x86/pci: Add a break condition when enabling BAR

Message ID jpga7yvotm2.fsf@linux.bootlegged.copy
State Not Applicable
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Series
  • x86/pci: Add a break condition when enabling BAR
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Commit Message

Bandan Das Dec. 7, 2017, 8 a.m.
On an old flaky system with AMD Opteron 6320, boot hangs
with the following trace since commit fa564ad9:

[   28.181012] Hardware name: HP ProLiant DL385p Gen8, BIOS A28 09/03/2014
[   28.184022] RIP: 0010:lock_acquire+0xd5/0x1e0
[   28.185010] RSP: 0018:ffffb7ad818c39a8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11
[   28.187010] RAX: ffffa074fb39b140 RBX: 0000000000000246 RCX: 0000000000000000
[   28.189014] RDX: ffffffffb20a55a9 RSI: 0000000000040009 RDI: 0000000000000246
[   28.191012] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000000
[   28.193020] R10: 0000000000000001 R11: 00000000dac664b5 R12: 0000000000000000
[   28.196013] R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
[   28.197011] FS:  0000000000000000(0000) GS:ffffa074fbd00000(0000) knlGS:0000000000000000
[   28.201014] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   28.201014] CR2: 0000000000000000 CR3: 00000003b6e10000 CR4: 00000000000406e0
[   28.205008] Call Trace:
[   28.205013]  ? request_resource_conflict+0x19/0x40
[   28.207013]  _raw_write_lock+0x2e/0x40
[   28.209008]  ? request_resource_conflict+0x19/0x40
[   28.209010]  request_resource_conflict+0x19/0x40
[   28.212013]  pci_amd_enable_64bit_bar+0x103/0x1a0
[   28.213025]  pci_fixup_device+0xd4/0x210
[   28.213025]  pci_setup_device+0x193/0x570
[   28.215010]  ? get_device+0x13/0x20
[   28.217008]  pci_scan_single_device+0x98/0xd0
[   28.217011]  pci_scan_slot+0x90/0x130
[   28.219010]  pci_scanild_bus_extend+0x3a/0x270
[   28.321008]  acpi_pci_root_create+0x1a9/0x210
[   28.321014]  ? pci_acpi_scan_root+0x135/0x1b0
[   28.324013]  pci_acpi_scan_root+0x15f/0x1b0
[   28.325008]  acpi_pci_root_add+0x283/0x560
[   28.325014]  ? acpi_match_device_ids+0xc/0x20
[   28.327013]  acpi_bus_attach+0xf9/0x1c0
[   28.329008]  acpi_bus_attach+0x82/0x1c0
[   28.329044]  acpi_bus_attach+0x82/0x1c0
[   28.331010]  acpi_bus_scan+0x47/0xa0
[   28.333008]  acpi_scan_init+0x12d/0x28d
[   28.333013]  ? bus_register+0x208/0x280
[   28.333013]  acpi_init+0x30f/0x36f
[   28.335010]  ? acpi_sleep_proc_init+0x24/0x24
[   28.337013]  do_one_initcall+0x4d/0x19c
[   28.337013]  ? do_early_param+0x29/0x86
[   28.340013]  kernel_init_freeable+0x209/0x2a4
[   28.341008]  ? set_debug_rodata+0x11/0x11
[   28.341011]  ? rest_init+0xc0/0xc0
[   28.343013]  kernel_init+0xa/0x104
[   28.345008]  ret_from_fork+0x24/0x30
[   28.345010] Code: 24 08 49 c1 e9 09 49 83 f1 01 41 83 e1 01 e8 73
e4 ff ff 65 48 8b 04 25 c0 d4 00 00 48 89 df c7 80 fc 0c 00 00 00 00
00 00 57 9d <0f> 1f 44 00 00 48 83 c4 30 5b 5d 41 5c 41 5d 41 5e 41 5f
c3 65

Since request_resource() will unconditionally return a conflict for invalid
regions, there will be no way to break out of the loop when enabling 64bit BAR.
Add checks and exit the loop in these cases without attempting to enable
BAR.

