[PATCH] sound/oss/emu10k1: handle userspace copy errors

Propagate copy_to/from_user() errors back through callers.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/sound/oss/emu10k1/audio.c b/sound/oss/emu10k1/audio.c
index 86dd239..49f902f 100644 (file)
--- a/sound/oss/emu10k1/audio.c
+++ b/sound/oss/emu10k1/audio.c
@@ -111,9 +111,15 @@ static ssize_t emu10k1_audio_read(struct file *file, char __user *buffer, size_t
 
                if ((bytestocopy >= wiinst->buffer.fragment_size)
                    || (bytestocopy >= count)) {
+                       int rc;
+
                        bytestocopy = min_t(u32, bytestocopy, count);
 
-                       emu10k1_wavein_xferdata(wiinst, (u8 __user *)buffer, &bytestocopy);
+                       rc = emu10k1_wavein_xferdata(wiinst,
+                                                    (u8 __user *)buffer,
+                                                    &bytestocopy);
+                       if (rc)
+                               return rc;
 
                        count -= bytestocopy;
                        buffer += bytestocopy;

diff --git a/sound/oss/emu10k1/cardwi.c b/sound/oss/emu10k1/cardwi.c
index 8bbf44b..060d1be 100644 (file)
--- a/sound/oss/emu10k1/cardwi.c
+++ b/sound/oss/emu10k1/cardwi.c
@@ -304,11 +304,12 @@ void emu10k1_wavein_getxfersize(struct wiinst *wiinst, u32 * size)
        }
 }
 
-static void copy_block(u8 __user *dst, u8 * src, u32 str, u32 len, u8 cov)
+static int copy_block(u8 __user *dst, u8 * src, u32 str, u32 len, u8 cov)
 {
-       if (cov == 1)
-               __copy_to_user(dst, src + str, len);
-       else {
+       if (cov == 1) {
+               if (__copy_to_user(dst, src + str, len))
+                       return -EFAULT;
+       } else {
                u8 byte;
                u32 i;
 
@@ -316,22 +317,26 @@ static void copy_block(u8 __user *dst, u8 * src, u32 str, u32 len, u8 cov)
 
                for (i = 0; i < len; i++) {
                        byte = src[2 * i] ^ 0x80;
-                       __copy_to_user(dst + i, &byte, 1);
+                       if (__copy_to_user(dst + i, &byte, 1))
+                               return -EFAULT;
                }
        }
+
+       return 0;
 }
 
-void emu10k1_wavein_xferdata(struct wiinst *wiinst, u8 __user *data, u32 * size)
+int emu10k1_wavein_xferdata(struct wiinst *wiinst, u8 __user *data, u32 * size)
 {
        struct wavein_buffer *buffer = &wiinst->buffer;
        u32 sizetocopy, sizetocopy_now, start;
        unsigned long flags;
+       int ret;
 
        sizetocopy = min_t(u32, buffer->size, *size);
        *size = sizetocopy;
 
        if (!sizetocopy)
-               return;
+               return 0;
 
        spin_lock_irqsave(&wiinst->lock, flags);
        start = buffer->pos;
@@ -345,11 +350,17 @@ void emu10k1_wavein_xferdata(struct wiinst *wiinst, u8 __user *data, u32 * size)
        if (sizetocopy > sizetocopy_now) {
                sizetocopy -= sizetocopy_now;
 
-               copy_block(data, buffer->addr, start, sizetocopy_now, buffer->cov);
-               copy_block(data + sizetocopy_now, buffer->addr, 0, sizetocopy, buffer->cov);
+               ret = copy_block(data, buffer->addr, start, sizetocopy_now,
+                                buffer->cov);
+               if (ret == 0)
+                       ret = copy_block(data + sizetocopy_now, buffer->addr, 0,
+                                        sizetocopy, buffer->cov);
        } else {
-               copy_block(data, buffer->addr, start, sizetocopy, buffer->cov);
+               ret = copy_block(data, buffer->addr, start, sizetocopy,
+                                buffer->cov);
        }
+
+       return ret;
 }
 
 void emu10k1_wavein_update(struct emu10k1_card *card, struct wiinst *wiinst)

diff --git a/sound/oss/emu10k1/cardwi.h b/sound/oss/emu10k1/cardwi.h
index 15cfb9b..e82029b 100644 (file)
--- a/sound/oss/emu10k1/cardwi.h
+++ b/sound/oss/emu10k1/cardwi.h
@@ -83,7 +83,7 @@ void emu10k1_wavein_close(struct emu10k1_wavedevice *);
 void emu10k1_wavein_start(struct emu10k1_wavedevice *);
 void emu10k1_wavein_stop(struct emu10k1_wavedevice *);
 void emu10k1_wavein_getxfersize(struct wiinst *, u32 *);
-void emu10k1_wavein_xferdata(struct wiinst *, u8 __user *, u32 *);
+int emu10k1_wavein_xferdata(struct wiinst *, u8 __user *, u32 *);
 int emu10k1_wavein_setformat(struct emu10k1_wavedevice *, struct wave_format *);
 void emu10k1_wavein_update(struct emu10k1_card *, struct wiinst *);
 

diff --git a/sound/oss/emu10k1/passthrough.c b/sound/oss/emu10k1/passthrough.c
index 4e3baca..6d21d43 100644 (file)
--- a/sound/oss/emu10k1/passthrough.c
+++ b/sound/oss/emu10k1/passthrough.c
@@ -162,12 +162,15 @@ ssize_t emu10k1_pt_write(struct file *file, const char __user *buffer, size_t co
 
                DPD(3, "prepend size %d, prepending %d bytes\n", pt->prepend_size, needed);
                if (count < needed) {
-                       copy_from_user(pt->buf + pt->prepend_size, buffer, count);
+                       if (copy_from_user(pt->buf + pt->prepend_size,
+                                          buffer, count))
+                               return -EFAULT;
                        pt->prepend_size += count;
                        DPD(3, "prepend size now %d\n", pt->prepend_size);
                        return count;
                }
-               copy_from_user(pt->buf + pt->prepend_size, buffer, needed);
+               if (copy_from_user(pt->buf + pt->prepend_size, buffer, needed))
+                       return -EFAULT;
                r = pt_putblock(wave_dev, (u16 *) pt->buf, nonblock);
                if (r)
                        return r;
@@ -178,7 +181,8 @@ ssize_t emu10k1_pt_write(struct file *file, const char __user *buffer, size_t co
        blocks_copied = 0;
        while (blocks > 0) {
                u16 __user *bufptr = (u16 __user *) buffer + (bytes_copied/2);
-               copy_from_user(pt->buf, bufptr, PT_BLOCKSIZE);
+               if (copy_from_user(pt->buf, bufptr, PT_BLOCKSIZE))
+                       return -EFAULT;
                r = pt_putblock(wave_dev, (u16 *)pt->buf, nonblock);
                if (r) {
                        if (bytes_copied)
@@ -193,7 +197,8 @@ ssize_t emu10k1_pt_write(struct file *file, const char __user *buffer, size_t co
        i = count - bytes_copied;
        if (i) {
                pt->prepend_size = i;
-               copy_from_user(pt->buf, buffer + bytes_copied, i);
+               if (copy_from_user(pt->buf, buffer + bytes_copied, i))
+                       return -EFAULT;
                bytes_copied += i;
                DPD(3, "filling prepend buffer with %d bytes", i);
        }