From c01226c3145d173a0d38f9d5b4f229cc23d99ae2 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 21 Sep 2009 16:37:12 +0200 Subject: [PATCH] warn about use of uninstalled kernel headers User applications frequently hit problems when they try to use the kernel headers directly, rather than the exported headers. This adds an explicit warning for this case, and points to a URL holding an explanation of why this is wrong and what to do about it. Signed-off-by: Arnd Bergmann Signed-off-by: Sam Ravnborg --- include/linux/kernel.h | 6 ++++++ scripts/headers_install.pl | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index d3cd23f3003..f4e3184fa05 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -659,6 +659,12 @@ extern int do_sysinfo(struct sysinfo *info); #endif /* __KERNEL__ */ +#ifndef __EXPORTED_HEADERS__ +#ifndef __KERNEL__ +#warning Attempt to use kernel headers from user space, see http://kernelnewbies.org/KernelHeaders +#endif /* __KERNEL__ */ +#endif /* __EXPORTED_HEADERS__ */ + #define SI_LOAD_SHIFT 16 struct sysinfo { long uptime; /* Seconds since boot */ diff --git a/scripts/headers_install.pl b/scripts/headers_install.pl index c6ae4052ab4..b89ca2c58fd 100644 --- a/scripts/headers_install.pl +++ b/scripts/headers_install.pl @@ -20,7 +20,7 @@ use strict; my ($readdir, $installdir, $arch, @files) = @ARGV; -my $unifdef = "scripts/unifdef -U__KERNEL__"; +my $unifdef = "scripts/unifdef -U__KERNEL__ -D__EXPORTED_HEADERS__"; foreach my $file (@files) { local *INFILE;