Signed-off-by: Bandan Das <bsd@redhat.com>
---
 arch/x86/pci/fixup.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

Christian König Dec. 7, 2017, 1:13 p.m. | #1
Hi Bandas,

thanks for the patch, but this is a known issue with a fix already on 
the way into the next -rc.

Regards,
Christian.

Am 07.12.2017 um 09:00 schrieb Bandan Das:
> On an old flaky system with AMD Opteron 6320, boot hangs
> with the following trace since commit fa564ad9:
>
> [   28.181012] Hardware name: HP ProLiant DL385p Gen8, BIOS A28 09/03/2014
> [   28.184022] RIP: 0010:lock_acquire+0xd5/0x1e0
> [   28.185010] RSP: 0018:ffffb7ad818c39a8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11
> [   28.187010] RAX: ffffa074fb39b140 RBX: 0000000000000246 RCX: 0000000000000000
> [   28.189014] RDX: ffffffffb20a55a9 RSI: 0000000000040009 RDI: 0000000000000246
> [   28.191012] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000000
> [   28.193020] R10: 0000000000000001 R11: 00000000dac664b5 R12: 0000000000000000
> [   28.196013] R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
> [   28.197011] FS:  0000000000000000(0000) GS:ffffa074fbd00000(0000) knlGS:0000000000000000
> [   28.201014] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   28.201014] CR2: 0000000000000000 CR3: 00000003b6e10000 CR4: 00000000000406e0
> [   28.205008] Call Trace:
> [   28.205013]  ? request_resource_conflict+0x19/0x40
> [   28.207013]  _raw_write_lock+0x2e/0x40
> [   28.209008]  ? request_resource_conflict+0x19/0x40
> [   28.209010]  request_resource_conflict+0x19/0x40
> [   28.212013]  pci_amd_enable_64bit_bar+0x103/0x1a0
> [   28.213025]  pci_fixup_device+0xd4/0x210
> [   28.213025]  pci_setup_device+0x193/0x570
> [   28.215010]  ? get_device+0x13/0x20
> [   28.217008]  pci_scan_single_device+0x98/0xd0
> [   28.217011]  pci_scan_slot+0x90/0x130
> [   28.219010]  pci_scanild_bus_extend+0x3a/0x270
> [   28.321008]  acpi_pci_root_create+0x1a9/0x210
> [   28.321014]  ? pci_acpi_scan_root+0x135/0x1b0
> [   28.324013]  pci_acpi_scan_root+0x15f/0x1b0
> [   28.325008]  acpi_pci_root_add+0x283/0x560
> [   28.325014]  ? acpi_match_device_ids+0xc/0x20
> [   28.327013]  acpi_bus_attach+0xf9/0x1c0
> [   28.329008]  acpi_bus_attach+0x82/0x1c0
> [   28.329044]  acpi_bus_attach+0x82/0x1c0
> [   28.331010]  acpi_bus_scan+0x47/0xa0
> [   28.333008]  acpi_scan_init+0x12d/0x28d
> [   28.333013]  ? bus_register+0x208/0x280
> [   28.333013]  acpi_init+0x30f/0x36f
> [   28.335010]  ? acpi_sleep_proc_init+0x24/0x24
> [   28.337013]  do_one_initcall+0x4d/0x19c
> [   28.337013]  ? do_early_param+0x29/0x86
> [   28.340013]  kernel_init_freeable+0x209/0x2a4
> [   28.341008]  ? set_debug_rodata+0x11/0x11
> [   28.341011]  ? rest_init+0xc0/0xc0
> [   28.343013]  kernel_init+0xa/0x104
> [   28.345008]  ret_from_fork+0x24/0x30
> [   28.345010] Code: 24 08 49 c1 e9 09 49 83 f1 01 41 83 e1 01 e8 73
> e4 ff ff 65 48 8b 04 25 c0 d4 00 00 48 89 df c7 80 fc 0c 00 00 00 00
> 00 00 57 9d <0f> 1f 44 00 00 48 83 c4 30 5b 5d 41 5c 41 5d 41 5e 41 5f
> c3 65
>
> Since request_resource() will unconditionally return a conflict for invalid
> regions, there will be no way to break out of the loop when enabling 64bit BAR.
> Add checks and exit the loop in these cases without attempting to enable
> BAR.
>
> Signed-off-by: Bandan Das <bsd@redhat.com>
> ---
>   arch/x86/pci/fixup.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
> index 1e996df..8933a1b 100644
> --- a/arch/x86/pci/fixup.c
> +++ b/arch/x86/pci/fixup.c
> @@ -696,8 +696,13 @@ static void pci_amd_enable_64bit_bar(struct pci_dev *dev)
>   	res->end = 0xfd00000000ull - 1;
>   
>   	/* Just grab the free area behind system memory for this */
> -	while ((conflict = request_resource_conflict(&iomem_resource, res)))
> +	while ((conflict = request_resource_conflict(&iomem_resource, res))) {
> +		if ((res->start > res->end) ||
> +		    (res->start < iomem_resource.start) ||
> +		    (res->end > iomem_resource.end))
> +			break;
>   		res->start = conflict->end + 1;
> +	}
>   
>   	dev_info(&dev->dev, "adding root bus resource %pR\n", res);
>
Bandan Das Dec. 7, 2017, 7:41 p.m. | #2
Christian König <christian.koenig@amd.com> writes:

