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 C8D221E503C for ; Tue, 22 Apr 2025 06:00:08 +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=1745301608; cv=none; b=Jxgjoi419TmIVb6bvu8T+3VQNXhVvHqpoZ/KveqPlK0wydxe7cSlR18z2NKQVh45Nyy2sfOid0bzDt2TpOnp3UYp4k7elkhj+lF1BhLNe55EDiqIy86Zyp9mAoJPfRIDQaqfEkt0lTx1wYbu9ng9miDNn954AobnEvf8/5u+zR0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745301608; c=relaxed/simple; bh=ERGYLnOT0kxkE5gPavRHLTTzjwfOuigaJAmQMfDVgGM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TMwqHPt+qOBkzYi0avW2zSYtxtTzXsetg3UPTE1gNtAuMS1NSBUH4Bw2UB9s7Aet8ZxsiiCrWvUzFC80Z0n7QDvA+9QjQnW5vKWb8NgiQsmIPsGE6dCMux7swbywHWQDlFrlqVeSlDzGvwMuhXbVdlLXAtEvYidoGim6E4em+/M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UJqo7Dr2; 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="UJqo7Dr2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB82CC4CEE9; Tue, 22 Apr 2025 06:00:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745301608; bh=ERGYLnOT0kxkE5gPavRHLTTzjwfOuigaJAmQMfDVgGM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UJqo7Dr2/sEhQxGy3gWYh5G/GxawK9Bno5gxj7BV8LlZS5J6jKR3k4slhG/uvzyJo hz0jE/iZ17tn3izgMqnV/8qVoIqX2uy3SR/mRkOvEoUdWdz3vIYmO6jLP7VT8oU/Nm ML3bc3274hj+lFONyxIt15r+HctgcoBZYYCLWXTNoaHfYd1aUpTp7VJaBQkhMthXBB tv/1KPVSk0yOgrWaLSfuaZaLJUpCg4vDu8iKy6l98qagOST0ZyBt3d1/ClTOybjZB+ P6NUdZVN4Q+C/b7UVJ1vonwtpdAqfW/us9edXBxVhnTQWPYj45zmpD6DDJiwcibKzg +zSXdH2IZlDPw== Date: Tue, 22 Apr 2025 09:00:00 +0300 From: Mike Rapoport To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Andy Shevchenko , Arnd Bergmann , Borislav Petkov , Juergen Gross , "H . Peter Anvin" , Kees Cook , Linus Torvalds , Paul Menzel , Peter Zijlstra , Thomas Gleixner , David Woodhouse Subject: Re: [PATCH 05/29] x86/boot/e820: Print gaps in the E820 table Message-ID: References: <20250421185210.3372306-1-mingo@kernel.org> <20250421185210.3372306-6-mingo@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250421185210.3372306-6-mingo@kernel.org> On Mon, Apr 21, 2025 at 08:51:45PM +0200, Ingo Molnar wrote: > 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 type) > > static void __init e820__print_table(const char *who) > { > + u64 range_end_prev = 0; > int i; > > for (i = 0; i < e820_table->nr_entries; i++) { > struct e820_entry *entry = e820_table->entries + i; > + u64 range_start, range_end; > > - pr_info("%s: [mem %#018Lx-%#018Lx] ", > - who, > - entry->addr, > - entry->addr + entry->size-1); > + range_start = entry->addr; > + range_end = entry->addr + entry->size; > > + /* Out of order E820 maps should not happen: */ > + if (range_start < range_end_prev) > + pr_info("BUG: out of order E820 entry!\n"); Maybe "BIOS BUG"? > + > + if (range_start > range_end_prev) { > + pr_info("%s: [gap %#018Lx-%#018Lx]\n", > + who, > + range_end_prev, > + range_start-1); 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 = range_end; > } > } > > -- > 2.45.2 > -- Sincerely yours, Mike.