path: root/init
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authorMasahiro Yamada <yamada.masahiro@socionext.com>2019-07-01 09:58:40 +0900
committerMasahiro Yamada <yamada.masahiro@socionext.com>2019-07-08 23:13:57 +0900
commitd6fc9fcbaa655cff2d2be05e16867d1918f78b85 (patch)
tree963ee9a8fa175e10b832aa6a5d724ae5acb1f5bd /init
parent1a927fd347ebb3c02046150ee489d4fe4e6b9e81 (diff)
kbuild: compile-test exported headers to ensure they are self-contained
Multiple people have suggested compile-testing UAPI headers to ensure they can be really included from user-space. "make headers_check" is obviously not enough to catch bugs, and we often leak unresolved references to user-space. Use the new header-test-y syntax to implement it. Please note exported headers are compile-tested with a completely different set of compiler flags. The header search path is set to $(objtree)/usr/include since exported headers should not include unexported ones. We use -std=gnu89 for the kernel space since the kernel code highly depends on GNU extensions. On the other hand, UAPI headers should be written in more standardized C, so they are compiled with -std=c90. This will emit errors if C++ style comments, the keyword 'inline', etc. are used. Please use C style comments (/* ... */), '__inline__', etc. in UAPI headers. There is additional compiler requirement to enable this test because many of UAPI headers include <stdlib.h>, <sys/ioctl.h>, <sys/time.h>, etc. directly or indirectly. You cannot use kernel.org pre-built toolchains [1] since they lack <stdlib.h>. I reused CONFIG_CC_CAN_LINK to check the system header availability. The intention is slightly different, but a compiler that can link userspace programs provide system headers. For now, a lot of headers need to be excluded because they cannot be compiled standalone, but this is a good start point. [1] https://mirrors.edge.kernel.org/pub/tools/crosstool/index.html Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Diffstat (limited to 'init')
1 files changed, 10 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig
index 2e9813daa2c1..74192de8ada6 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -108,6 +108,16 @@ config HEADER_TEST
If you are a developer or tester and want to ensure the requested
headers are self-contained, say Y here. Otherwise, choose N.
+ bool "Compile test UAPI headers"
+ help
+ Compile test headers exported to user-space to ensure they are
+ self-contained, i.e. compilable as standalone units.
+ If you are a developer or tester and want to ensure the exported
+ headers are self-contained, say Y here. Otherwise, choose N.
string "Local version - append to kernel release"

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