From: Krzysztof Helt <krzysztof.h1@xxxxx>
There is a lockdep warning in the hid_input_report() due to dynamic allocation
of a temporary buffer.
Change the buffer to a local variable. The buffer size is 512 chars.
The lockdep trace is:
WARNING: at kernel/lockdep.c:2457 lockdep_trace_alloc+0xca/0xd0()
Hardware name: Product Name
Modules linked in: usbhid(+) hid uhci_hcd ne2k_pci via_agp 8390 i2c_via
Pid: 0, comm: swapper Not tainted 2.6.31 #74
Call Trace:
[<c0243b8a>] ? lockdep_trace_alloc+0xca/0xd0
[<c0221d1c>] warn_slowpath_common+0x7c/0xa0
[<c0243b8a>] ? lockdep_trace_alloc+0xca/0xd0
[<c0221d55>] warn_slowpath_null+0x15/0x20
[<c0243b8a>] lockdep_trace_alloc+0xca/0xd0
[<c027d2c8>] kmem_cache_alloc+0x28/0x100
[<cc9359ef>] ? hid_input_report+0x6f/0x220 [hid]
[<cc9359ef>] hid_input_report+0x6f/0x220 [hid]
[<cc94cabf>] hid_ctrl+0x7f/0x180 [usbhid]
[<c03b28b1>] usb_hcd_giveback_urb+0x41/0xa0
[<cc91a3fc>] uhci_giveback_urb+0x8c/0x280 [uhci_hcd]
[<c0279853>] ? dma_pool_free+0xd3/0x120
[<cc919848>] ? uhci_free_td+0x58/0xa0 [uhci_hcd]
[<cc91ac01>] uhci_scan_schedule+0x301/0x910 [uhci_hcd]
[<cc91cac4>] uhci_irq+0x94/0x940 [uhci_hcd]
[<c0245c43>] ? __lock_acquire+0x433/0xab0
[<c0206246>] ? mask_and_ack_8259A+0x66/0x100
[<c03b494b>] usb_hcd_irq+0x6b/0x90
[<c0255e7d>] handle_IRQ_event+0x2d/0xc0
[<c0257e85>] handle_level_irq+0x65/0xe0
[<c0204c74>] handle_irq+0x34/0x60
[<c0204bc9>] do_IRQ+0x39/0xb0
[<c024365c>] ? trace_hardirqs_on_caller+0x12c/0x180
[<c020328e>] common_interrupt+0x2e/0x40
[<c0208d48>] ? default_idle+0x38/0x50
[<c02108df>] apm_cpu_idle+0x10f/0x290
[<c0201b11>] cpu_idle+0x21/0x40
[<c045892d>] rest_init+0x4d/0x60
[<c0575815>] start_kernel+0x235/0x280
[<c05751f0>] ? unknown_bootoption+0x0/0x210
[<c057503f>] __init_begin+0x3f/0x50
Signed-off-by: Krzysztof Helt <krzysztof.h1@xxxxx>
---
This lockdep is in the current git tree.
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 342b7d3..eb7968d 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1075,7 +1075,7 @@ int hid_input_report(struct hid_device *hid, int type, u8 *data, int size, int i
struct hid_report_enum *report_enum;
struct hid_driver *hdrv;
struct hid_report *report;
- char *buf;
+ char buf[HID_DEBUG_BUFSIZE];
unsigned int i;
int ret;
@@ -1089,21 +1089,12 @@ int hid_input_report(struct hid_device *hid, int type, u8 *data, int size, int i
return -1;
}
- buf = kmalloc(sizeof(char) * HID_DEBUG_BUFSIZE,
- interrupt ? GFP_ATOMIC : GFP_KERNEL);
-
- if (!buf) {
- report = hid_get_report(report_enum, data);
- goto nomem;
- }
-
snprintf(buf, HID_DEBUG_BUFSIZE - 1,
"\nreport (size %u) (%snumbered)\n", size, report_enum->numbered ? "" : "un");
hid_debug_event(hid, buf);
report = hid_get_report(report_enum, data);
if (!report) {
- kfree(buf);
return -1;
}
@@ -1118,9 +1109,6 @@ int hid_input_report(struct hid_device *hid, int type, u8 *data, int size, int i
}
hid_debug_event(hid, "\n");
- kfree(buf);
-
-nomem:
if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
ret = hdrv->raw_event(hid, report, data, size);
if (ret != 0)
--
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