[lttng-dev] [RFC PATCH lttng-ust 2/2] dl instrumentation: add dlmopen event, trace dlopen flags

[Thomas Petazzoni]

Hello,

On Tue, 21 Feb 2017 14:08:08 +0000 (UTC), Mathieu Desnoyers wrote:

> My expectation is that the dlmopen override symbol gets generated,
> but it is never invoked in builds where the libc does not implement
> it, so we never have to look it up dynamically through dlsym().

The main issue is that the Lmid_t type doesn't exist I believe.

> How does the build fail with musl ? Can you provide the build
> output ?

Sure:

  http://autobuild.buildroot.net/results/113/113fa95a054df183014b43ec36b329f9c59bd356/build-end.log

If you want to reproduce:

$ git clone git://git.busybox.net/buildroot
$ cd buildroot/
$ git checkout 2017.02-rc2
$ cat > .config
BR2_arm=y
BR2_cortex_a9=y
BR2_ARM_ENABLE_VFP=y
BR2_TOOLCHAIN_EXTERNAL=y
BR2_TOOLCHAIN_EXTERNAL_CUSTOM=y
BR2_TOOLCHAIN_EXTERNAL_DOWNLOAD=y
BR2_TOOLCHAIN_EXTERNAL_URL="http://autobuild.buildroot.org/toolchains/tarballs/br-arm-cortex-a9-musl-2017.02-rc1-2-g133c5ac.tar.bz2"
BR2_TOOLCHAIN_EXTERNAL_GCC_5=y
BR2_TOOLCHAIN_EXTERNAL_HEADERS_4_9=y
BR2_TOOLCHAIN_EXTERNAL_CUSTOM_MUSL=y
BR2_TOOLCHAIN_EXTERNAL_CXX=y
BR2_INIT_NONE=y
BR2_SYSTEM_BIN_SH_NONE=y
# BR2_PACKAGE_BUSYBOX is not set
BR2_PACKAGE_LTTNG_LIBUST=y
# BR2_TARGET_ROOTFS_TAR is not set
$ make olddefconfig
$ make

Takes ~5 minutes maybe for the all build to proceed until it breaks on
lttng-ust.

Thanks!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com