[libvirt] [PATCH 4/4] cfg.mk: block use of d_type from dirent by default

[Michal Privoznik]

On 4/2/19 2:40 PM, Daniel P. Berrangé wrote:
> The use of d_type is non-portable and leads to surprises when the OS
> does not fill in any value except DT_UNKNOWN. Blacklist its usage
> except in files which inherantly don't require portability (cgroup
> and selinux)

s/and selinux//

> 
> Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
> ---
>   cfg.mk | 16 ++++++++++++++++
>   1 file changed, 16 insertions(+)
> 
> diff --git a/cfg.mk b/cfg.mk
> index 2c473121a4..84d40d946a 100644
> --- a/cfg.mk
> +++ b/cfg.mk
> @@ -1083,6 +1083,19 @@ sc_prohibit_class:
>   	halt='use klass instead of class or _class' \
>   	  $(_sc_search_regexp)
>   
> +# The dirent "d_type" field is non-portable and even when it
> +# exists some filesystems will only ever return DT_UNKNOWN.
> +# This field should only be used by code which is exclusively
> +# run platforms supporting "d_type" and must expect DT_UNKNOWN.
> +# We blacklist it to discourage accidental usage which has
> +# happened many times. Add an exclude rule if it is genuinely
> +# needed and the above restrictions are acceptable.
> +sc_prohibit_dirent_d_type:
> +	@prohibit='(->|\.)d_type' \
> +	in_vc_files='\.[chx]$$' \
> +	halt='do not use the d_type field in "struct dirent"' \
> +	  $(_sc_search_regexp)
> +
>   
>   # We don't use this feature of maint.mk.
>   prev_version_file = /dev/null
> @@ -1337,3 +1350,6 @@ exclude_file_name_regexp--sc_prohibit_readdir = \
>   
>   exclude_file_name_regexp--sc_prohibit_cross_inclusion = \
>     ^(src/util/virclosecallbacks\.h|src/util/virhostdev\.h)$$
> +
> +exclude_file_name_regexp--sc_prohibit_dirent_d_type = \
> +  ^(src/util/vircgroup.c)$
> 

Michal