From: Davidlohr Bueso <dave@xxxxxxx> Layout the base for tips on debugging util-linux programs/wrappers. Signed-off-by: Davidlohr Bueso <dave@xxxxxxx> --- Documentation/README.debug | 30 ++++++++++++++++++++++++++++++ 1 files changed, 30 insertions(+), 0 deletions(-) create mode 100644 Documentation/README.debug diff --git a/Documentation/README.debug b/Documentation/README.debug new file mode 100644 index 0000000..7ead12f --- /dev/null +++ b/Documentation/README.debug @@ -0,0 +1,30 @@ +Debugging util-linux programs +----------------------------- + +There are considerations to be made when profiling or debugging some programs found +in the util-linux package. Because wrapper scripts are used for the binaries to make +sure all library dependencies are met, you cannot use tools such as gdb or valgrind +directly with them. + +Let's take for example the mount command: + +$> file /path/util-linux/mount/mount +mount: Bourne-Again shell script text executable + +The binary itself is located in the .libs/ dir: + +$> file /path/util-linux/mount/.libs/mount +mount: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.15, not stripped + +When this command is run, there's a library dependency error: +./mount: /lib/x86_64-linux-gnu/libblkid.so.1: version `BLKID_2.20' not found (required by ./mount) + +To overcome this we need set the LD_LIBRARY_PATH variable to read the path of the shared lib found in +the sources, and not system-wide: + +$> export LD_LIBRARY_PATH=/path/util-linux/libblkid/src/.libs/:$LD_LIBRARY_PATH + +Now external debugging tools can be run on the binary. + +Happy hacking! +Davidlohr Bueso, August 2011 -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
