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kmod: disable --gc-sections ld option when building for xtensa

PATCH New Max Filippov 2 participants 3 messages Mar 4, 2014

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PATCH 1/1 kmod: disable --gc-sections ld option when building for xtensa

This is a workaround for the following ld issue exhibited by --gc-sections option, until a proper fix for binutils is ready:

ld: BFD (GNU Binutils) 2.22 internal error, aborting at elf32-xtensa.c line 3374 in elf_xtensa_finish_dynamic_sections

---
 package/kmod/900-disable-gc-sections.patch.xtensa | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 package/kmod/900-disable-gc-sections.patch.xtensa
package/kmod/900-disable-gc-sections.patch.xtensa new file +12 -0
new file mode 100644
index 0000000..2b7a9cb
@@ -0,0 +1,12 @@
+--- kmod-16/configure	2013-12-23 01:31:12.456202872 +0400
++++ kmod-16.mod/configure	2014-03-04 22:53:37.132241845 +0400
+@@ -14511,8 +14511,7 @@
+ 
+ 
+   for flag in  \
+-		       -Wl,--as-needed \
+-		       -Wl,--gc-sections; do
++		       -Wl,--as-needed ; do
+ 
+   { $as_echo "$as_me:${as_lineno-$LINENO}: checking if $CC supports flag $flag in envvar LDFLAGS" >&5
+ $as_echo_n "checking if $CC supports flag $flag in envvar LDFLAGS... " >&6; }
Signature · 1 line
1.8.1.4
#1 lore raw

PATCH 1/1 kmod: disable --gc-sections ld option when building for xtensa

Dear Max Filippov,

Quoted 8 lines · Max Filippov

This is a workaround for the following ld issue exhibited by --gc-sections option, until a proper fix for binutils is ready:

ld: BFD (GNU Binutils) 2.22 internal error, aborting at elf32-xtensa.c line 3374 in elf_xtensa_finish_dynamic_sections

---
 package/kmod/900-disable-gc-sections.patch.xtensa | 12 ++++++++++++

The patch should be named kmod-01-<description>.patch. We no longer accept architecture-specific patches, so the .xtensa extension has to go, and we have to ensure that the fix is usable on all architectures.

So either we simply remove --gc-sections on all architecture, or the configure.ac test has to be made conditional on xtensa.

package/kmod/900-disable-gc-sections.patch.xtensa

Quoted 8 lines
 1 file changed, 12 insertions(+)
 create mode 100644 package/kmod/900-disable-gc-sections.patch.xtensa
package/kmod/900-disable-gc-sections.patch.xtensa new file +0 -0
new file mode 100644
index 0000000..2b7a9cb

The patch lacks a description. See
http://buildroot.org/downloads/manual/manual.html#patch-policy for more details about the format of the patches.

package/kmod/900-disable-gc-sections.patch.xtensa line 3

Quoted 4 lines
package/kmod/900-disable-gc-sections.patch.xtensa new file +3 -0
@@ -0,0 +1,12 @@
+--- kmod-16/configure	2013-12-23 01:31:12.456202872 +0400
++++ kmod-16.mod/configure	2014-03-04 22:53:37.132241845 +0400
+@@ -14511,8 +14511,7 @@

We normally prefer to patch configure.ac, and add KMOD_AUTORECONF = YES.

All that being said, I believe there is a much simpler solution. Don't use any patch at all, and add:

# --gc-sections triggers a bug in the current Xtensa binutils ifeq ($(BR2_xtensa),y)
KMOD_CONF_ENV += cc_cv_LDFLAGS__Wl___gc_sections=no endif

to package/kmod/kmod.mk.

Can you test that it works for you, and submit the corresponding patch?

Thanks!

Thomas

Signature · 3 lines
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
#2 lore raw

PATCH 1/1 kmod: disable --gc-sections ld option when building for xtensa

Hi Thomas,

Quoted 9 lines · Thomas Petazzoni
Quoted 8 lines · Max Filippov

This is a workaround for the following ld issue exhibited by --gc-sections option, until a proper fix for binutils is ready:

ld: BFD (GNU Binutils) 2.22 internal error, aborting at elf32-xtensa.c line 3374 in elf_xtensa_finish_dynamic_sections

---
 package/kmod/900-disable-gc-sections.patch.xtensa | 12 ++++++++++++

[...]

Quoted 11 lines

I believe there is a much simpler solution. Don't
use any patch at all, and add:

# --gc-sections triggers a bug in the current Xtensa binutils ifeq ($(BR2_xtensa),y)
KMOD_CONF_ENV += cc_cv_LDFLAGS__Wl___gc_sections=no endif

to package/kmod/kmod.mk.

Can you test that it works for you, and submit the corresponding patch?

thank you for the review and for the suggested solution, it works for me and I like it, though it doesn't look obvious. I'll submit v2.

Signature · 2 lines
Thanks.
-- Max