> Hi Bandas,
>
> thanks for the patch, but this is a known issue with a fix already on
> the way into the next -rc.

Oh great! Thank you, have a pointer to the patch so that I can test ?

> Regards,
> Christian.
>
> Am 07.12.2017 um 09:00 schrieb Bandan Das:
>> On an old flaky system with AMD Opteron 6320, boot hangs
>> with the following trace since commit fa564ad9:
>>
>> [   28.181012] Hardware name: HP ProLiant DL385p Gen8, BIOS A28 09/03/2014
>> [   28.184022] RIP: 0010:lock_acquire+0xd5/0x1e0
>> [   28.185010] RSP: 0018:ffffb7ad818c39a8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11
>> [   28.187010] RAX: ffffa074fb39b140 RBX: 0000000000000246 RCX: 0000000000000000
>> [   28.189014] RDX: ffffffffb20a55a9 RSI: 0000000000040009 RDI: 0000000000000246
>> [   28.191012] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000000
>> [   28.193020] R10: 0000000000000001 R11: 00000000dac664b5 R12: 0000000000000000
>> [   28.196013] R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
>> [   28.197011] FS:  0000000000000000(0000) GS:ffffa074fbd00000(0000) knlGS:0000000000000000
>> [   28.201014] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [   28.201014] CR2: 0000000000000000 CR3: 00000003b6e10000 CR4: 00000000000406e0
>> [   28.205008] Call Trace:
>> [   28.205013]  ? request_resource_conflict+0x19/0x40
>> [   28.207013]  _raw_write_lock+0x2e/0x40
>> [   28.209008]  ? request_resource_conflict+0x19/0x40
>> [   28.209010]  request_resource_conflict+0x19/0x40
>> [   28.212013]  pci_amd_enable_64bit_bar+0x103/0x1a0
>> [   28.213025]  pci_fixup_device+0xd4/0x210
>> [   28.213025]  pci_setup_device+0x193/0x570
>> [   28.215010]  ? get_device+0x13/0x20
>> [   28.217008]  pci_scan_single_device+0x98/0xd0
>> [   28.217011]  pci_scan_slot+0x90/0x130
>> [   28.219010]  pci_scanild_bus_extend+0x3a/0x270
>> [   28.321008]  acpi_pci_root_create+0x1a9/0x210
>> [   28.321014]  ? pci_acpi_scan_root+0x135/0x1b0
>> [   28.324013]  pci_acpi_scan_root+0x15f/0x1b0
>> [   28.325008]  acpi_pci_root_add+0x283/0x560
>> [   28.325014]  ? acpi_match_device_ids+0xc/0x20
>> [   28.327013]  acpi_bus_attach+0xf9/0x1c0
>> [   28.329008]  acpi_bus_attach+0x82/0x1c0
>> [   28.329044]  acpi_bus_attach+0x82/0x1c0
>> [   28.331010]  acpi_bus_scan+0x47/0xa0
>> [   28.333008]  acpi_scan_init+0x12d/0x28d
>> [   28.333013]  ? bus_register+0x208/0x280
>> [   28.333013]  acpi_init+0x30f/0x36f
>> [   28.335010]  ? acpi_sleep_proc_init+0x24/0x24
>> [   28.337013]  do_one_initcall+0x4d/0x19c
>> [   28.337013]  ? do_early_param+0x29/0x86
>> [   28.340013]  kernel_init_freeable+0x209/0x2a4
>> [   28.341008]  ? set_debug_rodata+0x11/0x11
>> [   28.341011]  ? rest_init+0xc0/0xc0
>> [   28.343013]  kernel_init+0xa/0x104
