Re: [PATCH] [PATCH v6] linux-user: syscall: ioctls: support DRM_IOCTL_VERSION

[Chen Gang]

That sounds good, I'll send patch v7, thanks.

On 2020/6/4 下午5:10, Laurent Vivier wrote:
> Le 04/06/2020 à 03:45, chengang@emindsoft.com.cn a écrit :
>> From: Chen Gang <chengang@emindsoft.com.cn>
>>
>> Another DRM_IOCTL_* commands will be done later.
>>
>> Signed-off-by: Chen Gang <chengang@emindsoft.com.cn>
>> ---
>>  configure                  | 10 ++++
>>  linux-user/ioctls.h        |  5 ++
>>  linux-user/syscall.c       | 95 ++++++++++++++++++++++++++++++++++++++
>>  linux-user/syscall_defs.h  | 15 ++++++
>>  linux-user/syscall_types.h | 11 +++++
>>  5 files changed, 136 insertions(+)
>>
>> diff --git a/configure b/configure
>> index f087d2bcd1..389dbb1d09 100755
>> --- a/configure
>> +++ b/configure
>> @@ -3136,6 +3136,13 @@ if ! check_include "ifaddrs.h" ; then
>>    have_ifaddrs_h=no
>>  fi
>>  
>> +#########################################
>> +# libdrm check
>> +have_drm_h=no
>> +if check_include "libdrm/drm.h" ; then
>> +    have_drm_h=yes
>> +fi
>> +
>>  ##########################################
>>  # VTE probe
>>  
>> @@ -7127,6 +7134,9 @@ fi
>>  if test "$have_ifaddrs_h" = "yes" ; then
>>      echo "HAVE_IFADDRS_H=y" >> $config_host_mak
>>  fi
>> +if test "$have_drm_h" = "yes" ; then
>> +  echo "HAVE_DRM_H=y" >> $config_host_mak
>> +fi
>>  if test "$have_broken_size_max" = "yes" ; then
>>      echo "HAVE_BROKEN_SIZE_MAX=y" >> $config_host_mak
>>  fi
>> diff --git a/linux-user/ioctls.h b/linux-user/ioctls.h
>> index 0defa1d8c1..f2e2fa9c87 100644
>> --- a/linux-user/ioctls.h
>> +++ b/linux-user/ioctls.h
>> @@ -574,6 +574,11 @@
>>    IOCTL_SPECIAL(SIOCDELRT, IOC_W, do_ioctl_rt,
>>                  MK_PTR(MK_STRUCT(STRUCT_rtentry)))
>>  
>> +#ifdef HAVE_DRM_H
>> +  IOCTL_SPECIAL(DRM_IOCTL_VERSION, IOC_RW, do_ioctl_drm,
>> +                MK_PTR(MK_STRUCT(STRUCT_drm_version)))
>> +#endif
>> +
>>  #ifdef TARGET_TIOCSTART
>>    IOCTL_IGNORE(TIOCSTART)
>>    IOCTL_IGNORE(TIOCSTOP)
>> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
>> index 7f6700c54e..1744e7acc7 100644
>> --- a/linux-user/syscall.c
>> +++ b/linux-user/syscall.c
>> @@ -112,6 +112,9 @@
>>  #include <linux/if_alg.h>
>>  #include <linux/rtc.h>
>>  #include <sound/asound.h>
>> +#ifdef HAVE_DRM_H
>> +#include <libdrm/drm.h>
>> +#endif
>>  #include "linux_loop.h"
>>  #include "uname.h"
>>  
>> @@ -5276,6 +5279,98 @@ static abi_long do_ioctl_tiocgptpeer(const IOCTLEntry 
>> *ie, uint8_t *buf_temp,
>>  }
>>  #endif
>>  
>> +#ifdef HAVE_DRM_H
>> +
>> +static void unlock_drm_version(struct drm_version *host_ver)
>> +{
>> +    unlock_user(host_ver->name, 0UL, 0);
>> +    unlock_user(host_ver->date, 0UL, 0);
>> +    unlock_user(host_ver->desc, 0UL, 0);
>> +}
> 
> This is correct but I would prefer to not have this kind of function
> with 0UL parameter.
> 
> You can use target_ver for the guest pointer and host_ver for the len,
> guest pointer will be ignored if host pointer is NULL.
> 
> You can have a generic function that not copies data in case of error:
> 
> static void unlock_drm_strings(struct drm_version *host_ver,
>                                struct target_drm_version *target_ver,
>                                int copy)
> {
>     unlock_user(host_ver->name, target_ver->name,
