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media: v4l2-core: fix compat v4l2_buffer handling for time64 ABI
authorArnd Bergmann <arnd@arndb.de>
Mon, 16 Dec 2019 14:15:06 +0000 (15:15 +0100)
committerMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Fri, 3 Jan 2020 14:53:46 +0000 (15:53 +0100)
Add support for the four new variants of ioctl commands for 64-bit time_t
in v4l2_buffer.

The existing v4l2_buffer32 structure for the traditional format gets
changed to match the new v4l2_buffer format, and the old layout is
now called v4l2_buffer32_time32. Neither of these matches the native
64-bit architecture format of v4l2_buffer, so both require special
handling in compat code.

Duplicating the existing handlers for the new types is a safe conversion
for now, but unfortunately this may turn into a maintenance burden
later. A larger-scale rework of the compat code might be a better
alternative, but is out of scope of the y2038 work.

Note: x32 support for v4l2_buffer32 has always been broken and remains
so after this change, fixing it would have required even more duplication,
and apparently nobody has cared so far.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil-cisco@xs4all.nl: remove spurious newline]
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
drivers/media/v4l2-core/v4l2-compat-ioctl32.c

index f8a4b0d..a99e82e 100644 (file)
@@ -468,13 +468,43 @@ struct v4l2_plane32 {
        __u32                   reserved[11];
 };
 
+/*
+ * This is correct for all architectures including i386, but not x32,
+ * which has different alignment requirements for timestamp
+ */
 struct v4l2_buffer32 {
        __u32                   index;
        __u32                   type;   /* enum v4l2_buf_type */
        __u32                   bytesused;
        __u32                   flags;
        __u32                   field;  /* enum v4l2_field */
-       struct compat_timeval   timestamp;
+       struct {
+               compat_s64      tv_sec;
+               compat_s64      tv_usec;
+       }                       timestamp;
+       struct v4l2_timecode    timecode;
+       __u32                   sequence;
+
+       /* memory location */
+       __u32                   memory; /* enum v4l2_memory */
+       union {
+               __u32           offset;
+               compat_long_t   userptr;
+               compat_caddr_t  planes;
+               __s32           fd;
+       } m;
+       __u32                   length;
+       __u32                   reserved2;
+       __s32                   request_fd;
+};
+
+struct v4l2_buffer32_time32 {
+       __u32                   index;
+       __u32                   type;   /* enum v4l2_buf_type */
+       __u32                   bytesused;
+       __u32                   flags;
+       __u32                   field;  /* enum v4l2_field */
+       struct old_timeval32    timestamp;
        struct v4l2_timecode    timecode;
        __u32                   sequence;
 
@@ -581,6 +611,31 @@ static int bufsize_v4l2_buffer(struct v4l2_buffer32 __user *p32, u32 *size)
        return 0;
 }
 
+static int bufsize_v4l2_buffer_time32(struct v4l2_buffer32_time32 __user *p32, u32 *size)
+{
+       u32 type;
+       u32 length;
+
+       if (!access_ok(p32, sizeof(*p32)) ||
+           get_user(type, &p32->type) ||
+           get_user(length, &p32->length))
+               return -EFAULT;
+
+       if (V4L2_TYPE_IS_MULTIPLANAR(type)) {
+               if (length > VIDEO_MAX_PLANES)
+                       return -EINVAL;
+
+               /*
+                * We don't really care if userspace decides to kill itself
+                * by passing a very big length value
+                */
+               *size = length * sizeof(struct v4l2_plane);
+       } else {
+               *size = 0;
+       }
+       return 0;
+}
+
 static int get_v4l2_buffer32(struct v4l2_buffer __user *p64,
                             struct v4l2_buffer32 __user *p32,
                             void __user *aux_buf, u32 aux_space)
@@ -681,6 +736,106 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *p64,
        return 0;
 }
 
