> Executables and dynamic libraries on Linux can encode a search path that the > dynamic linker will use when looking up library dependencies, generally > referred to as an "rpath". In the JDK we use this with the $ORIGIN feature to > set search paths relative to the location of the binary itself. Typically > executables in the bin/ directory have the rpath "$ORIGIN/../lib" to find > libjli.so. Most of the libraries in lib/ have rpath set to just "$ORIGIN" to > find each other. > > There are two different types of such rpaths, RPATH and RUNPATH. The former > is the earlier incantation but RUNPATH has been around since about 2003 and > has been default in prominent Linux distros for a long time, and now also > seems to be default in the linker directly from binutils. The toolchain used > by Oracle defaulted to RPATH until at least JDK 11, but since then with some > toolchain upgrade, the default was flipped to RUNPATH. > > The main (relevant in this case) difference between the two is that RPATH is > considered before the LD_LIBRARY_PATH environment variable, while RUNPATH is > only considered after LD_LIBRARY_PATH. For libraries that are part of a Linux > distribution, letting users, or the system, control and override builtin > rpaths with LD_LIBRARY_PATH seems like a reasonable thing to prefer. However, > for the JDK, there really is no usecase for having an externally configured > LD_LIBRARY_PATH potentially getting in the way of the JDK libraries finding > each other correctly. If a user environment sets LD_LIBRARY_PATH, and there > is a library in that path with the same name as a JDK library (e.g. libnet.so > or some other generically named library) that external library will be loaded > instead of the JDK internal library and that is basically guaranteed to break > the JDK. There is no supported usecase that I can think of for injecting > other versions of such libraries in a JDK distribution. > > I propose that we explicitly configure the JDK build to set RPATH instead of > RUNPATH for Linux binaries. This is done with the linker flag > "--disable-new-dtags".
Erik Joelsson has updated the pull request incrementally with one additional commit since the last revision: bug ref ------------- Changes: - all: https://git.openjdk.org/jdk/pull/18050/files - new: https://git.openjdk.org/jdk/pull/18050/files/faafef8a..8639eee5 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=18050&range=03 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18050&range=02-03 Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/18050.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/18050/head:pull/18050 PR: https://git.openjdk.org/jdk/pull/18050
