Create a new variant of snd_seq_expand_var_event() for expanding the data starting from the given byte offset. It'll be used by the new UMP sequencer code later.
Reviewed-by: Jaroslav Kysela perex@perex.cz Signed-off-by: Takashi Iwai tiwai@suse.de --- include/sound/seq_kernel.h | 2 + sound/core/seq/seq_memory.c | 86 +++++++++++++++++++++++++++++-------- 2 files changed, 69 insertions(+), 19 deletions(-)
diff --git a/include/sound/seq_kernel.h b/include/sound/seq_kernel.h index 658911926f3a..527e7f8ad661 100644 --- a/include/sound/seq_kernel.h +++ b/include/sound/seq_kernel.h @@ -70,6 +70,8 @@ int snd_seq_kernel_client_ctl(int client, unsigned int cmd, void *arg); typedef int (*snd_seq_dump_func_t)(void *ptr, void *buf, int count); int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf, int in_kernel, int size_aligned); +int snd_seq_expand_var_event_at(const struct snd_seq_event *event, int count, + char *buf, int offset); int snd_seq_dump_var_event(const struct snd_seq_event *event, snd_seq_dump_func_t func, void *private_data);
diff --git a/sound/core/seq/seq_memory.c b/sound/core/seq/seq_memory.c index c8d26bce69ff..a8d2db439f86 100644 --- a/sound/core/seq/seq_memory.c +++ b/sound/core/seq/seq_memory.c @@ -63,8 +63,9 @@ static int get_var_len(const struct snd_seq_event *event) return event->data.ext.len & ~SNDRV_SEQ_EXT_MASK; }
-int snd_seq_dump_var_event(const struct snd_seq_event *event, - snd_seq_dump_func_t func, void *private_data) +static int dump_var_event(const struct snd_seq_event *event, + snd_seq_dump_func_t func, void *private_data, + int offset, int maxlen) { int len, err; struct snd_seq_event_cell *cell; @@ -72,10 +73,16 @@ int snd_seq_dump_var_event(const struct snd_seq_event *event, len = get_var_len(event); if (len <= 0) return len; + if (len <= offset) + return 0; + if (maxlen && len > offset + maxlen) + len = offset + maxlen;
if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) { char buf[32]; char __user *curptr = (char __force __user *)event->data.ext.ptr; + curptr += offset; + len -= offset; while (len > 0) { int size = sizeof(buf); if (len < size) @@ -91,20 +98,35 @@ int snd_seq_dump_var_event(const struct snd_seq_event *event, return 0; } if (!(event->data.ext.len & SNDRV_SEQ_EXT_CHAINED)) - return func(private_data, event->data.ext.ptr, len); + return func(private_data, event->data.ext.ptr + offset, + len - offset);
cell = (struct snd_seq_event_cell *)event->data.ext.ptr; for (; len > 0 && cell; cell = cell->next) { int size = sizeof(struct snd_seq_event); + char *curptr = (char *)&cell->event; + + if (offset >= size) { + offset -= size; + len -= size; + continue; + } if (len < size) size = len; - err = func(private_data, &cell->event, size); + err = func(private_data, curptr + offset, size - offset); if (err < 0) return err; + offset = 0; len -= size; } return 0; } + +int snd_seq_dump_var_event(const struct snd_seq_event *event, + snd_seq_dump_func_t func, void *private_data) +{ + return dump_var_event(event, func, private_data, 0, 0); +} EXPORT_SYMBOL(snd_seq_dump_var_event);
@@ -132,11 +154,27 @@ static int seq_copy_in_user(void *ptr, void *src, int size) return 0; }
+static int expand_var_event(const struct snd_seq_event *event, + int offset, int size, char *buf, bool in_kernel) +{ + if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) { + if (! in_kernel) + return -EINVAL; + if (copy_from_user(buf, + (char __force __user *)event->data.ext.ptr + offset, + size)) + return -EFAULT; + return 0; + } + return dump_var_event(event, + in_kernel ? seq_copy_in_kernel : seq_copy_in_user, + &buf, offset, size); +} + int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf, int in_kernel, int size_aligned) { - int len, newlen; - int err; + int len, newlen, err;
len = get_var_len(event); if (len < 0) @@ -146,25 +184,35 @@ int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char newlen = roundup(len, size_aligned); if (count < newlen) return -EAGAIN; - - if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) { - if (! in_kernel) - return -EINVAL; - if (copy_from_user(buf, (void __force __user *)event->data.ext.ptr, len)) - return -EFAULT; - } else { - err = snd_seq_dump_var_event(event, - in_kernel ? seq_copy_in_kernel : seq_copy_in_user, - &buf); - if (err < 0) - return err; - } + err = expand_var_event(event, 0, len, buf, in_kernel); + if (err < 0) + return err; if (len != newlen) memset(buf + len, 0, newlen - len); return newlen; } EXPORT_SYMBOL(snd_seq_expand_var_event);
+int snd_seq_expand_var_event_at(const struct snd_seq_event *event, int count, + char *buf, int offset) +{ + int len, err; + + len = get_var_len(event); + if (len < 0) + return len; + if (len <= offset) + return 0; + len -= offset; + if (len > count) + len = count; + err = expand_var_event(event, offset, count, buf, true); + if (err < 0) + return err; + return len; +} +EXPORT_SYMBOL_GPL(snd_seq_expand_var_event_at); + /* * release this cell, free extended data if available */