[PATCH] mm, kasan: don't poison boot memory
George Kennedy
george.kennedy at oracle.com
Tue Feb 23 13:05:05 EST 2021
On 2/23/2021 10:47 AM, Mike Rapoport wrote:
> Hi George,
>
> On Tue, Feb 23, 2021 at 09:35:32AM -0500, George Kennedy wrote:
>> On 2/23/2021 5:33 AM, Mike Rapoport wrote:
>>> (re-added CC)
>>>
>>> On Mon, Feb 22, 2021 at 08:24:59PM -0500, George Kennedy wrote:
>>>> On 2/22/2021 4:55 PM, Mike Rapoport wrote:
>>>>> On Mon, Feb 22, 2021 at 01:42:56PM -0500, George Kennedy wrote:
>>>>>> On 2/22/2021 11:13 AM, David Hildenbrand wrote:
>>>>>>> On 22.02.21 16:13, George Kennedy wrote:
>>>>>>>
>>>>>>> The PFN 0xbe453 looks a little strange, though. Do we expect ACPI tables
>>>>>>> close to 3 GiB ? No idea. Could it be that you are trying to map a wrong
>>>>>>> table? Just a guess.
>>>>>>>
>>>>>>>> What would be the correct way to reserve the page so that the above
>>>>>>>> would not be hit?
>>>>>>> I would have assumed that if this is a binary blob, that someone (which
>>>>>>> I think would be acpi code) reserved via memblock_reserve() early during
>>>>>>> boot.
>>>>>>>
>>>>>>> E.g., see drivers/acpi/tables.c:acpi_table_upgrade()->memblock_reserve().
>>>>>> acpi_table_upgrade() gets called, but bails out before memblock_reserve() is
>>>>>> called. Thus, it appears no pages are getting reserved.
>>>>> acpi_table_upgrade() does not actually reserve memory but rather open
>>>>> codes memblock allocation with memblock_find_in_range() +
>>>>> memblock_reserve(), so it does not seem related anyway.
>>>>>
>>>>> Do you have by chance a full boot log handy?
>>>> Hello Mike,
>>>>
>>>> Are you after the console output? See attached.
>>>>
>>>> It includes my patch to set PG_Reserved along with the dump_page() debug
>>>> that David asked for - see: "page:"
>>> So, iBFT is indeed at pfn 0xbe453:
>>>
>>> [ 0.077698] ACPI: iBFT 0x00000000BE453000 000800 (v01 BOCHS BXPCFACP 00000000 00000000)
>>> and it's in E820_TYPE_RAM region rather than in ACPI data:
>>>
>>> [ 0.000000] BIOS-e820: [mem 0x0000000000810000-0x00000000008fffff] ACPI NVS
>>> [ 0.000000] BIOS-e820: [mem 0x0000000000900000-0x00000000be49afff] usable
>>> [ 0.000000] BIOS-e820: [mem 0x00000000be49b000-0x00000000be49bfff] ACPI data
>>>
>>> I could not find anywhere in x86 setup or in ACPI tables parsing the code
>>> that reserves this memory or any other ACPI data for that matter. It could
>>> be that I've missed some copying of the data to statically allocated
>>> initial_tables, but AFAICS any ACPI data that was not marked as such in
>>> e820 tables by BIOS resides in memory that is considered as free.
>>>
>> Close...
>>
>> Applied the patch, see "[ 30.136157] iBFT detected.", but now hit the
>> following (missing iounmap()? see full console output attached):
>>
>> diff --git a/drivers/firmware/iscsi_ibft_find.c
>> b/drivers/firmware/iscsi_ibft_find.c
>> index 64bb945..2e5e040 100644
>> --- a/drivers/firmware/iscsi_ibft_find.c
>> +++ b/drivers/firmware/iscsi_ibft_find.c
>> @@ -80,6 +80,21 @@ static int __init find_ibft_in_mem(void)
>> done:
>> return len;
>> }
>> +
>> +static void __init acpi_find_ibft_region(void)
>> +{
>> + int i;
>> + struct acpi_table_header *table = NULL;
>> +
>> + if (acpi_disabled)
>> + return;
>> +
>> + for (i = 0; i < ARRAY_SIZE(ibft_signs) && !ibft_addr; i++) {
>> + acpi_get_table(ibft_signs[i].sign, 0, &table);
>> + ibft_addr = (struct acpi_table_ibft *)table;
> Can you try adding
>
> acpi_put_table(table);
>
> here?
Mike,
It now crashes here:
[ 0.051019] ACPI: Early table checksum verification disabled
[ 0.056721] ACPI: RSDP 0x00000000BFBFA014 000024 (v02 BOCHS )
[ 0.057874] ACPI: XSDT 0x00000000BFBF90E8 00004C (v01 BOCHS BXPCFACP
00000001 01000013)
[ 0.059590] ACPI: FACP 0x00000000BFBF5000 000074 (v01 BOCHS BXPCFACP
00000001 BXPC 00000001)
[ 0.061306] ACPI: DSDT 0x00000000BFBF6000 00238D (v01 BOCHS BXPCDSDT
00000001 BXPC 00000001)
[ 0.063006] ACPI: FACS 0x00000000BFBFD000 000040
[ 0.063938] ACPI: APIC 0x00000000BFBF4000 000090 (v01 BOCHS BXPCAPIC
00000001 BXPC 00000001)
[ 0.065638] ACPI: HPET 0x00000000BFBF3000 000038 (v01 BOCHS BXPCHPET
00000001 BXPC 00000001)
[ 0.067335] ACPI: BGRT 0x00000000BE49B000 000038 (v01 INTEL EDK2
00000002 01000013)
[ 0.069030] ACPI: iBFT 0x00000000BE453000 000800 (v01 BOCHS BXPCFACP
00000000 00000000)
[ 0.070734] XXX acpi_find_ibft_region:
[ 0.071468] XXX iBFT, status=0
[ 0.072073] XXX about to call acpi_put_table()...
