Re: [PATCH 13/14] kdbus: add walk-through user space example

[Daniel Mack]

On 03/24/2015 07:22 PM, Michal Marek wrote:
> Dne 24.3.2015 v 18:37 Jiri Slaby napsal(a):

>> Oh, it's cut&paste, I see. This does not look correct though. The hack
>> inclusive. Host progs are intended to be run on the host where the
>> kernel is built. During the compilation or such (like x/menuconfig).
>> Quite misleading naming if you are used to the autotools one.
> 
> when cross compiling, we are a bit between a rock and a hard place with
> the sample userspace programs:
> - The target toolchain might not have libc support
> - The host toolchain might be lacking recent kernel headers (therefore
>   the need to do make headers_install)
> - It's not clean whether the samples are meant to be ran on the build
>   host or target.

Exactly. I just checked in a cross-compiled source tree, and none of the
compiled standalone executables from samples/ or Documentation/ are
actually built for the target platform. Only the samples which come as
kernel modules are.

> There has been some work by Sam Ravnborg to introduce uapiprogs-y to for
> sample userspace programs, but for now, please use hostprogs-y,
> -Iusr/include and make each sample opt-in.

Alright then. Does the attached patch fix your problem, Jiri?


Thanks,
Daniel

From 56309ab0717720fb086ec3209f1b1fa719072f61 Mon Sep 17 00:00:00 2001
From: Daniel Mack <daniel@xxxxxxxxxx>
Date: Tue, 24 Mar 2015 19:41:56 +0100
Subject: [PATCH] kdbus: sample: build kdbus-workers conditionally

Give the kdbus sample its own config switch and only build it if it's
explicitly switched on.

Reported-by: Jiri Slaby <jslaby@xxxxxxx>
Signed-off-by: Daniel Mack <daniel@xxxxxxxxxx>
---
 samples/Kconfig        | 7 +++++++
 samples/kdbus/Makefile | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/samples/Kconfig b/samples/Kconfig
index 224ebb4..a4c6b2f 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -55,6 +55,13 @@ config SAMPLE_KDB
 	  Build an example of how to dynamically add the hello
 	  command to the kdb shell.
 
+config SAMPLE_KDBUS
+	bool "Build kdbus API example"
+	depends on KDBUS
+	help
+	  Build an example of how the kdbus API can be used from
+	  userspace.
+
 config SAMPLE_RPMSG_CLIENT
 	tristate "Build rpmsg client sample -- loadable modules only"
 	depends on RPMSG && m
diff --git a/samples/kdbus/Makefile b/samples/kdbus/Makefile
index d009025..9e40c68 100644
--- a/samples/kdbus/Makefile
+++ b/samples/kdbus/Makefile
@@ -1,7 +1,7 @@
 # kbuild trick to avoid linker error. Can be omitted if a module is built.
 obj- := dummy.o
 
-hostprogs-y += kdbus-workers
+hostprogs-$(CONFIG_SAMPLE_KDBUS) += kdbus-workers
 
 always := $(hostprogs-y)
 
-- 
2.3.3