aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/usb/mon
diff options
context:
space:
mode:
authorPete Zaitcev <zaitcev@redhat.com>2005-08-15 19:53:57 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2005-09-08 19:28:36 -0400
commit0256839619d9b1e933cafc83e7f0deaad4216465 (patch)
treeafadd5815781a99e06ebb537d8ac677d307c09fe /drivers/usb/mon
parentd0384200f6b608e77fb5ddf7dfae1bf0e42c1c6e (diff)
[PATCH] usbmon in 2.6.13: peeking into DMA areas
This code looks at urb->transfer_dma, maps the page and takes the data. I am looking for volunteers to contribute architectures other than i386 or to develop an architecure-neutral API for it (or point me that it was done already). Signed-off-by: Pete Zaitcev <zaitcev@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/mon')
-rw-r--r--drivers/usb/mon/Makefile2
-rw-r--r--drivers/usb/mon/mon_dma.c55
-rw-r--r--drivers/usb/mon/mon_text.c35
-rw-r--r--drivers/usb/mon/usb_mon.h4
4 files changed, 77 insertions, 19 deletions
diff --git a/drivers/usb/mon/Makefile b/drivers/usb/mon/Makefile
index b0015b8a1d1f..3cf3ea3a88ed 100644
--- a/drivers/usb/mon/Makefile
+++ b/drivers/usb/mon/Makefile
@@ -2,7 +2,7 @@
2# Makefile for USB Core files and filesystem 2# Makefile for USB Core files and filesystem
3# 3#
4 4
5usbmon-objs := mon_main.o mon_stat.o mon_text.o 5usbmon-objs := mon_main.o mon_stat.o mon_text.o mon_dma.o
6 6
7# This does not use CONFIG_USB_MON because we want this to use a tristate. 7# This does not use CONFIG_USB_MON because we want this to use a tristate.
8obj-$(CONFIG_USB) += usbmon.o 8obj-$(CONFIG_USB) += usbmon.o
diff --git a/drivers/usb/mon/mon_dma.c b/drivers/usb/mon/mon_dma.c
new file mode 100644
index 000000000000..0a1367b760a0
--- /dev/null
+++ b/drivers/usb/mon/mon_dma.c
@@ -0,0 +1,55 @@
1/*
2 * The USB Monitor, inspired by Dave Harding's USBMon.
3 *
4 * mon_dma.c: Library which snoops on DMA areas.
5 *
6 * Copyright (C) 2005 Pete Zaitcev (zaitcev@redhat.com)
7 */
8#include <linux/kernel.h>
9#include <linux/list.h>
10#include <linux/highmem.h>
11#include <asm/page.h>
12
13#include <linux/usb.h> /* Only needed for declarations in usb_mon.h */
14#include "usb_mon.h"
15
16#ifdef __i386__ /* CONFIG_ARCH_I386 does not exit */
17#define MON_HAS_UNMAP 1
18
19#define phys_to_page(phys) pfn_to_page((phys) >> PAGE_SHIFT)
20
21char mon_dmapeek(unsigned char *dst, dma_addr_t dma_addr, int len)
22{
23 struct page *pg;
24 unsigned long flags;
25 unsigned char *map;
26 unsigned char *ptr;
27
28 /*
29 * On i386, a DMA handle is the "physical" address of a page.
30 * In other words, the bus address is equal to physical address.
31 * There is no IOMMU.
32 */
33 pg = phys_to_page(dma_addr);
34
35 /*
36 * We are called from hardware IRQs in case of callbacks.
37 * But we can be called from softirq or process context in case
38 * of submissions. In such case, we need to protect KM_IRQ0.
39 */
40 local_irq_save(flags);
41 map = kmap_atomic(pg, KM_IRQ0);
42 ptr = map + (dma_addr & (PAGE_SIZE-1));
43 memcpy(dst, ptr, len);
44 kunmap_atomic(map, KM_IRQ0);
45 local_irq_restore(flags);
46 return 0;
47}
48#endif /* __i386__ */
49
50#ifndef MON_HAS_UNMAP
51char mon_dmapeek(unsigned char *dst, dma_addr_t dma_addr, int len)
52{
53 return 'D';
54}
55#endif
diff --git a/drivers/usb/mon/mon_text.c b/drivers/usb/mon/mon_text.c
index 26266b30028e..417464dea9f6 100644
--- a/drivers/usb/mon/mon_text.c
+++ b/drivers/usb/mon/mon_text.c
@@ -91,25 +91,11 @@ static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb,
91 int len, char ev_type) 91 int len, char ev_type)
92{ 92{
93 int pipe = urb->pipe; 93 int pipe = urb->pipe;
94 unsigned char *data;
95
96 /*
97 * The check to see if it's safe to poke at data has an enormous
98 * number of corner cases, but it seems that the following is
99 * more or less safe.
100 *
101 * We do not even try to look transfer_buffer, because it can
102 * contain non-NULL garbage in case the upper level promised to
103 * set DMA for the HCD.
104 */
105 if (urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
106 return 'D';
107 94
108 if (len <= 0) 95 if (len <= 0)
109 return 'L'; 96 return 'L';
110 97 if (len >= DATA_MAX)
111 if ((data = urb->transfer_buffer) == NULL) 98 len = DATA_MAX;
112 return 'Z'; /* '0' would be not as pretty. */
113 99
114 /* 100 /*
115 * Bulk is easy to shortcut reliably. 101 * Bulk is easy to shortcut reliably.
@@ -126,8 +112,21 @@ static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb,
126 } 112 }
127 } 113 }
128 114
129 if (len >= DATA_MAX) 115 /*
130 len = DATA_MAX; 116 * The check to see if it's safe to poke at data has an enormous
117 * number of corner cases, but it seems that the following is
118 * more or less safe.
119 *
120 * We do not even try to look transfer_buffer, because it can
121 * contain non-NULL garbage in case the upper level promised to
122 * set DMA for the HCD.
123 */
124 if (urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
125 return mon_dmapeek(ep->data, urb->transfer_dma, len);
126
127 if (urb->transfer_buffer == NULL)
128 return 'Z'; /* '0' would be not as pretty. */
129
131 memcpy(ep->data, urb->transfer_buffer, len); 130 memcpy(ep->data, urb->transfer_buffer, len);
132 return 0; 131 return 0;
133} 132}
diff --git a/drivers/usb/mon/usb_mon.h b/drivers/usb/mon/usb_mon.h
index 9b06784d2c48..4be0f9346071 100644
--- a/drivers/usb/mon/usb_mon.h
+++ b/drivers/usb/mon/usb_mon.h
@@ -45,6 +45,10 @@ struct mon_reader {
45void mon_reader_add(struct mon_bus *mbus, struct mon_reader *r); 45void mon_reader_add(struct mon_bus *mbus, struct mon_reader *r);
46void mon_reader_del(struct mon_bus *mbus, struct mon_reader *r); 46void mon_reader_del(struct mon_bus *mbus, struct mon_reader *r);
47 47
48/*
49 */
50extern char mon_dmapeek(unsigned char *dst, dma_addr_t dma_addr, int len);
51
48extern struct semaphore mon_lock; 52extern struct semaphore mon_lock;
49 53
50extern struct file_operations mon_fops_text; 54extern struct file_operations mon_fops_text;