Binutils with MCST patches
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Srinath Parvathaneni 40eadf04ff [gdb][Arm]: gdb cannot step across CMSE secure entry function code.
GDB is not able to execute "step" command on function calls of Armv8-M cmse secure entry functions.
Everytime GNU linker come across definition of any cmse secure entry function in object file(s),
it creates two new instructions secure gateway (sg) and original branch destination (b.w),
place those two instructions in ".gnu.sgstubs" section of executable.
Any function calls to these cmse secure entry functions is re-directed through secure gateway (sg)
present in ".gnu.sgstubs" section.

Example:
Following is a function call to cmse secure entry function "foo":
        ...
        bl xxxx <foo>   --->(a)
        ...
        <foo>
        xxxx: push    {r7, lr}

GNU linker on finding out "foo" is a cmse secure entry function, created sg and b.w instructions and
place them in ".gnu.sgstubs" section (marked by c).

The "bl" instruction (marked by a) which is a call to cmse secure entry function is modified by GNU linker
(as marked by b) and call flow is re-directly through secure gateway (sg) in ".gnu.sgstubs" section.
       ...
       bl yyyy <foo>  ---> (b)
       ...
       section .gnu.sgstubs: ---> (c)
       yyyy <foo>
       yyyy: sg   // secure gateway
	     b.w xxxx <__acle_se_foo>  // original_branch_dest
       ...
       0000xxxx <__acle_se_foo>
       xxxx: push    {r7, lr} ---> (d)

On invoking GDB, when the control is at "b" and we pass "step" command, the pc returns "yyyy"
(sg address) which is a trampoline and which does not exist in source code. So GDB jumps
to next line without jumping to "__acle_se_foo" (marked by d).

The above details are published on the Arm website [1], please refer to section 5.4 (Entry functions)
and section 3.4.4 (C level development flow of secure code).

[1] https://developer.arm.com/architectures/cpu-architecture/m-profile/docs/ecm0359818/latest/armv8-m-security-extensions-requirements-on-development-tools-engineering-specification

This patch fixes above problem by returning target pc "xxxx" to GDB on executing "step"
command at "b", so that the control jumps to "__acle_se_foo" (marked by d).

gdb/ChangeLog:

	* arm-tdep.c (arm_skip_cmse_entry): New function.
	(arm_is_sgstubs_section): New function.
	(arm_skip_stub): Add call to arm_skip_cmse_entry function.

gdb/testsuite/ChangeLog:

	* gdb.arch/arm-cmse-sgstubs.c: New test.
	* gdb.arch/arm-cmse-sgstubs.exp: New file.
2019-07-23 12:06:05 +01:00
bfd SHF_GNU_MBIND requires ELFOSABI_GNU 2019-07-23 18:22:02 +09:30
binutils SHF_GNU_MBIND requires ELFOSABI_GNU 2019-07-23 18:22:02 +09:30
config
contrib
cpu cpu,opcodes,gas: use %r0 and %r6 instead of %a and %ctf in eBPF disassembler 2019-07-19 15:35:43 +02:00
elfcpp
etc
gas SHF_GNU_MBIND requires ELFOSABI_GNU 2019-07-23 18:22:02 +09:30
gdb [gdb][Arm]: gdb cannot step across CMSE secure entry function code. 2019-07-23 12:06:05 +01:00
gnulib
gold
gprof
include Allow objdump to recognise the System.Runtime.dll files that get shipped with .NET Core 2.1. 2019-07-23 09:44:57 +01:00
intl
ld Remove tests that test __gnu_lto_v1 symbol. 2019-07-23 12:47:16 +02:00
libctf libctf: introduce ctf_func_type_{info,args}, ctf_type_aname_raw 2019-07-18 20:53:57 +01:00
libdecnumber
libiberty
opcodes Add Changelog entry missing from previous delta. 2019-07-23 09:47:06 +01:00
readline
sim
texinfo
zlib
.cvsignore
.gitattributes
.gitignore
ar-lib
ChangeLog adjust src-release following the renaming of gdb/common/ to gdb/gdbsupport/ 2019-07-13 18:00:32 -07:00
compile
config-ml.in
config.guess
config.rpath
config.sub
configure
configure.ac
COPYING
COPYING3
COPYING3.LIB
COPYING.LIB
COPYING.LIBGLOSS
COPYING.NEWLIB
depcomp
djunpack.bat
install-sh
libtool.m4
lt~obsolete.m4
ltgcc.m4
ltmain.sh
ltoptions.m4
ltsugar.m4
ltversion.m4
MAINTAINERS
Makefile.def
Makefile.in
Makefile.tpl
makefile.vms
missing
mkdep
mkinstalldirs
move-if-change
multilib.am
README
README-maintainer-mode
setup.com
src-release.sh adjust src-release following the renaming of gdb/common/ to gdb/gdbsupport/ 2019-07-13 18:00:32 -07:00
symlink-tree
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ylwrap

		   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.