[Buildroot] [PATCH] uclibc: prevent rebuilding after installation to staging

[Buildroot] [PATCH] uclibc: prevent rebuilding after installation to staging

[Alexey Brodkin]

Currently we configure uClibc to use kernel headers from "staging" folder with
KERNEL_HEADERS="$(STAGING_DIR)/usr/include". This path is added to include
search path of uClibc build system in Rules.mak "CFLAGS += -I$(KERNEL_HEADERS)".

At the same time on uClibc installation to "staging" we point to the same
location "$(STAGING_DIR)/usr" (headers effectively go in "usr/include").

So after every installation to "staging" dependences get touched (even though we
copy the same headers every time) and so we may see lots of sources in uClibc
get rebuilt.

This has 2 consequences:
1. Longer build time - becase even on ordinary buildroot build uClibc is built
twice. On "uclibc building" and on "uclibc installation to target".

2. Symbols in libuClibc built initially (that is later installed in
"staging/sysroot") are situated with different offset compared to second build
(later copied in "target"). This happens because as described above only part
of sources get rebuilt and then on final linkage object files are linked in
different order.

And (2) leads to problems on remote rebugging: gdbserver reports offsets that
correspond to pointless assembly in libuClibc on host.

Here's how it looks like.

Before this patch:
$ cd ~/br2_output/i586/target/lib
$ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill
   423: 0000c42c    54 FUNC    GLOBAL DEFAULT    7 kill

$ cd ~/br2_output/i586/staging/lib
$ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill
   423: 0000b518    54 FUNC    GLOBAL DEFAULT    7 kill

After this patch:
$ cd ~/br2_output/i586/target/lib
$ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill
   423: 0000b518    54 FUNC    GLOBAL DEFAULT    7 kill

$ cd ~/br2_output/i586/staging/lib
$ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill
   423: 0000b518    54 FUNC    GLOBAL DEFAULT    7 kill

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Noam Camus <noamc@ezchip.com>
---
 package/linux-headers/linux-headers.mk | 14 ++++++++++++++
 package/uclibc/uclibc.mk               |  2 +-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/package/linux-headers/linux-headers.mk b/package/linux-headers/linux-headers.mk
index 7b3edf4..8302d56 100644
--- a/package/linux-headers/linux-headers.mk
+++ b/package/linux-headers/linux-headers.mk
@@ -26,6 +26,20 @@ LINUX_HEADERS_ADD_TOOLCHAIN_DEPENDENCY = NO
 # This results in seemingly errors like:
 #   [...]/scripts/gcc-version.sh: line 26: arc-linux-uclibc-gcc: command not found
 # Those can be safely ignored.
+
+# This step is required to have a separate linux headers location for
+# uClibc building. This way uClibc doesn't modify linux headers on installation
+# of "its" headers
+define LINUX_HEADERS_CONFIGURE_CMDS
+	(cd $(@D); \
+		$(TARGET_MAKE_ENV) $(MAKE) \
+			ARCH=$(KERNEL_ARCH) \
+			HOSTCC="$(HOSTCC)" \
+			HOSTCFLAGS="$(HOSTCFLAGS)" \
+			HOSTCXX="$(HOSTCXX)" \
+			headers_install)
+endef
+
 define LINUX_HEADERS_INSTALL_STAGING_CMDS
 	(cd $(@D); \
 		$(TARGET_MAKE_ENV) $(MAKE) \
diff --git a/package/uclibc/uclibc.mk b/package/uclibc/uclibc.mk
index 717cf53..144f993 100644
--- a/package/uclibc/uclibc.mk
+++ b/package/uclibc/uclibc.mk
@@ -418,7 +418,7 @@ define UCLIBC_SETUP_DOT_CONFIG
 	$(call UCLIBC_OPT_SET,CROSS_COMPILER_PREFIX,"$(TARGET_CROSS)",$(@D))
 	$(call UCLIBC_OPT_SET,TARGET_$(UCLIBC_TARGET_ARCH),y,$(@D))
 	$(call UCLIBC_OPT_SET,TARGET_ARCH,"$(UCLIBC_TARGET_ARCH)",$(@D))
-	$(call UCLIBC_OPT_SET,KERNEL_HEADERS,"$(STAGING_DIR)/usr/include",$(@D))
+	$(call UCLIBC_OPT_SET,KERNEL_HEADERS,"$(LINUX_HEADERS_DIR)/usr/include",$(@D))
 	$(call UCLIBC_OPT_SET,RUNTIME_PREFIX,"/",$(@D))
 	$(call UCLIBC_OPT_SET,DEVEL_PREFIX,"/usr",$(@D))
 	$(call UCLIBC_OPT_SET,SHARED_LIB_LOADER_PREFIX,"/lib",$(@D))
-- 
1.9.3

[Buildroot] [PATCH] uclibc: prevent rebuilding after installation to staging

[Alexey Brodkin]

