[fpc-pascal] Linux i386 libraries and PIC
Ludo Brands
ludo.brands at free.fr
Thu Jun 2 11:32:06 CEST 2011
Ran gdb to find out what happens on the addresses listed below.
In systutils, most are push imm32 DefaultFormatSettings (sysstr.inc).
DefaultFormatSettings is defined in sysinth.inc where it's declaration is
followed by Formatsettings : TFormatSettings absolute DefaultFormatSettings;
. Is the absolute directive known to cause PIC problems?
SYSUTILS_SUPPORTS$IUNKNOWN$TCLASS$formal$$BOOLEAN does a push imm32
IObjectInstance defined in objpash.inc.
The BASEUNIX_x (bunxovl.inc) make an absolute reference to the #0 string in
path:=path+#0;!!!
Any clues???
> -----Message d'origine-----
> De : fpc-pascal-bounces at lists.freepascal.org
> [mailto:fpc-pascal-bounces at lists.freepascal.org] De la part
> de Ludo Brands
> Envoyé : mercredi 1 juin 2011 17:17
> À : 'FPC-Pascal users discussions'
> Objet : RE : [fpc-pascal] Linux i386 libraries and PIC
>
>
> Scanelf -qT gives more information:
>
> libtestpic.so: (memory/data?) [0x241B7] in (optimized out: previous
> _$SYSTEM$_Ld159) [0x241B4]
> libtestpic.so: (memory/data?) [0x24397] in (optimized out: previous
> .La330) [0x24383]
> libtestpic.so: (memory/data?) [0x24577] in (optimized out: previous
> .La337) [0x24555]
> libtestpic.so: (memory/data?) [0x35318] in (optimized out: previous
> _$CLASSES$_Ld454) [0x350BE]
> libtestpic.so: (memory/data?) [0x48465] in (optimized out:
> previous .La29) [0x4844C]
> libtestpic.so: (memory/data?) [0x6201E] in (optimized out: previous
> SYSUTILS_FORMAT$ANSISTRING$array_of_const$$ANSISTRING) [0x62000]
> libtestpic.so: (memory/data?) [0x62168] in (optimized out: previous
> SYSUTILS_FORMATBUF$formal$LONGWORD$formal$LONGWORD$array_of_co
> nst$$LONGWORD)
> [0x62140]
> libtestpic.so: (memory/data?) [0x62261] in (optimized out: previous
> SYSUTILS_FMTSTR$ANSISTRING$ANSISTRING$array_of_const) [0x62240]
> libtestpic.so: (memory/data?) [0x622A1] in (optimized out: previous
> SYSUTILS_STRFMT$PCHAR$PCHAR$array_of_const$$PCHAR) [0x62280]
> libtestpic.so: (memory/data?) [0x62345] in (optimized out: previous
> SYSUTILS_STRLFMT$PCHAR$LONGWORD$PCHAR$array_of_const$$PCHAR) [0x62320]
> libtestpic.so: (memory/data?) [0x626AE] in (optimized out: previous
> DBG_BASEUNIX_TRLIMIT) [0x626A7]
> libtestpic.so: (memory/data?) [0x640EC] in (optimized out: previous
> SYSUTILS_FLOATTOTEXT$PCHAR$EXTENDED$TFLOATFORMAT$LONGINT$LONGI
> NT$$LONGINT)
> [0x640C0]
> libtestpic.so: (memory/data?) [0x64179] in (optimized out: previous
> SYSUTILS_FLOATTOSTRF$EXTENDED$TFLOATFORMAT$LONGINT$LONGINT$$AN
> SISTRING)
> [0x64150]
> libtestpic.so: (memory/data?) [0x64204] in (optimized out: previous
> SYSUTILS_FLOATTOSTRF$CURRENCY$TFLOATFORMAT$LONGINT$LONGINT$$AN
> SISTRING)
> [0x641E0]
> libtestpic.so: (memory/data?) [0x642AE] in (optimized out: previous
> SYSUTILS_FLOATTOSTRF$DOUBLE$TFLOATFORMAT$LONGINT$LONGINT$$ANSISTRING)
> [0x64280]
> libtestpic.so: (memory/data?) [0x64341] in (optimized out: previous
> SYSUTILS_FLOATTOSTRF$SINGLE$TFLOATFORMAT$LONGINT$LONGINT$$ANSISTRING)
> [0x64320]
> libtestpic.so: (memory/data?) [0x643D4] in (optimized out: previous
