From patchwork Mon Feb 10 22:16:24 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jordan Rome X-Patchwork-Id: 13968633 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F7D1C0219E for ; Mon, 10 Feb 2025 22:17:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0FB8828000D; Mon, 10 Feb 2025 17:17:14 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0AC68280006; Mon, 10 Feb 2025 17:17:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E664028000D; Mon, 10 Feb 2025 17:17:13 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id C33E1280006 for ; Mon, 10 Feb 2025 17:17:13 -0500 (EST) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 46A0FB0983 for ; Mon, 10 Feb 2025 22:17:13 +0000 (UTC) X-FDA: 83105446746.09.FC7E5C8 Received: from mout.perfora.net (mout.perfora.net [74.208.4.194]) by imf11.hostedemail.com (Postfix) with ESMTP id 8928240014 for ; Mon, 10 Feb 2025 22:17:11 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=jordanrome.com header.s=s1-ionos header.b=vCiWUozh; spf=pass (imf11.hostedemail.com: domain of linux@jordanrome.com designates 74.208.4.194 as permitted sender) smtp.mailfrom=linux@jordanrome.com; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1739225831; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:references:dkim-signature; bh=yJJHtP6Ybd5+FScfldyOtf8Z7tbm+0cUAU9G4HHYpKQ=; b=s5Vw8Wu9Xtv45rPpxP5lcfDgkU/cxillUlo1ml2z4I7pgwXssqdOnr0oHjmA/wDsWw6rVx NAUX+RHysTxU8+BMS5mc9SrapRj60X41NLf+WDFJq2NeugtVBG6A6jG8NHRUVtyaKqsJYO /l9myflJIJ6OJCevU0i6TB2XjFx/7EQ= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=jordanrome.com header.s=s1-ionos header.b=vCiWUozh; spf=pass (imf11.hostedemail.com: domain of linux@jordanrome.com designates 74.208.4.194 as permitted sender) smtp.mailfrom=linux@jordanrome.com; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1739225831; a=rsa-sha256; cv=none; b=PCoWNRpFNktSEcfDJtVoaMwjWO4P1xfsWkbWmA5TRSyK9vM+aYpHeJitUNWuU8gWdm4LAa 2Ux3vn1lnxOa+Zw8+Neyo+BuUWvSZMbysItsW6k2PDh479vBjmUIQ1jJHt71qDCeHozJw8 5IuVM56RucGabGty2byPCLgIF0EqasE= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jordanrome.com; s=s1-ionos; t=1739225791; x=1739830591; i=linux@jordanrome.com; bh=yJJHtP6Ybd5+FScfldyOtf8Z7tbm+0cUAU9G4HHYpKQ=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:Message-ID: MIME-Version:Content-Transfer-Encoding:cc: content-transfer-encoding:content-type:date:from:message-id: mime-version:reply-to:subject:to; b=vCiWUozhWlHq24G/JPxCPvVRfW8HDUhMwQeSCHtWxDbwQJGo7PC6Va/Nt8145ZVJ LHr4q+JOvbEv1GBcdApwnQLqmTtBNfg1Ck+l1Zliq7WBbViwNiG6MXSS1k0usNqsy re+eyCVsyJVkswO1CmOHf6yoHT+oTk7JJUsDE0rGOE5sG8+F506S1zWR2fLoD+u9F ODs4HiQvgoeGfcQjLXQYe8mYFl4Tn2ofIKmqXOO1fgML2hi0fUJPauDtTxB16nLPC ViK9SBrUhfShxW9l7e/7K0DzKrpRe9J/Wz0rOWrO/tZM2lMvaHtkWU08MV37SK7oZ alj+RYt8PHw/eaLF4g== X-UI-Sender-Class: 55c96926-9e95-11ee-ae09-1f7a4046a0f6 Received: from localhost ([69.171.251.115]) by mrelay.perfora.net (mreueus004 [74.208.5.2]) with ESMTPSA (Nemesis) id 1MsZaJ-1tNb9Q017L-00vbnZ; Mon, 10 Feb 2025 23:16:31 +0100 From: Jordan Rome To: bpf@vger.kernel.org Cc: linux-mm@kvack.org, Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Kernel Team , Andrew Morton , Shakeel Butt , Alexander Potapenko Subject: [bpf-next v7 1/3] mm: add copy_remote_vm_str Date: Mon, 10 Feb 2025 14:16:24 -0800 Message-ID: <20250210221626.2098522-1-linux@jordanrome.com> X-Mailer: git-send-email 2.43.5 MIME-Version: 1.0 X-Provags-ID: V03:K1:QNjPbdBmC6RgFhoMhi+mCZ4fNXpSAQszghe/PMKyIZTi/DfAfXf w7He5TL2nFLQABaNZqxupI7lA055F6UPvNK4p0YMNMT/M+dH8hbX+86FBWrdqurL6a3EBNx UJD3iOy09SzWgKSVQc18fTop5DM/yC1/DU2v7xFECrjFgJBKjY9dWeWnrpBz6Hgx24UHGGz m6Yf1klZNJmcSdXy0tQlg== UI-OutboundReport: notjunk:1;M01:P0:71o24VuHdlQ=;wPcmLcdhKW4VuPuIyLJ3k0Sjd/c 6Tz0sWNDUlBlmi4rEJcLEy/64yNEqKUucdKzAadGGsO4MyMV5uuVwJAeEgJQ7mmSkK4FzZVJN j9q4gZLlx9jwMNjHDjoN5Pgn33CJX68lgK1qN0VxZIsGMqMvprkQAVVmA38672AI+oIL+jKe9 2UZ+mC7Ohp6RSSP2W9xvYUxKqFQcrty1+K7YcRIr3IezgjmJ0Ns3c+PGW1/ByHakXr0zU44QE dm9vbMp5xXfwwqtZdDIb1m0VY8e8mZ0gv9MuS3TCsRLt38xXJrnp844Me+8fVGgTC5jVZi5X4 CSJcr+4m+ObHGRgqZr4g6bv3GbVvJM8GV2r9U2fRLm6Y/TimCN8X8grGzUww7hh3do9Lx7bWQ gv55dxTZKfcIA0K6xy5EP6LXG8BEMBKIF2l9DLatbcW9aQ/Uyolx5y434EGmK8wI3PAD5naqe akdxzx+BUihOD0KazfNwWqBkAEMr7mjU4l8KSRjHufNGcB+FFm2JeKPuIJ1e35jMzqBEJMuNN 0wccjl/V3yTUgBMd4LnyKUJKVJgi2APkeB6DqPu6nK2dA4ynkPl2u8zo85yEuWgC8DitQkOGM ceu+RujZE+YosngqKc+PWeqjSuClF34m2DQhY+qmAcfqWFbtwNY/+HtmC77t9hZCYppvgxr0z 