2013-07-26 09:10:55

by Ethan Zhao

[permalink] [raw]
Subject: [PATCH] x86/PCI: MMCONFIG: cleanup and add address warning to pci_mmconfig_insert

Cleanup the -EINVAL return value handling and add warning message for
invalid
start,end,addr parameters.

Signed-off-by: ethan.zhao <[email protected]>
---
arch/x86/pci/mmconfig-shared.c | 12 ++++++------
1 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 082e881..37f6c7f 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -700,8 +700,13 @@ int pci_mmconfig_insert(struct device *dev, u16
seg, u8 start, u8 end,
if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
return -ENODEV;

- if (start > end)
+ if (start > end || !addr) {
+ dev_warn(dev, FW_WARN
+ "Invalid address to add MMCONFIG"
+ "start %02x end %02x addr %pR\n",
+ start, end, addr);
return -EINVAL;
+ }

mutex_lock(&pci_mmcfg_lock);
cfg = pci_mmconfig_lookup(seg, start);
@@ -716,11 +721,6 @@ int pci_mmconfig_insert(struct device *dev, u16
seg, u8 start, u8 end,
return -EEXIST;
}

- if (!addr) {
- mutex_unlock(&pci_mmcfg_lock);
- return -EINVAL;
- }
-
rc = -EBUSY;
cfg = pci_mmconfig_alloc(seg, start, end, addr);
if (cfg == NULL) {
--
1.7.1



Attachments:
0001-x86-PCI-MMCONFIG-cleanup-and-add-address-warning-to-.patch (1.48 kB)

2013-07-26 12:36:27

by Yinghai Lu

[permalink] [raw]
Subject: Re: [PATCH] x86/PCI: MMCONFIG: cleanup and add address warning to pci_mmconfig_insert

On Fri, Jul 26, 2013 at 2:10 AM, ethan zhao <[email protected]> wrote:
> Cleanup the -EINVAL return value handling and add warning message for
> invalid
> start,end,addr parameters.
>
> Signed-off-by: ethan.zhao <[email protected]>
> ---
> arch/x86/pci/mmconfig-shared.c | 12 ++++++------
> 1 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
> index 082e881..37f6c7f 100644
> --- a/arch/x86/pci/mmconfig-shared.c
> +++ b/arch/x86/pci/mmconfig-shared.c
> @@ -700,8 +700,13 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8
> start, u8 end,
> if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
> return -ENODEV;
>
> - if (start > end)
> + if (start > end || !addr) {
> + dev_warn(dev, FW_WARN
> + "Invalid address to add MMCONFIG"
> + "start %02x end %02x addr %pR\n",
> + start, end, addr);
> return -EINVAL;
> + }
>
> mutex_lock(&pci_mmcfg_lock);
> cfg = pci_mmconfig_lookup(seg, start);
> @@ -716,11 +721,6 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8
> start, u8 end,
> return -EEXIST;
> }
>
> - if (!addr) {
> - mutex_unlock(&pci_mmcfg_lock);
> - return -EINVAL;
> - }
> -
> rc = -EBUSY;
> cfg = pci_mmconfig_alloc(seg, start, end, addr);
> if (cfg == NULL) {


Acked-by: Yinghai Lu <[email protected]>

2013-07-26 17:40:05

by Bjorn Helgaas

[permalink] [raw]
Subject: Re: [PATCH] x86/PCI: MMCONFIG: cleanup and add address warning to pci_mmconfig_insert

[+cc Jiang, linux-pci, -cc [email protected] (dead address)]

On Fri, Jul 26, 2013 at 05:10:39PM +0800, ethan zhao wrote:
> Cleanup the -EINVAL return value handling and add warning message
> for invalid
> start,end,addr parameters.
>
> Signed-off-by: ethan.zhao <[email protected]>

This patch was corrupted, so I couldn't apply it directly. ?See
Documentation/SubmittingPatches, sections 5-7.

