[PATCH 5/8] ALSA: Avoid using timespec for struct snd_rawmidi_status

From: Baolin Wang
Date: Tue Apr 24 2018 - 08:08:55 EST


The struct snd_rawmidi_status will use 'timespec' type variables to record
timestamp, which is not year 2038 safe on 32bits system.

Thus we introduced 'struct snd_rawmidi_status32' and 'struct snd_rawmidi_status64'
to handle 32bit time_t and 64bit time_t in native mode, which replace
timespec with s64 type.

In compat mode, we renamed or introduced new structures to handle 32bit/64bit
time_t in compatible mode. The 'struct snd_rawmidi_status32' and
snd_rawmidi_ioctl_status32() are used to handle 32bit time_t in compat mode.
'struct compat_snd_rawmidi_status64' is used to handle 64bit time_t.

When glibc changes time_t to 64-bit, any recompiled program will issue ioctl
commands that the kernel does not understand without this patch.

Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
---
include/uapi/sound/asound.h | 1 +
sound/core/rawmidi.c | 131 ++++++++++++++++++++++++++++++++++---------
sound/core/rawmidi_compat.c | 87 ++++++++--------------------
3 files changed, 126 insertions(+), 93 deletions(-)

diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h
index c9afde4..fad66ad 100644
--- a/include/uapi/sound/asound.h
+++ b/include/uapi/sound/asound.h
@@ -650,6 +650,7 @@ struct snd_rawmidi_params {

struct snd_rawmidi_status {
int stream;
+ unsigned char pad1[sizeof(time_t) - sizeof(int)];
struct timespec tstamp; /* Timestamp */
size_t avail; /* available bytes */
size_t xruns; /* count of overruns since last status (in bytes) */
diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index 69616d0..421b899 100644
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -63,6 +63,29 @@
#define rmidi_dbg(rmidi, fmt, args...) \
dev_dbg(&(rmidi)->dev, fmt, ##args)

+struct snd_rawmidi_status32 {
+ s32 stream;
+ s32 tstamp_sec; /* Timestamp */
+ s32 tstamp_nsec;
+ u32 avail; /* available bytes */
+ u32 xruns; /* count of overruns since last status (in bytes) */
+ unsigned char reserved[16]; /* reserved for future use */
+};
+
+#define SNDRV_RAWMIDI_IOCTL_STATUS32 _IOWR('W', 0x20, struct snd_rawmidi_status32)
+
+struct snd_rawmidi_status64 {
+ int stream;
+ u8 rsvd[sizeof(time_t) - sizeof(int)]; /* alignment */
+ s64 tstamp_sec; /* Timestamp */
+ s64 tstamp_nsec;
+ size_t avail; /* available bytes */
+ size_t xruns; /* count of overruns since last status (in bytes) */
+ unsigned char reserved[16]; /* reserved for future use */
+};
+
+#define SNDRV_RAWMIDI_IOCTL_STATUS64 _IOWR('W', 0x20, struct snd_rawmidi_status64)
+
static struct snd_rawmidi *snd_rawmidi_search(struct snd_card *card, int device)
{
struct snd_rawmidi *rawmidi;
@@ -689,7 +712,7 @@ int snd_rawmidi_input_params(struct snd_rawmidi_substream *substream,
EXPORT_SYMBOL(snd_rawmidi_input_params);

static int snd_rawmidi_output_status(struct snd_rawmidi_substream *substream,
- struct snd_rawmidi_status * status)
+ struct snd_rawmidi_status64 * status)
{
struct snd_rawmidi_runtime *runtime = substream->runtime;

@@ -702,7 +725,7 @@ static int snd_rawmidi_output_status(struct snd_rawmidi_substream *substream,
}

static int snd_rawmidi_input_status(struct snd_rawmidi_substream *substream,
- struct snd_rawmidi_status * status)
+ struct snd_rawmidi_status64 * status)
{
struct snd_rawmidi_runtime *runtime = substream->runtime;

@@ -716,6 +739,80 @@ static int snd_rawmidi_input_status(struct snd_rawmidi_substream *substream,
return 0;
}

