On Wed, Jan 02, 2008 at 10:53:11PM +0100, Sam Ravnborg wrote:

On Wed, Jan 02, 2008 at 01:08:31PM -0800, Roland McGrath wrote:

quoted

This patch should go in immediately after:

	commit 5e45efc63e33ee2bae9ff4d500b53d3bf86d2b48
	Author: Roland McGrath [off-list ref]

	    compat_binfmt_elf

Thanks,
Roland

---
[PATCH] compat_binfmt_elf Kconfig

This adds Kconfig and Makefile bits to build fs/compat_binfmt_elf.c,
just added.  Each arch that wants to use this file needs to add a
"select COMPAT_BINFMT_ELF" line in its Kconfig bits that enable COMPAT.

Signed-off-by: Roland McGrath <redacted>
---
 fs/Kconfig.binfmt |    4 ++++
 fs/Makefile       |    1 +
 2 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
index d4fc609..0000000 100644  
--- a/fs/Kconfig.binfmt
+++ b/fs/Kconfig.binfmt

@@ -23,6 +23,10 @@ config BINFMT_ELF
 	  ld.so (check the file <file:Documentation/Changes> for location and
 	  latest version).
 
+config COMPAT_BINFMT_ELF
+	bool
+	depends on COMPAT && MMU
+
 config BINFMT_ELF_FDPIC
 	bool "Kernel support for FDPIC ELF binaries"
 	default y

diff --git a/fs/Makefile b/fs/Makefile
index 500cf15..0000000 100644  
--- a/fs/Makefile
+++ b/fs/Makefile

@@ -39,6 +39,7 @@ obj-$(CONFIG_BINFMT_MISC)	+= binfmt_misc
 obj-y				+= binfmt_script.o
 
 obj-$(CONFIG_BINFMT_ELF)	+= binfmt_elf.o
+obj-$(CONFIG_COMPAT_BINFMT_ELF)	+= compat_binfmt_elf.o
 obj-$(CONFIG_BINFMT_ELF_FDPIC)	+= binfmt_elf_fdpic.o
 obj-$(CONFIG_BINFMT_SOM)	+= binfmt_som.o
 obj-$(CONFIG_BINFMT_FLAT)	+= binfmt_flat.o

You totally missed the point of having selectable features noted
by a config symbol named "HAVE_*".
When you see such a "HAVE_*" you know it is supposed to be selected
and thus you need to be much more careful about the dependencies.

And my patch was purely a cooked up example btw and not at all tested.
Should have been clear about that.

My comment refer to a private mail - but I saw this hit lkml so a bit out
of context.

	Sam