Steve Bennett [Tue, 28 Jan 2020 06:22:08 +0000 (16:22 +1000)]
microblaze: properly handle relocations in resolved symbol mode
The default is now to use -a -p, but microblaze currently has no support
for this.
Add support for the appropriate relocations and ignore
pc-relative and got(r20)-relative relocations.
Also:
- binfmt_flat can't support GOT data-relative relocations, so error out in that case
- Only output relocations debug if the relocation was actually created
- Tidy up the non-resolved symbol mode for microblaze
Signed-off-by: Steve Bennett <steveb@workware.net.au>
Thomas Petazzoni [Fri, 27 Dec 2019 15:40:42 +0000 (16:40 +0100)]
elf2flt.c: add support for SOURCE_DATE_EPOCH
The bFLT header has a "build_date" field which contains the date/time
at which the bFLT file was created. Unfortunately, this breaks
reproducible builds as two identical builds done at different times
will produce different results.
For example, on a bFLT binary, diffoscope reports the following
change:
In order to address this, this commit adds support for the
SOURCE_DATE_EPOCH environment variable, which is standardized by the
reproducible-builds.org group at
https://reproducible-builds.org/specs/source-date-epoch/.
We simply use the time from the SOURCE_DATE_EPOCH variable (which
contains the number of seconds since Epoch) when SOURCE_DATE_EPOCH is
available in the environment, and otherwise fallback to the existing
logic that takes the current time using time().
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Thomas Petazzoni [Sun, 13 Aug 2017 14:03:20 +0000 (16:03 +0200)]
ld-elf2flt: behave properly when called with a name different from TARGET_ALIAS
ld-elf2flt currently handles two cases:
1 It is called as the wrapper for <TARGET_ALIAS>-ld, generally
installed in the bin/ directory of a toolchain.
2 It is called as the wrapper for "ld", generally installed in the
TARGET_ALIAS/bin/ directory of a toolchain.
Unfortunately, if for some reason it gets called using a FOOBAR-ld
name that is different from <TARGET_ALIAS>-ld, it assumes it is in
case (2), while it really is in case (1). Due to this, the path
mangling logic doesn't work, and it doesn't find ld.real.
This happens for example when the binary program in bin/ is named
arm-buildroot-uclinux-uclibcgnueabi-ld, but also has a simpler symlink
named arm-linux-ld. In this case,
arm-buildroot-uclinux-uclibcgnueabi-ld is recognized by ld-elf2flt as
containing TARGET_ALIAS, and therefore the proper logic to find
ld.real is applied. However, when arm-linux-ld is used, ld-elf2flt
doesn't find TARGET_ALIAS, and therefore assumes we're being called as
TARGET_ALIAS/bin/ld.. and searches for a program called ld.real in
bin/, which doesn't exist.
See:
$ ./output/host/bin/arm-buildroot-uclinux-uclibcgnueabi-ld
/home/thomas/buildroot/buildroot/output/host/bin/../arm-buildroot-uclinux-uclibcgnueabi/bin/ld.real: no input files
$ ./output/host/bin/arm-linux-ld
arm-linux-ld (ld-elf2flt): error trying to exec '/home/thomas/buildroot/buildroot/output/host/bin/ld.real': execvp: No such file or directory
$ ./output/host/arm-buildroot-uclinux-uclibcgnueabi/bin/ld
/home/thomas/buildroot/buildroot/output/host/arm-buildroot-uclinux-uclibcgnueabi/bin/ld.real: no input files
This commit fixes that by inverting the logic: if we're being called
as just "ld", then we assume it's the program in
TARGET_ALIAS/bin/. Otherwise, we're called through some variant of
TARGET-ld.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Greg Ungerer [Wed, 30 Oct 2019 06:08:19 +0000 (16:08 +1000)]
elf2flt: fix relocations for read-only data
Readonly data sections are mapped into the "text" section in the
elf2flt.ld linker script. The relocation generation code is not handling
that case properly though, and is actually mapping any data section type
into the "data" section of the target binary.
This problem case has been detected with elf2flt core dumping when used
with binutils-2.33.1 (on ARM architecture targets). See thread at:
Mike Frysinger [Sun, 17 Feb 2019 21:14:33 +0000 (16:14 -0500)]
elf2flt: drop v850 reloc ifdefs
The binutils elf/v850.h header has used the elf/reloc-macros.h helpers
to create R_V850_xxx enums. They haven't been defines for a long time.
Trying to use #ifdef checks on them doesn't work.
This means we require binutils-2.24+ now which was released in 2013.
We can see if anyone notices if we need to support older versions.
Alexey Neyman [Mon, 27 Feb 2017 09:20:10 +0000 (01:20 -0800)]
Symlink required binutils/BFD headers to local dir
... to minimize the chance of clashes with system headers.
Also, remove the -lcygwin from Makefile.in: this breaks canadian
build on cygwin, as it tries to pass -lcygwin into non-Cygwin host
CC. This chunk pre-dates the addition of -lc into configure.ac and
passing -lc should be sufficient (it works for me).
