USB: Use (get|put)_unaligned for accessing wMaxPacketSize

In 9792987721c7980453fe6447c3fa6593b44f8458 Stefan describes a usecase
where the previous behavior of leaving wMaxPacketSize be unaligned
caused fatal problems.  The initial fix for this problem was incomplete
however as it showed another cases of non-aligned access that previously
worked implicitly.  This switches to making sure that all access of
wMaxPacketSize are done via (get|put)_unaligned.

In order to maintain a level of readability to the code in some cases
we now use a variable for the value of wMaxPacketSize and in others, a
macro.

Cc: Minkyu Kang <mk7.kang@samsung.com>
Cc: Remy Bohmer <linux@bohmer.net>
OpenRISC:
Tested-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Beagleboard xM, Pandaboard run-tested, s5p_goni build-tested.
Signed-off-by: Tom Rini <trini@ti.com>

diff --git a/common/cmd_usb.c b/common/cmd_usb.c
index d4ec2a291cddca5c340987b277290a9477bfda7a..320667f5fbcd873896d27ad73339715463b13dd1 100644 (file)
--- a/common/cmd_usb.c
+++ b/common/cmd_usb.c
@@ -28,6 +28,7 @@
 #include <common.h>
 #include <command.h>
 #include <asm/byteorder.h>
+#include <asm/unaligned.h>
 #include <part.h>
 #include <usb.h>
 
@@ -240,7 +241,7 @@ void usb_display_ep_desc(struct usb_endpoint_descriptor *epdesc)
                printf("Interrupt");
                break;
        }
-       printf(" MaxPacket %d", epdesc->wMaxPacketSize);
+       printf(" MaxPacket %d", get_unaligned(&epdesc->wMaxPacketSize));
        if ((epdesc->bmAttributes & 0x03) == 0x3)
                printf(" Interval %dms", epdesc->bInterval);
        printf("\n");

diff --git a/common/usb.c b/common/usb.c
index 4418c70f462c9282b2c911a65addf74680ad7059..63a11c8f50f0b96759d132a8cb3478af4cdc27b8 100644 (file)
--- a/common/usb.c
+++ b/common/usb.c
@@ -49,6 +49,7 @@
 #include <asm/processor.h>
 #include <linux/ctype.h>
 #include <asm/byteorder.h>
+#include <asm/unaligned.h>
 
 #include <usb.h>
 #ifdef CONFIG_4xx
@@ -279,30 +280,32 @@ usb_set_maxpacket_ep(struct usb_device *dev, int if_idx, int ep_idx)
 {
        int b;
        struct usb_endpoint_descriptor *ep;
+       u16 ep_wMaxPacketSize;
 
        ep = &dev->config.if_desc[if_idx].ep_desc[ep_idx];
 
        b = ep->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
+       ep_wMaxPacketSize = get_unaligned(&ep->wMaxPacketSize);
 
        if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
                                                USB_ENDPOINT_XFER_CONTROL) {
                /* Control => bidirectional */
-               dev->epmaxpacketout[b] = ep->wMaxPacketSize;
-               dev->epmaxpacketin[b] = ep->wMaxPacketSize;
+               dev->epmaxpacketout[b] = ep_wMaxPacketSize;
+               dev->epmaxpacketin[b] = ep_wMaxPacketSize;
                USB_PRINTF("##Control EP epmaxpacketout/in[%d] = %d\n",
                           b, dev->epmaxpacketin[b]);
        } else {
                if ((ep->bEndpointAddress & 0x80) == 0) {
                        /* OUT Endpoint */
-                       if (ep->wMaxPacketSize > dev->epmaxpacketout[b]) {
-                               dev->epmaxpacketout[b] = ep->wMaxPacketSize;
+                       if (ep_wMaxPacketSize > dev->epmaxpacketout[b]) {
+                               dev->epmaxpacketout[b] = ep_wMaxPacketSize;
                                USB_PRINTF("##EP epmaxpacketout[%d] = %d\n",
                                           b, dev->epmaxpacketout[b]);
                        }
                } else {
                        /* IN Endpoint */
-                       if (ep->wMaxPacketSize > dev->epmaxpacketin[b]) {
-                               dev->epmaxpacketin[b] = ep->wMaxPacketSize;
+                       if (ep_wMaxPacketSize > dev->epmaxpacketin[b]) {
+                               dev->epmaxpacketin[b] = ep_wMaxPacketSize;
                                USB_PRINTF("##EP epmaxpacketin[%d] = %d\n",
                                           b, dev->epmaxpacketin[b]);
                        }
@@ -333,6 +336,7 @@ int usb_parse_config(struct usb_device *dev, unsigned char *buffer, int cfgno)
        struct usb_descriptor_header *head;
        int index, ifno, epno, curr_if_num;
        int i;
+       u16 ep_wMaxPacketSize;
 