0sE2FwQB/CWNLc4zo9wdcBpi2OuDZprE05KUyqV6tqN1nXWBbvPMvDUyH43ifggKlGQ1In+NK KC8DfeHoxCrOuol4o03qeK11IK7vgRCzGVZ25S67r9WUaCDIzasG/VFJ/OTbqZqlm1pSFmrJO Iczu/utXrcPC655dGqWuBlNduTJBDNao4m0pAMYdagusYFX1HhxxFyF6uJtQDZfeNB1EcHP+a Y2SW1B/t25UiVFqDuZCLrCrnbb5AhCf+PH40vPPZFE+zpe4Zn+TS/GqjA0vgKIY8ZM+Y6K+KI t9OhEjrnSqr2MfcvZe5PhJiuvKwCYv3kLvBTW2Cgz/fxXhKk64gN5+BP/7jqrKRr0Jdt6/i/p TeIoJnWsKhvsE6z1vijj70gxvG/vGYhVOzP247cvmRO/NQZrqCQHvX4iUhvrmpLyV1ZQkvfTB SIeLXIFdKX2cKSyrMNRnlagKyWGBzxIrHtO+ti09Nws5bMfdtZViScg3t/hFiFCKpMQJoViix zWe3Brc7Sk3fFfbSDe4B6i/Wk0cK57t3P2v4Pjcd8WhtNbvLZ+eOWspNwBm9kvwDCeY7fm3vh N3dkBOeGC/5ZHIdPNfu1ea4wf5F1GTcikiS/3Xkd5sgRbL0VIyNdd1EuDZSUbhyFFT69BGdkg KZE9lhG9z3k6g2UChXarYe8Utb6UW1huCDs+iucAXWJPPU= X-Rspam-User: X-Stat-Signature: f6d4pruwzsb6tpy59m9na95i1r1jxkw5 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 8928240014 X-HE-Tag: 1739225831-140513 X-HE-Meta: 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 CxxOArzo SVCCm/apojg1IS6Z0/9UZ/f2AkY5ceCyg/51YIVgwk7JIOt3fkaw8H4t2RxVRNLDdTVCAggd/XPPWgFNcgKTDbfz1Siw2GrvNdccRZKII4NtEk6GDJpGedAql34l7M3pn9KFqhB1otaaxpSW/dsU8gtcfvJDlSgYLszMI2QSuXnG+VYqLKSdrlN8rX75bd09adzL8fgC8GZLu61hMTtQCEp7owZjKEkIzm2/R/HPnxXqdndo+eG+Mzq8SEyt1YeBmH9ZG9qCzwILnu4KKLtrb28UxOy1p41txjQRLDC4X9E83MnxL7wLKy71o480etYytno/Q+n/LQ23QgSXTSHiliTSy3ffWkMs3vh52FJATOkguc72E/D78WA5fK9/QojT9ay8l X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Similar to `access_process_vm` but specific to strings. Also chunks reads by page and utilizes `strscpy` for handling null termination. Signed-off-by: Jordan Rome Acked-by: Andrii Nakryiko Reviewed-by: Shakeel Butt --- include/linux/mm.h | 3 ++ mm/memory.c | 119 +++++++++++++++++++++++++++++++++++++++++++++ mm/nommu.c | 73 +++++++++++++++++++++++++++ 3 files changed, 195 insertions(+) -- 2.43.5 diff --git a/include/linux/mm.h b/include/linux/mm.h index 7b1068ddcbb7..aee23d84ce01 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2486,6 +2486,9 @@ extern int access_process_vm(struct task_struct *tsk, unsigned long addr, extern int access_remote_vm(struct mm_struct *mm, unsigned long addr, void *buf, int len, unsigned int gup_flags); +extern int copy_remote_vm_str(struct task_struct *tsk, unsigned long addr, + void *buf, int len, unsigned int gup_flags); + long get_user_pages_remote(struct mm_struct *mm, unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, diff --git a/mm/memory.c b/mm/memory.c index 539c0f7c6d54..e9d8584a7f56 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -6803,6 +6803,125 @@ int access_process_vm(struct task_struct *tsk, unsigned long addr, } EXPORT_SYMBOL_GPL(access_process_vm); +/* + * Copy a string from another process's address space as given in mm. + * If there is any error return -EFAULT. + */ +static int __copy_remote_vm_str(struct mm_struct *mm, unsigned long addr, + void *buf, int len, unsigned int gup_flags) +{ + void *old_buf = buf; + int err = 0; + + *(char *)buf = '\0'; + + if (mmap_read_lock_killable(mm)) + return -EFAULT; + + /* Untag the address before looking up the VMA */ + addr = untagged_addr_remote(mm, addr); + + /* Avoid triggering the temporary warning in __get_user_pages */ + if (!vma_lookup(mm, addr)) { + err = -EFAULT; + goto out; + } + + while (len) { + int bytes, offset, retval; + void *maddr; + struct page *page; + struct vm_area_struct *vma = NULL; + + page = get_user_page_vma_remote(mm, addr, gup_flags, &vma); + + if (IS_ERR(page)) { + /* + * Treat as a total failure for now until we decide how + * to handle the CONFIG_HAVE_IOREMAP_PROT case and + * stack expansion. + */ + *(char *)buf = '\0'; + err = -EFAULT; + goto out; + } + + bytes = len; + offset = addr & (PAGE_SIZE - 1); + if (bytes > PAGE_SIZE - offset) + bytes = PAGE_SIZE - offset; + + maddr = kmap_local_page(page); + retval = strscpy(buf, maddr + offset, bytes); + + if (retval >= 0) { + /* Found the end of the string */ + buf += retval; + unmap_and_put_page(page, maddr); + break; + } + + buf += bytes - 1; + /* + * Because strscpy always NUL terminates we need to + * copy the last byte in the page if we are going to + * load more pages + */ + if (bytes != len) { + addr += bytes - 1; + copy_from_user_page(vma, page, addr, buf, + maddr + (PAGE_SIZE - 1), 1); + + buf += 1; + addr += 1; + } + len -= bytes; + + unmap_and_put_page(page, maddr); + } + +out: + mmap_read_unlock(mm); + if (err) + return err; + + return buf - old_buf; +} + +/** + * copy_remote_vm_str - copy a string