Mike Frysinger [Wed, 1 Mar 2017 06:56:29 +0000 (23:56 -0700)]
elf2flt: clean up elf headers dependencies
The only reason we included cygwin-elf.h & elf.h was for the various
target reloc defines. However, since these are all provided by the
bfd library which we already include, we can switch to using that for
every target.
Now we don't have any dep on the host's ELF headers (either existing,
or being up-to-date).
Mike Frysinger [Mon, 12 Dec 2016 05:35:04 +0000 (00:35 -0500)]
elf2flt: fix unused warning for e1/bfin targets
The one call site for this func is inside of an e1/bfin ifdef check,
so add the same logic to the definition to fix a build error:
elf2flt.c:212:1: error: ‘get_symbol_offset’ defined but not used [-Werror=unused-function]
Mike Frysinger [Tue, 13 Sep 2016 06:37:14 +0000 (02:37 -0400)]
Merge pull request #3 from KirillSmirnov/uninitialized-var
My gcc is 5.4.0, target is m68k, binutils 2.26.
elf2flt.c: In function 'output_relocs':
elf2flt.c:1604:5: error: 'sym_reloc_size' may be used uninitialized in this function [-Werror=maybe-uninitialized]
printf(" RELOC[%d]: offset=0x%"BFD_VMA_FMT"x symbol=%s%s "
Greg Ungerer [Fri, 19 Aug 2016 13:49:51 +0000 (23:49 +1000)]
elf2flt: fix relocation support for R_ARM_TARGET types
R_ARM_TARGET1 (and I think R_ARM_TARGET2) relocation types should be
treated in the same way as R_ARM_ABS32. Fix them to write out the addend
to the flat binary in network byte order.
In output_relocs, we do "sprintf(&addstr[0], "+0x%lx", ...)", with addrstr
being a 16 bytes array.
On 64bits hosts, in the unlikely case the value overflows 32bits, the buffer
may overflow.
Indeed, the maximum theorical size is 20 bytes (16 bytes for the value + 3
bytes for "+0x" + the end of string marker).
The reason the value overflows 32bits is yet to be understood, as the ARMV7-M
is 32bits architecture, but this patch first ensure the sprintf call is robust
enough.
Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Greg Ungerer [Thu, 4 Oct 2012 02:32:38 +0000 (02:32 +0000)]
From: Larry Baker <baker@usgs.gov>
The _stack_start symbol needs to be in the same flatmem memory region
as text/data/bss, otherwise it will not end up with the correct address.
Direct the section into the flatmem region.
The GNU linker uses -v as a shortcut to --version, not --verbose. So atm,
if you run `ld -v` to get the linker version, ld-elf2flt throws out a lot
of verbose debugging information. So drop the -v checking in ld-elf2flt
to keep from breaking systems that parse the linker version.
David McCullough [Thu, 16 Dec 2010 01:37:41 +0000 (01:37 +0000)]
The .note.ABI-tag section exists to indicate to other projects (like gdb
or library loaders) information about the target OS. It doesn't actually
contain anything that is used at runtime. So while the current linker
script gathers this into the .data section, the final FLAT doesn't include
anything from it. But tools expect to find a dedicated section in ELFs
which the current section merge prevents.^M
So give .note.ABI-tag its own output section so gdb can locate and use it.
This shouldn't change the FLAT files produced in any way.
David McCullough [Tue, 17 Aug 2010 04:25:26 +0000 (04:25 +0000)]
When we converted ld-elf2flt from the shell script to C, one small nuance
was missed: argv[0] contains the full path only when invoked with the full
path. This is not the same behavior for shell scripts as $0 is always the
full path to the script in question. Most of the time this isn't an issue
as gcc will invoke all of its tools (like the linker) with a full relative
path to itself. However, if we attempt to invoke the linker directly, we
can see misbehavior such as:
bfin-uclinux-ld.real: cannot open linker script file ./../lib/elf2flt.ld:
No such file or directory
So, to fix this, we lean on more libiberty functions. Specifically, the
make_relative_prefix() function. This function locates a full argv[0] by
scanning $PATH to see where it was invoked. This might sound a little
dodgy, but this is fundamental to how gcc and binutils implement support
for their runtime relocation, so it can't break ld-elf2flt without first
breaking every one else ;).
In the fall out of this fix, we can cull a bunch of local code that does
custom path parsing. So not only do we get to fix an annoying bug, we get
to shrink code in the process.
Signed-off-by: Steve Kilbane <steve@whitecrow.demon.co.uk> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
David McCullough [Tue, 22 Jun 2010 06:12:47 +0000 (06:12 +0000)]
The current code misses checking a few args in order to determine the
default "print" mode (ktrace/l1stack/...). Rather than update a list
that people easily forget, rework the code to generically detect that
no arguments have been specified.