        ifno = -1;
        epno = -1;
@@ -378,8 +382,15 @@ int usb_parse_config(struct usb_device *dev, unsigned char *buffer, int cfgno)
                        dev->config.if_desc[ifno].no_of_ep++;
                        memcpy(&dev->config.if_desc[ifno].ep_desc[epno],
                                &buffer[index], buffer[index]);
-                       le16_to_cpus(&(dev->config.if_desc[ifno].ep_desc[epno].\
-                                                              wMaxPacketSize));
+                       ep_wMaxPacketSize = get_unaligned(&dev->config.\
+                                                       if_desc[ifno].\
+                                                       ep_desc[epno].\
+                                                       wMaxPacketSize);
+                       put_unaligned(le16_to_cpu(ep_wMaxPacketSize),
+                                       &dev->config.\
+                                       if_desc[ifno].\
+                                       ep_desc[epno].\
+                                       wMaxPacketSize);
                        USB_PRINTF("if %d, ep %d\n", ifno, epno);
                        break;
                default:

diff --git a/drivers/serial/usbtty.c b/drivers/serial/usbtty.c
index e2e87fef6936619eaeecac0abc256467cf1b6b6d..a263b2c1fc593ea015f685c6f3ace3806e6f01c8 100644 (file)
--- a/drivers/serial/usbtty.c
+++ b/drivers/serial/usbtty.c
@@ -25,6 +25,7 @@
 #include <config.h>
 #include <circbuf.h>
 #include <stdio_dev.h>
+#include <asm/unaligned.h>
 #include "usbtty.h"
 #include "usb_cdc_acm.h"
 #include "usbdescriptors.h"
@@ -626,6 +627,9 @@ static void usbtty_init_strings (void)
        usb_strings = usbtty_string_table;
 }
 
+#define init_wMaxPacketSize(x) le16_to_cpu(get_unaligned(\
+                       &ep_descriptor_ptrs[(x) - 1]->wMaxPacketSize));
+
 static void usbtty_init_instances (void)
 {
        int i;
@@ -688,14 +692,12 @@ static void usbtty_init_instances (void)
                endpoint_instance[i].rcv_attributes =
                        ep_descriptor_ptrs[i - 1]->bmAttributes;
 
-               endpoint_instance[i].rcv_packetSize =
-                       le16_to_cpu(ep_descriptor_ptrs[i - 1]->wMaxPacketSize);
+               endpoint_instance[i].rcv_packetSize = init_wMaxPacketSize(i);
 
                endpoint_instance[i].tx_attributes =
                        ep_descriptor_ptrs[i - 1]->bmAttributes;
 
-               endpoint_instance[i].tx_packetSize =
-                       le16_to_cpu(ep_descriptor_ptrs[i - 1]->wMaxPacketSize);
+               endpoint_instance[i].tx_packetSize = init_wMaxPacketSize(i);
 
                endpoint_instance[i].tx_attributes =
                        ep_descriptor_ptrs[i - 1]->bmAttributes;

diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 18964894215f025063f66b69e6e8311ed19b7c34..5b8776e0b70b4e479cdb48aebfa8dacf22b9cf97 100644 (file)
--- a/drivers/usb/gadget/epautoconf.c
+++ b/drivers/usb/gadget/epautoconf.c
@@ -25,6 +25,7 @@
 #include <linux/usb/ch9.h>
 #include <asm/errno.h>
 #include <linux/usb/gadget.h>
+#include <asm/unaligned.h>
 #include "gadget_chips.h"
 