+static int get_v4l2_buffer32_time32(struct v4l2_buffer_time32 __user *p64,
+                                   struct v4l2_buffer32_time32 __user *p32,
+                                   void __user *aux_buf, u32 aux_space)
+{
+       u32 type;
+       u32 length;
+       s32 request_fd;
+       enum v4l2_memory memory;
+       struct v4l2_plane32 __user *uplane32;
+       struct v4l2_plane __user *uplane;
+       compat_caddr_t p;
+       int ret;
+
+       if (!access_ok(p32, sizeof(*p32)) ||
+           assign_in_user(&p64->index, &p32->index) ||
+           get_user(type, &p32->type) ||
+           put_user(type, &p64->type) ||
+           assign_in_user(&p64->flags, &p32->flags) ||
+           get_user(memory, &p32->memory) ||
+           put_user(memory, &p64->memory) ||
+           get_user(length, &p32->length) ||
+           put_user(length, &p64->length) ||
+           get_user(request_fd, &p32->request_fd) ||
+           put_user(request_fd, &p64->request_fd))
+               return -EFAULT;
+
+       if (V4L2_TYPE_IS_OUTPUT(type))
+               if (assign_in_user(&p64->bytesused, &p32->bytesused) ||
+                   assign_in_user(&p64->field, &p32->field) ||
+                   assign_in_user(&p64->timestamp.tv_sec,
+                                  &p32->timestamp.tv_sec) ||
+                   assign_in_user(&p64->timestamp.tv_usec,
+                                  &p32->timestamp.tv_usec))
+                       return -EFAULT;
+
+       if (V4L2_TYPE_IS_MULTIPLANAR(type)) {
+               u32 num_planes = length;
+
+               if (num_planes == 0) {
+                       /*
+                        * num_planes == 0 is legal, e.g. when userspace doesn't
+                        * need planes array on DQBUF
+                        */
+                       return put_user(NULL, &p64->m.planes);
+               }
+               if (num_planes > VIDEO_MAX_PLANES)
+                       return -EINVAL;
+
+               if (get_user(p, &p32->m.planes))
+                       return -EFAULT;
+
+               uplane32 = compat_ptr(p);
+               if (!access_ok(uplane32,
+                              num_planes * sizeof(*uplane32)))
+                       return -EFAULT;
+
+               /*
+                * We don't really care if userspace decides to kill itself
+                * by passing a very big num_planes value
+                */
+               if (aux_space < num_planes * sizeof(*uplane))
+                       return -EFAULT;
+
+               uplane = aux_buf;
+               if (put_user_force(uplane, &p64->m.planes))
+                       return -EFAULT;
+
+               while (num_planes--) {
+                       ret = get_v4l2_plane32(uplane, uplane32, memory);
+                       if (ret)
+                               return ret;
+                       uplane++;
+                       uplane32++;
+               }
+       } else {
+               switch (memory) {
+               case V4L2_MEMORY_MMAP:
+               case V4L2_MEMORY_OVERLAY:
+                       if (assign_in_user(&p64->m.offset, &p32->m.offset))
+                               return -EFAULT;
+                       break;
+               case V4L2_MEMORY_USERPTR: {
+                       compat_ulong_t userptr;
+
+                       if (get_user(userptr, &p32->m.userptr) ||
+                           put_user((unsigned long)compat_ptr(userptr),
+                                    &p64->m.userptr))
+                               return -EFAULT;
+                       break;
+               }
+               case V4L2_MEMORY_DMABUF:
+                       if (assign_in_user(&p64->m.fd, &p32->m.fd))
+                               return -EFAULT;
+                       break;
+               }
+       }
+
+       return 0;
+}
+
 static int put_v4l2_buffer32(struct v4l2_buffer __user *p64,
                             struct v4l2_buffer32 __user *p32)
 {
@@ -761,6 +916,86 @@ static int put_v4l2_buffer32(struct v4l2_buffer __user *p64,
        return 0;
 }
 
+static int put_v4l2_buffer32_time32(struct v4l2_buffer_time32 __user *p64,
+                                   struct v4l2_buffer32_time32 __user *p32)
+{
+       u32 type;
+       u32 length;
+       enum v4l2_memory memory;
+       struct v4l2_plane32 __user *uplane32;
+       struct v4l2_plane *uplane;
+       compat_caddr_t p;
+       int ret;
+
+       if (!access_ok(p32, sizeof(*p32)) ||
+           assign_in_user(&p32->index, &p64->index) ||
+           get_user(type, &p64->type) ||
+           put_user(type, &p32->type) ||
+           assign_in_user(&p32->flags, &p64->flags) ||
+           get_user(memory, &p64->memory) ||
+           put_user(memory, &p32->memory))
+               return -EFAULT;
+
+       if (assign_in_user(&p32->bytesused, &p64->bytesused) ||
+           assign_in_user(&p32->field, &p64->field) ||
+           assign_in_user(&p32->timestamp.tv_sec, &p64->timestamp.tv_sec) ||
+           assign_in_user(&p32->timestamp.tv_usec, &p64->timestamp.tv_usec) ||
+           copy_in_user(&p32->timecode, &p64->timecode, sizeof(p64->timecode)) ||
+           assign_in_user(&p32->sequence, &p64->sequence) ||
+           assign_in_user(&p32->reserved2, &p64->reserved2) ||
+           assign_in_user(&p32->request_fd, &p64->request_fd) ||
+           get_user(length, &p64->length) ||
+           put_user(length, &p32->length))
+               return -EFAULT;
+
+       if (V4L2_TYPE_IS_MULTIPLANAR(type)) {
+               u32 num_planes = length;
+
+               if (num_planes == 0)
+                       return 0;
+               /* We need to define uplane without __user, even though
+                * it does point to data in userspace here. The reason is
+                * that v4l2-ioctl.c copies it from userspace to kernelspace,
+                * so its definition in videodev2.h doesn't have a
+                * __user markup. Defining uplane with __user causes
+                * smatch warnings, so instead declare it without __user
+                * and cast it as a userspace pointer to put_v4l2_plane32().
+                */
+               if (get_user(uplane, &p64->m.planes))
+                       return -EFAULT;
+               if (get_user(p, &p32->m.planes))
+                       return -EFAULT;
+               uplane32 = compat_ptr(p);
+
+               while (num_planes--) {
+                       ret = put_v4l2_plane32((void __user *)uplane,
+                                              uplane32, memory);
+                       if (ret)
+                               return ret;
+                       ++uplane;
+                       ++uplane32;
+               }
+       } else {
+               switch (memory) {
+               case V4L2_MEMORY_MMAP:
+               case V4L2_MEMORY_OVERLAY:
+                       if (assign_in_user(&p32->m.offset, &p64->m.offset))
+                               return -EFAULT;
+                       break;
+               case V4L2_MEMORY_USERPTR:
+                       if (assign_in_user(&p32->m.userptr, &p64->m.userptr))
+                               return -EFAULT;
+                       break;
+               case V4L2_MEMORY_DMABUF:
+                       if (assign_in_user(&p32->m.fd, &p64->m.fd))
+                               return -EFAULT;
+                       break;
+               }
+       }
+
+       return 0;
+}
+
 struct v4l2_framebuffer32 {
        __u32                   capability;
        __u32                   flags;
@@ -1150,10 +1385,13 @@ static int put_v4l2_edid32(struct v4l2_edid __user *p64,
 #define VIDIOC_G_FMT32         _IOWR('V',  4, struct v4l2_format32)
 #define VIDIOC_S_FMT32         _IOWR('V',  5, struct v4l2_format32)
 #define VIDIOC_QUERYBUF32      _IOWR('V',  9, struct v4l2_buffer32)
+#define VIDIOC_QUERYBUF32_TIME32 _IOWR('V',  9, struct v4l2_buffer32_time32)
 #define VIDIOC_G_FBUF32                _IOR ('V', 10, struct v4l2_framebuffer32)
 #define VIDIOC_S_FBUF32                _IOW ('V', 11, struct v4l2_framebuffer32)
 #define VIDIOC_QBUF32          _IOWR('V', 15, struct v4l2_buffer32)
+#define VIDIOC_QBUF32_TIME32   _IOWR('V', 15, struct v4l2_buffer32_time32)
 #define VIDIOC_DQBUF32         _IOWR('V', 17, struct v4l2_buffer32)
+#define VIDIOC_DQBUF32_TIME32  _IOWR('V', 17, struct v4l2_buffer32_time32)
 #define VIDIOC_ENUMSTD32       _IOWR('V', 25, struct v4l2_standard32)
 #define VIDIOC_ENUMINPUT32     _IOWR('V', 26, struct v4l2_input32)
 #define VIDIOC_G_EDID32                _IOWR('V', 40, struct v4l2_edid32)
@@ -1166,6 +1404,7 @@ static int put_v4l2_edid32(struct v4l2_edid __user *p64,
 #define        VIDIOC_DQEVENT32_TIME32 _IOR ('V', 89, struct v4l2_event32_time32)
 #define VIDIOC_CREATE_BUFS32   _IOWR('V', 92, struct v4l2_create_buffers32)
 #define VIDIOC_PREPARE_BUF32   _IOWR('V', 93, struct v4l2_buffer32)
+#define VIDIOC_PREPARE_BUF32_TIME32 _IOWR('V', 93, struct v4l2_buffer32_time32)
 
 #define VIDIOC_OVERLAY32       _IOW ('V', 14, s32)
 #define VIDIOC_STREAMON32      _IOW ('V', 18, s32)
@@ -1235,10 +1474,13 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
        case VIDIOC_G_FMT32: ncmd = VIDIOC_G_FMT; break;
        case VIDIOC_S_FMT32: ncmd = VIDIOC_S_FMT; break;
        case VIDIOC_QUERYBUF32: ncmd = VIDIOC_QUERYBUF; break;
+       case VIDIOC_QUERYBUF32_TIME32: ncmd = VIDIOC_QUERYBUF_TIME32; break;
        case VIDIOC_G_FBUF32: ncmd = VIDIOC_G_FBUF; break;
        case VIDIOC_S_FBUF32: ncmd = VIDIOC_S_FBUF; break;
        case VIDIOC_QBUF32: ncmd = VIDIOC_QBUF; break;
+       case VIDIOC_QBUF32_TIME32: ncmd = VIDIOC_QBUF_TIME32; break;
        case VIDIOC_DQBUF32: ncmd = VIDIOC_DQBUF; break;
+       case VIDIOC_DQBUF32_TIME32: ncmd = VIDIOC_DQBUF_TIME32; break;
        case VIDIOC_ENUMSTD32: ncmd = VIDIOC_ENUMSTD; break;
        case VIDIOC_ENUMINPUT32: ncmd = VIDIOC_ENUMINPUT; break;
        case VIDIOC_TRY_FMT32: ncmd = VIDIOC_TRY_FMT; break;
@@ -1258,6 +1500,7 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
        case VIDIOC_S_OUTPUT32: ncmd = VIDIOC_S_OUTPUT; break;
        case VIDIOC_CREATE_BUFS32: ncmd = VIDIOC_CREATE_BUFS; break;
        case VIDIOC_PREPARE_BUF32: ncmd = VIDIOC_PREPARE_BUF; break;
+       case VIDIOC_PREPARE_BUF32_TIME32: ncmd = VIDIOC_PREPARE_BUF_TIME32; break;
        case VIDIOC_G_EDID32: ncmd = VIDIOC_G_EDID; break;
        case VIDIOC_S_EDID32: ncmd = VIDIOC_S_EDID; break;
        default: ncmd = cmd; break;
@@ -1339,6 +1582,22 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
                compatible_arg = 0;
                break;
 
+       case VIDIOC_PREPARE_BUF32_TIME32:
+       case VIDIOC_QUERYBUF32_TIME32:
+       case VIDIOC_QBUF32_TIME32:
+       case VIDIOC_DQBUF32_TIME32:
+               err = bufsize_v4l2_buffer_time32(p32, &aux_space);
+               if (!err)
+                       err = alloc_userspace(sizeof(struct v4l2_buffer),
+                                             aux_space, &new_p64);
+               if (!err) {
+                       aux_buf = new_p64 + sizeof(struct v4l2_buffer);
+                       err = get_v4l2_buffer32_time32(new_p64, p32,
+                                                      aux_buf, aux_space);
+               }
+               compatible_arg = 0;
+               break;
+
        case VIDIOC_S_FBUF32:
                err = alloc_userspace(sizeof(struct v4l2_framebuffer), 0,
                                      &new_p64);
@@ -1487,6 +1746,13 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
                err = put_v4l2_buffer32(new_p64, p32);
                break;
 
+       case VIDIOC_PREPARE_BUF32_TIME32:
+       case VIDIOC_QUERYBUF32_TIME32:
+       case VIDIOC_QBUF32_TIME32:
+       case VIDIOC_DQBUF32_TIME32:
+               err = put_v4l2_buffer32_time32(new_p64, p32);
+               break;
+
        case VIDIOC_ENUMSTD32:
                err = put_v4l2_standard32(new_p64, p32);
                break;