* [PATCH 0/1] Fix DMA_API_DEBUG warning in hid-lenovo @ 2016-03-28 13:22 Josh Boyer 2016-03-28 13:22 ` [PATCH] HID: lenovo: Don't use stack variables for DMA buffers Josh Boyer 0 siblings, 1 reply; 4+ messages in thread From: Josh Boyer @ 2016-03-28 13:22 UTC (permalink / raw) To: Jiri Kosina, Benjamin Tissoires; +Cc: linux-input, linux-kernel We've had a report[1] in Fedora of the hid-lenovo driver throwing the backtrace below when CONFIG_DMA_API_DEBUG is set. The following patch should fix this. WARNING: CPU: 3 PID: 385 at lib/dma-debug.c:1169 check_for_stack+0x90/0xd0 ohci-pci 0000:00:13.0: DMA-API: device driver maps memory from stack [addr=ffff880426cafa7d] Modules linked in: serio_raw amdkfd amd_iommu_v2 alx mdio radeon(+) hid_lenovo(+) ax88179_178a(+) pata_atiixp usbnet i2c_algo_bit drm_kms_helper ttm drm r8169 mii fjes CPU: 3 PID: 385 Comm: systemd-udevd Not tainted 4.6.0-0.rc0.git20.1.fc25.x86_64 #1 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./FM2A88X-ITX+, BIOS P3.20 12/03/2015 0000000000000286 00000000a490d2cf ffff880426caf670 ffffffff8145b265 ffff880426caf6c0 0000000000000000 ffff880426caf6b0 ffffffff810b2f2b 0000049126caf708 ffff880426cafa7d ffff88042d6a9098 ffff88042d6277a0 Call Trace: [<ffffffff8145b265>] dump_stack+0x86/0xc1 [<ffffffff810b2f2b>] __warn+0xcb/0xf0 [<ffffffff810b2faf>] warn_slowpath_fmt+0x5f/0x80 [<ffffffff8148d2a0>] check_for_stack+0x90/0xd0 [<ffffffff8148d899>] debug_dma_map_page+0xf9/0x150 [<ffffffff816678db>] usb_hcd_map_urb_for_dma+0x5db/0x780 [<ffffffff8166808b>] usb_hcd_submit_urb+0x37b/0xb60 [<ffffffff815bcbef>] ? dev_vprintk_emit+0xbf/0x230 [<ffffffff81118771>] ? __raw_spin_lock_init+0x21/0x60 [<ffffffff8110f034>] ? lockdep_init_map+0x64/0x6c0 [<ffffffff811121a5>] ? trace_hardirqs_on_caller+0xf5/0x1b0 [<ffffffff81669a74>] usb_submit_urb+0x2f4/0x550 [<ffffffff8166a3f4>] usb_start_wait_urb+0x74/0x180 [<ffffffff8166a5dc>] usb_control_msg+0xdc/0x120 [<ffffffff8173dad9>] usbhid_raw_request+0xa9/0x180 [<ffffffffc02930a1>] lenovo_send_cmd_cptkbd+0xa1/0xc0 [hid_lenovo] [<ffffffffc02941c3>] lenovo_probe+0x313/0x460 [hid_lenovo] [<ffffffff81730e30>] ? hid_match_device+0xa0/0xb0 [<ffffffff81733207>] hid_device_probe+0xd7/0x160 [<ffffffff815c18cc>] driver_probe_device+0x22c/0x440 [<ffffffff815c1bb5>] __driver_attach+0xd5/0x100 [<ffffffff815c1ae0>] ? driver_probe_device+0x440/0x440 [<ffffffff815bf113>] bus_for_each_dev+0x73/0xc0 [<ffffffff815c0f9e>] driver_attach+0x1e/0x20 [<ffffffff815c09c6>] bus_add_driver+0x1c6/0x290 [<ffffffffc00bf000>] ? 0xffffffffc00bf000 [<ffffffff815c2880>] driver_register+0x60/0xe0 [<ffffffff81732106>] __hid_register_driver+0x66/0xa0 [<ffffffffc00bf01e>] lenovo_driver_init+0x1e/0x1000 [hid_lenovo] [<ffffffff81002123>] do_one_initcall+0xb3/0x1f0 [<ffffffff81131df5>] ? rcu_read_lock_sched_held+0x45/0x80 [<ffffffff8126b6fc>] ? kmem_cache_alloc_trace+0x2ac/0x310 [<ffffffff811f3f4e>] ? do_init_module+0x27/0x1da [<ffffffff811f3f86>] do_init_module+0x5f/0x1da [<ffffffff8115e588>] load_module+0x21e8/0x2950 [<ffffffff8115ab30>] ? __symbol_put+0x70/0x70 [<ffffffff81159b30>] ? show_coresize+0x30/0x30 [<ffffffff8103fd19>] ? sched_clock+0x9/0x10 [<ffffffff8115ee62>] SYSC_init_module+0x172/0x1b0 [<ffffffff8115efce>] SyS_init_module+0xe/0x10 [<ffffffff81004039>] do_syscall_64+0x69/0x190 [<ffffffff818ce5ff>] entry_SYSCALL64_slow_path+0x25/0x25 josh [1] https://bugzilla.redhat.com/show_bug.cgi?id=1321421 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH] HID: lenovo: Don't use stack variables for DMA buffers 2016-03-28 13:22 [PATCH 0/1] Fix DMA_API_DEBUG warning in hid-lenovo Josh Boyer @ 2016-03-28 13:22 ` Josh Boyer 2016-03-29 6:50 ` Benjamin Tissoires 0 siblings, 1 reply; 4+ messages in thread From: Josh Boyer @ 2016-03-28 13:22 UTC (permalink / raw) To: Jiri Kosina, Benjamin Tissoires; +Cc: linux-input, linux-kernel The lenovo_send_cmd_cptkbd function uses a stack variable to submit commands via hid_hw_raw_request. Eventually this gets to the usb_hcd_map_urb_for_dma function, which causes a warning to be thrown if the CONFIG_DMA_API_DEBUG option is enabled. Fix this by allocating a temporary buffer instead. Reported-by: lejeczek <peljasz@yahoo.co.uk> Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org> --- drivers/hid/hid-lenovo.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c index 0125e356bd8d..2ba5e8ea66a4 100644 --- a/drivers/hid/hid-lenovo.c +++ b/drivers/hid/hid-lenovo.c @@ -184,21 +184,31 @@ static int lenovo_send_cmd_cptkbd(struct hid_device *hdev, unsigned char byte2, unsigned char byte3) { int ret; - unsigned char buf[] = {0x18, byte2, byte3}; + unsigned char *buf = NULL; + + buf = kzalloc(3, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + buf[0] = 0x18; + buf[1] = byte2; + buf[2] = byte3; switch (hdev->product) { case USB_DEVICE_ID_LENOVO_CUSBKBD: - ret = hid_hw_raw_request(hdev, 0x13, buf, sizeof(buf), + ret = hid_hw_raw_request(hdev, 0x13, buf, 3, HID_FEATURE_REPORT, HID_REQ_SET_REPORT); break; case USB_DEVICE_ID_LENOVO_CBTKBD: - ret = hid_hw_output_report(hdev, buf, sizeof(buf)); + ret = hid_hw_output_report(hdev, buf, 3); break; default: ret = -EINVAL; break; } + kfree(buf); + return ret < 0 ? ret : 0; /* BT returns 0, USB returns sizeof(buf) */ } -- 2.5.5 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] HID: lenovo: Don't use stack variables for DMA buffers 2016-03-28 13:22 ` [PATCH] HID: lenovo: Don't use stack variables for DMA buffers Josh Boyer @ 2016-03-29 6:50 ` Benjamin Tissoires 2016-03-29 13:40 ` Jiri Kosina 0 siblings, 1 reply; 4+ messages in thread From: Benjamin Tissoires @ 2016-03-29 6:50 UTC (permalink / raw) To: Josh Boyer; +Cc: Jiri Kosina, linux-input, linux-kernel On Mar 28 2016 or thereabouts, Josh Boyer wrote: > The lenovo_send_cmd_cptkbd function uses a stack variable to submit > commands via hid_hw_raw_request. Eventually this gets to the > usb_hcd_map_urb_for_dma function, which causes a warning to be thrown > if the CONFIG_DMA_API_DEBUG option is enabled. > > Fix this by allocating a temporary buffer