> SYSUTILS_FLOATTOSTRF$COMP$TFLOATFORMAT$LONGINT$LONGINT$$ANSISTRING)
> [0x643B0]
> libtestpic.so: (memory/data?) [0x64474] in (optimized out: previous
> SYSUTILS_FLOATTOSTRF$INT64$TFLOATFORMAT$LONGINT$LONGINT$$ANSISTRING)
> [0x64450]
> libtestpic.so: (memory/data?) [0x68E78] in (optimized out: previous
> SYSUTILS_STRTODATE$PCHAR$LONGINT$ANSISTRING$CHAR$$TDATETIME) [0x68E30]
> libtestpic.so: (memory/data?) [0x69995] in (optimized out: previous
> SYSUTILS_STRTOTIME$PCHAR$LONGINT$CHAR$$TDATETIME) [0x69950]
> libtestpic.so: (memory/data?) [0x6AFC8] in (optimized out: previous
> SYSUTILS_TRYSTRTODATE$SHORTSTRING$TDATETIME$ANSISTRING$CHAR$$BOOLEAN)
> [0x6AF80]
> libtestpic.so: (memory/data?) [0x6B0A0] in (optimized out: previous
> SYSUTILS_TRYSTRTODATE$ANSISTRING$TDATETIME$ANSISTRING$CHAR$$BOOLEAN)
> [0x6B040]
> libtestpic.so: (memory/data?) [0x6B305] in (optimized out: previous
> SYSUTILS_TRYSTRTOTIME$SHORTSTRING$TDATETIME$CHAR$$BOOLEAN) [0x6B2C0]
> libtestpic.so: (memory/data?) [0x6B40D] in (optimized out: previous
> SYSUTILS_TRYSTRTOTIME$ANSISTRING$TDATETIME$CHAR$$BOOLEAN) [0x6B3B0]
> libtestpic.so: (memory/data?) [0x6E36E] in (optimized out: previous
> SYSUTILS_WIDEFORMAT$WIDESTRING$array_of_const$$WIDESTRING) [0x6E350]
> libtestpic.so: (memory/data?) [0x6E4B8] in (optimized out:
> previous
> SYSUTILS_WIDEFORMATBUF$formal$LONGWORD$formal$LONGWORD$array_o
> f_const$$LONGW
> ORD) [0x6E490]
> libtestpic.so: (memory/data?) [0x6E5B1] in (optimized out: previous
> SYSUTILS_WIDEFMTSTR$WIDESTRING$WIDESTRING$array_of_const) [0x6E590]
> libtestpic.so: (memory/data?) [0x6FEFE] in (optimized out: previous
> SYSUTILS_UNICODEFORMAT$UNICODESTRING$array_of_const$$UNICODESTRING)
> [0x6FEE0]
> libtestpic.so: (memory/data?) [0x70048] in (optimized out:
> previous
> SYSUTILS_UNICODEFORMATBUF$formal$LONGWORD$formal$LONGWORD$arra
> y_of_const$$LO
> NGWORD) [0x70020]
> libtestpic.so: (memory/data?) [0x70141] in (optimized out: previous
> SYSUTILS_UNICODEFMTSTR$UNICODESTRING$UNICODESTRING$array_of_co
> nst) [0x70120]
> libtestpic.so: (memory/data?) [0x7116B] in (optimized out: previous
> SYSUTILS_SUPPORTS$IUNKNOWN$TCLASS$formal$$BOOLEAN) [0x71140]
> libtestpic.so: (memory/data?) [0x7BF23] in (optimized out: previous
> UNIX_READTIMEZONEFILE$SHORTSTRING) [0x7BE50]
> libtestpic.so: (memory/data?) [0x7EC41] in (optimized out: previous
> BASEUNIX_FPGETENV$SHORTSTRING$$PCHAR) [0x7EC10]
> libtestpic.so: (memory/data?) [0x80C64] in (optimized out: previous
> BASEUNIX_FPOPEN$SHORTSTRING$LONGINT$$LONGINT) [0x80C30]
> libtestpic.so: (memory/data?) [0x80CD7] in (optimized out: previous
> BASEUNIX_FPOPEN$SHORTSTRING$LONGINT$LONGWORD$$LONGINT) [0x80CA0]
> libtestpic.so: (memory/data?) [0x80DB1] in (optimized out: previous
> BASEUNIX_FPOPENDIR$SHORTSTRING$$PDIR) [0x80D80]
> libtestpic.so: (memory/data?) [0x80E24] in (optimized out: previous
> BASEUNIX_FPSTAT$SHORTSTRING$STAT$$LONGINT) [0x80DF0]
> libtestpic.so: (memory/data?) [0x8162C] in (optimized out: previous
> UNIXUTIL_STRINGTOPPCHAR$SHORTSTRING$SMALLINT$$PPCHAR) [0x81610]
> libtestpic.so
>
> AFAIK these are all part of the rtl. Why are only these remaining?
