Enable the required option to have the "Universal TUN/TAP device driver support" working on a Morello SoC in the default defconfig for Morello Transitional PCuABI (morello_transitional_pcuabi_defconfig): - CONFIG_TUN=y

Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- arch/arm64/configs/morello_transitional_pcuabi_defconfig | 1 + 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/configs/morello_transitional_pcuabi_defconfig b/arch/arm64/configs/morello_transitional_pcuabi_defconfig index 8500619dce2f..edc5e3e6def5 100644 --- a/arch/arm64/configs/morello_transitional_pcuabi_defconfig +++ b/arch/arm64/configs/morello_transitional_pcuabi_defconfig @@ -96,6 +96,7 @@ CONFIG_SATA_AHCI=y CONFIG_MD=y CONFIG_BLK_DEV_DM=y CONFIG_NETDEVICES=y +CONFIG_TUN=y CONFIG_VETH=y CONFIG_VIRTIO_NET=y CONFIG_R8169=y

On 23/02/2023 13:56, Vincenzo Frascino wrote:

With the introduction of capabilities, the PCuABI expects a capability when dealing with the user pointers.

When the TUN driver is enabled in a PCuABI compatible kernel, the compilation reports the error below:

drivers/net/tun.c:3478:20: error: incompatible function pointer types initializing 'long (*)(struct file *, unsigned int, user_uintptr_t)' (aka 'long (*)(struct file *, unsigned int, unsigned __intcap)') with an expression of type 'long (struct file *, unsigned int, unsigned long)' [-Werror,-Wincompatible-function-pointer-types] .unlocked_ioctl = tun_chr_ioctl, ^~~~~~~~~~~~~ 1 error generated.

Address a compilation issue using the proper type to represent user pointers (user_uintptr_t) and redirecting the .compat_ioctl.

Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com

Thanks for the patch! Regarding the commit title, how about using the "tun:" tag to shorten it, also "function pointer" may be misinterpreted, so maybe something like:

net: tun: Fix ioctl handler argument type

---

drivers/net/tun.c | 35 +++-------------------------------- 1 file changed, 3 insertions(+), 32 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c index dbe4c0a4be2c..d76131b29bbc 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -3018,7 +3018,7 @@ static unsigned char tun_get_addr_len(unsigned short type) } static long __tun_chr_ioctl(struct file *file, unsigned int cmd,

• 	    unsigned long arg, int ifreq_len)
  

• 	    user_uintptr_t arg, int ifreq_len)
  

{ struct tun_file *tfile = file->private_data; struct net *net = sock_net(&tfile->sk); @@ -3349,40 +3349,11 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, } static long tun_chr_ioctl(struct file *file,

• 	  unsigned int cmd, unsigned long arg)
  

• 	  unsigned int cmd, user_uintptr_t arg)
  

{ return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq)); } -#ifdef CONFIG_COMPAT -static long tun_chr_compat_ioctl(struct file *file,

• 	 unsigned int cmd, unsigned long arg)
  

-{

• switch (cmd) {
• case TUNSETIFF:
• case TUNGETIFF:
• case TUNSETTXFILTER:
• case TUNGETSNDBUF:
• case TUNSETSNDBUF:
• case SIOCGIFHWADDR:
• case SIOCSIFHWADDR:

• arg = (unsigned long)compat_ptr(arg);
  

• break;
  

• default:

• arg = (compat_ulong_t)arg;
  

• break;
  

• }
• /*

• * compat_ifreq is shorter than ifreq, so we must not access beyond
  

• * the end of that structure. All fields that are used in this
  

• * driver are compatible though, we don't need to convert the
  

• * contents.
  

• */
  

• return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));

I think we still need this special compat handling. struct compat_ifreq is smaller than struct ifreq so we need to pass a different size in compat.

That said the switch above is indeed broken as in fact most commands expect a pointer. Using (user_uintptr_t)compat_ptr(arg) unconditionally would be fine by me.

Happy with the rest and patch 2.

Kevin

-} -#endif /* CONFIG_COMPAT */

static int tun_chr_fasync(int fd, struct file *file, int on) { struct tun_file *tfile = file->private_data; @@ -3477,7 +3448,7 @@ static const struct file_operations tun_fops = { .poll = tun_chr_poll, .unlocked_ioctl = tun_chr_ioctl, #ifdef CONFIG_COMPAT

• .compat_ioctl = tun_chr_compat_ioctl,

• .compat_ioctl = compat_ptr_ioctl,

#endif .open = tun_chr_open, .release = tun_chr_close,