 #define isdigit(c)      ('0' <= (c) && (c) <= '9')
@@ -127,7 +128,7 @@ static int ep_matches(
         * where it's an output parameter representing the full speed limit.
         * the usb spec fixes high speed bulk maxpacket at 512 bytes.
         */
-       max = 0x7ff & le16_to_cpu(desc->wMaxPacketSize);
+       max = 0x7ff & le16_to_cpu(get_unaligned(&desc->wMaxPacketSize));
        switch (type) {
        case USB_ENDPOINT_XFER_INT:
                /* INT:  limit 64 bytes full speed, 1024 high speed */
@@ -143,7 +144,8 @@ static int ep_matches(
                        return 0;
 
                /* BOTH:  "high bandwidth" works only at high speed */
-               if ((desc->wMaxPacketSize & __constant_cpu_to_le16(3<<11))) {
+               if ((get_unaligned(&desc->wMaxPacketSize) &
+                                       __constant_cpu_to_le16(3<<11))) {
                        if (!gadget->is_dualspeed)
                                return 0;
                        /* configure your hardware with enough buffering!! */
@@ -176,7 +178,7 @@ static int ep_matches(
                /* min() doesn't work on bitfields with gcc-3.5 */
                if (size > 64)
                        size = 64;
-               desc->wMaxPacketSize = cpu_to_le16(size);
+               put_unaligned(cpu_to_le16(size), &desc->wMaxPacketSize);
        }
        return 1;
 }

diff --git a/drivers/usb/gadget/s3c_udc_otg.c b/drivers/usb/gadget/s3c_udc_otg.c
index 5a3ac78ff26202859a47e7b0ad359d4091dfe837..901fac982a4153fafbac42bede8cf1d89deaf7ca 100644 (file)
--- a/drivers/usb/gadget/s3c_udc_otg.c
+++ b/drivers/usb/gadget/s3c_udc_otg.c
@@ -40,6 +40,7 @@
 #include <linux/usb/gadget.h>
 
 #include <asm/byteorder.h>
+#include <asm/unaligned.h>
 #include <asm/io.h>
 
 #include <asm/mach-types.h>
@@ -586,7 +587,8 @@ static int s3c_ep_enable(struct usb_ep *_ep,
        if (!_ep || !desc || ep->desc || _ep->name == ep0name
            || desc->bDescriptorType != USB_DT_ENDPOINT
            || ep->bEndpointAddress != desc->bEndpointAddress
-           || ep_maxpacket(ep) < le16_to_cpu(desc->wMaxPacketSize)) {
+           || ep_maxpacket(ep) <
+           le16_to_cpu(get_unaligned(&desc->wMaxPacketSize))) {
 
                DEBUG("%s: bad ep or descriptor\n", __func__);
                return -EINVAL;
@@ -603,8 +605,8 @@ static int s3c_ep_enable(struct usb_ep *_ep,
 
        /* hardware _could_ do smaller, but driver doesn't */
        if ((desc->bmAttributes == USB_ENDPOINT_XFER_BULK
-            && le16_to_cpu(desc->wMaxPacketSize) != ep_maxpacket(ep))
-           || !desc->wMaxPacketSize) {
+            && le16_to_cpu(get_unaligned(&desc->wMaxPacketSize)) !=
+            ep_maxpacket(ep)) || !get_unaligned(&desc->wMaxPacketSize)) {
 
                DEBUG("%s: bad %s maxpacket\n", __func__, _ep->name);
                return -ERANGE;
@@ -620,7 +622,7 @@ static int s3c_ep_enable(struct usb_ep *_ep,
        ep->stopped = 0;
        ep->desc = desc;
        ep->pio_irqs = 0;
-       ep->ep.maxpacket = le16_to_cpu(desc->wMaxPacketSize);
+       ep->ep.maxpacket = le16_to_cpu(get_unaligned(&desc->wMaxPacketSize));
 
        /* Reset halt state */
        s3c_udc_set_nak(ep);

diff --git a/include/usbdescriptors.h b/include/usbdescriptors.h
index 392fcf53780162fc87f6fbb58fdcb8496009111f..2dec3b93d65438cfc5c16ec4a1f04ee62a469ac7 100644 (file)
--- a/include/usbdescriptors.h
+++ b/include/usbdescriptors.h
@@ -199,7 +199,7 @@ struct usb_endpoint_descriptor {
        u8 bmAttributes;
        u16 wMaxPacketSize;
        u8 bInterval;
-} __attribute__ ((packed)) __attribute__ ((aligned(2)));
+} __attribute__ ((packed));
 
 struct usb_interface_descriptor {
        u8 bLength;