From nobody Tue Dec 16 16:38:46 2025 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 2BE4F1EEA3B for ; Mon, 21 Apr 2025 18:53:03 +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=1745261584; cv=none; b=g0/pvmK4C0OaCvd7WnbwwphWMCST2HyU7v28nEcsB5gx6dorD2n8IktBNWGh3mdOEaR71Jin1x6iovIHZDDq7KXYlSSla6oFV62KW/Yz/J5rXqkNEnv5iSrLpSPme8cF+iv93TUgYxE0Tppw6stNACeQRcavBwRqzIBlMwgAPZo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745261584; c=relaxed/simple; bh=LP2D+HLFeAICx5kFnVqbT4i5U0kN48Tpqo6HL2ellsQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Hhg5vdmC+LGBMPTAm+KW494W2fZV9H3+uys5n1SXSwM1zfGZ+ABSes3Fq6g1qFYNSKIqF7vJLvD4A5ctqKo7n3Ps7Vmy+3rgKYhVHojRwBOgI0+U5NDQ93lQ1v/G+XYpugdpoejPRQ4kstkk8uXdyRaUkDDUOSEGGK1W8cC3ALI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=o/UWrYX8; 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="o/UWrYX8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28487C4CEE4; Mon, 21 Apr 2025 18:53:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745261583; bh=LP2D+HLFeAICx5kFnVqbT4i5U0kN48Tpqo6HL2ellsQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o/UWrYX8O5Tw00G+NW3i3tWs3FBC6kDp3eSdUyqV/Oe0NG2r6gzCJYJwzVNR7VBOT l5A1ZLJzxgCqo0f8xuEbrDBjJgU7dFNbAlM5qhXzz1u+OeJNGGeVhg16GJWEoQ+eES d3GcmRbD3awrHRiqUqxyOAJv5haj9EVAoSWITh2Ngv3MLEWr3MJO/VCPArOl2oqczq YxPicD1PWTKbPs/2OsdiA7lEDZx2ospqR26Kmhy1t43ogkS7a2v8LZc7fnG0aA2VU3 c2GNklfG8SDdQBKpHLjFRmLh8VNrMtiqHHNon+K/AYhjb0kQ02G/Bd5loDqQxTvzB0 r5f4/0/1uFYIg== From: Ingo Molnar To: linux-kernel@vger.kernel.org Cc: Andy Shevchenko , Arnd Bergmann , Borislav Petkov , Juergen Gross , "H . Peter Anvin" , Kees Cook , Linus Torvalds , Mike Rapoport , Paul Menzel , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , David Woodhouse Subject: [PATCH 05/29] x86/boot/e820: Print gaps in the E820 table Date: Mon, 21 Apr 2025 20:51:45 +0200 Message-ID: <20250421185210.3372306-6-mingo@kernel.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20250421185210.3372306-1-mingo@kernel.org> References: <20250421185210.3372306-1-mingo@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Gaps in the E820 table are not obvious at a glance and can easily be overlooked. Print out gaps in the E820 table: Before: BIOS-provided physical RAM map: BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved BIOS-e820: [mem 0x0000000000100000-0x000000007ffdbfff] usable BIOS-e820: [mem 0x000000007ffdc000-0x000000007fffffff] reserved BIOS-e820: [mem 0x00000000b0000000-0x00000000bfffffff] reserved BIOS-e820: [mem 0x00000000fed1c000-0x00000000fed1ffff] reserved BIOS-e820: [mem 0x00000000feffc000-0x00000000feffffff] reserved BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved BIOS-e820: [mem 0x000000fd00000000-0x000000ffffffffff] reserved After: BIOS-provided physical RAM map: BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved BIOS-e820: [gap 0x00000000000a0000-0x00000000000effff] BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved BIOS-e820: [mem 0x0000000000100000-0x000000007ffdbfff] usable BIOS-e820: [mem 0x000000007ffdc000-0x000000007fffffff] reserved BIOS-e820: [gap 0x0000000080000000-0x00000000afffffff] BIOS-e820: [mem 0x00000000b0000000-0x00000000bfffffff] reserved BIOS-e820: [gap 0x00000000c0000000-0x00000000fed1bfff] BIOS-e820: [mem 0x00000000fed1c000-0x00000000fed1ffff] reserved BIOS-e820: [gap 0x00000000fed20000-0x00000000feffbfff] BIOS-e820: [mem 0x00000000feffc000-0x00000000feffffff] reserved BIOS-e820: [gap 0x00000000ff000000-0x00000000fffbffff] BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved BIOS-e820: [gap 0x0000000100000000-0x000000fcffffffff] BIOS-e820: [mem 0x000000fd00000000-0x000000ffffffffff] reserved Also warn about badly ordered E820 table entries: BUG: out of order E820 entry! ( this is printed before the entry is printed, so there's no need to print any additional data with the warning. ) Signed-off-by: Ingo Molnar Cc: Andy Shevchenko Cc: Arnd Bergmann Cc: David Woodhouse Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Mike Rapoport (Microsoft) --- arch/x86/kernel/e820.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 4244b6d53fd0..a8edfa375fbd 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -201,18 +201,32 @@ static void __init e820_print_type(enum e820_type typ= e) =20 static void __init e820__print_table(const char *who) { + u64 range_end_prev =3D 0; int i; =20 for (i =3D 0; i < e820_table->nr_entries; i++) { struct e820_entry *entry =3D e820_table->entries + i; + u64 range_start, range_end; =20 - pr_info("%s: [mem %#018Lx-%#018Lx] ", - who, - entry->addr, - entry->addr + entry->size-1); + range_start =3D entry->addr; + range_end =3D entry->addr + entry->size; =20 + /* Out of order E820 maps should not happen: */ + if (range_start < range_end_prev) + pr_info("BUG: out of order E820 entry!\n"); + + if (range_start > range_end_prev) { + pr_info("%s: [gap %#018Lx-%#018Lx]\n", + who, + range_end_prev, + range_start-1); + } + + pr_info("%s: [mem %#018Lx-%#018Lx] ", who, range_start, range_end-1); e820_print_type(entry->type); pr_cont("\n"); + + range_end_prev =3D range_end; } } =20 --=20 2.45.2