[LEDE-DEV] [PATCH ubox] getrandom: Define SYS_getrandom if no definition exists

[Florian Fainelli]

Le 17/09/2016 à 16:49, Etienne Champetier a écrit :
> Hi Florian,
> 
> What is your use case?

Pre-built toolchain which ships with kernel headers 3.8 at the moment.

> If you run it on kernel less than 3.17 this will then fail at run time ...

I run a kernel newer than 3.17, but that's a good point.

> I would prefer to not compile it instead of having an unusable binary

Ok, so something more like that:

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6cf0c934aac6..1d04c1d77662 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,10 +16,15 @@ IF(DEBUG)
   ADD_DEFINITIONS(-DDEBUG -g3)
 ENDIF()

-ADD_EXECUTABLE(getrandom getrandom.c)
-INSTALL(TARGETS getrandom
+INCLUDE (CheckSymbolExists)
+CHECK_SYMBOL_EXISTS(SYS_getrandom sycall.h getrandom)
+
+IF(getrandom)
+  ADD_EXECUTABLE(getrandom getrandom.c)
+  INSTALL(TARGETS getrandom
        RUNTIME DESTINATION bin
-)
+  )
+ENDIF()

 ADD_EXECUTABLE(kmodloader kmodloader.c)
 TARGET_LINK_LIBRARIES(kmodloader ubox)

diff --git a/package/system/ubox/Makefile b/package/system/ubox/Makefile
index 9f0c4dc10250..48371e168fd3 100644
--- a/package/system/ubox/Makefile
+++ b/package/system/ubox/Makefile
@@ -32,7 +32,7 @@ define Package/ubox/install
        $(INSTALL_DIR) $(1)/sbin $(1)/usr/sbin $(1)/lib $(1)/usr/bin
$(1)/etc/init.d

        $(INSTALL_BIN)
$(PKG_INSTALL_DIR)/usr/sbin/{kmodloader,validate_data} $(1)/sbin/
-       $(INSTALL_BIN) $(PKG_INSTALL_DIR)/usr/bin/getrandom $(1)/usr/bin/
+       -$(INSTALL_BIN) $(PKG_INSTALL_DIR)/usr/bin/getrandom $(1)/usr/bin/
        $(INSTALL_DATA) $(PKG_INSTALL_DIR)/usr/lib/libvalidate.so $(1)/lib

        $(LN) ../../sbin/kmodloader $(1)/usr/sbin/rmmod


> 
> Regards
> Etienne
> 
> 
> Le 17 sept. 2016 10:17 PM, "Florian Fainelli" <f.fainelli at gmail.com
> <mailto:f.fainelli at gmail.com>> a écrit :
> 
>     Building ubox against kernel headers earlier than 3.17 would fail since
>     SYS_getrandom was not defined, so provide a definition for it.
> 
>     Signed-off-by: Florian Fainelli <f.fainelli at gmail.com
>     <mailto:f.fainelli at gmail.com>>
>     ---
>      getrandom.c | 4 ++++
>      1 file changed, 4 insertions(+)
> 
>     diff --git a/getrandom.c b/getrandom.c
>     index 96712028589b..e324072fcf0e 100644
>     --- a/getrandom.c
>     +++ b/getrandom.c
>     @@ -32,6 +32,10 @@ static int usage(char *name)
>          return EXIT_FAILURE;
>      }
> 
>     +#ifndef SYS_getrandom
>     +#define SYS_getrandom  278
>     +#endif
>     +
>      int main(int argc, char *argv[])
>      {
>          if (argc != 2)
>     --
>     2.7.4
> 


-- 
Florian