=0ci1K0OGiVqlrbjf6n+dt/e4BXEFqQkMZBWMsE/R76w=; b=RfnvkIgh4g0IwnKtSDMP8iexJYGY+Ke9FjJoeBQpiOmMoIqC3Hryed+uV4nzHnTU9/ xrkB8FAuWLmgqTaey4MHxbIO/eHEJoGT1+BvgObcF2C3RykWIWfoFp+DCzCnz2Z/FeES EHSjZQ/BJfG88JskzGIdAY75g6dnEDdAHxHmEsbpQwLNhT5oxbHTS1R8mWarbdsdwJPT nhFIQb/gjRqAcSOxvWxcnFhwuQihKBXx4w57EVqdCTeWd+nk5ca2oU2Uy8pUbO9U6i6Z +mNzmqnzZ6PEzTCEI1l8HlQQ5H106EEHfRaLH4/VwG3jnhf1RL8kcXXObyqsc3ZzaHy4 B9iA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680887932; x=1683479932; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=0ci1K0OGiVqlrbjf6n+dt/e4BXEFqQkMZBWMsE/R76w=; b=tryvQZt0Vp4QH/Q9dkIXRgEv9tgOV+LhPJYm3bmPSBRe6PCnpAd7npEDlNJwAiTRYL Mfcx7bpYz+4sZgIcpA4M0B0HoUa0ecXLWsSD7fzAPeoolY/xb34BxO2Aiez64KFscEyo 82M6fViQtpNa+IEKvGI2DrMg9gXqd9v80TEfT0D6popyaMKjyENHvQMkqzGyrsQHWjjT z71wsvufv+CZmWWn/tqKQz+lWEAwnPx0ZlJZdJUstxU+tE5jOqz+bMNzNnr8I43/2zjq oLYYsoA7tpvuudVnQCRHRzx68RzjwKwtz9wSw9ZRtnr0xp8NyqQzyyJVU4U6O0/M5suK dvJQ== X-Gm-Message-State: AAQBX9ewj99+kPgBUyDNZnqDSjsDZBi1Rd4Z0bqYjhmqMO1NPt0lc3zV W5LHvfu5QMIwFMJlHffVZ5Wx1yLlr9gXs3A= X-Google-Smtp-Source: AKy350bObB0l+Qh6SdSADGp0fPGwtHdjk3zbGi0WJnsqEAKVYV+X8FOv8TKQxwcclwTj2zfryUhiAA== X-Received: by 2002:a05:6870:55a0:b0:17f:f2e0:2e14 with SMTP id n32-20020a05687055a000b0017ff2e02e14mr2006391oao.16.1680887931843; Fri, 07 Apr 2023 10:18:51 -0700 (PDT) Received: from fedora.mshome.net ([104.184.156.161]) by smtp.gmail.com with ESMTPSA id l9-20020a9d7349000000b006a2ddc13c46sm1816730otk.78.2023.04.07.10.18.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Apr 2023 10:18:51 -0700 (PDT) From: Gregory Price X-Google-Original-From: Gregory Price To: linux-kernel@vger.kernel.org Cc: linux-doc@vger.kernel.org, linux-arch@vger.kernel.org, oleg@redhat.com, avagin@gmail.com, peterz@infradead.org, luto@kernel.org, krisman@collabora.com, tglx@linutronix.de, corbet@lwn.net, shuah@kernel.org, catalin.marinas@arm.com, arnd@arndb.de, Gregory Price Subject: [PATCH v16 3/4] ptrace,syscall_user_dispatch: checkpoint/restore support for SUD Date: Fri, 7 Apr 2023 13:18:33 -0400 Message-Id: <20230407171834.3558-4-gregory.price@memverge.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230407171834.3558-1-gregory.price@memverge.com> References: <20230407171834.3558-1-gregory.price@memverge.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Implement ptrace getter/setter interface for syscall user dispatch. These prctl settings are presently write-only, making it impossible to implement transparent checkpoint/restore via software like CRIU. 'on_dispatch' field is not exposed because it is a kernel-internal only field that cannot be 'true' when returning to userland. Signed-off-by: Gregory Price Reviewed-by: Oleg Nesterov --- .../admin-guide/syscall-user-dispatch.rst | 4 ++ include/linux/syscall_user_dispatch.h | 18 ++++++++ include/uapi/linux/ptrace.h | 29 +++++++++++++ kernel/entry/syscall_user_dispatch.c | 42 +++++++++++++++++++ kernel/ptrace.c | 9 ++++ 5 files changed, 102 insertions(+) diff --git a/Documentation/admin-guide/syscall-user-dispatch.rst b/Document= ation/admin-guide/syscall-user-dispatch.rst index 60314953c728..f7648c08297e 100644 --- a/Documentation/admin-guide/syscall-user-dispatch.rst +++ b/Documentation/admin-guide/syscall-user-dispatch.rst @@ -73,6 +73,10 @@ thread-wide, without the need to invoke the kernel direc= tly. selector can be set to SYSCALL_DISPATCH_FILTER_ALLOW or SYSCALL_DISPATCH_FILTER_BLO= CK. Any other value should terminate the program with a SIGSYS. =20 +Additionally, a task's syscall user dispatch configuration can be peeked +and poked via the PTRACE_(GET|SET)_SYSCALL_USER_DISPATCH_CONFIG ptrace +requests. This is useful for checkpoint/restart software. + Security Notes -------------- =20 diff --git a/include/linux/syscall_user_dispatch.h b/include/linux/syscall_= user_dispatch.h index a0ae443fb7df..641ca8880995 100644 --- a/include/linux/syscall_user_dispatch.h +++ b/include/linux/syscall_user_dispatch.h @@ -22,6 +22,12 @@ int set_syscall_user_dispatch(unsigned long mode, unsign= ed long offset, #define clear_syscall_work_syscall_user_dispatch(tsk) \ clear_task_syscall_work(tsk, SYSCALL_USER_DISPATCH) =20 +int syscall_user_dispatch_get_config(struct task_struct *task, unsigned lo= ng size, + void __user *data); + +int syscall_user_dispatch_set_config(struct task_struct *task, unsigned lo= ng size, + void __user *data); + #else struct syscall_user_dispatch {}; =20 @@ -35,6 +41,18 @@ static inline void clear_syscall_work_syscall_user_dispa= tch(struct task_struct * { } =20 +static inline int syscall_user_dispatch_get_config(struct task_struct *tas= k, + unsigned long size, void __user *data) +{ + return -EINVAL; +} + +static inline int syscall_user_dispatch_set_config(struct task_struct *tas= k, + unsigned long size, void __user *data) +{ + return -EINVAL; +} + #endif /* CONFIG_GENERIC_ENTRY */ =20 #endif /* _SYSCALL_USER_DISPATCH_H */ diff --git a/include/uapi/linux/ptrace.h b/include/uapi/linux/ptrace.h index 195ae64a8c87..1e77b02344c3 100644 --- a/include/uapi/linux/ptrace.h +++ b/include/uapi/linux/ptrace.h @@ -112,6 +112,35 @@ struct ptrace_rseq_configuration { __u32 pad; }; =20 +#define PTRACE_SET_SYSCALL_USER_DISPATCH_CONFIG 0x4210 +#define PTRACE_GET_SYSCALL_USER_DISPATCH_CONFIG 0x4211 + +/* + * struct ptrace_sud_config - Per-task configuration for SUD + * @mode: One of PR_SYS_DISPATCH_ON or PR_SYS_DISPATCH_OFF + * @selector: Tracee's user virtual address of SUD selector + * @offset: SUD exclusion area (virtual address) + * @len: Length of SUD exclusion area + * + * Used to get/set the syscall user dispatch configuration for tracee. + * process. Selector is optional (may be NULL), and if invalid will produ= ce + * a SIGSEGV in the tracee upon first access. + * + * If mode is PR_SYS_DISPATCH_ON, syscall dispatch will be enabled. If + * PR_SYS_DISPATCH_OFF, syscall dispatch will be disabled and all other + * parameters must be 0. The value in *selector (if not null), also deter= mines + * whether syscall dispatch will occur. + * + * The SUD Exclusion area described by offset/len is the virtual address s= pace + * from which syscalls will not produce a user dispatch. + */ +struct ptrace_sud_config { + __u64 mode; + __u64 selector; + __u64 offset; + __u64 len; +}; + /* * These values are stored in task->ptrace_message * by ptrace_stop to describe the current syscall-stop. diff --git a/kernel/entry/syscall_user_dispatch.c b/kernel/entry/syscall_us= er_dispatch.c index 424f24350f8b..3af4e73b62b4 100644 --- a/kernel/entry/syscall_user_dispatch.c +++ b/kernel/entry/syscall_user_dispatch.c @@ -4,6 +4,7 @@ */ #include #include +#include #include #include #include @@ -120,3 +121,44 @@ int set_syscall_user_dispatch(unsigned long mode, unsi= gned long offset, { return task_set_syscall_user_dispatch(current, mode, offset, len, selecto= r); } + +int syscall_user_dispatch_get_config(struct task_struct *task, unsigned lo= ng size, + void __user *data) +{ + struct syscall_user_dispatch *sd =3D &task->syscall_dispatch; + struct ptrace_sud_config cfg; + + if (size !=3D sizeof(cfg)) + return -EINVAL; + + if (test_task_syscall_work(task, SYSCALL_USER_DISPATCH)) + cfg.mode =3D PR_SYS_DISPATCH_ON; + else + cfg.mode =3D PR_SYS_DISPATCH_OFF; + + cfg.offset =3D sd->offset; + cfg.len =3D sd->len; + cfg.selector =3D (__u64)(uintptr_t)sd->selector; + + if (copy_to_user(data, &cfg, sizeof(cfg))) + return -EFAULT; + + return 0; +} + +int syscall_user_dispatch_set_config(struct task_struct *task, unsigned lo= ng size, + void __user *data) +{ + int rc; + struct ptrace_sud_config cfg; + + if (size !=3D sizeof(cfg)) + return -EINVAL; + + if (copy_from_user(&cfg, data, sizeof(cfg))) + return -EFAULT; + + rc =3D task_set_syscall_user_dispatch(task, cfg.mode, cfg.offset, cfg.len, + (char __user *)(uintptr_t)cfg.selector); + return rc; +} diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 54482193e1ed..d99376532b56 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -32,6 +32,7 @@ #include #include #include +#include =20 #include /* for syscall_get_* */ =20 @@ -1259,6 +1260,14 @@ int ptrace_request(struct task_struct *child, long r= equest, break; #endif =20 + case PTRACE_SET_SYSCALL_USER_DISPATCH_CONFIG: + ret =3D syscall_user_dispatch_set_config(child, addr, datavp); + break; + + case PTRACE_GET_SYSCALL_USER_DISPATCH_CONFIG: + ret =3D syscall_user_dispatch_get_config(child, addr, datavp); + break; + default: break; } --=20 2.39.1 From nobody Tue Sep 9 00:02:22 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A6E64C77B6F for ; Fri, 7 Apr 2023 17:19:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229803AbjDGRTT (ORCPT ); Fri, 7 Apr 2023 13:19:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229724AbjDGRS6 (ORCPT ); Fri, 7 Apr 2023 13:18:58 -0400 Received: from mail-ot1-x344.google.com (mail-ot1-x344.google.com [IPv6:2607:f8b0:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D94DD1BD2; 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Fri, 07 Apr 2023 10:18:55 -0700 (PDT) From: Gregory Price X-Google-Original-From: Gregory Price To: linux-kernel@vger.kernel.org Cc: linux-doc@vger.kernel.org, linux-arch@vger.kernel.org, oleg@redhat.com, avagin@gmail.com, peterz@infradead.org, luto@kernel.org, krisman@collabora.com, tglx@linutronix.de, corbet@lwn.net, shuah@kernel.org, catalin.marinas@arm.com, arnd@arndb.de, Gregory Price Subject: [PATCH v16 4/4] selftest,ptrace: Add selftest for syscall user dispatch config api Date: Fri, 7 Apr 2023 13:18:34 -0400 Message-Id: <20230407171834.3558-5-gregory.price@memverge.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230407171834.3558-1-gregory.price@memverge.com> References: <20230407171834.3558-1-gregory.price@memverge.