<div dir="ltr"><div dir="ltr"> </div> <div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Thu, Oct 1, 2026 at 10:19 AM David Marchand <<a href="mailto:david.marchand@redhat.com">david.marchand@redhat.com</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Wed, 30 Sept 2026 at 17:37, Maxime Coquelin <<a href="mailto:maxime.coquelin@redhat.com" target="_blank">maxime.coquelin@redhat.com</a>> wrote: > On Wed, Sep 30, 2026 at 5:26 PM Stephen Hemminger <<a href="mailto:stephen@networkplumber.org" target="_blank">stephen@networkplumber.org</a>> wrote: >> >> On Wed, 30 Sep 2026 11:57:59 +0200 >> Maxime Coquelin <<a href="mailto:maxime.coquelin@redhat.com" target="_blank">maxime.coquelin@redhat.com</a>> wrote: >> >> > This patch adds a compatibility define for __counted_by attribute, >> > which is not present in older compilers but required for recent UAPI >> > headers like vfio.h. >> > >> > Signed-off-by: Maxime Coquelin <<a href="mailto:maxime.coquelin@redhat.com" target="_blank">maxime.coquelin@redhat.com</a>> >> > --- >> > config/rte_config.h | 9 +++++++++ >> > 1 file changed, 9 insertions(+) >> > >> > diff --git a/config/rte_config.h b/config/rte_config.h >> > index 0447cdf2ad..307e7dac62 100644 >> > --- a/config/rte_config.h >> > +++ b/config/rte_config.h >> > @@ -25,6 +25,15 @@ >> > #define RTE_TOOLCHAIN_MSVC 1 >> > #endif >> > >> > +/* >> > + * Compatibility define for Linux kernel UAPI headers that may use __counted_by >> > + * attribute for bounds checking. This attribute is not understood by userspace >> > + * compilers, so define it as empty if not already provided. >> > + */ >> > +#ifndef __counted_by >> > +#define __counted_by(m) >> > +#endif >> > + >> > /* legacy defines */ >> > #ifdef RTE_EXEC_ENV_LINUX >> > #define RTE_EXEC_ENV_LINUXAPP 1 >> >> NAK this is best done by keeping up to date stddef over in virtio headers. > > This is for VFIO, not Virtio but that does not change the issue. > > Problem is importing stddef in UAPI as currently done, does not work, > because the system version is included first so the imported one is discarded. > > An alternative solution I tested would be to include the imported headers first, > but it means imported headers get silently intermixed, which worked in my test > but could lead to hard to debug issues. I don't like the alternative, for the reason you listed, plus the fact that this intermixing is invisible. At the moment, using an imported uapi header is opt-in, and I prefer it like this. > While not ideal, the solution proposed in this patch is harmless, we are talking > about an attribute defined as empty. Your solution of wrapping __counted_by is simple. On the other hand, fixing the existing import script would require relying on an external tool (unifef), which could be acceptable. </blockquote><div> </div><div>Your solution is certainly more future-proof.</div><div>If others agree, can you send a series that supersedes mine so that we can get it merged early?</div><div>Eugenio will need to rebase his series on top of it.</div><div> </div><div>Thanks,</div><div>Maxime</div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> I tried some: diff --git a/devtools/linux-uapi.sh b/devtools/linux-uapi.sh index dbf3163bc8..189164928c 100755 --- a/devtools/linux-uapi.sh +++ b/devtools/linux-uapi.sh @@ -13,6 +13,9 @@ file="" check_headers=false quiet=false +# Require unifdef +unifdef -h 2>&1 >/dev/null || { echo "This script requires unifdef."; exit 1; } + print_usage() { echo "Usage: $(basename $0) [-h] [-i FILE] [-u VERSION] [-c] [-q]" @@ -85,6 +88,9 @@ fixup_includes() sed -i 's|#$define$[[:space:]]*_UAPI|#\1 |' $path sed -i 's|#$endif[[:space:]]*/[*]$[[:space:]]*_UAPI|#\1 |' $path + unifdef -U__KERNEL__ -D__EXPORTED_HEADERS__ -o ${path}.tmp $path || [ $? -lt 2 ] + mv -f ${path}.tmp $path + # Prepend include path with "uapi/" if the header is imported for include in $(sed -ne 's/^#include <$.*$>$/\1/p' $path); do if [ -f "$base_path$include" ]; then diff --git a/doc/guides/contributing/linux_uapi.rst b/doc/guides/contributing/linux_uapi.rst index b8febfc420..a3490bfbb6 100644 --- a/doc/guides/contributing/linux_uapi.rst +++ b/doc/guides/contributing/linux_uapi.rst @@ -27,6 +27,8 @@ Importing or updating an uAPI header file To ensure that imported uAPI headers are unmodified and sourced from an official Linux kernel release, a helper script is provided and must be used. +This script requires the ``unifdef`` tool. + Below is an example to import ``linux/vduse.h`` file from Linux ``v6.10``: .. code-block:: console Then imported linux/types.h, linux/posix_types.h and linux/stddef.h. And net/nbl needs some fixing... as it includes uapi/linux/vfio.h too late... Only occurence in the whole DPDK tree: $ git grep -l '# *include.*uapi' :^devtools/linux-uapi.sh :^doc/guides/contributing/linux_uapi.rst | while read file; do [ $(git grep -B100 '# *include.*uapi' $file | grep '# *include' | wc -l) = 1 ] || echo $file; done drivers/net/nbl/nbl_common/nbl_userdev.c -- David Marchand </blockquote></div></div>