From mboxrd@z Thu Jan 1 00:00:00 1970 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 4E7E814AA9; Mon, 14 Oct 2024 15:18:50 +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=1728919130; cv=none; b=IlBws4I0mQjGVjCQQjjynZMcR0vP3e1rhR72SEClK6RZMZwr3IXAOTCkEKqxyIV2UCtqvCnmh1n4KTyiF8fMxplspSk6sfOr5tz/WIDFGFVHA5EtU2ALliZ8zPDs01wE2sseV6icG/qjGObqvS3c/EtaDVUcFcl+sptZp5c0bgg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728919130; c=relaxed/simple; bh=YYCgFtiPxpFwp7gM6Mc5ckMaJ8IeJ2cUBmmPRAL6SgU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FTcxlkOJdkbKbej46PFxfBF0NojGBlpj2/z0UzvderWVWVT9mJsMOrvBpdD4CprF/ySyYgxqwAYmkHmQMcu+DFl+3YPLK0sB76Yju7UR2uQVxAR88AryIKrpDT7NwxWUitKDJ0n02Nr+/CNPSryIsFsQy2A9cB45IyPTqgRtF9A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZN15bLbZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ZN15bLbZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1108C4CEC7; Mon, 14 Oct 2024 15:18:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1728919130; bh=YYCgFtiPxpFwp7gM6Mc5ckMaJ8IeJ2cUBmmPRAL6SgU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZN15bLbZx5uRiWYKmN3cCkbQ8cZuzR9zvDop3h93cNDv5UZCSK64dQF5UiBY2Wc08 hs+IyglU3mRTUhR8MJUxAPmdcb+XcIfZfdwfL3mf0q5le7yFFvjb44dBVlJfqJ+3/6 Gjz6LOofSutVbTZrW2n/isnzGQWb/Y/yu2h3pFGk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Jason A. Donenfeld" , Christophe Leroy , Michael Ellerman , Sasha Levin Subject: [PATCH 6.1 520/798] powerpc/vdso: Fix VDSO data access when running in a non-root time namespace Date: Mon, 14 Oct 2024 16:17:54 +0200 Message-ID: <20241014141238.407673956@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241014141217.941104064@linuxfoundation.org> References: <20241014141217.941104064@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christophe Leroy [ Upstream commit c73049389e58c01e2e3bbfae900c8daeee177191 ] When running in a non-root time namespace, the global VDSO data page is replaced by a dedicated namespace data page and the global data page is mapped next to it. Detailed explanations can be found at commit 660fd04f9317 ("lib/vdso: Prepare for time namespace support"). When it happens, __kernel_get_syscall_map and __kernel_get_tbfreq and __kernel_sync_dicache don't work anymore because they read 0 instead of the data they need. To address that, clock_mode has to be read. When it is set to VDSO_CLOCKMODE_TIMENS, it means it is a dedicated namespace data page and the global data is located on the following page. Add a macro called get_realdatapage which reads clock_mode and add PAGE_SIZE to the pointer provided by get_datapage macro when clock_mode is equal to VDSO_CLOCKMODE_TIMENS. Use this new macro instead of get_datapage macro except for time functions as they handle it internally. Fixes: 74205b3fc2ef ("powerpc/vdso: Add support for time namespaces") Reported-by: Jason A. Donenfeld Closes: https://lore.kernel.org/all/ZtnYqZI-nrsNslwy@zx2c4.com/ Signed-off-by: Christophe Leroy Acked-by: Michael Ellerman Signed-off-by: Jason A. Donenfeld Signed-off-by: Sasha Levin --- arch/powerpc/include/asm/vdso_datapage.h | 15 +++++++++++++++ arch/powerpc/kernel/asm-offsets.c | 2 ++ arch/powerpc/kernel/vdso/cacheflush.S | 2 +- arch/powerpc/kernel/vdso/datapage.S | 4 ++-- 4 files changed, 20 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h index a585c8e538ff0..939daf6b695ef 100644 --- a/arch/powerpc/include/asm/vdso_datapage.h +++ b/arch/powerpc/include/asm/vdso_datapage.h @@ -111,6 +111,21 @@ extern struct vdso_arch_data *vdso_data; addi \ptr, \ptr, (_vdso_datapage - 999b)@l .endm +#include +#include + +.macro get_realdatapage ptr scratch + get_datapage \ptr +#ifdef CONFIG_TIME_NS + lwz \scratch, VDSO_CLOCKMODE_OFFSET(\ptr) + xoris \scratch, \scratch, VDSO_CLOCKMODE_TIMENS@h + xori \scratch, \scratch, VDSO_CLOCKMODE_TIMENS@l + cntlzw \scratch, \scratch + rlwinm \scratch, \scratch, PAGE_SHIFT - 5, 1 << PAGE_SHIFT + add \ptr, \ptr, \scratch +#endif +.endm + #endif /* __ASSEMBLY__ */ #endif /* __KERNEL__ */ diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 4ce2a4aa39854..65d79dd0c92ce 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -347,6 +347,8 @@ int main(void) #else OFFSET(CFG_SYSCALL_MAP32, vdso_arch_data, syscall_map); #endif + OFFSET(VDSO_CLOCKMODE_OFFSET, vdso_arch_data, data[0].clock_mode); + DEFINE(VDSO_CLOCKMODE_TIMENS, VDSO_CLOCKMODE_TIMENS); #ifdef CONFIG_BUG DEFINE(BUG_ENTRY_SIZE, sizeof(struct bug_entry)); diff --git a/arch/powerpc/kernel/vdso/cacheflush.S b/arch/powerpc/kernel/vdso/cacheflush.S index 0085ae464dac9..3b2479bd2f9a1 100644 --- a/arch/powerpc/kernel/vdso/cacheflush.S +++ b/arch/powerpc/kernel/vdso/cacheflush.S @@ -30,7 +30,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE) #ifdef CONFIG_PPC64 mflr r12 .cfi_register lr,r12 - get_datapage r10 + get_realdatapage r10, r11 mtlr r12 .cfi_restore lr #endif diff --git a/arch/powerpc/kernel/vdso/datapage.S b/arch/powerpc/kernel/vdso/datapage.S index db8e167f01667..2b19b6201a33a 100644 --- a/arch/powerpc/kernel/vdso/datapage.S +++ b/arch/powerpc/kernel/vdso/datapage.S @@ -28,7 +28,7 @@ V_FUNCTION_BEGIN(__kernel_get_syscall_map) mflr r12 .cfi_register lr,r12 mr. r4,r3 - get_datapage r3 + get_realdatapage r3, r11 mtlr r12 #ifdef __powerpc64__ addi r3,r3,CFG_SYSCALL_MAP64 @@ -52,7 +52,7 @@ V_FUNCTION_BEGIN(__kernel_get_tbfreq) .cfi_startproc mflr r12 .cfi_register lr,r12 - get_datapage r3 + get_realdatapage r3, r11 #ifndef __powerpc64__ lwz r4,(CFG_TB_TICKS_PER_SEC + 4)(r3) #endif -- 2.43.0