> ---
> arch/x86/pci/mmconfig-shared.c | 12 ++++++------
> 1 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
> index 082e881..37f6c7f 100644
> --- a/arch/x86/pci/mmconfig-shared.c
> +++ b/arch/x86/pci/mmconfig-shared.c
> @@ -700,8 +700,13 @@ int pci_mmconfig_insert(struct device *dev, u16
> seg, u8 start, u8 end,
> if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
> return -ENODEV;
>
> - if (start > end)
> + if (start > end || !addr) {
> + dev_warn(dev, FW_WARN
> + "Invalid address to add MMCONFIG"
> + "start %02x end %02x addr %pR\n",
> + start, end, addr);
> return -EINVAL;
> + }

I like the "!addr" cleanup.

Did you actually see this problem on a machine?

I expect this would be a BIOS bug, and one that should be found
early in development, long before a machine is released.
Therefore, I doubt that it's worth adding another printk for it.
If an end-user sees this problem, I think we'll already get a
generic message from check_segment().

I propose the patch below; what do you think?

>
> mutex_lock(&pci_mmcfg_lock);
> cfg = pci_mmconfig_lookup(seg, start);
> @@ -716,11 +721,6 @@ int pci_mmconfig_insert(struct device *dev, u16
> seg, u8 start, u8 end,
> return -EEXIST;
> }
>
> - if (!addr) {
> - mutex_unlock(&pci_mmcfg_lock);
> - return -EINVAL;
> - }
> -
> rc = -EBUSY;
> cfg = pci_mmconfig_alloc(seg, start, end, addr);
> if (cfg == NULL) {



Author: ethan.zhao <[email protected]>
Date: Fri Jul 26 11:21:24 2013 -0600

x86/PCI: MMCONFIG: Check earlier for MMCONFIG region at address zero

We can check for addr being zero earlier and thus avoid the mutex_unlock()
cleanup path.

[bhelgaas: changelog, drop printk]
Signed-off-by: ethan.zhao <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Acked-by: Yinghai Lu <[email protected]>

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 082e881..5596c7b 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -700,7 +700,7 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
return -ENODEV;

- if (start > end)
+ if (start > end || !addr)
return -EINVAL;

mutex_lock(&pci_mmcfg_lock);
@@ -716,11 +716,6 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
return -EEXIST;
}

- if (!addr) {
- mutex_unlock(&pci_mmcfg_lock);
- return -EINVAL;
- }
-
rc = -EBUSY;
cfg = pci_mmconfig_alloc(seg, start, end, addr);
if (cfg == NULL) {

2013-07-27 14:27:06

by Yinghai Lu

[permalink] [raw]
Subject: Re: [PATCH] x86/PCI: MMCONFIG: cleanup and add address warning to pci_mmconfig_insert

On Fri, Jul 26, 2013 at 10:39 AM, Bjorn Helgaas <[email protected]> wrote:
> [+cc Jiang, linux-pci, -cc [email protected] (dead address)]
>
> On Fri, Jul 26, 2013 at 05:10:39PM +0800, ethan zhao wrote:
>> Cleanup the -EINVAL return value handling and add warning message
>> for invalid
>> start,end,addr parameters.
>>
>> Signed-off-by: ethan.zhao <[email protected]>
>
> This patch was corrupted, so I couldn't apply it directly. See
> Documentation/SubmittingPatches, sections 5-7.
>
>> ---
>> arch/x86/pci/mmconfig-shared.c | 12 ++++++------
>> 1 files changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
>> index 082e881..37f6c7f 100644
>> --- a/arch/x86/pci/mmconfig-shared.c
>> +++ b/arch/x86/pci/mmconfig-shared.c
>> @@ -700,8 +700,13 @@ int pci_mmconfig_insert(struct device *dev, u16
>> seg, u8 start, u8 end,
>> if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
>> return -ENODEV;
>>
>> - if (start > end)
>> + if (start > end || !addr) {
>> + dev_warn(dev, FW_WARN
>> + "Invalid address to add MMCONFIG"
>> + "start %02x end %02x addr %pR\n",
>> + start, end, addr);
>> return -EINVAL;
>> + }
>
> I like the "!addr" cleanup.
>
> Did you actually see this problem on a machine?
>
> I expect this would be a BIOS bug, and one that should be found
> early in development, long before a machine is released.
> Therefore, I doubt that it's worth adding another printk for it.
> If an end-user sees this problem, I think we'll already get a
> generic message from check_segment().
>
> I propose the patch below; what do you think?
>
>>
>> mutex_lock(&pci_mmcfg_lock);
>> cfg = pci_mmconfig_lookup(seg, start);
>> @@ -716,11 +721,6 @@ int pci_mmconfig_insert(struct device *dev, u16
>> seg, u8 start, u8 end,
>> return -EEXIST;
>> }
>>
>> - if (!addr) {
>> - mutex_unlock(&pci_mmcfg_lock);
>> - return -EINVAL;
>> - }
>> -
>> rc = -EBUSY;
>> cfg = pci_mmconfig_alloc(seg, start, end, addr);
>> if (cfg == NULL) {
>
>
>
> Author: ethan.zhao <[email protected]>
> Date: Fri Jul 26 11:21:24 2013 -0600
>
> x86/PCI: MMCONFIG: Check earlier for MMCONFIG region at address zero
>
> We can check for addr being zero earlier and thus avoid the mutex_unlock()
> cleanup path.
>
> [bhelgaas: changelog, drop printk]
> Signed-off-by: ethan.zhao <[email protected]>
> Signed-off-by: Bjorn Helgaas <[email protected]>
> Acked-by: Yinghai Lu <[email protected]>

