On 21-02-2013 16:44, Konstantin Belousov wrote: > On Thu, Feb 21, 2013 at 12:57:45AM +0200, Damjan Jovanovic wrote: >> On Wed, Feb 20, 2013 at 10:51 PM, Tijl Coosemans <t...@coosemans.org> wrote: >>> On 20-02-2013 16:48, Konstantin Belousov wrote: >>>> On Wed, Feb 20, 2013 at 05:29:01PM +0200, Damjan Jovanovic wrote: >>>>> Hi >>>>> >>>>> Wine needs some of its libraries to be loaded at specific base >>>>> addresses (https://wiki.freebsd.org/Wine), something FreeBSD currently >>>>> lacks. >>>>> >>>>> I've written a patch to the dynamic loader (/libexec/ld-elf.so.1) that >>>>> loads libraries at their preferred base addresses >>>>> (http://www.freebsd.org/cgi/query-pr.cgi?pr=176216), as well as a port >>>>> of Prelink to FreeBSD which Wine uses to set base addresses >>>>> (http://www.freebsd.org/cgi/query-pr.cgi?pr=176283). Both work :-), >>>>> the changed dynamic loader doesn't show any problems in a few days of >>>>> testing, and prelink works with the --reloc-only option as used by >>>>> Wine. >>>>> >>>>> Please review/test/comment/commit. >>>> >>>> Unfortunately, it is not safe. MAP_FIXED overrides any previous mappings >>>> which could exist at the specified address. >>> >>> I've simplified the rtld patch to a single line. The second patch makes >>> Wine use -Ttext-segment linker flag instead of prelink. This requires >>> binutils from ports, but it's easier than porting prelink. >>> >> >> All of that occurred to me as well. >> >> The problem with that one-line rtld patch is that loading an >> application will now fail if any of its libraries cannot be loaded at >> their requested address. > But this is intended behaviour. Also, the default virtaddr base for the > shared libraries is 0, so the existing binaries should be not affected. > >> >> The problem with -Ttext-segment (and isn't it just -Ttext?) is that it >> doesn't seem to work: the base_vaddr seen by rtld will remain 0, and >> the address listed in /proc/.../map is different from what it should >> be. Also run "readelf -l" on a library compiled that way and compare >> with the output of one run through "prelink --reloc-only", you'll see >> the lowest VirtAddr and PhysAddr in LOAD headers change only with >> prelink. I really ported prelink because there was no other choice. > The -Ttext-segment does work. As indicated by Tijl, you need recent > binutils. I just verified that ld 2.32.1 obeys -Ttext-segment. > > You can also take a look at the default linker script to see how > -Ttext-segment is used, look for SEGMENT_START("text-segment").
Yes, -Ttext sets the address of the .text section and -Ttext-segment that of the text segment. It does work for me. The output of /proc/.../map looks correct as does the output of "info share" in winedbg, but to be sure I've asked on wine-devel mailing list if they see any problem with this approach.
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