On 5/21/20 9:56 AM, Konstantin Belousov wrote: > 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.
I am fine with reverting the l_addr semantic. I'm still not sure how to resolve the original PR, though perhaps Wine just has to carry a local patch forever? GDB will work via the current accident so long as we never pre-link libraries. As long as PIE binaries have a starting VA of 0 like our shared libraries then I think GDB will be ok with our PIE binaries as well. -- John Baldwin _______________________________________________ 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"