from another process's address space. + * @tsk: the task of the target address space + * @addr: start address to read from + * @buf: destination buffer + * @len: number of bytes to copy + * @gup_flags: flags modifying lookup behaviour + * + * The caller must hold a reference on @mm. + * + * Return: number of bytes copied from @addr (source) to @buf (destination); + * not including the trailing NUL. Always guaranteed to leave NUL-terminated + * buffer. On any error, return -EFAULT. + */ +int copy_remote_vm_str(struct task_struct *tsk, unsigned long addr, + void *buf, int len, unsigned int gup_flags) +{ + struct mm_struct *mm; + int ret; + + mm = get_task_mm(tsk); + if (!mm) { + *(char *)buf = '\0'; + return -EFAULT; + } + + ret = __copy_remote_vm_str(mm, addr, buf, len, gup_flags); + + mmput(mm); + + return ret; +} +EXPORT_SYMBOL_GPL(copy_remote_vm_str); + /* * Print the name of a VMA. */ diff --git a/mm/nommu.c b/mm/nommu.c index baa79abdaf03..ec3bfcb35215 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1708,6 +1708,79 @@ int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, in } EXPORT_SYMBOL_GPL(access_process_vm); +/* + * Copy a string from another process's address space as given in mm. + * If there is any error return -EFAULT. + */ +static int __copy_remote_vm_str(struct mm_struct *mm, unsigned long addr, + void *buf, int len) +{ + unsigned long addr_end; + struct vm_area_struct *vma; + int ret = -EFAULT; + + *(char *)buf = '\0'; + + if (mmap_read_lock_killable(mm)) + return ret; + + /* the access must start within one of the target process's mappings */ + vma = find_vma(mm, addr); + if (!vma) + goto out; + + if (check_add_overflow(addr, len, &addr_end)) + goto out; + /* don't overrun this mapping */ + if (addr_end > vma->vm_end) + len = vma->vm_end - addr; + + /* only read mappings where it is permitted */ + if (vma->vm_flags & VM_MAYREAD) { + ret = strscpy(buf, (char *)addr, len); + if (ret < 0) + ret = len - 1; + } + +out: + mmap_read_unlock(mm); + return ret; +} + +/** + * copy_remote_vm_str - copy a string from another process's address space. + * @tsk: the task of the target address space + * @addr: start address to read from + * @buf: destination buffer + * @len: number of bytes to copy + * @gup_flags: flags modifying lookup behaviour (unused) + * + * The caller must hold a reference on @mm. + * + * Return: number of bytes copied from @addr (source) to @buf (destination); + * not including the trailing NUL. Always guaranteed to leave NUL-terminated + * buffer. On any error, return -EFAULT. + */ +int copy_remote_vm_str(struct task_struct *tsk, unsigned long addr, + void *buf, int len, unsigned int gup_flags) +{ + struct mm_struct *mm; + int ret; + + mm = get_task_mm(tsk); + if (!mm) { + *(char *)buf = '\0'; + return -EFAULT; + } + + ret = __copy_remote_vm_str(mm, addr, buf, len); + + mmput(mm); + + return ret; +} +EXPORT_SYMBOL_GPL(copy_remote_vm_str); + /** * nommu_shrink_inode_mappings - Shrink the shared mappings on an inode * @inode: The inode to check From patchwork Mon Feb 10 22:16:25 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jordan Rome X-Patchwork-Id: 13968631 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id A53A5C02198 for ; Mon, 10 Feb 2025 22:17:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3928E280008; Mon, 10 Feb 2025 17:17:07 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 34214280006; Mon, 10 Feb 2025 17:17:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1E4E7280008; Mon, 10 Feb 2025 17:17:07 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id ED91D280006 for ; Mon, 10 Feb 2025 17:17:06 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 9BB5B44682 for ; Mon, 10 Feb 2025 22:17:06 +0000 (UTC) X-FDA: 83105446452.23.D77F491 Received: from mout.perfora.net (mout.perfora.net [74.208.4.197]) by imf29.hostedemail.com (Postfix) with ESMTP id 99B17120007 for ; Mon, 10 Feb 2025 22:17:04 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=jordanrome.com header.s=s1-ionos header.b=LKvEeupG; spf=pass (imf29.hostedemail.com: domain of linux@jordanrome.com designates 74.208.4.197 as permitted sender) smtp.mailfrom=linux@jordanrome.com; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1739225824; a=rsa-sha256; cv=none; b=Bw+JYYxVUg3b3cmTTcA7zYu3LufeQOULj0VBEs7iFRnMYzFOc3FynEeE9OjRythvy5urbJ rpMzpQ8frAyJ7tUpLwJDw+7AStbfBgiLNO7M8RievJVsBubkTIO4b5E5iM2LXuGHx/u2KT