[RFC PATCH 4/7] sound: core: Avoid using timespec for struct snd_rawmidi_status

From: Baolin Wang
Date: Thu Sep 21 2017 - 02:18:56 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. 'struct compat_snd_rawmidi_status32' and
snd_rawmidi_ioctl_status_compat() are used to handle 32bit time_t in compat mode.
'struct compat_snd_rawmidi_status64' and snd_rawmidi_ioctl_status_compat64() are used
to handle 64bit time_t with 64bit alignment. 'struct compat_snd_rawmidi_status64_x86_32'
and snd_rawmidi_ioctl_status_compat64_x86_32() are used to handle 64bit time_t with
32bit alignment.

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>
---
sound/core/rawmidi.c | 74 ++++++++++++++++++++++++++++++++---
sound/core/rawmidi_compat.c | 90 ++++++++++++++++++++++++++++++++-----------
2 files changed, 135 insertions(+), 29 deletions(-)

diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index b3b353d..7afb1a4 100644
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -63,6 +63,28 @@
#define rmidi_dbg(rmidi, fmt, args...) \
dev_dbg(&(rmidi)->dev, fmt, ##args)

+#if __BITS_PER_LONG == 32
+struct snd_rawmidi_status32 {
+ int stream;
+ struct { s32 tv_sec; s32 tv_nsec; } tstamp; /* Timestamp */
+ 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_STATUS32 _IOWR('W', 0x20, struct snd_rawmidi_status32)
+#endif
+
+struct snd_rawmidi_status64 {
+ int stream;
+ struct { s64 tv_sec; s64 tv_nsec; } tstamp; /* Timestamp */
+ 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;
@@ -680,7 +702,7 @@ 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;

@@ -693,7 +715,7 @@ 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;

@@ -751,11 +773,50 @@ static long snd_rawmidi_ioctl(struct file *file, unsigned int cmd, unsigned long
return -EINVAL;
}
}
- case SNDRV_RAWMIDI_IOCTL_STATUS:
+#if __BITS_PER_LONG == 32
+ case SNDRV_RAWMIDI_IOCTL_STATUS32:
+ {
+ 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;
+
+ if (put_user(status64.stream, &status->stream) ||
+ put_user(status64.tstamp.tv_sec, &status->tstamp.tv_sec) ||
+ put_user(status64.tstamp.tv_nsec, &status->tstamp.tv_nsec) ||
+ put_user(status64.avail, &status->avail) ||
+ put_user(status64.xruns, &status->xruns))
+ return -EFAULT;
+ return 0;
+ }
+#endif
+ case SNDRV_RAWMIDI_IOCTL_STATUS64:
{
int err = 0;
- struct snd_rawmidi_status status;
- if (copy_from_user(&status, argp, sizeof(struct snd_rawmidi_status)))
+ 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:
@@ -773,7 +834,8 @@ static long snd_rawmidi_ioctl(struct file *file, unsigned int cmd, unsigned long
}
if (err < 0)
return err;
- if (copy_to_user(argp, &status, sizeof(struct snd_rawmidi_status)))
+ if (copy_to_user(argp, &status,
+ sizeof(struct snd_rawmidi_status64)))
return -EFAULT;
return 0;
}
diff --git a/sound/core/rawmidi_compat.c b/sound/core/rawmidi_compat.c
index f69764d..4b5a612 100644
--- a/sound/core/rawmidi_compat.c
+++ b/sound/core/rawmidi_compat.c
@@ -53,7 +53,7 @@ static int snd_rawmidi_ioctl_params_compat(struct snd_rawmidi_file *rfile,
return -EINVAL;
}

-struct snd_rawmidi_status32 {
+struct compat_snd_rawmidi_status32 {
s32 stream;
struct compat_timespec tstamp;
u32 avail;
@@ -62,10 +62,10 @@ struct snd_rawmidi_status32 {
} __attribute__((packed));

static int snd_rawmidi_ioctl_status_compat(struct snd_rawmidi_file *rfile,
- struct snd_rawmidi_status32 __user *src)
+ struct compat_snd_rawmidi_status32 __user *src)
{
int err;
- struct snd_rawmidi_status status;
+ struct snd_rawmidi_status64 status;

if (rfile->output == NULL)
return -EINVAL;
@@ -85,7 +85,8 @@ 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) ||
+ if (put_user(status.tstamp.tv_sec, &src->tstamp.tv_sec) ||
+ put_user(status.tstamp.tv_nsec, &src->tstamp.tv_nsec) ||
put_user(status.avail, &src->avail) ||
put_user(status.xruns, &src->xruns))
return -EFAULT;
@@ -93,24 +94,63 @@ static int snd_rawmidi_ioctl_status_compat(struct snd_rawmidi_file *rfile,
return 0;
}