>                 copy ? host_ver->name_len : 0);
> ...
> 
>> +
>> +static inline abi_long target_to_host_drmversion(struct drm_version 
>> *host_ver,
>> +                                          struct target_drm_version 
>> *target_ver)
>> +{
>> +    memset(host_ver, 0, sizeof(*host_ver));
>> +
>> +    __get_user(host_ver->name_len, &target_ver->name_len);
>> +    if (host_ver->name_len) {
>> +        host_ver->name = lock_user(VERIFY_WRITE, target_ver->name,
>> +                                   target_ver->name_len, 0);
>> +        if (!host_ver->name) {
>> +            goto err;
>> +        }
>> +    }
>> +
>> +    __get_user(host_ver->date_len, &target_ver->date_len);
>> +    if (host_ver->date_len) {
>> +        host_ver->date = lock_user(VERIFY_WRITE, target_ver->date,
>> +                                   target_ver->date_len, 0);
>> +        if (!host_ver->date) {
>> +            goto err;
>> +        }
>> +    }
>> +
>> +    __get_user(host_ver->desc_len, &target_ver->desc_len);
>> +    if (host_ver->desc_len) {
>> +        host_ver->desc = lock_user(VERIFY_WRITE, target_ver->desc,
>> +                                   target_ver->desc_len, 0);
>> +        if (!host_ver->desc) {
>> +            goto err;
>> +        }
>> +    }
>> +
>> +    return 0;
>> +err:
>> +    unlock_drm_version(host_ver);
> 
> unlock_drm_strings(host_ver, target_ver, 0);
> 
>> +    return -EFAULT;
>> +}
>> +
>> +static inline abi_long host_to_target_drmversion(
>> +                                          struct target_drm_version 
>> *target_ver,
>> +                                          struct drm_version *host_ver)
>> +{
>> +    __put_user(host_ver->version_major, &target_ver->version_major);
>> +    __put_user(host_ver->version_minor, &target_ver->version_minor);
>> +    __put_user(host_ver->version_patchlevel, 
>> &target_ver->version_patchlevel);
>> +    __put_user(host_ver->name_len, &target_ver->name_len);
>> +    __put_user(host_ver->date_len, &target_ver->date_len);
>> +    __put_user(host_ver->desc_len, &target_ver->desc_len);
>> +    unlock_user(host_ver->name, target_ver->name, host_ver->name_len);
>> +    unlock_user(host_ver->date, target_ver->date, host_ver->date_len);
>> +    unlock_user(host_ver->desc, target_ver->desc, host_ver->desc_len);
> 
> unlock_drm_strings(host_ver, target_ver, 1);
> 
>> +    return 0;
>> +}
>> +
>> +static abi_long do_ioctl_drm(const IOCTLEntry *ie, uint8_t *buf_temp,
>> +                             int fd, int cmd, abi_long arg)
>> +{
>> +    struct drm_version *ver;
>> +    struct target_drm_version *target_ver;
>> +    abi_long ret;
>> +
>> +    switch (ie->host_cmd) {
>> +    case DRM_IOCTL_VERSION:
>> +        if (!lock_user_struct(VERIFY_WRITE, target_ver, arg, 0)) {
>> +            return -TARGET_EFAULT;
>> +        }
>> +        ver = (struct drm_version *)buf_temp;
>> +        ret = target_to_host_drmversion(ver, target_ver);
>> +        if (!is_error(ret)) {
>> +            ret = get_errno(safe_ioctl(fd, ie->host_cmd, ver));
>> +            if (!is_error(ret)) {
>> +                ret = host_to_target_drmversion(target_ver, ver);
>> +            }
>> +            unlock_drm_version(ver);
> 
> } else {
>     unlock_drm_strings(host_ver, target_ver, 0);
> }
> 
> Thanks,
> Laurent
> 
> 
> 
>