'struct snd_timer_gparams' includes some members with 'unsigned long', therefore its size differs depending on data models (ILP32/LP64). As a result, x86/x32 applications fail to execute ioctl(2) with SNDRV_TIMER_GPARAMS on x86_64 machine.
This commit fixes this bug by adding a pair of structure and ioctl command for the compatibility.
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- sound/core/timer_compat.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-)
diff --git a/sound/core/timer_compat.c b/sound/core/timer_compat.c index 2e90822..5809387 100644 --- a/sound/core/timer_compat.c +++ b/sound/core/timer_compat.c @@ -22,6 +22,18 @@
#include <linux/compat.h>
+/* + * In LP64, 64 bit storage alignment is used, therefore the size of this + * structure is expanded to multiple of 8. But the size should be aligned to + * multiple of 4 for ILP32. This is a reason to use 'packed' attribute. + */ +struct snd_timer_gparams32 { + struct snd_timer_id tid; + u32 period_num; + u32 period_den; + unsigned char reserved[32]; +}__attribute__((packed)); + struct snd_timer_info32 { u32 flags; s32 card; @@ -32,6 +44,19 @@ struct snd_timer_info32 { unsigned char reserved[64]; };
+static int snd_timer_user_gparams_compat(struct file *file, + struct snd_timer_gparams32 __user *user) +{ + struct snd_timer_gparams gparams; + + if (copy_from_user(&gparams, user, + sizeof(struct snd_timer_id) + sizeof(u32) + sizeof(u32))) + return -EFAULT; + + return snd_timer_user_gparams(file, + (struct snd_timer_gparams __user *)&gparams); +} + static int snd_timer_user_info_compat(struct file *file, struct snd_timer_info32 __user *_info) { @@ -99,6 +124,7 @@ static int snd_timer_user_status_compat(struct file *file, */
enum { + SNDRV_TIMER_IOCTL_GPARAMS32 = _IOR('T', 0x04, struct snd_timer_gparams32), SNDRV_TIMER_IOCTL_INFO32 = _IOR('T', 0x11, struct snd_timer_info32), SNDRV_TIMER_IOCTL_STATUS32 = _IOW('T', 0x14, struct snd_timer_status32), #ifdef CONFIG_X86_X32 @@ -114,7 +140,6 @@ static long snd_timer_user_ioctl_compat(struct file *file, unsigned int cmd, uns case SNDRV_TIMER_IOCTL_PVERSION: case SNDRV_TIMER_IOCTL_TREAD: case SNDRV_TIMER_IOCTL_GINFO: - case SNDRV_TIMER_IOCTL_GPARAMS: case SNDRV_TIMER_IOCTL_GSTATUS: case SNDRV_TIMER_IOCTL_SELECT: case SNDRV_TIMER_IOCTL_PARAMS: @@ -128,6 +153,8 @@ static long snd_timer_user_ioctl_compat(struct file *file, unsigned int cmd, uns case SNDRV_TIMER_IOCTL_PAUSE_OLD: case SNDRV_TIMER_IOCTL_NEXT_DEVICE: return snd_timer_user_ioctl(file, cmd, (unsigned long)argp); + case SNDRV_TIMER_IOCTL_GPARAMS32: + return snd_timer_user_gparams_compat(file, argp); case SNDRV_TIMER_IOCTL_INFO32: return snd_timer_user_info_compat(file, argp); case SNDRV_TIMER_IOCTL_STATUS32: