[PATCH v2 8/8] media: v4l2: remove remaining compat_ioctl

Arnd Bergmann
2020-10-30T16:56:02Z

There are no remaining conversions in v4l2_compat_ioctl32(),
so all the infrastructure for it can be removed, with the
only remaining bit being the compat_ioctl32() callback into
drivers that implement their own incompatible data structures.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 197 +-----------------
1 file changed, 2 insertions(+), 195 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index f54f49bebea7..dfab9f662490 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -23,103 +23,6 @@
#include <media/v4l2-ctrls.h>
#include <media/v4l2-ioctl.h>

-/**
- * assign_in_user() - Copy from one __user var to another one
- *
- * @to: __user var where data will be stored
- * @from: __user var where data will be retrieved.
- *
- * As this code very often needs to allocate userspace memory, it is easier
- * to have a macro that will do both get_user() and put_user() at once.
- *
- * This function complements the macros defined at asm-generic/uaccess.h.
- * It uses the same argument order as copy_in_user()
- */
-#define assign_in_user(to, from) \
-({ \
- typeof(*from) __assign_tmp; \
- \
- get_user(__assign_tmp, from) || put_user(__assign_tmp, to); \
-})
-
-/**
- * get_user_cast() - Stores at a kernelspace local var the contents from a
- * pointer with userspace data that is not tagged with __user.
- *
- * @__x: var where data will be stored
- * @__ptr: var where data will be retrieved.
- *
- * Sometimes we need to declare a pointer without __user because it
- * comes from a pointer struct field that will be retrieved from userspace
- * by the 64-bit native ioctl handler. This function ensures that the
- * @__ptr will be cast to __user before calling get_user() in order to
- * avoid warnings with static code analyzers like smatch.
- */
-#define get_user_cast(__x, __ptr) \
-({ \
- get_user(__x, (typeof(*__ptr) __user *)(__ptr)); \
-})
-
-/**
- * put_user_force() - Stores the contents of a kernelspace local var
- * into a userspace pointer, removing any __user cast.
- *
- * @__x: var where data will be stored
- * @__ptr: var where data will be retrieved.
- *
- * Sometimes we need to remove the __user attribute from some data,
- * by passing the __force macro. This function ensures that the
- * @__ptr will be cast with __force before calling put_user(), in order to
- * avoid warnings with static code analyzers like smatch.
- */
-#define put_user_force(__x, __ptr) \
-({ \
- put_user((typeof(*__x) __force *)(__x), __ptr); \
-})
-
-/**
- * assign_in_user_cast() - Copy from one __user var to another one
- *
- * @to: __user var where data will be stored
- * @from: var where data will be retrieved that needs to be cast to __user.
- *
- * As this code very often needs to allocate userspace memory, it is easier
- * to have a macro that will do both get_user_cast() and put_user() at once.
- *
- * This function should be used instead of assign_in_user() when the @from
- * variable was not declared as __user. See get_user_cast() for more details.
- *
- * This function complements the macros defined at asm-generic/uaccess.h.
- * It uses the same argument order as copy_in_user()
- */
-#define assign_in_user_cast(to, from) \
-({ \
- typeof(*from) __assign_tmp; \
- \
- get_user_cast(__assign_tmp, from) || put_user(__assign_tmp, to);\
-})
-
-/**
- * native_ioctl - Ancillary function that calls the native 64 bits ioctl
- * handler.
- *
- * @file: pointer to &struct file with the file handler
- * @cmd: ioctl to be called
- * @arg: arguments passed from/to the ioctl handler
- *
- * This function calls the native ioctl handler at v4l2-dev, e. g. v4l2_ioctl()
- */
-static long native_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
-{
- long ret = -ENOIOCTLCMD;
-
- if (file->f_op->unlocked_ioctl)
- ret = file->f_op->unlocked_ioctl(file, cmd, arg);
-
- return ret;
-}
-
-
/*
* Per-ioctl data copy handlers.
*
@@ -1305,103 +1208,6 @@ int v4l2_compat_put_array_args(struct file *file, void __user *user_ptr,
return err;
}

-
-/**
- * alloc_userspace() - Allocates a 64-bits userspace pointer compatible
- * for calling the native 64-bits version of an ioctl.
- *
- * @size: size of the structure itself to be allocated.
- * @aux_space: extra size needed to store "extra" data, e.g. space for
- * other __user data that is pointed to fields inside the
- * structure.
- * @new_p64: pointer to a pointer to be filled with the allocated struct.
- *
- * Return:
- *
- * if it can't allocate memory, either -ENOMEM or -EFAULT will be returned.
- * Zero otherwise.
- */
-static int alloc_userspace(unsigned int size, u32 aux_space,
- void __user **new_p64)
-{
- *new_p64 = compat_alloc_user_space(size + aux_space);
- if (!*new_p64)
- return -ENOMEM;
- if (clear_user(*new_p64, size))
- return -EFAULT;
- return 0;
-}
-
-/**
- * do_video_ioctl() - Ancillary function with handles a compat32 ioctl call
- *
- * @file: pointer to &struct file with the file handler
- * @cmd: ioctl to be called
- * @arg: arguments passed from/to the ioctl handler
- *
- * This function is called when a 32 bits application calls a V4L2 ioctl
- * and the Kernel is compiled with 64 bits.
- *
- * This function is called by v4l2_compat_ioctl32() when the function is
- * not private to some specific driver.
- *
- * It converts a 32-bits struct into a 64 bits one, calls the native 64-bits
- * ioctl handler and fills back the 32-bits struct with the results of the
- * native call.
- */
-static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
-{
- void __user *p32 = compat_ptr(arg);
- void __user *new_p64 = NULL;
- void __user *aux_buf;
- u32 aux_space;
- int compatible_arg = 1;
- long err = 0;
- unsigned int ncmd;
-
- /*
- * 1. When struct size is different, converts the command.
- */
- switch (cmd) {
- default: ncmd = cmd; break;
- }
-
- /*
- * 2. Allocates a 64-bits userspace pointer to store the
- * values of the ioctl and copy data from the 32-bits __user
- * argument into it.
- */
- switch (cmd) {
- }
- if (err)
- return err;
-
- /*
- * 3. Calls the native 64-bits ioctl handler.
- *
- * For the functions where a conversion was not needed,
- * compatible_arg is true, and it will call it with the arguments
- * provided by userspace and stored at @p32 var.
- *
- * Otherwise, it will pass the newly allocated @new_p64 argument.
- */
- if (compatible_arg)
- err = native_ioctl(file, ncmd, (unsigned long)p32);
- else
- err = native_ioctl(file, ncmd, (unsigned long)new_p64);
-
- if (err == -ENOTTY)
- return err;
-
- /*
- * 5. Copy the data returned at the 64 bits userspace pointer to
- * the original 32 bits structure.
- */
- switch (cmd) {
- }
- return err;
-}
-
/**
* v4l2_compat_ioctl32() - Handles a compat32 ioctl call
*
@@ -1425,7 +1231,8 @@ long v4l2_compat_ioctl32(struct file *file, unsigned int cmd, unsigned long arg)
return ret;

if (_IOC_TYPE(cmd) == 'V' && _IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
- ret = do_video_ioctl(file, cmd, arg);
+ ret = file->f_op->unlocked_ioctl(file, cmd,
+ (unsigned long)compat_ptr(arg));
else if (vdev->fops->compat_ioctl32)
ret = vdev->fops->compat_ioctl32(file, cmd, arg);

--
2.27.0