| Message ID | 20190831180113.16025-1-itsatharva@gmail.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v2,1/2] toolchain/toolchain-wrapper: explicitly set Build ID to none if BR2_REPRODUCIBLE | expand |
Hi Atharva, Le 31/08/2019 à 20:01, Atharva Lele a écrit : > Build ID is added to binaries at link time. Building in different output > directories causes some packages to have different Build IDs, thus resulting in > non-reproducibility. > > Adding "-Wl,--build-id=none" fixes this issue by disabling setting of Build ID. > > Diffoscope output for Build ID issue: https://gitlab.com/snippets/1886180/raw > > After this patch, build is reproducible - i.e. diffoscope does not produce any > output. --build-id option is available in binutils since 2.18 release (from 2007). (Add a new ELF linker option, --build-id, to generate a unique per-binary identifier embedded in a note section.) [1] I don't think there is still toolchain using such old version with an up-to-date Buildroot tree :) [1] https://lwn.net/Articles/273637/ Reviewed-by: Romain Naour <romain.naour@smile.fr> Best regards, Romain > > Signed-off-by: Atharva Lele <itsatharva@gmail.com> > --- > Changes v1 -> v2: > - Handle inside toolchain-wrapper.mk instead of both .mk and .c > --- > toolchain/toolchain-wrapper.mk | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/toolchain/toolchain-wrapper.mk b/toolchain/toolchain-wrapper.mk > index 970bde76a0..88695a5b2d 100644 > --- a/toolchain/toolchain-wrapper.mk > +++ b/toolchain/toolchain-wrapper.mk > @@ -21,6 +21,10 @@ TOOLCHAIN_WRAPPER_OPTS = \ > $(call qstrip,$(BR2_SSP_OPTION)) \ > $(call qstrip,$(BR2_TARGET_OPTIMIZATION)) > > +ifeq ($(BR2_REPRODUCIBLE),y) > +TOOLCHAIN_WRAPPER_OPTS += -Wl,--build-id=none > +endif > + > # We create a list like '"-mfoo", "-mbar", "-mbarfoo"' so that each flag is a > # separate argument when used in execv() by the toolchain wrapper. > TOOLCHAIN_WRAPPER_ARGS += \ >
On Sat, 31 Aug 2019 23:31:12 +0530 Atharva Lele <itsatharva@gmail.com> wrote: > Build ID is added to binaries at link time. Building in different output > directories causes some packages to have different Build IDs, thus resulting in > non-reproducibility. > > Adding "-Wl,--build-id=none" fixes this issue by disabling setting of Build ID. > > Diffoscope output for Build ID issue: https://gitlab.com/snippets/1886180/raw > > After this patch, build is reproducible - i.e. diffoscope does not produce any > output. > > Signed-off-by: Atharva Lele <itsatharva@gmail.com> > --- > Changes v1 -> v2: > - Handle inside toolchain-wrapper.mk instead of both .mk and .c > --- > toolchain/toolchain-wrapper.mk | 4 ++++ > 1 file changed, 4 insertions(+) Applied to master, thanks. Thomas
diff --git a/toolchain/toolchain-wrapper.mk b/toolchain/toolchain-wrapper.mk index 970bde76a0..88695a5b2d 100644 --- a/toolchain/toolchain-wrapper.mk +++ b/toolchain/toolchain-wrapper.mk @@ -21,6 +21,10 @@ TOOLCHAIN_WRAPPER_OPTS = \ $(call qstrip,$(BR2_SSP_OPTION)) \ $(call qstrip,$(BR2_TARGET_OPTIMIZATION)) +ifeq ($(BR2_REPRODUCIBLE),y) +TOOLCHAIN_WRAPPER_OPTS += -Wl,--build-id=none +endif + # We create a list like '"-mfoo", "-mbar", "-mbarfoo"' so that each flag is a # separate argument when used in execv() by the toolchain wrapper. TOOLCHAIN_WRAPPER_ARGS += \
Build ID is added to binaries at link time. Building in different output directories causes some packages to have different Build IDs, thus resulting in non-reproducibility. Adding "-Wl,--build-id=none" fixes this issue by disabling setting of Build ID. Diffoscope output for Build ID issue: https://gitlab.com/snippets/1886180/raw After this patch, build is reproducible - i.e. diffoscope does not produce any output. Signed-off-by: Atharva Lele <itsatharva@gmail.com> --- Changes v1 -> v2: - Handle inside toolchain-wrapper.mk instead of both .mk and .c --- toolchain/toolchain-wrapper.mk | 4 ++++ 1 file changed, 4 insertions(+)