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 0723525A357; Wed, 29 Apr 2026 09:15:39 +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=1777454139; cv=none; b=Q/xntl39MqiXi6VYeuOWanHPxRKcfug62k3ns94xRqEo4O1yTKzHlQBc/nyqNYAfx8yxKXL+XxtoV1zwRNVvRBJfE9iT6tKz0Kf6m36rCbuBcFlvGw2U6LjilC2jDXjKOM2zNPICqM9x/rAVBStFa//WWibB++DqWvwawIM1d8c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777454139; c=relaxed/simple; bh=HoyPdVcg4KZlmtH8kv+yXCW7meKR7jg9DcjSYZOX9mk=; h=MIME-Version:Date:From:To:Cc:Message-Id:In-Reply-To:References: Subject:Content-Type; b=tpzuDO9P4kJcYqz23iSihOctXK4nFGeWojQbKrSV/5ZInO02dLWcVP4ZQyCQACEpwxt7LfJlGl/Q10uD66GWa3VGMxl3YS1MFjAAn2E+k+hObHWzWy0bwOVeVmVKCBUy2ISRJ+xJAqI5C97JM3LAhtuRyg0NvzX+84uP1SnkkUk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=K1MUYtdD; 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="K1MUYtdD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 94B9AC2BCB3; Wed, 29 Apr 2026 09:15:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777454138; bh=HoyPdVcg4KZlmtH8kv+yXCW7meKR7jg9DcjSYZOX9mk=; h=Date:From:To:Cc:In-Reply-To:References:Subject:From; b=K1MUYtdDpxlSJvO468pK1Q4pFGoXnoPf7tewA696iSmy5As+lw3kwrXm+b9Pkf21m RT9RbZwT1TlP2koscC2smFfSFrNfG+fhalRTxGq+w13oESIc34Ccgndqagn5ODj88I oqZgkLVrWoM/uhXFl/Hgo5Hz+Nn9oQxg2ZhS2ICeGoz3aA/Qr/9d/hxNFjsopW687n 7YsiOWtrM3cRVoN4AzpAqo3iCDwRXf1ox9WguY7XxhSCQnxZOJW0Jzeena3oePjG6O Q0XGfP6ru+5p3ckU8B86+pXdKOs3Q/bwcL7o9vXAgqwISz0GYZ0U/+/8oqTnrJC/5f OKInKF+XS340A== Received: from phl-compute-01.internal (phl-compute-01.internal [10.202.2.41]) by mailfauth.phl.internal (Postfix) with ESMTP id A8B68F40068; Wed, 29 Apr 2026 05:15:37 -0400 (EDT) Received: from phl-imap-02 ([10.202.2.81]) by phl-compute-01.internal (MEProxy); Wed, 29 Apr 2026 05:15:37 -0400 X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefhedrtddtgdekgedthecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpuffrtefokffrpgfnqfghnecuuegr ihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjug hrpefoggffhffvvefkjghfufgtgfesthhqredtredtjeenucfhrhhomhepfdetrhguuceu ihgvshhhvghuvhgvlhdfuceorghruggssehkvghrnhgvlhdrohhrgheqnecuggftrfgrth htvghrnhepueetieduieegkeejvdehudeiheettefgtdeugffhjefghfeftdelhedvheff hfdvnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomheprg hrugdomhgvshhmthhprghuthhhphgvrhhsohhnrghlihhthidqudeijedthedttdejledq feefvdduieegudehqdgrrhgusgeppehkvghrnhgvlhdrohhrghesfihorhhkohhfrghrug drtghomhdpnhgspghrtghpthhtohepledpmhhouggvpehsmhhtphhouhhtpdhrtghpthht oheplhhishgrsegshihtvghflhihrdhsphgrtggvpdhrtghpthhtoheprheshhgvvhdrtg gtpdhrtghpthhtoheptghhvghnhhhurggtrghisehkvghrnhgvlhdrohhrghdprhgtphht thhopehilhhirghsrdgrphgrlhhoughimhgrsheslhhinhgrrhhordhorhhgpdhrtghpth htoheplhhoohhnghgrrhgthheslhhishhtshdrlhhinhhugidruggvvhdprhgtphhtthho pehsuhhnhhgrihihohhngheslhhoohhnghhsohhnrdgtnhdprhgtphhtthhopehlihhnuh igqdgvfhhisehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidq khgvrhhnvghlsehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtohepkhgvrhhnvg hlseigvghntdhnrdhnrghmvg X-ME-Proxy: Feedback-ID: ice86485a:Fastmail Received: by