On Thu, May 21, 2020 at 09:03:44AM -0700, John Baldwin wrote: > On 5/21/20 8:12 AM, Mark Johnston wrote: > > On Thu, May 21, 2020 at 04:41:52PM +0300, Konstantin Belousov wrote: > >> On Thu, May 21, 2020 at 03:02:07PM +0200, Antoine Brodin wrote: > >>> On Thu, May 21, 2020 at 12:08 AM Konstantin Belousov <k...@freebsd.org> > >>> wrote: > >>>> > >>>> Author: kib > >>>> Date: Wed May 20 22:08:26 2020 > >>>> New Revision: 361303 > >>>> URL: https://svnweb.freebsd.org/changeset/base/361303 > >>>> > >>>> Log: > >>>> Change the samantic of struct link_map l_addr member. > >>>> > >>>> It previously returned the object map base address, while all other > >>>> ELF operating systems return load offset, i.e. the difference between > >>>> map base and the link base. > >>>> > >>>> Explain the meaning of the field in the man page. > >>>> > >>>> Stop filling the mips-only l_offs member, which is apparently unused. > >>>> > >>>> PR: 246561 > >>>> Requested by: Damjan Jovanovic <damjan....@gmail.com> > >>>> Reviewed by: emaste, jhb, cem (previous version) > >>>> Sponsored by: The FreeBSD Foundation > >>>> MFC after: 1 week > >>>> Differential revision: https://reviews.freebsd.org/D24918 > >>>> > >>>> Modified: > >>>> head/lib/libc/gen/dlinfo.3 > >>>> head/libexec/rtld-elf/rtld.c > >>>> head/sys/sys/link_elf.h > >>> > >>> Hi, > >>> > >>> After this commit, some ports fail to build with signal 11. > >>> For instance lang/perl5.30 fails to build with default options (DTRACE on) > >>> Disabling the DTRACE option makes it able to build again. > >>> > >> I see, thank you for reporting. > >> > >> So drti.c:dtrace_dof_init() does read l_addr, and the dtrace code assumes > >> that l_addr is the base, not relocbase. > >> > >> Mark, was dofhp_addr initialization changed comparing to Solaris ? > > > > It appears it has been the same since DTrace was imported. illumos > > still has similar code. > > > > Note that drti.o is linked into any executable and shlib that defines > > static probes, so the ABI change affects more than just dtrace(1). > > Would it be possible to define a new value for RTLD_DI_LINKMAP, and > > preserve the old behaviour for the old value? > > I think a bigger question is if Solaris/illumos treat l_addr as mapbase > (absolute address) or relocbase (relative address). In the discussion > in the phabricator I had assumed that all other OS's treated l_addr as > the relative offset (relocbase). Does the code for illumos assume an > absolute address or does it assume a relative address in l_addr?
It is rather clear, since the dtrace code was pristine, that Solaris provides the mapbase. I do not have Solaris/Illumos box anymore (for quite some time), so I cannot check directly. My current PoV is that l_addr semantic must be restored, and relocbase provided by newly added member. BTW, it is strange that perl triggers it, is it linked as PIE on HEAD ? _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