Hi all,

On Thu, 2014-06-05 at 00:27 +0400, Alexey Brodkin wrote:
> Currently we configure uClibc to use kernel headers from "staging" folder with
> KERNEL_HEADERS="$(STAGING_DIR)/usr/include". This path is added to include
> search path of uClibc build system in Rules.mak "CFLAGS += -I$(KERNEL_HEADERS)".
> 
> At the same time on uClibc installation to "staging" we point to the same
> location "$(STAGING_DIR)/usr" (headers effectively go in "usr/include").
> 
> So after every installation to "staging" dependences get touched (even though we
> copy the same headers every time) and so we may see lots of sources in uClibc
> get rebuilt.
> 
> This has 2 consequences:
> 1. Longer build time - becase even on ordinary buildroot build uClibc is built
> twice. On "uclibc building" and on "uclibc installation to target".
> 
> 2. Symbols in libuClibc built initially (that is later installed in
> "staging/sysroot") are situated with different offset compared to second build
> (later copied in "target"). This happens because as described above only part
> of sources get rebuilt and then on final linkage object files are linked in
> different order.
> 
> And (2) leads to problems on remote rebugging: gdbserver reports offsets that
> correspond to pointless assembly in libuClibc on host.
> 
> Here's how it looks like.
> 
> Before this patch:
> $ cd ~/br2_output/i586/target/lib
> $ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill
>    423: 0000c42c    54 FUNC    GLOBAL DEFAULT    7 kill
> 
> $ cd ~/br2_output/i586/staging/lib
> $ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill
>    423: 0000b518    54 FUNC    GLOBAL DEFAULT    7 kill
> 
> After this patch:
> $ cd ~/br2_output/i586/target/lib
> $ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill
>    423: 0000b518    54 FUNC    GLOBAL DEFAULT    7 kill
> 
> $ cd ~/br2_output/i586/staging/lib
> $ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill
>    423: 0000b518    54 FUNC    GLOBAL DEFAULT    7 kill

Any thoughts on this one?

Regards,
Alexey

[Buildroot] [PATCH] uclibc: prevent rebuilding after installation to staging

[Peter Korsgaard]

>>>>> "Alexey" == Alexey Brodkin <Alexey.Brodkin@synopsys.com> writes:

Hi,

 > Any thoughts on this one?

Sorry, I haven't had time to review it yet. It certainly sounds good. I
will get back to you later today or tomorrow.

-- 
Bye, Peter Korsgaard 

[Buildroot] [PATCH] uclibc: prevent rebuilding after installation to staging

[Alexey Brodkin]

Dear Peter,

On Tue, 2014-06-10 at 21:21 +0200, Peter Korsgaard wrote:
> >>>>> "Alexey" == Alexey Brodkin <Alexey.Brodkin@synopsys.com> writes:
> 
> Hi,
> 
>  > Any thoughts on this one?
> 
> Sorry, I haven't had time to review it yet. It certainly sounds good. I
> will get back to you later today or tomorrow.
> 

Please pardon me for this reminder but I'm wondering if you were able to
try this patch?

Regards,
Alexey

[Buildroot] [PATCH] uclibc: prevent rebuilding after installation to staging

[Peter Korsgaard]

>>>>> "Alexey" == Alexey Brodkin <Alexey.Brodkin@synopsys.com> writes:

 > Dear Peter,

 >> > Any thoughts on this one?
 >> 
 >> Sorry, I haven't had time to review it yet. It certainly sounds good. I
 >> will get back to you later today or tomorrow.
 >> 

 > Please pardon me for this reminder but I'm wondering if you were able to
 > try this patch?

I'm really sorry, but real life got in the way. I'll test it now.

-- 
Bye, Peter Korsgaard 

[Buildroot] [PATCH] uclibc: prevent rebuilding after installation to staging

[Alexey Brodkin]

Dear Peter,


On Mon, 2014-06-16 at 09:20 +0200, Peter Korsgaard wrote:
> >>>>> "Alexey" == Alexey Brodkin <Alexey.Brodkin@synopsys.com> writes:
> 
>  > Dear Peter,
> 
>  >> > Any thoughts on this one?
>  >> 
>  >> Sorry, I haven't had time to review it yet. It certainly sounds good. I
>  >> will get back to you later today or tomorrow.
>  >> 
> 
>  > Please pardon me for this reminder but I'm wondering if you were able to
>  > try this patch?
> 
> I'm really sorry, but real life got in the way. I'll test it now.

I'm wondering if you faced any issues during your testing, may I help
you somehow?

Regards,
Alexey

[Buildroot] [PATCH] uclibc: prevent rebuilding after installation to staging

[Peter Korsgaard]

>>>>> "Alexey" == Alexey Brodkin <Alexey.Brodkin@synopsys.com> writes:

Hi,

 >> > Please pardon me for this reminder but I'm wondering if you were able to
 >> > try this patch?
 >> 
 >> I'm really sorry, but real life got in the way. I'll test it now.

 > I'm wondering if you faced any issues during your testing, may I help
 > you somehow?

Sorry, I didn't got around to check it before now. Looks good, and I
have verified that it isn't needed for glibc and musl.

Committed, thanks.

-- 
Bye, Peter Korsgaard