From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail05.groups.io (mail05.groups.io [45.79.224.7]) by spool.mail.gandi.net (Postfix) with ESMTPS id 8FD6C740040 for ; Wed, 15 Jan 2025 18:52:58 +0000 (UTC) DKIM-Signature: a=rsa-sha256; bh=4SQiZ0IsQf8lfUbgq/RJiSJzbip1Wp1l0Ul6ZYBVlNo=; c=relaxed/simple; d=groups.io; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References:MIME-Version:Precedence:List-Subscribe:List-Help:Sender:List-Id:Mailing-List:Delivered-To:Resent-Date:Resent-From:Reply-To:List-Unsubscribe-Post:List-Unsubscribe:Content-Transfer-Encoding; s=20240830; t=1736967178; v=1; x=1737226377; b=dSxEgZvNINzw3OunI9tnmocgYoNqaxTDKYgtx2sMBsONlSq4x/vfpt1dNnNMVHIWRpF588PT 2yv9//lF2sxcN6bWCsNz+6ykVbIJYTz1z9XVliEKNngMSHqSZdUz8iafCSALI+jV0vw73cTkYEk wHv2ChsFZS9iK1iuJ53MDBW6DYga+42OArhdU1P7F874q3+p7BZ4OOZ0fRUeRj3w0OODx3rpnW/ /wpkE/w9rXZv8Y8tyzdUBAjfQMAQ+nG57q3LxmDqgMB1i+rBc2pUx4SUWEl21e+t9Iv6TSB4Ddm vvcA9x71dmvZhDk24o3U8GYCq8GhlVHpMHLkNCPzF3LKg== X-Received: by 127.0.0.2 with SMTP id t5c9YY7687511xaNorkTM8UJ; Wed, 15 Jan 2025 10:52:57 -0800 X-Received: from mail-qv1-f52.google.com (mail-qv1-f52.google.com [209.85.219.52]) by mx.groups.io with SMTP id smtpd.web11.33553.1736373624156608890 for ; Wed, 08 Jan 2025 14:00:24 -0800 X-Received: by mail-qv1-f52.google.com with SMTP id 6a1803df08f44-6d900c27af7so2934766d6.2 for ; Wed, 08 Jan 2025 14:00:24 -0800 (PST) X-Forwarded-Encrypted: i=1; AJvYcCWf+lTwPKzx2XuImtGQiIVmJwEz0TkmWUEw1akNS+GXzEEe7wfReM7Ou3qA1ABYdsrDjrjuEw==@edk2.groups.io X-Gm-Message-State: TtdO7yVj9bAG90nlFYlNcoxbx7686176AA= X-Gm-Gg: ASbGncvOdoG9xfyn1izuqNeAx+ttqp40/fnbCiPnb+JblwcBhqHF7sUAeKKfxjs+JEE qbZPaIL0+DL/cDxYpY25cDHz4VerxeFiBj8+wgkZvFH5XU9379QsR5PFc2fHPZNtidPmrrs40b6 MW5oCKPICUSFvC4ZrhzgH7rHhzqGLu/QFFb7o2d9lSGKWD8tsUIhI+45g8tFreZScdupOJ1Rt/2 y62RNfTZVeSYBy1d4Gbu1mWX2X3XzSyO6cDcxU5imvENHyy1kNrBg== X-Google-Smtp-Source: AGHT+IERhB4z90VYqb4Dv2R+PhhDYDodptRvo0eGmXLkrsvBtS5WFJP/mvaGuTVc1PGcKc2NU8POeg== X-Received: by 2002:a05:6214:3008:b0:6d4:2646:109c with SMTP id 6a1803df08f44-6df9b1cf3c5mr54781556d6.3.1736373623069; Wed, 08 Jan 2025 14:00:23 -0800 (PST) X-Received: from localhost ([2a03:2880:20ff:6::]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6dd181372easm195398346d6.63.2025.01.08.14.00.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Jan 2025 14:00:21 -0800 (PST) From: "Usama Arif via groups.io" To: linux-efi@vger.kernel.org, devel@edk2.groups.io, kexec@lists.infradead.org Cc: ardb@kernel.org, hannes@cmpxchg.org, dyoung@redhat.com, x86@kernel.org, linux-kernel@vger.kernel.org, leitao@debian.org, gourry@gourry.net, kernel-team@meta.com, Usama Arif Subject: [edk2-devel] [RFC 2/2] efi/memattr: add efi_mem_attr_table as a reserved region in 820_table_firmware Date: Wed, 8 Jan 2025 21:53:37 +0000 Message-ID: <20250108215957.3437660-3-usamaarif642@gmail.com> In-Reply-To: <20250108215957.3437660-1-usamaarif642@gmail.com> References: <20250108215957.3437660-1-usamaarif642@gmail.com> MIME-Version: 1.0 Precedence: Bulk List-Subscribe: List-Help: Sender: devel@edk2.groups.io List-Id: Mailing-List: list devel@edk2.groups.io; contact devel+owner@edk2.groups.io Resent-Date: Wed, 15 Jan 2025 10:52:52 -0800 Resent-From: usamaarif642@gmail.com Reply-To: devel@edk2.groups.io,usamaarif642@gmail.com List-Unsubscribe-Post: List-Unsubscribe=One-Click List-Unsubscribe: Content-Transfer-Encoding: 8bit X-GND-Status: LEGIT Authentication-Results: spool.mail.gandi.net; dkim=pass header.d=groups.io header.s=20240830 header.b=dSxEgZvN; dmarc=pass (policy=none) header.from=groups.io; spf=pass (spool.mail.gandi.net: domain of bounce@groups.io designates 45.79.224.7 as permitted sender) smtp.mailfrom=bounce@groups.io When this area is not reserved, it comes up as usable in /sys/firmware/memmap. This means that kexec, which uses that memmap to find usable memory regions, can select the region where efi_mem_attr_table is and overwrite it and relocate_kernel. Since the patch in [1] was merged, all boots after kexec are producing the warning that it introduced. Having a fix in firmware can be difficult to get through. The next ideal place would be in libstub. However, it looks like InstallMemoryAttributesTable [2] is not available as a boot service call option [3], [4], and