forked from Imagelibrary/binutils-gdb
b892828bcb
With -m32 -fcf-protection, GCC generates an `endbr32` instruction at the
function entry:
[hjl@gnu-cfl-2 gdb]$ cat /tmp/x.c
int
main(void)
{
return 0;
}
[hjl@gnu-cfl-2 gdb]$ gcc -g -fcf-protection /tmp/x.c -m32
(gdb) b main
Breakpoint 1 at 0x8049176: file /tmp/x.c, line 3.
(gdb) r
Breakpoint 1, main () at /tmp/x.c:3
3 {
(gdb) disass
Dump of assembler code for function main:
=> 0x08049176 <+0>: endbr32
0x0804917a <+4>: push %ebp
0x0804917b <+5>: mov %esp,%ebp
0x0804917d <+7>: mov $0x0,%eax
0x08049182 <+12>: pop %ebp
0x08049183 <+13>: ret
End of assembler dump.
(gdb)
Update i386_analyze_prologue to skip `endbr32`:
(gdb) b main
Breakpoint 1 at 0x804917d: file /tmp/x.c, line 4.
(gdb) r
Breakpoint 1, main () at /tmp/x.c:4
4 return 0;
(gdb) disass
Dump of assembler code for function main:
0x08049176 <+0>: endbr32
0x0804917a <+4>: push %ebp
0x0804917b <+5>: mov %esp,%ebp
=> 0x0804917d <+7>: mov $0x0,%eax
0x08049182 <+12>: pop %ebp
0x08049183 <+13>: ret
End of assembler dump.
(gdb)
Tested with
$ make check RUNTESTFLAGS="--target_board='unix{-m32,}' i386-prologue-skip-cf-protection.exp"
on Fedora 32/x86-64.
2020-0X-YY Victor Collod <vcollod@nvidia.com>
gdb/ChangeLog:
PR gdb/26635
* i386-tdep.c (i386_skip_endbr): Add a helper function to skip endbr.
(i386_analyze_prologue): Call i386_skip_endbr.
gdb/testsuite/ChangeLog:
PR gdb/26635
* gdb.arch/amd64-prologue-skip-cf-protection.exp: Make the test
compatible with i386, and move it to...
* gdb.arch/i386-prologue-skip-cf-protection.exp: ... here.
* gdb.arch/amd64-prologue-skip-cf-protection.c: Move to...
* gdb.arch/i386-prologue-skip-cf-protection.c: ... here.
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.