The bflt loader in the kernel will, however, add a small extra data table
just before .data's content (cf. handling of MAX_SHARED_LIBS in
binfmt_flat.c:load_flat_file).
Now, if .text and .data are in the same segment, directly following each
other in the binary file, but have that extra data table added in the
run-time memory layout, GDB will get very confused when trying to access
items in the now-moved .data section. Without any kernel (loader) / GDB
changes, the solution is to tell the linker to always put .text and .data
into separate segments, which GDB will handle gracefully then.
Poor getopt() implementations as found in many BSD/Darwin systems will
stop processing options after a non-option is encountered. That means
ld-elf2flt has to be careful to not stick options after non-options when
executing sub children. In a default setup, it will invoke `elf2flt` with
the output followed by the -a option which subsequently fails:
elf2flt: Can't open '-a': No such file or directory
David McCullough [Tue, 14 Jul 2009 23:00:33 +0000 (23:00 +0000)]
the "all" target should not be depending on "ld-elf2flt"
anymore as this is handled through the PROG vars. it isnt a problem
for Linux systems, but when EXEEXT is set, things go boom.
David McCullough [Sun, 12 Jul 2009 23:28:58 +0000 (23:28 +0000)]
Due to shell portability issues (which is to say shell scripts are not
portable -- think Windows), convert elf2flt to C code.
I've updated this code base to the latest elf2flt tree and actually done
some basic tests -- building the three Blackfin tuples (ELF, FLAT, FDPIC)
and running programs on my Blackfin boards. This process found errors in
the original implementation as well as some of the cleanups I did.
Signed-off-by: Nathan Sidwell <nathan@codesourcery.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Unify the duplicated windows and other system fallback logic in stubs.h
and add some fatal() helper functions to standardize the error output when
falling over. This way we don't end up with obscure error messages with
no idea what util they are coming from.
This cleans up the Makefile handling of the different compiler flags such
that it uses standard names across the board as well as unifies the link
method.
Rather than putting the `rm` at the end of the script before the normal
exit point, create a trap to automatically delete the script when exiting.
This way the linker script gets cleaned up whenever there is an error as
well. Otherwise every link invocation that ends in a failure could leave
behind crap. On my system, i found almost 2 million of these suckers in
my /tmp dir.
David McCullough [Sun, 24 May 2009 23:33:48 +0000 (23:33 +0000)]
When the relocs are larger than 16bits, incorrect values are written when
the .H/.L loading are reversed. Normally this wouldn't happen because the
gcc compiler always outputs in the same order (first hi, then lo).
Signed-off-by: Jie Zhang <jie.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
David McCullough [Sun, 17 May 2009 23:14:54 +0000 (23:14 +0000)]
The header logic for pulling in ELF defines mixes common ELF headers and
target specific headers. In the Blackfin case, we always want to pull in
the bfin.h since most of the time, the common ELF headers do not have our
relocation defines. This fixes building for mingw targets.
The FLAT structure is all built on 32bit types, so make sure the elf2flt
code uses 32bit types rather than long's. This way we get correct
behavior when the host sizeof(long) is not 32bit as is on all 64bit
systems nowadays.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
GCC properly provides CTOR/DTOR END/LIST symbols already via the normal
crtbegin and crtend objects. Since it's been doing this for a while, add
a configure option to control the manual list found in the elf2flt linker
script and default it to off now.
Often build systems will use -shared when creating shared libraries, so
don't barf on the flag when we see it. This makes porting efforts easier.
As a sanity check, make sure we see the -shared-lib-id flag when creating
a shared library.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Some arches (like the Blackfin architecture) have an ABI where all symbols
get a symbol prefix. In our case, it's an underscore ("_"). So we set the
symbol prefix in the configure script and output it in the linker script and
all relevant files.
David McCullough [Thu, 27 Nov 2008 12:20:48 +0000 (12:20 +0000)]
When compiled with CVS binutils, busybox fails to execute properly.
That's because it's using --gc-sections, and the elf2flt linker script
allows the linker to remove parts of the .init and .fini sections. This
patch fixes it.
David McCullough [Thu, 27 Nov 2008 01:08:04 +0000 (01:08 +0000)]
Kazu Hirata wrote:
> Attached is a patch to fix elf2flt.ld so that C++ programs will link
> successfully.
>
> Nathan Sidwell says:
> nathan@codesourcery.com
>
> "The problem is the .eh_frame_hdr optimization. firstly that input
> section was not mentioned in the linker script and secondly, the
> linker requires .eh_frame_hdr and .eh_frame section in the output,
> so it can optimize them. I move gcc_except_table out of .data, for
> consistency."
I've been trying to get CVS binutils up and running on the Blackfin, and
after debugging a C++ link failure I eventually tracked it down to the
elf2flt linker script, and google pointed me at this thread which I'd
completely forgotten in the meantime. The patch is needed, please apply
to elf2flt.
projects / elf2flt.git / log