wireless: iwlwifi - add dma_mapping_error() checks to avoid warnings

PATCH In review Shuah Khan 2 participants 5 messages Nov 4, 2012 – Nov 5, 2012

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Networking Network drivers Networking drivers (wireless)

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Shuah Khan

author

2012-11-04 01:40 UTC #0 lore raw

PATCH 1/1 wireless: iwlwifi - add dma_mapping_error() checks to avoid warnings

Add missing dma_mapping_error() checks to validate dma addresses returned by dma_map_page() calls to avoid the following warning:

[   28.475686] WARNING: at lib/dma-debug.c:933 check_unmap+0x459/0x8a0()
[   28.475688] Hardware name: HP EliteBook 6930p
[   28.475690] iwlwifi 0000:03:00.0: DMA-API: device driver failed to check map error[device address=0x00000000ffffa000] [size=8192 bytes] [mapped as page]
[   28.475691] Modules linked in: arc4 bnep rfcomm iwldvm mac80211 snd_hda_codec_analog radeon snd_hda_intel snd_hda_codec coretemp kvm_intel snd_hwdep snd_pcm iwlwifi kvm btusb bluetooth snd_seq_midi snd_rawmidi ttm cfg80211 snd_seq_midi_event drm_kms_helper pata_pcmcia drm snd_seq binfmt_misc pcmcia snd_timer snd_seq_device tpm_infineon snd dm_multipath yenta_socket joydev pcmcia_rsrc pcmcia_core hp_wmi psmouse hp_accel microcode soundcore i2c_algo_bit sparse_keymap wmi ppdev lpc_ich lis3lv02d snd_page_alloc video tpm_tis serio_raw parport_pc input_polldev mac_hid lp parport firewire_ohci firewire_core crc_itu_t sdhci_pci sdhci e1000e
[   28.475727] Pid: 0, comm: swapper/1 Not tainted 3.7.0-rc2-next-20121026+ #2
[   28.475728] Call Trace:
[   28.475729]  <IRQ>  [<ffffffff8105832f>] warn_slowpath_common+0x7f/0xc0
[   28.475736]  [<ffffffff81058426>] warn_slowpath_fmt+0x46/0x50
[   28.475738]  [<ffffffff81347599>] check_unmap+0x459/0x8a0
[   28.475741]  [<ffffffff81347b7c>] debug_dma_unmap_page+0x5c/0x60
[   28.475751]  [<ffffffffa041e2dd>] iwl_irq_tasklet+0x4dd/0x1040 [iwlwifi]
[   28.475755]  [<ffffffffa041d50a>] ? iwl_read32+0x2a/0xa0 [iwlwifi]
[   28.475759]  [<ffffffff81410131>] ? add_interrupt_randomness+0x41/0x190
[   28.475763]  [<ffffffff813b6e53>] ? arch_local_irq_enable+0x8/0xd
[   28.475766]  [<ffffffff81060f54>] tasklet_action+0x64/0xe0
[   28.475768]  [<ffffffff81060a90>] __do_softirq+0xc0/0x240
[   28.475772]  [<ffffffff816950ae>] ? _raw_spin_lock+0xe/0x20
[   28.475774]  [<ffffffff8169ed1c>] call_softirq+0x1c/0x30
[   28.475778]  [<ffffffff810162e5>] do_softirq+0x65/0xa0
[   28.475780]  [<ffffffff81060d6e>] irq_exit+0x8e/0xb0
[   28.475782]  [<ffffffff8169f5a3>] do_IRQ+0x63/0xe0
[   28.475785]  [<ffffffff816956ad>] common_interrupt+0x6d/0x6d
[   28.475786]  <EOI>  [<ffffffff813b6e53>] ? arch_local_irq_enable+0x8/0xd
[   28.475790]  [<ffffffff813b79e9>] acpi_idle_enter_c1+0x94/0xb9
[   28.475793]  [<ffffffff815404f9>] cpuidle_enter+0x19/0x20
[   28.475795]  [<ffffffff81540b8c>] cpuidle_idle_call+0xac/0x2b0
[   28.475798]  [<ffffffff8101d56f>] cpu_idle+0xcf/0x120
[   28.475801]  [<ffffffff8168050e>] start_secondary+0x1ec/0x1f3
[   28.475802] ---[ end trace 4c30cc65c19b6dc1 ]---
[   28.475803] Mapped at:
[   28.475804]  [<ffffffff813465f9>] debug_dma_map_page+0xb9/0x160
[   28.475806]  [<ffffffffa041d704>] iwl_rx_allocate+0x94/0x2b0 [iwlwifi]
[   28.475811]  [<ffffffffa041ddad>] iwl_rx_replenish+0x2d/0x60 [iwlwifi]
[   28.475815]  [<ffffffffa0424c1b>] iwl_trans_pcie_start_fw+0x1fb/0x1450 [iwlwifi]
[   28.475819]  [<ffffffffa05ba57e>] iwl_load_ucode_wait_alive+0xbe/0x540 [iwldvm]

