[Buildroot] [PATCH 4 of 4] alsa-utils: fix build on no-mmu targets

[Peter Korsgaard <jacmet@uclibc.org>]

>>>>> "Thomas" == Thomas De Schampheleire <patrickdepinguin@gmail.com> writes:

 > alsa-utils uses fork, which doesn't work on targets without mmu, such as
 > Blackfin. Apply a patch by the Blackfin developers to fix this.

 > Fixes
 > http://autobuild.buildroot.org/results/9f8/9f8e572c9f1c677155cc7d1828371bcf572ff878

 > Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>

What is the upstream status of this?

 > ---
 >  package/alsa-utils/alsa-utils-0001-no-mmu.patch |  61 ++++++++++++++++++++
 >  package/alsa-utils/alsa-utils.mk                |   1 +
 >  2 files changed, 62 insertions(+), 0 deletions(-)

 > diff --git a/package/alsa-utils/alsa-utils-0001-no-mmu.patch b/package/alsa-utils/alsa-utils-0001-no-mmu.patch
 > new file mode 100644
 > --- /dev/null
 > +++ b/package/alsa-utils/alsa-utils-0001-no-mmu.patch
 > @@ -0,0 +1,61 @@
 > +Signed-off-by: Aaron Wu <Aaron.wu@analog.com>
 > +
 > +Add no-mmu support for alsa-utils mainly for Blackfin
 > +---
 > + alsactl/init_utils_run.c |    4 ++++
 > + alsaloop/alsaloop.c      |    8 ++++++++
 > + configure.in             |    1 +
 > + 3 files changed, 13 insertions(+)
 > +
 > +diff --git a/alsactl/init_utils_run.c b/alsactl/init_utils_run.c
 > +--- a/alsactl/init_utils_run.c
 > ++++ b/alsactl/init_utils_run.c
 > +@@ -89,7 +89,11 @@ int run_program0(struct space *space,
 > + 		argv[0] = program;
 > + 	}
 > + 
 > ++	#ifdef HAVE_FORK
 > + 	pid = fork();
 > ++	#else
 > ++	pid = vfork();
 > ++	#endif

I would be a lot happier with a patch simply doing s/fork/vfork/. If
vfork is safe to use, we might as well use it everywhere - And if not,
we shouldn't do it on nommu either.


 > + 	switch(pid) {
 > + 	case 0:
 > + 		/* child closes parent ends of pipes */

I'm far from a vfork expert, but as parent and child shares stack, how
does it work with both calling close() on the pipes?

-- 
Bye, Peter Korsgaard