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Validate that the following new ptrace requests work as expected * PTRACE_GET_SYSCALL_USER_DISPATCH_CONFIG - returns the contents of task->syscall_dispatch if enabled * PTRACE_SET_SYSCALL_USER_DISPATCH_CONFIG - sets the contents of task->syscall_dispatch Signed-off-by: Gregory Price --- tools/testing/selftests/ptrace/.gitignore | 1 + tools/testing/selftests/ptrace/Makefile | 2 +- tools/testing/selftests/ptrace/get_set_sud.c | 72 ++++++++++++++++++++ 3 files changed, 74 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/ptrace/get_set_sud.c diff --git a/tools/testing/selftests/ptrace/.gitignore b/tools/testing/self= tests/ptrace/.gitignore index 792318aaa30c..b7dde152e75a 100644 --- a/tools/testing/selftests/ptrace/.gitignore +++ b/tools/testing/selftests/ptrace/.gitignore @@ -1,4 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only get_syscall_info +get_set_sud peeksiginfo vmaccess diff --git a/tools/testing/selftests/ptrace/Makefile b/tools/testing/selfte= sts/ptrace/Makefile index 2f1f532c39db..33a36b73bcb9 100644 --- a/tools/testing/selftests/ptrace/Makefile +++ b/tools/testing/selftests/ptrace/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0-only CFLAGS +=3D -std=3Dc99 -pthread -iquote../../../../include/uapi -Wall =20 -TEST_GEN_PROGS :=3D get_syscall_info peeksiginfo vmaccess +TEST_GEN_PROGS :=3D get_syscall_info peeksiginfo vmaccess get_set_sud =20 include ../lib.mk diff --git a/tools/testing/selftests/ptrace/get_set_sud.c b/tools/testing/s= elftests/ptrace/get_set_sud.c new file mode 100644 index 000000000000..5297b10d25c3 --- /dev/null +++ b/tools/testing/selftests/ptrace/get_set_sud.c @@ -0,0 +1,72 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE +#include "../kselftest_harness.h" +#include +#include +#include +#include +#include +#include + +#include "linux/ptrace.h" + +static int sys_ptrace(int request, pid_t pid, void *addr, void *data) +{ + return syscall(SYS_ptrace, request, pid, addr, data); +} + +TEST(get_set_sud) +{ + struct ptrace_sud_config config; + pid_t child; + int ret =3D 0; + int status; + + child =3D fork(); + ASSERT_GE(child, 0); + if (child =3D=3D 0) { + ASSERT_EQ(0, sys_ptrace(PTRACE_TRACEME, 0, 0, 0)) { + TH_LOG("PTRACE_TRACEME: %m"); + } + kill(getpid(), SIGSTOP); + _exit(1); + } + + waitpid(child, &status, 0); + + memset(&config, 0xff, sizeof(config)); + config.mode =3D PR_SYS_DISPATCH_ON; + + ret =3D sys_ptrace(PTRACE_GET_SYSCALL_USER_DISPATCH_CONFIG, child, + (void *)sizeof(config), &config); + + ASSERT_EQ(ret, 0); + ASSERT_EQ(config.mode, PR_SYS_DISPATCH_OFF); + ASSERT_EQ(config.selector, 0); + ASSERT_EQ(config.offset, 0); + ASSERT_EQ(config.len, 0); + + config.mode =3D PR_SYS_DISPATCH_ON; + config.selector =3D 0; + config.offset =3D 0x400000; + config.len =3D 0x1000; + + ret =3D sys_ptrace(PTRACE_SET_SYSCALL_USER_DISPATCH_CONFIG, child, + (void *)sizeof(config), &config); + + ASSERT_EQ(ret, 0); + + memset(&config, 1, sizeof(config)); + ret =3D sys_ptrace(PTRACE_GET_SYSCALL_USER_DISPATCH_CONFIG, child, + (void *)sizeof(config), &config); + + ASSERT_EQ(ret, 0); + ASSERT_EQ(config.mode, PR_SYS_DISPATCH_ON); + ASSERT_EQ(config.selector, 0); + ASSERT_EQ(config.offset, 0x400000); + ASSERT_EQ(config.len, 0x1000); + + kill(child, SIGKILL); +} + +TEST_HARNESS_MAIN --=20 2.39.1