Q9JnzkuBbMMQoDefBZj1DX5Grx5KLlU= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=jordanrome.com header.s=s1-ionos header.b=LKvEeupG; spf=pass (imf29.hostedemail.com: domain of linux@jordanrome.com designates 74.208.4.197 as permitted sender) smtp.mailfrom=linux@jordanrome.com; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1739225824; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=QaM92VVJ8sVRDEhsj6U41D+q2njMPqo34UDqJs8UQDM=; b=zheXUlxy0PD6iWCFeqqBT5x0YN4C/YzBjNE5Hw2p3Y0Hr/wmuyvNoZtL9OPLmQdINyRRdF To95EyH3Rp7WQlhO1CtlnBqHRRULnim8byVgzFfm7NoJUGyO8Tw96iKvao3w/YGPjcHtP2 nA9K3ZWWi8kTb9BMamhZOhKLoOmlA0U= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jordanrome.com; s=s1-ionos; t=1739225798; x=1739830598; i=linux@jordanrome.com; bh=QaM92VVJ8sVRDEhsj6U41D+q2njMPqo34UDqJs8UQDM=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:Message-ID:In-Reply-To: References:MIME-Version:Content-Transfer-Encoding:cc: content-transfer-encoding:content-type:date:from:message-id: mime-version:reply-to:subject:to; b=LKvEeupGPfe5VDHeVwLcPZcsNl9mbdjcbAGupYVSESJqXFas1bc6prQk88qYU4em nWUqkEI/UZE4Z5VcM8pS5YadDBlpdaLASU5quHqwE1xT36cQ7yaxrg/vjxIWTLuIL 3gID7IkRTR/OsWRw8Dm+/aca2X66m5lqGcxzAztn/BhKUOK2GQGmrGISTj2Oc90js cnzGbzz1DVO7UVL85mvZNkKYVbkLMo/VHUHJXEtABEwshSZkt6oD2NQqsDmeiCjb/ t+N8d43rR88zAFeWZuBb3EsSz97IesWLdDkd/mCJ7gtDvnZIjZJq/FjRP6EKb9Y1I oi48YSkuRNjVkHGhmg== X-UI-Sender-Class: 55c96926-9e95-11ee-ae09-1f7a4046a0f6 Received: from localhost ([69.171.251.14]) by mrelay.perfora.net (mreueus003 [74.208.5.2]) with ESMTPSA (Nemesis) id 0LiF41-1t3pED2EV9-00mb9D; Mon, 10 Feb 2025 23:16:38 +0100 From: Jordan Rome To: bpf@vger.kernel.org Cc: linux-mm@kvack.org, Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Kernel Team , Andrew Morton , Shakeel Butt , Alexander Potapenko Subject: [bpf-next v7 2/3] bpf: Add bpf_copy_from_user_task_str kfunc Date: Mon, 10 Feb 2025 14:16:25 -0800 Message-ID: <20250210221626.2098522-2-linux@jordanrome.com> X-Mailer: git-send-email 2.43.5 In-Reply-To: <20250210221626.2098522-1-linux@jordanrome.com> References: <20250210221626.2098522-1-linux@jordanrome.com> MIME-Version: 1.0 X-Provags-ID: V03:K1:iLPVhn1+1T95Aqyp/JoIzbEjvhwnm9MHdVWbq76iWd1Re8CFMgw rw6VicYNKMeojX/XL2VmjLIFPKguyvuuU+J6EyYOAzGPQySiFSjF7ctjENRQvCrZj6Im6kz 2J8ksGTtnLnS40qhd8iKGnWzhTDvXQJMdaFq68jYYtZMNFeG2sJTYO+nWDltRNpYuoEA7BA aYeT/Kun571gsnGj4oHzA== UI-OutboundReport: notjunk:1;M01:P0:chudMfkribQ=;9xayh3pkTZc/XYyilRffcHsje+n Ln2UqEkPNsEeWzt8Dj7X8+1gvMU7c06r/bF4BkGwjOncdvAG501E6pKHkLoE0QWeJ0UtAZEkc Q3HJbCiF9toUTc8I5qN8tzxGPVutmO6lyfFJj43d2X92UjIbOGudc7z+2imbziWVk0HxDlUCv q9BIhZnrfPHaVBMWOtkNRnIgaBqJUrfPUyuW9BRlzEkPnlpdRUp0UPy4GqZtUbkerHyYvKt9h HJFS12daS93TFSCNGLvqTB8ZncJiJh9R+pzYxwaMFgJ3aDkNZVbif9r8RORA/EAtaDJB/EO+w DUgyZqyG5M7WbxVQ6nA7BGmAxY8MZfUjY+0rwCxwSXWiBK8skpTMNjz0Bq1jjHOqB8XCpkpcW lpUvOPkba4inlkrf4wkiGCpAKK27bdrUki5bzhNxqY+7qcyUjsQ6Dc/Cmx+bc5ty9JoRTwHX8 hCMBwfXAwVuem99djaJLmgxj28T+WwJxl/58bRfnFiAtmHNvP65rat0FmIpUyq3r0M1Q7zCTP SPPHiZGzATVvKY786tSI0ukFU6eFCf9YokZ9pZ2sUVhk3fsFwky+Pa858xhso2VRGAeBF6lQ+ 0zyD0v92E7z277r5TBV8w0Zz8IFoKGS5oRXRkOaXj1wMqiAE3kkdzlLeqtoYDbhDOgZ286PSP OTCUW6xewfxS9BnmSvbUVFR94IYf4Bo8C2x8XByfqeOL/pRv8K352sD3PDiGVzMqypEwFg63R VF5EvgPmoarKf7brmaNvXwh3mLPPZcOjAE++AtRMGg6dIDik6ZgIxD6Hi9IQShvtXqCV/oc47 uO23umGm6aYpXHZHu2mPZRE0n2cIbSTPuV5rTTZW++dqnDpAve57JjC86O3LPUC1oq4VQ8It/ SJuRaVbET8RGPMOZSzUc7Shjrxln7ReClmki8llBw+UasB1s0lZrJy/ltOJGkDPMNBBMkZ0OY SVD7J6cc2JV/xaxVEiLRdXsTCcmtjWudA9nRtK9U8+OixIRshd5d6zrRbENf2dOINbu26fGuB SbNY80cl1el9uhYwFCjjqe8ke2Q0bldzI/ViASJ3N8aSsu0GgIl+pXNLqzLvzGOEYoBN7MPQv V/7Zuu1RkGZEjIwLU7lwrraEP52+4r9Twy7FMdw+DLg5Rqiqsd/LlXf8KMxv654UBxeX+QTgz 9ZMkTA8V1RaG9Bb1sJJ9ofr01joUZ7Z14QnPq8mFjwWMqdYOns6VuJxyFd5z8SAqYh3u68C8O 1hPiq0uOqr/aRrFA2DJibSGorAlJ3FvHPpgvbOhhLp+30it+Q9/OL4Z3/aF4MPHHophgN9YB/ eAoU2CS1V/D142OBDZEJFCI02GOHvdKe9RkBSBeKk60bbc= X-Stat-Signature: 6moi1djcwugmbtp6mt1zoqytfb7wpw6z X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 99B17120007 X-Rspam-User: X-HE-Tag: 1739225824-235767 X-HE-Meta: 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 rQf0rQ0+ TFAguV43hh3DyV7C4cl2tuFtKhtsT/S2RREmtN/6EmX3NHmy1jVr7rhuCsq/aQ89H4SzEmHqoAY7/j+vu+l+OT63FUd1STGhZUuwXOShnrXuPj0y7c1zX/A8qq4KLs2kA65vQpFe8dTr6pPxB6ifbppb0v9pm5cZOd9qtrHdsUDhbO2RkweYu6bZ1RAEK40u8/IrxZJmJmEQLujtT38YfoX/NcIiIlROLEz/DUBcnGPkFPvKlmRjLm5SzpcTMCjdiv2ABSQTKIipKjKJiozVydjz+z4rA1azgM+kpD2cqJXSxb7UU77znntP/k3vHVVy4JsZLAjwv/7ZGczFSpiNDOUbx0FXIQVHxk6qqFzjleBNyyVF8J9MFDp+Ho/2lhNIJ5xDwr4N5U+FNA3e8RvMQCdq/3ZA/IDvAbqjFq1fJB8WQaj6P+W6qJ9LhIxVlGof8u0BlfOe/gp9d8qAaKqd+3P7kKGFK5MoN0iKY0duX2cAkEjR1zTCFWjDnhRHYA7OSUfW9TLSgO7vVsbA= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: This new kfunc will be able to copy a string from another process's/task's address space. This is similar to `bpf_copy_from_user_str` but accepts a `struct task_struct*` argument. Acked-by: Andrii Nakryiko Signed-off-by: Jordan Rome --- kernel/bpf/helpers.c | 48 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) -- 2.43.5 diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index f27ce162427a..a33f72a4c31f 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -3082,6 +3082,53 @@ __bpf_kfunc void bpf_local_irq_restore(unsigned long *flags__irq_flag) local_irq_restore(*flags__irq_flag); } +/** + * bpf_copy_from_user_task_str() - Copy a string from an task's address space + * @dst: Destination address, in kernel space. This buffer must be + * at least @dst__sz bytes long. + * @dst__sz: Maximum number of bytes to copy, includes the trailing NUL. + * @unsafe_ptr__ign: Source address in the task's address space. + * @tsk: The task whose address space will be used + * @flags: The only supported flag is BPF_F_PAD_ZEROS + * + * Copies a NUL terminated string from a task's address space to @dst__sz + * buffer. If user string is too long this will still ensure zero termination + * in the @dst__sz buffer unless buffer size is 0. + * + * If BPF_F_PAD_ZEROS flag is set, memset the tail of @dst__sz to 0 on success + * and memset all of @dst__sz on failure. + * + * Return: The number of copied bytes on success including the NUL terminator. + * A negative error code on failure. + */ +__bpf_kfunc int bpf_copy_from_user_task_str(void *dst, + u32 dst__sz, + const void __user *unsafe_ptr__ign, + struct task_struct *tsk, + u64 flags) +{ + int ret; + + if (unlikely(flags & ~BPF_F_PAD_ZEROS)) + return -EINVAL; + + if (unlikely(!dst__sz)) + return 0; + + ret = copy_remote_vm_str(tsk, (unsigned long)unsafe_ptr__ign, dst, dst__sz, 0); + + if (ret < 0) { + if (flags & BPF_F_PAD_ZEROS) + memset(dst, 0, dst__sz); + return ret; + } + + if (flags & BPF_F_PAD_ZEROS) + memset(dst + ret, 0, dst__sz - ret); + + return ret + 1; +} + __bpf_kfunc_end_defs(); BTF_KFUNCS_START(generic_btf_ids) @@ -3174,6 +3221,7 @@ BTF_ID_FLAGS(func, bpf_iter_bits_new, KF_ITER_NEW) BTF_ID_FLAGS(func, bpf_iter_bits_next, KF_ITER_NEXT | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_iter_bits_destroy, KF_ITER_DESTROY) BTF_ID_FLAGS(func, bpf_copy_from_user_str, KF_SLEEPABLE) +BTF_ID_FLAGS(func, bpf_copy_from_user_task_str, KF_SLEEPABLE) BTF_ID_FLAGS(func, bpf_get_kmem_cache) BTF_ID_FLAGS(func, bpf_iter_kmem_cache_new, KF_ITER_NEW | KF_SLEEPABLE) BTF_ID_FLAGS(func, bpf_iter_kmem_cache_next, KF_ITER_NEXT | KF_RET_NULL | KF_SLEEPABLE) From patchwork Mon Feb 10 22:16:26 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jordan Rome X-Patchwork-Id: 13968632 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7578DC02198 for ; Mon, 10 Feb 2025 22:17:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 084F228000B; Mon, 10 Feb 2025 17:17:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 034DD280006; Mon, 10 Feb 2025 17:17:11 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DF14A28000B; Mon, 10 Feb 2025 17:17:11 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id BF14A280006 for ; Mon, 10 Feb 2025 17:17:11 -0500 (EST) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 72B111604F6 for ; Mon, 10 Feb 2025 22:17:11 +0000 (UTC) X-FDA: 83105446662.28.FF50D17 Received: from mout.perfora.net (mout.perfora.net [74.208.4.196]) by imf14.hostedemail.com (Postfix) with ESMTP id 8D60610000A for ; Mon, 10 Feb 2025 22:17:09 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=jordanrome.com header.s=s1-ionos header.b=kbppA2X9; spf=pass (imf14.hostedemail.com: domain of linux@jordanrome.com designates 74.208.4.196 as permitted sender) smtp.mailfrom=linux@jordanrome.com; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1739225829; a=rsa-sha256; cv=none; b=VP8k2qoHfkpm3UV3VwvOl42+G+7g+bYFkRUv0oEjJf1eH3ra82HR7P7lzVXYRrl8bJeTwI MjWXC0DBFbFIbrgIkhXCBc/HqNNwjfC2JOGx/mzyWhf8HTugUNPj2mmQixIJ/zlva2jyAG VMP8t0/ZtliNblS64S+PlYJCwIgR0U4= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=jordanrome.com header.s=s1-ionos header.b=kbppA2X9; spf=pass (imf14.hostedemail.com: domain of linux@jordanrome.com designates 74.208.4.196 as permitted sender) smtp.mailfrom=linux@jordanrome.com; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1739225829; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=LhJJH5WuMX5aq6LX3M5eXAA/nYkW+PydFm8hbRxet3Y=; b=2MSrb3O3a6QRxKePya89Axc31g9ovsOkqTcrVZJ2dy5OYsO1SNvCp/4och2Eg/pDzzfPqW SmqRhzx/hZ0+t83hWKbRhGyv7Wi/A5ikqkY3vewnh5N28D5bWYAlnz3m9CPK3pjx4Qi6zU mo7ZIE9b6ekgPUbQrLApAn0TCV4aJaM= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jordanrome.com; s=s1-ionos; t=1739225800; x=1739830600; i=linux@jordanrome.com; bh=LhJJH5WuMX5aq6LX3M5eXAA/nYkW+PydFm8hbRxet3Y=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:Message-ID:In-Reply-To: References:MIME-Version:Content-Transfer-Encoding:cc: content-transfer-encoding:content-type:date:from:message-id: mime-version:reply-to:subject:to; b=kbppA2X9lp4HV9p/fSZ7ZX7COxEK2xZAgVPBkc4oY+FGFKbHZP96dyeScCdiqBtQ MOg49PI3DPelGfVouokbFUggTVrnAaCp453Stk69YSwLpEbHiXzbL0HtYlrh5eVoa ComlbQQAICzz2HMDzpnzHS5S0Dfrcq8MSV21GXl6VUkBfqUqtynFuSxut3JcMgnE7 dfjKrSSBLFp53CmUA3Yj0sTqFH13nGBrZbAFv3t5vFNBH4h6I9Py1uhOlpAG4WHI3 Jzjsy1xYP1sBXzoYwW6KQLWSHS+N+Yog9PEtdvCriOJppQMVaGtDSdKDfaftwM30Z +vvrK4xMDWmr/USqRw== X-UI-Sender-Class: 55c96926-9e95-11ee-ae09-1f7a4046a0f6 Received: from localhost ([69.171.251.8]) by mrelay.perfora.net (mreueus003 [74.208.5.2]) with ESMTPSA (Nemesis) id 0MXJY3-1tw4Xl2evN-00WYTR; Mon, 10 Feb 2025 23:16:40 +0100 From: Jordan Rome To: bpf@vger.kernel.org Cc: linux-mm@kvack.org, Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Kernel Team , Andrew Morton , Shakeel Butt , Alexander Potapenko Subject: [bpf-next v7 3/3] selftests/bpf: Add tests for bpf_copy_from_user_task_str Date: Mon, 10 Feb 2025 14:16:26 -0800 Message-ID: <20250210221626.2098522-3-linux@jordanrome.com> X-Mailer: git-send-email 2.43.5 In-Reply-To: <20250210221626.2098522-1-linux@jordanrome.com> References: <20250210221626.2098522-1-linux@jordanrome.com> MIME-Version: 1.0 X-Provags-ID: V03:K1:rodj2MYcuAbXFChH1oH6zsmF7imrjIQv8jjEaoyBkAjNHKmW9ts 1bmnnXCS0Wvj7gGViaayE/+897AdXvzD6W8sNnWtz3CmIAQsbB+guqKq/c+gFcqWPZMd0ei +ebdl9g75+L6TdDY4HP5u6J7wmX68ZPgmgKKSqmutCaReZCPYlOV7qEVYF7yZoBhrzkwHgj gixScR+f+Xo3trU4r6RiQ== UI-OutboundReport: notjunk:1;M01:P0:bL0YwG6w2nI=;PqYdef34nimU2bBV+LAl2B9wzP5 rdwP0lDX0Uymt5PjdWsvpneLhj4jZshN1VJYGlTZVcHkPcOmajYsKQjxnGjZjTY1Ob9QfjInP 8iKlrqZbBL0V4WRt2bbIxQyOoY4KIyz9XesVUja5CFZPtyodN0LsXuYaJBv9iKop/hBXMPY+9 jjXvngDu6hrW30WFYXHwI4pOlGafEXJOifcYbG+jZgrjquWYxT7UvA2e/kU+D6OKpocsilwk6 4PMfmNWp1yoyBOijgaKgRskwjXQ+Os6vZo6MKXhnCFf7Kx1qdE7N5ZdK54dt4m4939dGEbeFx s7nDkCznWUvkaQMap49nO79SwNJ6x5QBvVCGx8r0uMCTk9LDiUBioTgOD9arEOV/miJqG8hJQ CxqE2p6asxVPX1KpzA0i/iCRE/0CrlVrOtubX+UJNg6Bc8myrUml66veHXyVWcys8pL42rpf1 XxVNZ0P4bAo/revHMf/tEroZ0/CP7aAxXJ6ylfpR4bg8aVsvyXKYEViLg7iaM9qUx3JwQgFjg Och2CbZryd+OPKrXz3WYPmLYWYJcZ1CbloTZ7MomvSl+OAhv1se1VMI81LkvCVr91CqmXKMin pdKge7z1jCIxWonGpkvbapEHWKSoPKUu6OleKXjrpYBcUAqTfDrIZ01MAKyB3N9MjOsyIDhr8 NGB+mbmsAU547EITYNZuJDYhhqndbZKtDXoSbUpMvaLLXatEjxR0Svv1a+Z9+wPsAjD9a8KtP Hvl9e0bGSPgTtEVCrrq+rQ4xRTitRdmpT1/5FG+qsNYUfX6UDrpL7x3Nfw1epTZWZWOiAOWNL PYXeL5pwFy4+M7IEVqwkcj9Jx061LMhx7IVe+DPeOI6XF5jrLJfstOt9im5Rhws8DyGli6Fkq i75Ay00YnIyekcSOkEKwYnZeGrXSyDbauJkifGkG6gxB30NhQfrmlVu+9zrEPHbqS47wM5OYf 5ivcX3qJRtg1KS+vyS2WhVdgYhpxi1cl2458HAmOyvkOzfbktRhoVbxoSI6CvW/8dn1d1HhSP mptev5KVHP2V/lb0i8BfFDlW6Px+YSD9x9ydcYr2AKIVs/ndzY5lK/R2Mj4hJ+JvU9K+TORR/ kkkosUlfMdkG9z30V8uIUx96O4xQUFbZAjcIQ/fSN24Ju0HwpqchtrOgYWJmQoJnnUfbLHaKJ cFIWhIdATzZgYBGObbnalORtRZOoTmA2aRJCRDl7dlSX0ksoQSi0DvPNumst+1NHGpimoUy5U +TRK8dV3F1G+nkbTAf83Qa/oLQBkNfD0DXuLHh2G4KGC6tvbp+TODi5gqBXm82onDKBjVmOfY udSmbS58DhSMP6Pt3Xk8O8fP6BXST4246vTpHkNTKlRMUY= X-Rspamd-Queue-Id: 8D60610000A X-Stat-Signature: xgz3sqhkttr9n1krhwindssw6nih9ybj X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1739225829-957393 X-HE-Meta: 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 oTru5aHX 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: This adds tests for both the happy path and the error path (with and without the BPF_F_PAD_ZEROS flag). Signed-off-by: Jordan Rome --- .../selftests/bpf/prog_tests/bpf_iter.c | 68 +++++++++++ .../selftests/bpf/prog_tests/read_vsyscall.c | 1 + .../selftests/bpf/progs/bpf_iter_tasks.c | 110 ++++++++++++++++++ .../selftests/bpf/progs/read_vsyscall.c | 11 +- 4 files changed, 188 insertions(+), 2 deletions(-) -- 