Add support for BPF

Signed-off-by: Richard Henderson <rth@redhat.com>

6 files changed, 183 insertions, 4 deletions

diff --git a/backends/ChangeLog b/backends/ChangeLog
index afda37a9..7cd19065 100644
--- a/backends/ChangeLog
+++ b/backends/ChangeLog
@@ -1,3 +1,13 @@
+2016-06-28  Richard Henderson <rth@redhat.com>
+
+	* Makefile.am (modules): Add bpf.
+	(libebl_pic): Add libebl_bpf_pic.a.
+	(am_libebl_bpf_pic_a_OBJECTS): New.
+	* bpf_init.c, bpf_regs.c, bpf_reloc.def: New files.
+	* common-reloc.c (copy_reloc_p): Honor NO_COPY_RELOC.
+	(init_reloc): Likewise.
+
+
 2016-05-20  Andreas Schwab  <schwab@linux-m68k.org>
 
 	* Makefile.am (modules): Add m68k.
diff --git a/backends/Makefile.am b/backends/Makefile.am
index bf523912..b553ec34 100644
--- a/backends/Makefile.am
+++ b/backends/Makefile.am
@@ -33,12 +33,12 @@ AM_CPPFLAGS += -I$(top_srcdir)/libebl -I$(top_srcdir)/libasm \
 
 
 modules = i386 sh x86_64 ia64 alpha arm aarch64 sparc ppc ppc64 s390 \
-	  tilegx m68k
+	  tilegx m68k bpf
 libebl_pic = libebl_i386_pic.a libebl_sh_pic.a libebl_x86_64_pic.a    \
 	     libebl_ia64_pic.a libebl_alpha_pic.a libebl_arm_pic.a    \
 	     libebl_aarch64_pic.a libebl_sparc_pic.a libebl_ppc_pic.a \
 	     libebl_ppc64_pic.a libebl_s390_pic.a libebl_tilegx_pic.a \
-	     libebl_m68k_pic.a
+	     libebl_m68k_pic.a libebl_bpf_pic.a
 noinst_LIBRARIES = $(libebl_pic)
 noinst_DATA = $(libebl_pic:_pic.a=.so)
 
@@ -118,6 +118,16 @@ m68k_SRCS = m68k_init.c m68k_symbol.c m68k_regs.c \
 libebl_m68k_pic_a_SOURCES = $(m68k_SRCS)
 am_libebl_m68k_pic_a_OBJECTS = $(m68k_SRCS:.c=.os)
 
+bpf_SRCS = bpf_init.c bpf_regs.c
+# The disam hook depends on this if we have linux/bpf.h.
+if HAVE_LINUX_BPF_H
+cpu_bpf = ../libcpu/libcpu_bpf.a
+else
+cpu_bpf = 
+endif
+libebl_bpf_pic_a_SOURCES = $(bpf_SRCS)
+am_libebl_bpf_pic_a_OBJECTS = $(bpf_SRCS:.c=.os)
+
 
 libebl_%.so libebl_%.map: libebl_%_pic.a $(libelf) $(libdw)
 	@rm -f $(@:.so=.map)
@@ -131,6 +141,7 @@ libebl_%.so libebl_%.map: libebl_%_pic.a $(libelf) $(libdw)
 
 libebl_i386.so: $(cpu_i386)
 libebl_x86_64.so: $(cpu_x86_64)
+libebl_bpf.so: $(cpu_bpf)
 