>> [   28.345008]  ret_from_fork+0x24/0x30
>> [   28.345010] Code: 24 08 49 c1 e9 09 49 83 f1 01 41 83 e1 01 e8 73
>> e4 ff ff 65 48 8b 04 25 c0 d4 00 00 48 89 df c7 80 fc 0c 00 00 00 00
>> 00 00 57 9d <0f> 1f 44 00 00 48 83 c4 30 5b 5d 41 5c 41 5d 41 5e 41 5f
>> c3 65
>>
>> Since request_resource() will unconditionally return a conflict for invalid
>> regions, there will be no way to break out of the loop when enabling 64bit BAR.
>> Add checks and exit the loop in these cases without attempting to enable
>> BAR.
>>
>> Signed-off-by: Bandan Das <bsd@redhat.com>
>> ---
>>   arch/x86/pci/fixup.c | 7 ++++++-
>>   1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
>> index 1e996df..8933a1b 100644
>> --- a/arch/x86/pci/fixup.c
>> +++ b/arch/x86/pci/fixup.c
>> @@ -696,8 +696,13 @@ static void pci_amd_enable_64bit_bar(struct pci_dev *dev)
>>   	res->end = 0xfd00000000ull - 1;
>>     	/* Just grab the free area behind system memory for this */
>> -	while ((conflict = request_resource_conflict(&iomem_resource, res)))
>> +	while ((conflict = request_resource_conflict(&iomem_resource, res))) {
>> +		if ((res->start > res->end) ||
>> +		    (res->start < iomem_resource.start) ||
>> +		    (res->end > iomem_resource.end))
>> +			break;
>>   		res->start = conflict->end + 1;
>> +	}
>>     	dev_info(&dev->dev, "adding root bus resource %pR\n", res);
>>
Bjorn Helgaas Dec. 7, 2017, 8:11 p.m. | #3
On Thu, Dec 07, 2017 at 02:41:03PM -0500, Bandan Das wrote:
> Christian König <christian.koenig@amd.com> writes:
> 
> > Hi Bandas,
> >
> > thanks for the patch, but this is a known issue with a fix already on
> > the way into the next -rc.
> 
> Oh great! Thank you, have a pointer to the patch so that I can test ?

It's in linux-next.  If you want just the patch, see
https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git/log/?h=for-linus
(there are a couple patches there).

There's still one fix for a related issue that I haven't applied yet
because it needs a little more detailed changelog.

Bjorn

Patch

diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index 1e996df..8933a1b 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -696,8 +696,13 @@  static void pci_amd_enable_64bit_bar(struct pci_dev *dev)
 	res->end = 0xfd00000000ull - 1;
 
 	/* Just grab the free area behind system memory for this */
-	while ((conflict = request_resource_conflict(&iomem_resource, res)))
+	while ((conflict = request_resource_conflict(&iomem_resource, res))) {
+		if ((res->start > res->end) ||
+		    (res->start < iomem_resource.start) ||
+		    (res->end > iomem_resource.end))
+			break;
 		res->start = conflict->end + 1;
+	}
 
 	dev_info(&dev->dev, "adding root bus resource %pR\n", res);