instead. > > Reported-by: lejeczek <peljasz@yahoo.co.uk> > Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org> > --- The patch is Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> There is just one nitpick that can be solved while committing (or not, depending on how Jiri handles it :-P ). > drivers/hid/hid-lenovo.c | 16 +++++++++++++--- > 1 file changed, 13 insertions(+), 3 deletions(-) > > diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c > index 0125e356bd8d..2ba5e8ea66a4 100644 > --- a/drivers/hid/hid-lenovo.c > +++ b/drivers/hid/hid-lenovo.c > @@ -184,21 +184,31 @@ static int lenovo_send_cmd_cptkbd(struct hid_device *hdev, > unsigned char byte2, unsigned char byte3) > { > int ret; > - unsigned char buf[] = {0x18, byte2, byte3}; > + unsigned char *buf = NULL; No need to initialized buf here :) Cheers, Benjamin > + > + buf = kzalloc(3, GFP_KERNEL); > + if (!buf) > + return -ENOMEM; > + > + buf[0] = 0x18; > + buf[1] = byte2; > + buf[2] = byte3; > > switch (hdev->product) { > case USB_DEVICE_ID_LENOVO_CUSBKBD: > - ret = hid_hw_raw_request(hdev, 0x13, buf, sizeof(buf), > + ret = hid_hw_raw_request(hdev, 0x13, buf, 3, > HID_FEATURE_REPORT, HID_REQ_SET_REPORT); > break; > case USB_DEVICE_ID_LENOVO_CBTKBD: > - ret = hid_hw_output_report(hdev, buf, sizeof(buf)); > + ret = hid_hw_output_report(hdev, buf, 3); > break; > default: > ret = -EINVAL; > break; > } > > + kfree(buf); > + > return ret < 0 ? ret : 0; /* BT returns 0, USB returns sizeof(buf) */ > } > > -- > 2.5.5 > ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] HID: lenovo: Don't use stack variables for DMA buffers 2016-03-29 6:50 ` Benjamin Tissoires @ 2016-03-29 13:40 ` Jiri Kosina 0 siblings, 0 replies; 4+ messages in thread From: Jiri Kosina @ 2016-03-29 13:40 UTC (permalink / raw) To: Benjamin Tissoires; +Cc: Josh Boyer, linux-input, linux-kernel On Tue, 29 Mar 2016, Benjamin Tissoires wrote: > > The lenovo_send_cmd_cptkbd function uses a stack variable to submit > > commands via hid_hw_raw_request. Eventually this gets to the > > usb_hcd_map_urb_for_dma function, which causes a warning to be thrown > > if the CONFIG_DMA_API_DEBUG option is enabled. > > > > Fix this by allocating a temporary buffer instead. > > > > Reported-by: lejeczek <peljasz@yahoo.co.uk> > > Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org> > > --- > > The patch is > Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > There is just one nitpick that can be solved while committing (or not, > depending on how Jiri handles it :-P ). I've nuked the NULL-initialization and applied, thanks! -- Jiri Kosina SUSE Labs ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-03-29 13:40 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2016-03-28 13:22 [PATCH 0/1] Fix DMA_API_DEBUG warning in hid-lenovo Josh Boyer 2016-03-28 13:22 ` [PATCH] HID: lenovo: Don't use stack variables for DMA buffers Josh Boyer 2016-03-29 6:50 ` Benjamin Tissoires 2016-03-29 13:40 ` Jiri Kosina
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).