looks like I had typo in ack. please update to

Acked-by: Yinghai Lu <[email protected]>

>
> diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
> index 082e881..5596c7b 100644
> --- a/arch/x86/pci/mmconfig-shared.c
> +++ b/arch/x86/pci/mmconfig-shared.c
> @@ -700,7 +700,7 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
> if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
> return -ENODEV;
>
> - if (start > end)
> + if (start > end || !addr)
> return -EINVAL;
>
> mutex_lock(&pci_mmcfg_lock);
> @@ -716,11 +716,6 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
> return -EEXIST;
> }
>
> - if (!addr) {
> - mutex_unlock(&pci_mmcfg_lock);
> - return -EINVAL;
> - }
> -
> rc = -EBUSY;
> cfg = pci_mmconfig_alloc(seg, start, end, addr);
> if (cfg == NULL) {

2013-07-27 16:10:18

by Bjorn Helgaas

[permalink] [raw]
Subject: Re: [PATCH] x86/PCI: MMCONFIG: cleanup and add address warning to pci_mmconfig_insert

On Sat, Jul 27, 2013 at 8:27 AM, Yinghai Lu <[email protected]> wrote:
> On Fri, Jul 26, 2013 at 10:39 AM, Bjorn Helgaas <[email protected]> wrote:

>> [bhelgaas: changelog, drop printk]
>> Signed-off-by: ethan.zhao <[email protected]>
>> Signed-off-by: Bjorn Helgaas <[email protected]>
>> Acked-by: Yinghai Lu <[email protected]>
>
> looks like I had typo in ack. please update to
>
> Acked-by: Yinghai Lu <[email protected]>

Done, thanks, sorry I didn't notice that :)

2013-07-27 23:47:53

by ethan zhao

[permalink] [raw]
Subject: Re: [PATCH] x86/PCI: MMCONFIG: cleanup and add address warning to pci_mmconfig_insert

On Sat, Jul 27, 2013 at 1:39 AM, Bjorn Helgaas <[email protected]> wrote:
> [+cc Jiang, linux-pci, -cc [email protected] (dead address)]
>
> On Fri, Jul 26, 2013 at 05:10:39PM +0800, ethan zhao wrote:
>> Cleanup the -EINVAL return value handling and add warning message
>> for invalid
>> start,end,addr parameters.
>>
>> Signed-off-by: ethan.zhao <[email protected]>
>
> This patch was corrupted, so I couldn't apply it directly. See
> Documentation/SubmittingPatches, sections 5-7.
>
>> ---
>> arch/x86/pci/mmconfig-shared.c | 12 ++++++------
>> 1 files changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
>> index 082e881..37f6c7f 100644
>> --- a/arch/x86/pci/mmconfig-shared.c
>> +++ b/arch/x86/pci/mmconfig-shared.c
>> @@ -700,8 +700,13 @@ int pci_mmconfig_insert(struct device *dev, u16
>> seg, u8 start, u8 end,
>> if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
>> return -ENODEV;
>>
>> - if (start > end)
>> + if (start > end || !addr) {
>> + dev_warn(dev, FW_WARN
>> + "Invalid address to add MMCONFIG"
>> + "start %02x end %02x addr %pR\n",
>> + start, end, addr);
>> return -EINVAL;
>> + }
>
> I like the "!addr" cleanup.
>
> Did you actually see this problem on a machine?
>
> I expect this would be a BIOS bug, and one that should be found
> early in development, long before a machine is released.
> Therefore, I doubt that it's worth adding another printk for it.
> If an end-user sees this problem, I think we'll already get a
> generic message from check_segment().
>