 install: install-am install-ebl-modules
 install-ebl-modules:
diff --git a/backends/bpf_init.c b/backends/bpf_init.c
new file mode 100644
index 00000000..22842e26
--- /dev/null
+++ b/backends/bpf_init.c
@@ -0,0 +1,60 @@
+/* Initialization of BPF specific backend library.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#define BACKEND		bpf_
+#define RELOC_PREFIX	R_BPF_
+#include "libebl_CPU.h"
+
+/* This defines the common reloc hooks based on bpf_reloc.def.  */
+#define NO_RELATIVE_RELOC
+#define NO_COPY_RELOC
+#include "common-reloc.c"
+
+
+const char *
+bpf_init (Elf *elf __attribute__ ((unused)),
+	  GElf_Half machine __attribute__ ((unused)),
+	  Ebl *eh, size_t ehlen)
+{
+  /* Check whether the Elf_BH object has a sufficent size.  */
+  if (ehlen < sizeof (Ebl))
+    return NULL;
+
+  /* We handle it.  */
+  eh->name = "BPF";
+  bpf_init_reloc (eh);
+  HOOK (eh, register_info);
+#ifdef HAVE_LINUX_BPF_H
+  HOOK (eh, disasm);
+#endif
+
+  return MODVERSION;
+}
diff --git a/backends/bpf_regs.c b/backends/bpf_regs.c
new file mode 100644
index 00000000..180af83b
--- /dev/null
+++ b/backends/bpf_regs.c
@@ -0,0 +1,64 @@
+/* Register names and numbers for BPF DWARF.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdio.h>
+#include <string.h>
+
+#ifdef HAVE_LINUX_BPF_H
+#include <linux/bpf.h>
+#else
+#define MAX_BPF_REG 10
+#endif
+
+#define BACKEND bpf_
+#include "libebl_CPU.h"
+
+ssize_t
+bpf_register_info (Ebl *ebl __attribute__ ((unused)),
+		   int regno, char *name, size_t namelen,
+		   const char **prefix, const char **setname,
+		   int *bits, int *type)
+{
+  ssize_t len;
+
+  if (name == NULL)
+    return MAX_BPF_REG;
+  if (regno < 0 || regno >= MAX_BPF_REG)
+    return -1;
+
+  *prefix = "";
+  *setname = "integer";
+  *bits = 64;
+  *type = DW_ATE_signed;
+
+  len = snprintf(name, namelen, "r%d", regno);
+  return ((size_t)len < namelen ? len : -1);
+}
diff --git a/backends/bpf_reloc.def b/backends/bpf_reloc.def
new file mode 100644
index 00000000..a410da97
--- /dev/null
+++ b/backends/bpf_reloc.def
@@ -0,0 +1,31 @@
+/* List the relocation types for BPF.  -*- C -*-
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+/*	    NAME,		REL|EXEC|DYN	*/
+
+RELOC_TYPE (NONE,		EXEC|DYN)
+RELOC_TYPE (MAP_FD,		REL|EXEC|DYN)
diff --git a/backends/common-reloc.c b/backends/common-reloc.c
index 3317b6c9..096ed1c7 100644
--- a/backends/common-reloc.c
+++ b/backends/common-reloc.c
@@ -124,12 +124,13 @@ EBLHOOK(reloc_valid_use) (Elf *elf, int reloc)
   return type > ET_NONE && type < ET_CORE && (uses & (1 << (type - 1)));
 }
 
-
+#ifndef NO_COPY_RELOC
 bool
 EBLHOOK(copy_reloc_p) (int reloc)
 {
   return reloc == R_TYPE (COPY);
 }
+#endif
 
 bool
 EBLHOOK(none_reloc_p) (int reloc)
@@ -151,8 +152,10 @@ EBLHOOK(init_reloc) (Ebl *ebl)
   ebl->reloc_type_name = EBLHOOK(reloc_type_name);
   ebl->reloc_type_check = EBLHOOK(reloc_type_check);
   ebl->reloc_valid_use = EBLHOOK(reloc_valid_use);
-  ebl->copy_reloc_p = EBLHOOK(copy_reloc_p);
   ebl->none_reloc_p = EBLHOOK(none_reloc_p);
+#ifndef NO_COPY_RELOC
+  ebl->copy_reloc_p = EBLHOOK(copy_reloc_p);
+#endif
 #ifndef NO_RELATIVE_RELOC
   ebl->relative_reloc_p = EBLHOOK(relative_reloc_p);
 #endif