2.43.5 diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c index 6f1bfacd7375..add4a18c33bd 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -323,19 +323,87 @@ static void test_task_pidfd(void) static void test_task_sleepable(void) { struct bpf_iter_tasks *skel; + int pid, status, err, data_pipe[2], finish_pipe[2], c; + char *test_data = NULL; + char *test_data_long = NULL; + char *data[2]; + + if (!ASSERT_OK(pipe(data_pipe), "data_pipe") || + !ASSERT_OK(pipe(finish_pipe), "finish_pipe")) + return; skel = bpf_iter_tasks__open_and_load(); if (!ASSERT_OK_PTR(skel, "bpf_iter_tasks__open_and_load")) return; + pid = fork(); + if (!ASSERT_GE(pid, 0, "fork")) + return; + + if (pid == 0) { + /* child */ + close(data_pipe[0]); + close(finish_pipe[1]); + + test_data = malloc(sizeof(char) * 10); + strncpy(test_data, "test_data", 10); + test_data[9] = '\0'; + + test_data_long = malloc(sizeof(char) * 5000); + for (int i = 0; i < 5000; ++i) { + if (i % 2 == 0) + test_data_long[i] = 'b'; + else + test_data_long[i] = 'a'; + } + test_data_long[4999] = '\0'; + + data[0] = test_data; + data[1] = test_data_long; + + write(data_pipe[1], &data, sizeof(data)); + + /* keep child alive until after the test */ + err = read(finish_pipe[0], &c, 1); + if (err != 1) + exit(-1); + + close(data_pipe[1]); + close(finish_pipe[0]); + _exit(0); + } + + /* parent */ + close(data_pipe[1]); + close(finish_pipe[0]); + + err = read(data_pipe[0], &data, sizeof(data)); + ASSERT_EQ(err, sizeof(data), "read_check"); + + skel->bss->user_ptr = data[0]; + skel->bss->user_ptr_long = data[1]; + skel->bss->pid = pid; + do_dummy_read(skel->progs.dump_task_sleepable); ASSERT_GT(skel->bss->num_expected_failure_copy_from_user_task, 0, "num_expected_failure_copy_from_user_task"); ASSERT_GT(skel->bss->num_success_copy_from_user_task, 0, "num_success_copy_from_user_task"); + ASSERT_GT(skel->bss->num_expected_failure_copy_from_user_task_str, 0, + "num_expected_failure_copy_from_user_task_str"); + ASSERT_GT(skel->bss->num_success_copy_from_user_task_str, 0, + "num_success_copy_from_user_task_str"); bpf_iter_tasks__destroy(skel); + + write(finish_pipe[1], &c, 1); + err = waitpid(pid, &status, 0); + ASSERT_EQ(err, pid, "waitpid"); + ASSERT_EQ(status, 0, "zero_child_exit"); + + close(data_pipe[0]); + close(finish_pipe[1]); } static void test_task_stack(void) diff --git a/tools/testing/selftests/bpf/prog_tests/read_vsyscall.c b/tools/testing/selftests/bpf/prog_tests/read_vsyscall.c index c7b9ba8b1d06..a8d1eaa67020 100644 --- a/tools/testing/selftests/bpf/prog_tests/read_vsyscall.c +++ b/tools/testing/selftests/bpf/prog_tests/read_vsyscall.c @@ -24,6 +24,7 @@ struct read_ret_desc { { .name = "copy_from_user", .ret = -EFAULT }, { .name = "copy_from_user_task", .ret = -EFAULT }, { .name = "copy_from_user_str", .ret = -EFAULT }, + { .name = "copy_from_user_task_str", .ret = -EFAULT }, }; void test_read_vsyscall(void) diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_tasks.c b/tools/testing/selftests/bpf/progs/bpf_iter_tasks.c index bc10c4e4b4fa..966ee5a7b066 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter_tasks.c +++ b/tools/testing/selftests/bpf/progs/bpf_iter_tasks.c @@ -9,6 +9,13 @@ char _license[] SEC("license") = "GPL"; uint32_t tid = 0; int num_unknown_tid = 0; int num_known_tid = 0; +void *user_ptr = 0; +void *user_ptr_long = 0; +uint32_t pid = 0; + +static char big_str1[5000]; +static char big_str2[5005]; +static char big_str3[4996]; SEC("iter/task") int dump_task(struct bpf_iter__task *ctx) @@ -35,7 +42,9 @@ int dump_task(struct bpf_iter__task *ctx) } int num_expected_failure_copy_from_user_task = 0; +int num_expected_failure_copy_from_user_task_str = 0; int num_success_copy_from_user_task = 0; +int num_success_copy_from_user_task_str = 0; SEC("iter.s/task") int dump_task_sleepable(struct bpf_iter__task *ctx) @@ -44,6 +53,9 @@ int dump_task_sleepable(struct bpf_iter__task *ctx) struct task_struct *task = ctx->task; static const char info[] = " === END ==="; struct pt_regs *regs; + char task_str1[10] = "aaaaaaaaaa"; + char task_str2[10], task_str3[10]; + char task_str4[20] = "aaaaaaaaaaaaaaaaaaaa"; void *ptr; uint32_t user_data = 0; int ret; @@ -78,8 +90,106 @@ int dump_task_sleepable(struct bpf_iter__task *ctx) BPF_SEQ_PRINTF(seq, "%s\n", info); return 0; } + ++num_success_copy_from_user_task; + /* Read an invalid pointer and ensure we get an error */ + ptr = NULL; + ret = bpf_copy_from_user_task_str((char *)task_str1, sizeof(task_str1), ptr, task, 0); + if (ret >= 0 || task_str1[9] != 'a' || task_str1[0] != '\0') { + BPF_SEQ_PRINTF(seq, "%s\n", info); + return 0; + } + + /* Read an invalid pointer and ensure we get error with pad zeros flag */ + ptr = NULL; + ret = bpf_copy_from_user_task_str((char *)task_str1, sizeof(task_str1), + ptr, task, BPF_F_PAD_ZEROS); + if (ret >= 0 || task_str1[9] != '\0' || task_str1[0] != '\0') { + BPF_SEQ_PRINTF(seq, "%s\n", info); + return 0; + } + + ++num_expected_failure_copy_from_user_task_str; + + /* Same length as the string */ + ret = bpf_copy_from_user_task_str((char *)task_str2, 10, user_ptr, task, 0); + /* only need to do the task pid check once */ + if (bpf_strncmp(task_str2, 10, "test_data\0") != 0 || ret != 10 || task->tgid != pid) { + BPF_SEQ_PRINTF(seq, "%s\n", info); + return 0; + } + + /* Shorter length than the string */ + ret = bpf_copy_from_user_task_str((char *)task_str3, 2, user_ptr, task, 0); + if (bpf_strncmp(task_str3, 2, "t\0") != 0 || ret != 2) { + BPF_SEQ_PRINTF(seq, "%s\n", info); + return 0; + } + + /* Longer length than the string */ + ret = bpf_copy_from_user_task_str((char *)task_str4, 20, user_ptr, task, 0); + if (bpf_strncmp(task_str4, 10, "test_data\0") != 0 || ret != 10 + || task_str4[sizeof(task_str4) - 1] != 'a') { + BPF_SEQ_PRINTF(seq, "%s\n", info); + return 0; + } + + /* Longer length than the string with pad zeros flag */ + ret = bpf_copy_from_user_task_str((char *)task_str4, 20, user_ptr, task, BPF_F_PAD_ZEROS); + if (bpf_strncmp(task_str4, 10, "test_data\0") != 0 || ret != 10 + || task_str4[sizeof(task_str4) - 1] != '\0') { + BPF_SEQ_PRINTF(seq, "%s\n", info); + return 0; + } + + /* Longer length than the string past a page boundary */ + ret = bpf_copy_from_user_task_str(big_str1, 5000, user_ptr, task, 0); + if (bpf_strncmp(big_str1, 10, "test_data\0") != 0 || ret != 10) { + BPF_SEQ_PRINTF(seq, "%s\n", info); + return 0; + } + + /* String that crosses a page boundary */ + ret = bpf_copy_from_user_task_str(big_str1, 5000, user_ptr_long, task, BPF_F_PAD_ZEROS); + if (bpf_strncmp(big_str1, 4, "baba") != 0 || ret != 5000 + || bpf_strncmp(big_str1 + 4996, 4, "bab\0") != 0) { + BPF_SEQ_PRINTF(seq, "%s\n", info); + return 0; + } + + for (int i = 0; i < 4999; ++i) { + if (i % 2 == 0) { + if (big_str1[i] != 'b') { + BPF_SEQ_PRINTF(seq, "%s\n", info); + return 0; + } + } else { + if (big_str1[i] != 'a') { + BPF_SEQ_PRINTF(seq, "%s\n", info); + return 0; + } + } + } + + /* Longer length than the string that crosses a page boundary */ + ret = bpf_copy_from_user_task_str(big_str2, 5005, user_ptr_long, task, BPF_F_PAD_ZEROS); + if (bpf_strncmp(big_str2, 4, "baba") != 0 || ret != 5000 + || bpf_strncmp(big_str2 + 4996, 5, "bab\0\0") != 0) { + BPF_SEQ_PRINTF(seq, "%s\n", info); + return 0; + } + + /* Shorter length than the string that crosses a page boundary */ + ret = bpf_copy_from_user_task_str(big_str3, 4996, user_ptr_long, task, 0); + if (bpf_strncmp(big_str3, 4, "baba") != 0 || ret != 4996 + || bpf_strncmp(big_str3 + 4992, 4, "bab\0") != 0) { + BPF_SEQ_PRINTF(seq, "%s\n", info); + return 0; + } + + ++num_success_copy_from_user_task_str; + if (ctx->meta->seq_num == 0) BPF_SEQ_PRINTF(seq, " tgid gid data\n"); diff --git a/tools/testing/selftests/bpf/progs/read_vsyscall.c b/tools/testing/selftests/bpf/progs/read_vsyscall.c index 39ebef430059..395591374d4f 100644 --- a/tools/testing/selftests/bpf/progs/read_vsyscall.c +++ b/tools/testing/selftests/bpf/progs/read_vsyscall.c @@ -8,14 +8,16 @@ int target_pid = 0; void *user_ptr = 0; -int read_ret[9]; +int read_ret[10]; char _license[] SEC("license") = "GPL"; /* - * This is the only kfunc, the others are helpers + * These are the kfuncs, the others are helpers */ int bpf_copy_from_user_str(void *dst, u32, const void *, u64) __weak __ksym; +int bpf_copy_from_user_task_str(void *dst, u32, const void *, + struct task_struct *, u64) __weak __ksym; SEC("fentry/" SYS_PREFIX "sys_nanosleep") int do_probe_read(void *ctx) @@ -47,6 +49,11 @@ int do_copy_from_user(void *ctx) read_ret[7] = bpf_copy_from_user_task(buf, sizeof(buf), user_ptr, bpf_get_current_task_btf(), 0); read_ret[8] = bpf_copy_from_user_str((char *)buf, sizeof(buf), user_ptr, 0); + read_ret[9] = bpf_copy_from_user_task_str((char *)buf, + sizeof(buf), + user_ptr, + bpf_get_current_task_btf(), + 0); return 0; }