Yes, Maybe I met a BIOS bug, but the mmconfig just yelled a failed message like
this, no other information

"fail to add MMCONFIG information, xx--xx can't access extended PCI
configuration space under this bridge"

While I look into the code, found there are detail messages for other
return values in pci_mmconfig_insert(),
But no for -EINVAL, that is not fair and force me to add more code to
debug the cause.


> I propose the patch below; what do you think?
>
>>
>> mutex_lock(&pci_mmcfg_lock);
>> cfg = pci_mmconfig_lookup(seg, start);
>> @@ -716,11 +721,6 @@ int pci_mmconfig_insert(struct device *dev, u16
>> seg, u8 start, u8 end,
>> return -EEXIST;
>> }
>>
>> - if (!addr) {
>> - mutex_unlock(&pci_mmcfg_lock);
>> - return -EINVAL;
>> - }
>> -
>> rc = -EBUSY;
>> cfg = pci_mmconfig_alloc(seg, start, end, addr);
>> if (cfg == NULL) {
>
>
>
> Author: ethan.zhao <[email protected]>
> Date: Fri Jul 26 11:21:24 2013 -0600
>
> x86/PCI: MMCONFIG: Check earlier for MMCONFIG region at address zero
>
> We can check for addr being zero earlier and thus avoid the mutex_unlock()
> cleanup path.
>
> [bhelgaas: changelog, drop printk]
> Signed-off-by: ethan.zhao <[email protected]>
> Signed-off-by: Bjorn Helgaas <[email protected]>
> Acked-by: Yinghai Lu <[email protected]>
>
> diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
> index 082e881..5596c7b 100644
> --- a/arch/x86/pci/mmconfig-shared.c
> +++ b/arch/x86/pci/mmconfig-shared.c
> @@ -700,7 +700,7 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
> if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
> return -ENODEV;
>
> - if (start > end)
> + if (start > end || !addr)
> return -EINVAL;
>
> mutex_lock(&pci_mmcfg_lock);
> @@ -716,11 +716,6 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
> return -EEXIST;
> }
>
> - if (!addr) {
> - mutex_unlock(&pci_mmcfg_lock);
> - return -EINVAL;
> - }
> -
> rc = -EBUSY;
> cfg = pci_mmconfig_alloc(seg, start, end, addr);
> if (cfg == NULL) {

2013-07-27 23:50:25

by ethan zhao

[permalink] [raw]
Subject: Re: [PATCH] x86/PCI: MMCONFIG: cleanup and add address warning to pci_mmconfig_insert

Seems there are code style issues etc after I pasted it in my mail client.
I will correct it and resend v2.

Thanks.

On Sun, Jul 28, 2013 at 12:09 AM, Bjorn Helgaas <[email protected]> wrote:
> On Sat, Jul 27, 2013 at 8:27 AM, Yinghai Lu <[email protected]> wrote:
>> On Fri, Jul 26, 2013 at 10:39 AM, Bjorn Helgaas <[email protected]> wrote:
>
>>> [bhelgaas: changelog, drop printk]
>>> Signed-off-by: ethan.zhao <[email protected]>
>>> Signed-off-by: Bjorn Helgaas <[email protected]>
>>> Acked-by: Yinghai Lu <[email protected]>
>>
>> looks like I had typo in ack. please update to
>>
>> Acked-by: Yinghai Lu <[email protected]>
>
> Done, thanks, sorry I didn't notice that :)