+static int snd_rawmidi_ioctl_status32(struct snd_rawmidi_file *rfile,
+ struct snd_rawmidi_status32 __user *argp)
+{
+ int err = 0;
+ struct snd_rawmidi_status32 __user *status = argp;
+ struct snd_rawmidi_status32 status32;
+ struct snd_rawmidi_status64 status64;
+
+ if (copy_from_user(&status32, argp,
+ sizeof(struct snd_rawmidi_status32)))
+ return -EFAULT;
+
+ switch (status32.stream) {
+ case SNDRV_RAWMIDI_STREAM_OUTPUT:
+ if (rfile->output == NULL)
+ return -EINVAL;
+ err = snd_rawmidi_output_status(rfile->output, &status64);
+ break;
+ case SNDRV_RAWMIDI_STREAM_INPUT:
+ if (rfile->input == NULL)
+ return -EINVAL;
+ err = snd_rawmidi_input_status(rfile->input, &status64);
+ break;
+ default:
+ return -EINVAL;
+ }
+ if (err < 0)
+ return err;
+
+ status32 = (struct snd_rawmidi_status32) {
+ .stream = status64.stream,
+ .tstamp_sec = status64.tstamp_sec,
+ .tstamp_nsec = status64.tstamp_nsec,
+ .avail = status64.avail,
+ .xruns = status64.xruns,
+ };
+
+ if (copy_to_user(status, &status32, sizeof(*status)))
+ return -EFAULT;
+
+ return 0;
+}
+
+static int snd_rawmidi_ioctl_status64(struct snd_rawmidi_file *rfile,
+ struct snd_rawmidi_status64 __user *argp)
+{
+ int err = 0;
+ struct snd_rawmidi_status64 status;
+
+ if (copy_from_user(&status, argp, sizeof(struct snd_rawmidi_status64)))
+ return -EFAULT;
+
+ switch (status.stream) {
+ case SNDRV_RAWMIDI_STREAM_OUTPUT:
+ if (rfile->output == NULL)
+ return -EINVAL;
+ err = snd_rawmidi_output_status(rfile->output, &status);
+ break;
+ case SNDRV_RAWMIDI_STREAM_INPUT:
+ if (rfile->input == NULL)
+ return -EINVAL;
+ err = snd_rawmidi_input_status(rfile->input, &status);
+ break;
+ default:
+ return -EINVAL;
+ }
+ if (err < 0)
+ return err;
+ if (copy_to_user(argp, &status,
+ sizeof(struct snd_rawmidi_status64)))
+ return -EFAULT;
+ return 0;
+}
+
static long snd_rawmidi_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct snd_rawmidi_file *rfile;
@@ -760,32 +857,10 @@ static long snd_rawmidi_ioctl(struct file *file, unsigned int cmd, unsigned long
return -EINVAL;
}
}
- case SNDRV_RAWMIDI_IOCTL_STATUS:
- {
- int err = 0;
- struct snd_rawmidi_status status;
- if (copy_from_user(&status, argp, sizeof(struct snd_rawmidi_status)))
- return -EFAULT;
- switch (status.stream) {
- case SNDRV_RAWMIDI_STREAM_OUTPUT:
- if (rfile->output == NULL)
- return -EINVAL;
- err = snd_rawmidi_output_status(rfile->output, &status);
- break;
- case SNDRV_RAWMIDI_STREAM_INPUT:
- if (rfile->input == NULL)
- return -EINVAL;
- err = snd_rawmidi_input_status(rfile->input, &status);
- break;
- default:
- return -EINVAL;
- }
- if (err < 0)
- return err;
- if (copy_to_user(argp, &status, sizeof(struct snd_rawmidi_status)))
- return -EFAULT;
- return 0;
- }
+ case SNDRV_RAWMIDI_IOCTL_STATUS32:
+ return snd_rawmidi_ioctl_status32(rfile, argp);
+ case SNDRV_RAWMIDI_IOCTL_STATUS64:
+ return snd_rawmidi_ioctl_status64(rfile, argp);
case SNDRV_RAWMIDI_IOCTL_DROP:
{
int val;
diff --git a/sound/core/rawmidi_compat.c b/sound/core/rawmidi_compat.c
index e30e30b..c817441 100644
--- a/sound/core/rawmidi_compat.c
+++ b/sound/core/rawmidi_compat.c
@@ -55,19 +55,22 @@ static int snd_rawmidi_ioctl_params_compat(struct snd_rawmidi_file *rfile,
return -EINVAL;
}

-struct snd_rawmidi_status32 {
+struct compat_snd_rawmidi_status64 {
s32 stream;
- struct compat_timespec tstamp;
+ u8 rsvd[sizeof(time_t) - sizeof(s32)]; /* alignment */
+ s64 tstamp_sec;
+ s64 tstamp_nsec;
u32 avail;
u32 xruns;
unsigned char reserved[16];
} __attribute__((packed));

