sound/core/seq/seq_compat.c
Source file repositories/reference/linux-study-clean/sound/core/seq/seq_compat.c
File Facts
- System
- Linux kernel
- Corpus path
sound/core/seq/seq_compat.c- Extension
.c- Size
- 4096 bytes
- Lines
- 124
- Domain
- Driver Families
- Bucket
- sound/core
- Inferred role
- Driver Families: implementation source
- Status
- source implementation candidate
Why This File Exists
Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Touches user memory; correctness depends on fault-safe copying and privilege boundary handling.
- Allocates kernel memory; connect allocation flags and lifetime to context constraints.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/compat.hlinux/slab.h
Detected Declarations
struct snd_seq_port_info32function snd_seq_call_port_info_ioctlfunction snd_seq_ioctl_compat
Annotated Snippet
struct snd_seq_port_info32 {
struct snd_seq_addr addr; /* client/port numbers */
char name[64]; /* port name */
u32 capability; /* port capability bits */
u32 type; /* port type bits */
s32 midi_channels; /* channels per MIDI port */
s32 midi_voices; /* voices per MIDI port */
s32 synth_voices; /* voices per SYNTH port */
s32 read_use; /* R/O: subscribers for output (from this port) */
s32 write_use; /* R/O: subscribers for input (to this port) */
u32 kernel; /* reserved for kernel use (must be NULL) */
u32 flags; /* misc. conditioning */
unsigned char time_queue; /* queue # for timestamping */
char reserved[59]; /* for future use */
};
static int snd_seq_call_port_info_ioctl(struct snd_seq_client *client, unsigned int cmd,
struct snd_seq_port_info32 __user *data32)
{
int err;
struct snd_seq_port_info *data __free(kfree) =
kmalloc_obj(*data);
if (!data)
return -ENOMEM;
if (copy_from_user(data, data32, sizeof(*data32)) ||
get_user(data->flags, &data32->flags) ||
get_user(data->time_queue, &data32->time_queue))
return -EFAULT;
data->kernel = NULL;
err = snd_seq_kernel_client_ctl(client->number, cmd, data);
if (err < 0)
return err;
if (copy_to_user(data32, data, sizeof(*data32)) ||
put_user(data->flags, &data32->flags) ||
put_user(data->time_queue, &data32->time_queue))
return -EFAULT;
return err;
}
/*
*/
enum {
SNDRV_SEQ_IOCTL_CREATE_PORT32 = _IOWR('S', 0x20, struct snd_seq_port_info32),
SNDRV_SEQ_IOCTL_DELETE_PORT32 = _IOW ('S', 0x21, struct snd_seq_port_info32),
SNDRV_SEQ_IOCTL_GET_PORT_INFO32 = _IOWR('S', 0x22, struct snd_seq_port_info32),
SNDRV_SEQ_IOCTL_SET_PORT_INFO32 = _IOW ('S', 0x23, struct snd_seq_port_info32),
SNDRV_SEQ_IOCTL_QUERY_NEXT_PORT32 = _IOWR('S', 0x52, struct snd_seq_port_info32),
};
static long snd_seq_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
{
struct snd_seq_client *client = file->private_data;
void __user *argp = compat_ptr(arg);
if (snd_BUG_ON(!client))
return -ENXIO;
switch (cmd) {
case SNDRV_SEQ_IOCTL_PVERSION:
case SNDRV_SEQ_IOCTL_USER_PVERSION:
case SNDRV_SEQ_IOCTL_CLIENT_ID:
case SNDRV_SEQ_IOCTL_SYSTEM_INFO:
case SNDRV_SEQ_IOCTL_GET_CLIENT_INFO:
case SNDRV_SEQ_IOCTL_SET_CLIENT_INFO:
case SNDRV_SEQ_IOCTL_GET_CLIENT_UMP_INFO:
case SNDRV_SEQ_IOCTL_SET_CLIENT_UMP_INFO:
case SNDRV_SEQ_IOCTL_SUBSCRIBE_PORT:
case SNDRV_SEQ_IOCTL_UNSUBSCRIBE_PORT:
case SNDRV_SEQ_IOCTL_CREATE_QUEUE:
case SNDRV_SEQ_IOCTL_DELETE_QUEUE:
case SNDRV_SEQ_IOCTL_GET_QUEUE_INFO:
case SNDRV_SEQ_IOCTL_SET_QUEUE_INFO:
case SNDRV_SEQ_IOCTL_GET_NAMED_QUEUE:
case SNDRV_SEQ_IOCTL_GET_QUEUE_STATUS:
case SNDRV_SEQ_IOCTL_GET_QUEUE_TEMPO:
case SNDRV_SEQ_IOCTL_SET_QUEUE_TEMPO:
case SNDRV_SEQ_IOCTL_GET_QUEUE_TIMER:
case SNDRV_SEQ_IOCTL_SET_QUEUE_TIMER:
case SNDRV_SEQ_IOCTL_GET_QUEUE_CLIENT:
Annotation
- Immediate include surface: `linux/compat.h`, `linux/slab.h`.
- Detected declarations: `struct snd_seq_port_info32`, `function snd_seq_call_port_info_ioctl`, `function snd_seq_ioctl_compat`.
- Atlas domain: Driver Families / sound/core.
- Implementation status: source implementation candidate.
- This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.