ibft_addr=ffffffffff240000
[ 0.073449] XXX acpi_find_ibft_region(EXIT):
PANIC: early exception 0x0e IP 10:ffffffff9259f439 error 0 cr2
0xffffffffff240004
[ 0.075711] CPU: 0 PID: 0 Comm: swapper Not tainted 5.11.0-34a2105 #8
[ 0.076983] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 0.0.0 02/06/2015
[ 0.078579] RIP: 0010:find_ibft_region+0x470/0x577
[ 0.079541] Code: f1 40 0f 9e c6 84 c9 0f 95 c1 40 84 ce 75 11 83 e0
07 38 c2 0f 9e c1 84 d2 0f 95 c0 84 c1 74 0a be 04 00 00 00 e8 37 f8 5f
ef <8b> 5b 04 4c 89 fa b8 ff ff 37 00 48 c1 ea 03 48 c1 e0 2a 81 c3 ff
[ 0.083207] RSP: 0000:ffffffff8fe07ca8 EFLAGS: 00010046 ORIG_RAX:
0000000000000000
[ 0.084709] RAX: 0000000000000000 RBX: ffffffffff240000 RCX:
ffffffff815fcf01
[ 0.086109] RDX: dffffc0000000000 RSI: 0000000000000001 RDI:
ffffffffff240004
[ 0.087509] RBP: ffffffff8fe07d60 R08: fffffbfff1fc0f21 R09:
fffffbfff1fc0f21
[ 0.088911] R10: ffffffff8fe07907 R11: fffffbfff1fc0f20 R12:
ffffffff8fe07d38
[ 0.090310] R13: 0000000000000001 R14: 0000000000000001 R15:
ffffffff8fe07e80
[ 0.091716] FS: 0000000000000000(0000) GS:ffffffff92409000(0000)
knlGS:0000000000000000
[ 0.093304] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.094435] CR2: ffffffffff240004 CR3: 0000000027630000 CR4:
00000000000006a0
[ 0.095843] Call Trace:
[ 0.096345] ? acpi_table_init+0x3eb/0x428
[ 0.097164] ? dmi_id_init+0x871/0x871
[ 0.097912] ? early_memunmap+0x22/0x27
[ 0.098683] ? smp_scan_config+0x20e/0x230
[ 0.099500] setup_arch+0xd3e/0x181d
[ 0.100221] ? reserve_standard_io_resources+0x3e/0x3e
[ 0.101265] ? __sanitizer_cov_trace_pc+0x21/0x50
[ 0.102203] ? vprintk_func+0xe9/0x200
[ 0.102953] ? printk+0xac/0xd4
[ 0.103589] ? record_print_text.cold.38+0x16/0x16
[ 0.104540] ? write_comp_data+0x2f/0x90
[ 0.105325] ? __sanitizer_cov_trace_pc+0x21/0x50
[ 0.106262] start_kernel+0x6c/0x474
[ 0.106981] x86_64_start_reservations+0x37/0x39
[ 0.107902] x86_64_start_kernel+0x7b/0x7e
[ 0.108722] secondary_startup_64_no_verify+0xb0/0xbb
Added debug to dump out the ibft_addr:
[root at gkennedy-20210107-1202 linux-upwork]# git diff
diff --git a/drivers/firmware/iscsi_ibft_find.c
b/drivers/firmware/iscsi_ibft_find.c
index 2e5e040..a246373 100644
--- a/drivers/firmware/iscsi_ibft_find.c
+++ b/drivers/firmware/iscsi_ibft_find.c
@@ -83,16 +83,22 @@ static int __init find_ibft_in_mem(void)
static void __init acpi_find_ibft_region(void)
{
- int i;
+ int i, status;
struct acpi_table_header *table = NULL;
-
+printk(KERN_ERR "XXX acpi_find_ibft_region:\n");
if (acpi_disabled)
return;
for (i = 0; i < ARRAY_SIZE(ibft_signs) && !ibft_addr; i++) {
- acpi_get_table(ibft_signs[i].sign, 0, &table);
- ibft_addr = (struct acpi_table_ibft *)table;
+ status = acpi_get_table(ibft_signs[i].sign, 0, &table);
+ printk(KERN_ERR "XXX %s, status=%x\n",
ibft_signs[i].sign, status);
+ if (ACPI_SUCCESS(status)) {
+ ibft_addr = (struct acpi_table_ibft *)table;
+ printk(KERN_ERR "XXX about to call
acpi_put_table()... ibft_addr=%llx\n", (u64)ibft_addr);
+ acpi_put_table(table);
+ }
}
+printk(KERN_ERR "XXX acpi_find_ibft_region(EXIT):\n");
}
/*
(END)
George
>
>> + }
>> +}
>> +
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