-static int snd_rawmidi_ioctl_status_compat(struct snd_rawmidi_file *rfile,
- struct snd_rawmidi_status32 __user *src)
+static int snd_rawmidi_ioctl_status_compat64(struct snd_rawmidi_file *rfile,
+ struct compat_snd_rawmidi_status64 __user *src)
{
int err;
- struct snd_rawmidi_status status;
+ struct snd_rawmidi_status64 status;
+ struct compat_snd_rawmidi_status64 compat_status;

if (get_user(status.stream, &src->stream))
return -EFAULT;
@@ -89,68 +92,24 @@ static int snd_rawmidi_ioctl_status_compat(struct snd_rawmidi_file *rfile,
if (err < 0)
return err;

- if (compat_put_timespec(&status.tstamp, &src->tstamp) ||
- put_user(status.avail, &src->avail) ||
- put_user(status.xruns, &src->xruns))
- return -EFAULT;
-
- return 0;
-}
-
-#ifdef CONFIG_X86_X32
-/* X32 ABI has 64bit timespec and 64bit alignment */
-struct snd_rawmidi_status_x32 {
- s32 stream;
- u32 rsvd; /* alignment */
- struct timespec tstamp;
- u32 avail;
- u32 xruns;
- unsigned char reserved[16];
-} __attribute__((packed));
-
-#define put_timespec(src, dst) copy_to_user(dst, src, sizeof(*dst))
-
-static int snd_rawmidi_ioctl_status_x32(struct snd_rawmidi_file *rfile,
- struct snd_rawmidi_status_x32 __user *src)
-{
- int err;
- struct snd_rawmidi_status status;
-
- if (get_user(status.stream, &src->stream))
- return -EFAULT;
-
- switch (status.stream) {
- case SNDRV_RAWMIDI_STREAM_OUTPUT:
- if (!rfile->output)
- return -EINVAL;
- err = snd_rawmidi_output_status(rfile->output, &status);
- break;
- case SNDRV_RAWMIDI_STREAM_INPUT:
- if (!rfile->input)
- return -EINVAL;
- err = snd_rawmidi_input_status(rfile->input, &status);
- break;
- default:
- return -EINVAL;
- }
- if (err < 0)
- return err;
+ compat_status = (struct compat_snd_rawmidi_status64) {
+ .stream = status.stream,
+ .tstamp_sec = status.tstamp_sec,
+ .tstamp_nsec = status.tstamp_nsec,
+ .avail = status.avail,
+ .xruns = status.xruns,
+ };

- if (put_timespec(&status.tstamp, &src->tstamp) ||
- put_user(status.avail, &src->avail) ||
- put_user(status.xruns, &src->xruns))
+ if (copy_to_user(src, &compat_status, sizeof(*src)))
return -EFAULT;

return 0;
}
-#endif /* CONFIG_X86_X32 */

enum {
SNDRV_RAWMIDI_IOCTL_PARAMS32 = _IOWR('W', 0x10, struct snd_rawmidi_params32),
- SNDRV_RAWMIDI_IOCTL_STATUS32 = _IOWR('W', 0x20, struct snd_rawmidi_status32),
-#ifdef CONFIG_X86_X32
- SNDRV_RAWMIDI_IOCTL_STATUS_X32 = _IOWR('W', 0x20, struct snd_rawmidi_status_x32),
-#endif /* CONFIG_X86_X32 */
+ SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT32 = _IOWR('W', 0x20, struct snd_rawmidi_status32),
+ SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT64 = _IOWR('W', 0x20, struct compat_snd_rawmidi_status64),
};

static long snd_rawmidi_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
@@ -167,12 +126,10 @@ static long snd_rawmidi_ioctl_compat(struct file *file, unsigned int cmd, unsign
return snd_rawmidi_ioctl(file, cmd, (unsigned long)argp);
case SNDRV_RAWMIDI_IOCTL_PARAMS32:
return snd_rawmidi_ioctl_params_compat(rfile, argp);
- case SNDRV_RAWMIDI_IOCTL_STATUS32:
- return snd_rawmidi_ioctl_status_compat(rfile, argp);
-#ifdef CONFIG_X86_X32
- case SNDRV_RAWMIDI_IOCTL_STATUS_X32:
- return snd_rawmidi_ioctl_status_x32(rfile, argp);
-#endif /* CONFIG_X86_X32 */
+ case SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT32:
+ return snd_rawmidi_ioctl_status32(rfile, argp);
+ case SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT64:
+ return snd_rawmidi_ioctl_status_compat64(rfile, argp);
}
return -ENOIOCTLCMD;
}
--
1.7.9.5