mailuser.phl.internal (Postfix, from userid 501) id 84989700065; Wed, 29 Apr 2026 05:15:37 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface Precedence: bulk X-Mailing-List: linux-efi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Date: Wed, 29 Apr 2026 11:15:16 +0200 From: "Ard Biesheuvel" To: "WANG Rui" Cc: "Huacai Chen" , "WANG Xuerui" , "Ilias Apalodimas" , "Haiyong Sun" , "Lisa Robinson" , loongarch@lists.linux.dev, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org Message-Id: <08229417-cc68-4cfc-9896-4dd82ada1b56@app.fastmail.com> In-Reply-To: References: <20260429051318.1581350-1-r@hev.cc> <20260429051318.1581350-2-r@hev.cc> Subject: Re: [PATCH v3 1/3] efi/loongarch: Randomize kernel preferred address for KASLR Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On Wed, 29 Apr 2026, at 11:04, WANG Rui wrote: > Hi Ard, > > On Wed, Apr 29, 2026 at 4:55=E2=80=AFPM Ard Biesheuvel wrote: >> >> >> >> On Wed, 29 Apr 2026, at 07:13, WANG Rui wrote: >> > Introduce efi_get_kimg_kaslr_address() to compute the preferred >> > kernel image address dynamically when CONFIG_RANDOMIZE_BASE is >> > enabled. The function derives a random offset using EFI-provided >> > randomness combined with the timer value, and constrains it within >> > CONFIG_RANDOMIZE_BASE_MAX_OFFSET. >> > >> > Update EFI_KIMG_PREFERRED_ADDRESS to call this helper so that the >> > EFI stub can select a randomized load address when KASLR is active, >> > while preserving the original base address behavior when KASLR is >> > disabled or nokaslr is specified. >> > >> > Signed-off-by: WANG Rui >> > --- >> > arch/loongarch/include/asm/efi.h | 4 +++- >> > drivers/firmware/efi/libstub/loongarch.c | 16 ++++++++++++++++ >> > 2 files changed, 19 insertions(+), 1 deletion(-) >> > >> > diff --git a/arch/loongarch/include/asm/efi.h b/arch/loongarch/incl= ude/asm/efi.h >> > index eddc8e79b3fa..f831320efd41 100644 >> > --- a/arch/loongarch/include/asm/efi.h >> > +++ b/arch/loongarch/include/asm/efi.h >> > @@ -30,6 +30,8 @@ static inline unsigned long efi_get_kimg_min_alig= n(void) >> > return SZ_2M; >> > } >> > >> > -#define EFI_KIMG_PREFERRED_ADDRESS PHYSADDR(VMLINUX_LOAD_ADDRESS) >> > +unsigned long efi_get_kimg_kaslr_address(void); >> > + >> >> Where is the call to this function being added? >> >> > +#define EFI_KIMG_PREFERRED_ADDRESS efi_get_kimg_kaslr_address() > > 1. drivers/firmware/efi/libstub/loongarch-stub.c > > efi_status_t handle_kernel_image(...) > { > ... > status =3D efi_relocate_kernel(&kernel_addr, kernel_fsize, kerne= l_asize, > EFI_KIMG_PREFERRED_ADDRESS, efi_get_kimg_min_align(), 0= x0); > ... > } > > 2. drivers/firmware/efi/libstub/zboot.c > > static unsigned long alloc_preferred_address(...) > { > #ifdef EFI_KIMG_PREFERRED_ADDRESS > efi_physical_addr_t efi_addr =3D EFI_KIMG_PREFERRED_ADDRESS; > > if (efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS, EFI_LOADER= _DATA, > alloc_size / EFI_PAGE_SIZE, &efi_addr) =3D=3D EFI_SUCCES= S) > return efi_addr; > #endif > return ULONG_MAX; > } > Ah apologies - I misread the patch.