| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Sun, 14 Jul 2013 15:07:25 -0400
From: Parag Warudkar <parag.lkml@...il.com>
To: LKML <linux-kernel@...r.kernel.org>, linux-acpi@...r.kernel.org,
luto@...capital.net, josh@...htriplett.org
Subject: BGRT Pointer in System RAM
Saw this warning running latest git (Ubuntu daily mainline.) It looked
similar to what Andy saw on MSI hardware -
http://www.spinics.net/lists/linux-acpi/msg43410.html . The patch for
it doesn't seem to be merged, although it won't help in my case -
different hardware with valid status instead of invalid and image
address falling in system RAM instead of just being wild.
Unsure how this should be handled - moving the is_ram() check in
efi_bgrt_init and ignoring the BGRT in case where the check succeeds?
Doesn't sound completely right to me - since the BGRT is valid and
exists somewhere, but..
[ 0.015141] ------------[ cut here ]------------
[ 0.015147] WARNING: CPU: 0 PID: 0 at
/home/apw/COD/linux/arch/x86/mm/ioremap.c:102
__ioremap_caller+0x312/0x390()
[ snip ]
[ 0.015160] Call Trace:
[ 0.015165] [<ffffffff8170a704>] dump_stack+0x46/0x58
[ 0.015169] [<ffffffff8106406c>] warn_slowpath_common+0x8c/0xc0
[ 0.015171] [<ffffffff810640ba>] warn_slowpath_null+0x1a/0x20
[ 0.015173] [<ffffffff81054e32>] __ioremap_caller+0x312/0x390
[ 0.015176] [<ffffffff814013d4>] ? acpi_tb_verify_table+0x54/0x58
[ 0.015179] [<ffffffff81d35551>] ? efi_bgrt_init+0x8f/0x143
[ 0.015181] [<ffffffff81054f07>] ioremap_nocache+0x17/0x20
[ 0.015183] [<ffffffff81d35551>] efi_bgrt_init+0x8f/0x143
[ 0.015186] [<ffffffff81401d36>] ? acpi_tb_initialize_facs+0x32/0x34
[ 0.015188] [<ffffffff81d34e7f>] efi_late_init+0x9/0xb
[ 0.015190] [<ffffffff81d18f17>] start_kernel+0x3fd/0x419
[ 0.015192] [<ffffffff81d189ac>] ? do_early_param+0x87/0x87
[ 0.015194] [<ffffffff81d18120>] ? early_idt_handlers+0x120/0x120
[ 0.015196] [<ffffffff81d185e6>] x86_64_start_reservations+0x2a/0x2c
ioremap.c:102
/*
* Don't allow anybody to remap normal RAM that we're using..
*/
last_pfn = last_addr >> PAGE_SHIFT;
for (pfn = phys_addr >> PAGE_SHIFT; pfn <= last_pfn; pfn++) {
int is_ram = page_is_ram(pfn);
if (is_ram && pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)))
return NULL;
WARN_ON_ONCE(is_ram);
}
Looking at the BGRT table from IASL, the status seems to be valid but
the image address *seems* to me that is falling under system RAM.
[000h 0000 4] Signature : "BGRT" [Boot
Graphics Resource Table]
[004h 0004 4] Table Length : 00000038
[008h 0008 1] Revision : 00
[009h 0009 1] Checksum : 3D
[00Ah 0010 6] Oem ID : "HPQOEM"
[010h 0016 8] Oem Table ID : "SLIC-CPC"
[018h 0024 4] Oem Revision : 01072009
[01Ch 0028 4] Asl Compiler ID : "AMI "
[020h 0032 4] Asl Compiler Revision : 00010013
[024h 0036 2] Version : 0001
[026h 0038 1] Status : 01
[027h 0039 1] Image Type : 00
[028h 0040 8] Image Address : 00000000B2E1B018
[030h 0048 4] Image OffsetX : 00000279
[034h 0052 4] Image OffsetY : 0000014F
Below is from 3.8 kernel - I think that shouldn't make a difference
given ioremap also find the address in RAM.
$ cat /proc/iomem |grep RAM00010000-0009ffff : System RAM
00100000-bdb6bfff : System RAM
be6ef000-be6effff : System RAM
be8f6000-bed2ffff : System RAM
beff3000-beffffff : System RAM
bf000000-bfffffff : RAM buffer
100001000-2beffffff : System RAM
2bf000000-2bfffffff : RAM buffer
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists