Binutils with MCST patches
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Palmer Dabbelt ed0816bd93 RISC-V: Avoid emitting invalid instructions in mixed RVC/no-RVC code
When linking the following code

    .global _prog_start
    _prog_start:
            mv x1, x1
            mv x2, x2
    .align 2
    rvc_boundry:
    .option norvc
    .align 3
            mv x3, x3

we currently emit an invalid two-byte 0 instruction.  The actual output
code looks like

    0000000080000000 <_prog_start>:
        80000000:   8086                    mv      ra,ra
        80000002:   810a                    mv      sp,sp

    0000000080000004 <rvc_boundry>:
        80000004:   0000                    unimp
        80000006:   0001                    nop
        80000008:   00018193                mv      gp,gp

This ends up manifesting due to the two-byte compressed NOP that's
pessimisticly emitted by the ".align 2", which results in "rvc_boundry"
being 2-byte aligned.  frag_align_code() then goes and outputs a 2-byte
NOP (which is invalid in no-RVC mode) to align the code back to a 4-byte
boundry, which can't be relaxed away by the linker as it's not part of
the R_RISCV_RELAX relocation.

The fix is to just always emit the worst case possible alignment into
the output as a single R_RISCV_RELAX, which the linker will then fix up.

With this patch I get the expected code generation

    0000000080000000 <_prog_start>:
        80000000:   8086                    mv      ra,ra
        80000002:   810a                    mv      sp,sp

    0000000080000004 <rvc_boundry>:
        80000004:   00000013                nop
        80000008:   00018193                mv      gp,gp

gas/ChangeLog

2017-09-07  Palmer Dabbelt  <palmer@dabbelt.com>

        * config/tc-riscv.c (riscv_frag_align_code): Emit the entire
        alignment sequence inside R_RISCV_ALIGN.
2017-09-07 09:45:40 -07:00
bfd RISC-V: Print an error when unable to align a section 2017-09-07 09:45:35 -07:00
binutils Fix a buffer overrun when parsing a corrupt MIPS ELF binary. 2017-09-05 12:09:14 +01:00
config
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gas RISC-V: Avoid emitting invalid instructions in mixed RVC/no-RVC code 2017-09-07 09:45:40 -07:00
gdb Document the GDB 8.0.1 release in gdb/ChangeLog 2017-09-07 07:53:34 -07:00
gold
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include Missing relocation R_PPC_VLE_ADDR20 and add VLE flag to details in readelf 2017-09-05 08:42:27 +09:30
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ld x86-64: Add R_X86_64_converted_reloc_bit 2017-09-06 05:06:35 -07:00
libdecnumber
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sim Honor an existing CC_FOR_BUILD in the environment for sim. 2017-09-06 10:16:12 -07:00
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		   README for GNU development tools

This directory contains various GNU compilers, assemblers, linkers, 
debuggers, etc., plus their support routines, definitions, and documentation.

If you are receiving this as part of a GDB release, see the file gdb/README.
If with a binutils release, see binutils/README;  if with a libg++ release,
see libg++/README, etc.  That'll give you info about this
package -- supported targets, how to use it, how to report bugs, etc.

It is now possible to automatically configure and build a variety of
tools with one command.  To build all of the tools contained herein,
run the ``configure'' script here, e.g.:

	./configure 
	make

To install them (by default in /usr/local/bin, /usr/local/lib, etc),
then do:
	make install

(If the configure script can't determine your type of computer, give it
the name as an argument, for instance ``./configure sun4''.  You can
use the script ``config.sub'' to test whether a name is recognized; if
it is, config.sub translates it to a triplet specifying CPU, vendor,
and OS.)

If you have more than one compiler on your system, it is often best to
explicitly set CC in the environment before running configure, and to
also set CC when running make.  For example (assuming sh/bash/ksh):

	CC=gcc ./configure
	make

A similar example using csh:

	setenv CC gcc
	./configure
	make

Much of the code and documentation enclosed is copyright by
the Free Software Foundation, Inc.  See the file COPYING or
COPYING.LIB in the various directories, for a description of the
GNU General Public License terms under which you can copy the files.

REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info
on where and how to report problems.