Signed-off-by Shuah Khan <[email protected]>

---
 drivers/net/wireless/iwlwifi/pcie/rx.c |    4 ++++
 1 file changed, 4 insertions(+)

drivers/net/wireless/iwlwifi/pcie/rx.c +4 -0

index 137af4c..3731442 100644
@@ -321,6 +321,8 @@ static void iwl_rx_allocate(struct iwl_trans *trans, gfp_t priority)
 			dma_map_page(trans->dev, page, 0,
 				     PAGE_SIZE << trans_pcie->rx_page_order,
 				     DMA_FROM_DEVICE);
+		if (dma_mapping_error(trans->dev, rxb->page_dma))
+			BUG();
 		/* dma address must be no more than 36 bits */
 		BUG_ON(rxb->page_dma & ~DMA_BIT_MASK(36));
 		/* and also 256 byte aligned! */

@@ -489,6 +491,8 @@ static void iwl_rx_handle_rxbuf(struct iwl_trans *trans,
 			dma_map_page(trans->dev, rxb->page, 0,
 				     PAGE_SIZE << trans_pcie->rx_page_order,
 				     DMA_FROM_DEVICE);
+		if (dma_mapping_error(trans->dev, rxb->page_dma))
+			BUG();
 		list_add_tail(&rxb->list, &rxq->rx_free);
 		rxq->free_count++;
 	} else

Signature · 8 lines

1.7.9.5



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Johannes Berg

maintainer

2012-11-04 09:16 UTC #1 lore raw

Quoted 7 lines · Shuah Khan

Add missing dma_mapping_error() checks to validate dma addresses returned by dma_map_page() calls to avoid the following warning:

[   28.475686] WARNING: at lib/dma-debug.c:933 check_unmap+0x459/0x8a0()
[   28.475688] Hardware name: HP EliteBook 6930p
[   28.475690] iwlwifi 0000:03:00.0: DMA-API: device driver failed to check map error[device address=0x00000000ffffa000] [size=8192 bytes] [mapped as page]
[   28.475691] Modules linked in: arc4 bnep rfcomm iwldvm mac80211 snd_hda_codec_analog radeon snd_hda_intel snd_hda_codec coretemp kvm_intel snd_hwdep snd_pcm iwlwifi kvm btusb bluetooth snd_seq_midi snd_rawmidi ttm cfg80211 snd_seq_midi_event drm_kms_helper pata_pcmcia drm snd_seq binfmt_misc pcmcia snd_timer snd_seq_device tpm_infineon snd dm_multipath yenta_socket joydev pcmcia_rsrc pcmcia_core hp_wmi psmouse hp_accel microcode soundcore i2c_algo_bit sparse_keymap wmi ppdev lpc_ich lis3lv02d snd_page_alloc video tpm_tis serio_raw parport_pc input_polldev mac_hid lp parport firewire_ohci firewire_core crc_itu_t sdhci_pci sdhci e1000e

Thanks for the report. Since I think doing BUG_ON() in such a scenario is a really bad idea, I've applied a different patch with your Reported-by.

johannes

Shuah Khan

author

2012-11-05 16:26 UTC #2 lore raw

Quoted 4 lines · Johannes Berg

Quoted 3 lines · Shuah Khan
Add missing dma_mapping_error() checks to validate dma addresses returned by dma_map_page() calls to avoid the following warning:

Quoted 8 lines

Quoted 4 lines

[   28.475686] WARNING: at lib/dma-debug.c:933 check_unmap+0x459/0x8a0()
[   28.475688] Hardware name: HP EliteBook 6930p
[   28.475690] iwlwifi 0000:03:00.0: DMA-API: device driver failed to check map error[device address=0x00000000ffffa000] [size=8192 bytes] [mapped as page]
[   28.475691] Modules linked in: arc4 bnep rfcomm iwldvm mac80211 snd_hda_codec_analog radeon snd_hda_intel snd_hda_codec coretemp kvm_intel snd_hwdep snd_pcm iwlwifi kvm btusb bluetooth snd_seq_midi snd_rawmidi ttm cfg80211 snd_seq_midi_event drm_kms_helper pata_pcmcia drm snd_seq binfmt_misc pcmcia snd_timer snd_seq_device tpm_infineon snd dm_multipath yenta_socket joydev pcmcia_rsrc pcmcia_core hp_wmi psmouse hp_accel microcode soundcore i2c_algo_bit sparse_keymap wmi ppdev lpc_ich lis3lv02d snd_page_alloc video tpm_tis serio_raw parport_pc input_polldev mac_hid lp parport firewire_ohci firewire_core crc_itu_t sdhci_pci sdhci e1000e

