binutils-gdb/ld
Maciej W. Rozycki e54cb31aa3 MIPS/LD: Fix a segfault from ELF `e_flags' access with non-ELF output BFD
Fix a commit 861fb55ab5 ("Defer allocation of R_MIPS_REL32 GOT
slots"), <https://sourceware.org/ml/binutils/2008-08/msg00096.html>,
regression and a more recent:

FAIL: ld-unique/pr21529

new LD test case failure, observed with all the relevant MIPS targets
whenever the linker is invoked with one or more ELF inputs and the
output format set to `binary'.

The culprit is a segmentation fault caused in `mips_before_allocation'
by a null pointer dereference, where an attempt is made to access the
ELF file header's `e_flags' member, for the purpose of determining
whether to produce a PLT and copy relocations, without first checking
that the output BFD is ELF.  The `e_flags' member is stored in BFD's
private data pointed to by `tdep', which in the case of the `binary' BFD
is null, causing the segmentation fault.  With other non-ELF BFDs such
as SREC `tdep' is not null and consequently no crash may happen and in
that case random data will be interpreted as it was `e_flags'.

Disable the access to `e_flags' then and all the associated checks and
consequently never produce a PLT and copy relocations if output is not a
MIPS ELF BFD, matching `_bfd_mips_elf_merge_private_bfd_data' that does
not process `e_flags' in that case either and therefore does not let us
decide here anyway if all the input objects included in the link are
suitable for use with a PLT and copy relocations.

	ld/
	* emultempl/mipself.em (mips_before_allocation): Avoid ELF
	processing if not MIPS ELF.
	* testsuite/ld-mips-elf/binary.d: New test.
	* testsuite/ld-mips-elf/binary.ld: New test linker script.
	* testsuite/ld-mips-elf/binary.s: New test source.
	* testsuite/ld-mips-elf/mips-elf.exp: Run the new test.
2017-07-07 17:58:03 +01:00
..
emulparams S/390: Add support for pgste marker 2017-06-23 08:00:46 +02:00
emultempl MIPS/LD: Fix a segfault from ELF `e_flags' access with non-ELF output BFD 2017-07-07 17:58:03 +01:00
po Regenerate pot files. 2017-07-03 17:02:01 +02:00
scripttempl Move location of .jumptables section and add .hightext section to AVR linker script. 2017-06-14 12:23:39 +01:00
testsuite MIPS/LD: Fix a segfault from ELF `e_flags' access with non-ELF output BFD 2017-07-07 17:58:03 +01:00
.gitignore
aclocal.m4
ChangeLog MIPS/LD: Fix a segfault from ELF `e_flags' access with non-ELF output BFD 2017-07-07 17:58:03 +01:00
ChangeLog-0001
ChangeLog-0203
ChangeLog-2004
ChangeLog-2005
ChangeLog-2006
ChangeLog-2007
ChangeLog-2008
ChangeLog-2009
ChangeLog-2010
ChangeLog-2011
ChangeLog-2012
ChangeLog-2013
ChangeLog-2014
ChangeLog-2015
ChangeLog-2016
ChangeLog-9197
ChangeLog-9899
config.in Introduce --enable-new-dtags configure option. 2017-06-05 09:58:05 +09:30
configure Regenerate configure. 2017-07-04 11:15:33 +02:00
configure.ac Introduce --enable-new-dtags configure option. 2017-06-05 09:58:05 +09:30
configure.host
configure.tgt Accept more epiphany targets 2017-06-14 06:59:37 +02:00
deffile.h
deffilep.y
dep-in.sed
elf-hints-local.h
fdl.texi
gen-doc.texi S/390: Add support for pgste marker 2017-06-23 08:00:46 +02:00
genscrba.sh
genscripts.sh
h8-doc.texi
ld.h ld: Fix spelling mistake in comment. 2017-06-06 10:15:27 +01:00
ld.texinfo S/390: Add support for pgste marker 2017-06-23 08:00:46 +02:00
ldbuildid.c
ldbuildid.h
ldcref.c
ldctor.c
ldctor.h
ldemul.c
ldemul.h
ldexp.c
ldexp.h
ldfile.c Treat a prefix of "$SYSROOT" in the same way as "=" when parsing linker search paths. 2017-05-18 15:07:59 +01:00
ldfile.h
ldgram.y ld: Allow section groups to be resolved as part of a relocatable link 2017-06-06 09:53:38 +01:00
ldint.texinfo
ldlang.c Rewrite __start and __stop symbol handling 2017-06-16 23:38:28 +09:30
ldlang.h
ldlex-wrapper.c
ldlex.h ld: Allow section groups to be resolved as part of a relocatable link 2017-06-06 09:53:38 +01:00
ldlex.l ld: Allow section groups to be resolved as part of a relocatable link 2017-06-06 09:53:38 +01:00
ldmain.c ld: Allow section groups to be resolved as part of a relocatable link 2017-06-06 09:53:38 +01:00
ldmain.h
ldmisc.c
ldmisc.h
ldver.c
ldver.h
ldwrite.c
ldwrite.h
lexsup.c Correct "ld --help" to display "-z stack-size=SIZE" 2017-06-15 12:30:53 -07:00
MAINTAINERS
Makefile.am Apply ld/Makefile.in patch to the correct file 2017-07-07 10:35:31 +09:30
Makefile.in S/390: Add support for pgste marker 2017-06-23 08:00:46 +02:00
mri.c
mri.h
NEWS Add markers. 2017-07-04 11:07:03 +02:00
pe-dll.c Support pe-bigobj-x86-64 as an output format in 64-bit PE based linkers. 2017-05-09 14:42:43 +01:00
pe-dll.h
pep-dll.c
pep-dll.h
plugin.c Rename non_ir_ref to non_ir_ref_regular 2017-05-16 10:35:02 +09:30
plugin.h
README
stamp-h.in
sysdep.h
testplug2.c
testplug3.c
testplug4.c
testplug.c
TODO

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		README for LD

This is the GNU linker.  It is distributed with other "binary
utilities" which should be in ../binutils.  See ../binutils/README for
more general notes, including where to send bug reports.

There are many features of the linker:

* The linker uses a Binary File Descriptor library (../bfd)
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* The linker supports a number of different object file
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* There is a user manual (ld.texinfo), as well as the
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Installation
============

See ../binutils/README.

If you want to make a cross-linker, you may want to specify
a different search path of -lfoo libraries than the default.
You can do this by setting the LIB_PATH variable in ./Makefile
or using the --with-lib-path configure switch.

To build just the linker, make the target all-ld from the top level
directory (one directory above this one).

Porting to a new target
=======================

See the ldint.texinfo manual.

Reporting bugs etc
===========================

See ../binutils/README.

Known problems
==============

The Solaris linker normally exports all dynamic symbols from an
executable.  The GNU linker does not do this by default.  This is
because the GNU linker tries to present the same interface for all
similar targets (in this case, all native ELF targets).  This does not
matter for normal programs, but it can make a difference for programs
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the GNU linker export all dynamic symbols with the -E or
--export-dynamic command line option.

HP/UX 9.01 has a shell bug that causes the linker scripts to be
generated incorrectly.  The symptom of this appears to be "fatal error
- scanner input buffer overflow" error messages.  There are various
workarounds to this:
  * Build and install bash, and build with "make SHELL=bash".
  * Update to a version of HP/UX with a working shell (e.g., 9.05).
  * Replace "(. ${srcdir}/scripttempl/${SCRIPT_NAME}.sc)" in
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