>
>
>
> > -----Message d'origine-----
> > De : fpc-pascal-bounces at lists.freepascal.org
> > [mailto:fpc-pascal-bounces at lists.freepascal.org] De la part
> > de Ludo Brands
> > Envoyé : mercredi 1 juin 2011 15:23
> > À : 'FPC-Pascal users discussions'
> > Objet : [fpc-pascal] Linux i386 libraries and PIC
> >
> >
> > Dear all,
> >
> > I'm trying to create a library on linux i386 that contains
> > only PIC code. The library is a driver that runs unconfined
> > causing SELinux (Fedora) to block the loading of the library.
> > The library is compiled with -fPIC but eu-findtextrel reports
> > a lot of relocations (4933 in my library and 3852 in a small
> > testlibrary). The problem seems to be that the RTL isn't
> > compiled with -fPIC. And that is where I need your help. Here
> > is what I tried so far (fpc 2.5.1 svn 17622):
> > 1) (bootstrap compiler 2.4.4)
> > make clean all OPT="-fPIC"
> > --> EAccessViolation when compiling system.pp with ppc386 (the
> > --> bootstrap)
> >
> > 2) (bootstrap compiler 2.5.1 build with make clean all)
> > make clean all OPT="-fPIC" PP=/path/to/2.5.1/compiler
> > --> EAccessViolation when compiling ../unix/classes with ppc1
> >
> > Compiler doesn't need to be PIC. So try rebuilding rtl only.
> >
> > 3) (fpc 2.4.4)
> > make clean all OPT="-g -gw"
> > cd rtl
> > make clean OPT="-fPIC -g -gw"
> > --> EAccessViolation when compiling system.pp
> >
> > 4) (still in dir rtl)
> > make clean OPT="-fPIC -g -gw" PP=/path/to/2.5.1/compiler
> > cd ..
> > sudo make install
> > --> changed checksum for system.pp, recompile cairo, can't find unit
> > --> cairo
> >
> > 5)
> > sudo make install OPT="-Fu/path/to/svn/packages/*/src/"
> > PP=/path/to/2.5.1/compiler
> > sudo make sourceinstall PP=/path/to/2.5.1/compiler
> >
> > All OK. RTL should be PIC now. Rebuild testlibrary. Result
> > from eu-findtextrel 38: relocations for the testproject.
> > Much, much better, but not zero :( Although the compiler (and
> > the testproject) was build with -g -gw, eu-findtextrel
> > doesn't provide any usefull info on the relocation. It only
> > says "the file containing the function 'test' might not be
> > compiled with -fpic/-fPIC" for avery relocation found.
> > eu-readelf -r shows 9692 386_relative and 4 386_JMP_SLOT
> > type relocations.
> >
> > What did I do wrong? Or is a rtl PIC not enough?
> >
> > BTW. Linux x64 works perfectly. 0 relocations and a happy SELinux.
> >
> > Thanks, Ludo
> >
> >
> >
> > _______________________________________________
> > fpc-pascal maillist - fpc-pascal at lists.freepascal.org
> > http://lists.freepascal.org/mailman/listinfo/fpc-pascal
> >
>
> _______________________________________________
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