-#ifdef CONFIG_X86_X32
-/* X32 ABI has 64bit timespec and 64bit alignment */
-struct snd_rawmidi_status_x32 {
+struct compat_snd_rawmidi_status64 {
s32 stream;
u32 rsvd; /* alignment */
- struct timespec tstamp;
+ struct { s64 tv_sec; s64 tv_nsec; } 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_compat64(struct snd_rawmidi_file *rfile,
+ struct compat_snd_rawmidi_status64 __user *src)
+{
+ int err;
+ struct snd_rawmidi_status64 status;
+
+ if (rfile->output == NULL)
+ return -EINVAL;
+ if (get_user(status.stream, &src->stream))
+ return -EFAULT;
+
+ switch (status.stream) {
+ case SNDRV_RAWMIDI_STREAM_OUTPUT:
+ err = snd_rawmidi_output_status(rfile->output, &status);
+ break;
+ case SNDRV_RAWMIDI_STREAM_INPUT:
+ err = snd_rawmidi_input_status(rfile->input, &status);
+ break;
+ default:
+ return -EINVAL;
+ }
+ if (err < 0)
+ return err;
+
+ if (put_user(status.tstamp.tv_sec, &src->tstamp.tv_sec) ||
+ put_user(status.tstamp.tv_nsec, &src->tstamp.tv_nsec) ||
+ put_user(status.avail, &src->avail) ||
+ put_user(status.xruns, &src->xruns))
+ return -EFAULT;
+
+ return 0;
+}
+
+#ifdef IA32_EMULATION
+struct compat_snd_rawmidi_status64_x86_32 {
+ s32 stream;
+ struct { s64 tv_sec; s64 tv_nsec; } tstamp;
+ u32 avail;
+ u32 xruns;
+ unsigned char reserved[16];
+} __attribute__((packed));

-static int snd_rawmidi_ioctl_status_x32(struct snd_rawmidi_file *rfile,
- struct snd_rawmidi_status_x32 __user *src)
+static int
+snd_rawmidi_ioctl_status_compat64_x86_32(struct snd_rawmidi_file *rfile,
+ struct compat_snd_rawmidi_status64_x86_32 __user *src)
{
int err;
- struct snd_rawmidi_status status;
+ struct snd_rawmidi_status64 status;

if (rfile->output == NULL)
return -EINVAL;
@@ -130,21 +170,23 @@ static int snd_rawmidi_ioctl_status_x32(struct snd_rawmidi_file *rfile,
if (err < 0)
return err;

- if (put_timespec(&status.tstamp, &src->tstamp) ||
+ if (put_user(status.tstamp.tv_sec, &src->tstamp.tv_sec) ||
+ put_user(status.tstamp.tv_nsec, &src->tstamp.tv_nsec) ||
put_user(status.avail, &src->avail) ||
put_user(status.xruns, &src->xruns))
return -EFAULT;

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

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 compat_snd_rawmidi_status32),
+ SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT64 = _IOWR('W', 0x20, struct compat_snd_rawmidi_status64),
+#ifdef IA32_EMULATION
+ SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT64_X86_32 = _IOWR('W', 0x20, struct compat_snd_rawmidi_status64_x86_32),
+#endif
};

static long snd_rawmidi_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
@@ -161,12 +203,14 @@ 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:
+ case SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT32:
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_COMPAT64:
+ return snd_rawmidi_ioctl_status_compat64(rfile, argp);
+#ifdef IA32_EMULATION
+ case SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT64_X86_32:
+ return snd_rawmidi_ioctl_status_compat64_x86_32(rfile, argp);
+#endif
}
return -ENOIOCTLCMD;
}
--
1.7.9.5