Thanks for the report. Since I think doing BUG_ON() in such a scenario is a really bad idea, I've applied a different patch with your Reported-by.

Yeah. I wasn't sure about BUS() either. Did you notice the other cases of BUG_ON() in this path in iwl_rx_allocate()? I would think those need fixing as well.

              rxb->page_dma =
                        dma_map_page(trans->dev, page, 0,
                                     PAGE_SIZE <<
trans_pcie->rx_page_order,
                                     DMA_FROM_DEVICE);
                /* dma address must be no more than 36 bits */
                BUG_ON(rxb->page_dma & ~DMA_BIT_MASK(36));
                /* and also 256 byte aligned! */
                BUG_ON(rxb->page_dma & DMA_BIT_MASK(8));

Could you please send me commitID for the patch you did. I am interested in seeing the failure handling in your patch?

-- Shuah

Johannes Berg

maintainer

2012-11-05 16:29 UTC #3 lore raw

Quoted 8 lines · Shuah Khan

Quoted 3 lines
Thanks for the report. Since I think doing BUG_ON() in such a scenario is a really bad idea, I've applied a different patch with your Reported-by.
Yeah. I wasn't sure about BUS() either. Did you notice the other cases of BUG_ON() in this path in iwl_rx_allocate()? I would think those need fixing as well.

Quoted 9 lines

              rxb->page_dma =
                        dma_map_page(trans->dev, page, 0,
                                     PAGE_SIZE <<
trans_pcie->rx_page_order,
                                     DMA_FROM_DEVICE);
                /* dma address must be no more than 36 bits */
                BUG_ON(rxb->page_dma & ~DMA_BIT_MASK(36));
                /* and also 256 byte aligned! */
                BUG_ON(rxb->page_dma & DMA_BIT_MASK(8));

Well, yes, we could convert them, but we can leave them as they are because these are assertions that the DMA mapping API guarantees. If this breaks, it's a bug in the DMA mapping code.

In contrast, if it fails to map, it's not a bug in the code, it's just running out of memory or IO space or whatever.

Quoted 2 lines

Could you please send me commitID for the patch you did. I am interested in seeing the failure handling in your patch?

It's here:
http://git.kernel.org/?p=linux/kernel/git/iwlwifi/iwlwifi-fixes.git;a=commit;h=7c34158231b2eda8dcbd297be2bb1559e69cb433

johannes

Shuah Khan

author

2012-11-05 16:44 UTC #4 lore raw

Quoted 20 lines · Johannes Berg

Quoted 8 lines · Shuah Khan
Quoted 3 lines
Thanks for the report. Since I think doing BUG_ON() in such a scenario is a really bad idea, I've applied a different patch with your Reported-by.
Yeah. I wasn't sure about BUS() either. Did you notice the other cases of BUG_ON() in this path in iwl_rx_allocate()? I would think those need fixing as well.
Quoted 9 lines
              rxb->page_dma =
                        dma_map_page(trans->dev, page, 0,
                                     PAGE_SIZE <<
trans_pcie->rx_page_order,
                                     DMA_FROM_DEVICE);
                /* dma address must be no more than 36 bits */
                BUG_ON(rxb->page_dma & ~DMA_BIT_MASK(36));
                /* and also 256 byte aligned! */
                BUG_ON(rxb->page_dma & DMA_BIT_MASK(8));

Quoted 6 lines

Well, yes, we could convert them, but we can leave them as they are because these are assertions that the DMA mapping API guarantees. If this breaks, it's a bug in the DMA mapping code.
In contrast, if it fails to map, it's not a bug in the code, it's just running out of memory or IO space or whatever.

Right.

Quoted 7 lines

Quoted 3 lines
Could you please send me commitID for the patch you did. I am interested in seeing the failure handling in your patch?
It's here:
http://git.kernel.org/?p=linux/kernel/git/iwlwifi/iwlwifi-fixes.git;a=commit;h=7c34158231b2eda8dcbd297be2bb1559e69cb433

Thanks.