install_configuration_table does not seem to work as a valid substitute. As a last option for a fix, this patch marks that region as reserved in e820_table_firmware if it is currently E820_TYPE_RAM so that kexec doesn't use it for kernel segments. [1] https://lore.kernel.org/all/20241031175822.2952471-2-ardb+git@google.com/ [2] https://github.com/tianocore/edk2/blob/master/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c#L100 [3] https://github.com/tianocore/edk2/blob/42a141800c0c26a09d2344e84a89ce4097a263ae/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c#L41 [4] https://elixir.bootlin.com/linux/v6.12.6/source/drivers/firmware/efi/libstub/efistub.h#L327 Reported-by: Breno Leitao Signed-off-by: Usama Arif --- arch/x86/include/asm/e820/api.h | 2 ++ arch/x86/kernel/e820.c | 6 ++++++ arch/x86/platform/efi/efi.c | 9 +++++++++ drivers/firmware/efi/memattr.c | 1 + include/linux/efi.h | 7 +++++++ 5 files changed, 25 insertions(+) diff --git a/arch/x86/include/asm/e820/api.h b/arch/x86/include/asm/e820/api.h index 2e74a7f0e935..4e9aa24f03bd 100644 --- a/arch/x86/include/asm/e820/api.h +++ b/arch/x86/include/asm/e820/api.h @@ -16,6 +16,8 @@ extern bool e820__mapped_all(u64 start, u64 end, enum e820_type type); extern void e820__range_add (u64 start, u64 size, enum e820_type type); extern u64 e820__range_update(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type); +extern u64 e820__range_update_firmware(u64 start, u64 size, enum e820_type old_type, + enum e820_type new_type); extern u64 e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type); extern u64 e820__range_update_table(struct e820_table *t, u64 start, u64 size, enum e820_type old_type, enum e820_type new_type); diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 82b96ed9890a..01d7d3c0d299 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -538,6 +538,12 @@ u64 __init e820__range_update_table(struct e820_table *t, u64 start, u64 size, return __e820__range_update(t, start, size, old_type, new_type); } +u64 __init e820__range_update_firmware(u64 start, u64 size, enum e820_type old_type, + enum e820_type new_type) +{ + return __e820__range_update(e820_table_firmware, start, size, old_type, new_type); +} + /* Remove a range of memory from the E820 table: */ u64 __init e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type) { diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index a7ff189421c3..13684c5d7c05 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -168,6 +168,15 @@ static void __init do_add_efi_memmap(void) e820__update_table(e820_table); } +/* Reserve firmware area if it was marked as RAM */ +void arch_update_firmware_area(u64 addr, u64 size) +{ + if (e820__get_entry_type(addr, addr + size) == E820_TYPE_RAM) { + e820__range_update_firmware(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED); + e820__update_table(e820_table_firmware); + } +} + /* * Given add_efi_memmap defaults to 0 and there is no alternative * e820 mechanism for soft-reserved memory, import the full EFI memory diff --git a/drivers/firmware/efi/memattr.c b/drivers/firmware/efi/memattr.c index d3bc161361fb..d131781e2d7b 100644 --- a/drivers/firmware/efi/memattr.c +++ b/drivers/firmware/efi/memattr.c @@ -53,6 +53,7 @@ int __init efi_memattr_init(void) size = tbl->num_entries * tbl->desc_size; tbl_size = sizeof(*tbl) + size; memblock_reserve(efi_mem_attr_table, tbl_size); + arch_update_firmware_area(efi_mem_attr_table, tbl_size); set_bit(EFI_MEM_ATTR, &efi.flags); unmap: diff --git a/include/linux/efi.h b/include/linux/efi.h index e5815867aba9..8eb9698bd6a4 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1358,4 +1358,11 @@ extern struct blocking_notifier_head efivar_ops_nh; void efivars_generic_ops_register(void); void efivars_generic_ops_unregister(void); +#ifdef CONFIG_X86_64 +void __init arch_update_firmware_area(u64 addr, u64 size); +#else +static inline void __init arch_update_firmware_area(u64 addr, u64 size) +{ +} +#endif #endif /* _LINUX_EFI_H */ -- 2.43.5 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#121001): https://edk2.groups.io/g/devel/message/121001 Mute This Topic: https://groups.io/mt/110633386/7686176 Group Owner: devel+owner@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io] -=-=-=-=-=-=-=-=-=-=-=-