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Diffstat (limited to 'libc/sysdeps/linux/sh/bits/elf-fdpic.h')
-rw-r--r--libc/sysdeps/linux/sh/bits/elf-fdpic.h115
1 files changed, 115 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/sh/bits/elf-fdpic.h b/libc/sysdeps/linux/sh/bits/elf-fdpic.h
new file mode 100644
index 000000000..6b957bdfe
--- /dev/null
+++ b/libc/sysdeps/linux/sh/bits/elf-fdpic.h
@@ -0,0 +1,115 @@
+/* Copyright 2003, 2004 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public License as
+published by the Free Software Foundation; either version 2.1 of the
+License, or (at your option) any later version.
+
+In addition to the permissions in the GNU Lesser General Public
+License, the Free Software Foundation gives you unlimited
+permission to link the compiled version of this file with other
+programs, and to distribute those programs without any restriction
+coming from the use of this file. (The GNU Lesser General Public
+License restrictions do apply in other respects; for example, they
+cover modification of the file, and distribution when not linked
+into another program.)
+
+The GNU C Library 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with the GNU C Library; see the file COPYING.LIB. If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+#ifndef _BITS_ELF_FDPIC_H
+#define _BITS_ELF_FDPIC_H
+
+/* These data structures are described in the FDPIC ABI extension.
+ The kernel passes a process a memory map, such that for every LOAD
+ segment there is an elf32_fdpic_loadseg entry. A pointer to an
+ elf32_fdpic_loadmap is passed in R8 at start-up, and a pointer to
+ an additional such map is passed in R9 for the interpreter, when
+ there is one. */
+
+#include <elf.h>
+
+/* This data structure represents a PT_LOAD segment. */
+struct elf32_fdpic_loadseg
+{
+ /* Core address to which the segment is mapped. */
+ Elf32_Addr addr;
+ /* VMA recorded in the program header. */
+ Elf32_Addr p_vaddr;
+ /* Size of this segment in memory. */
+ Elf32_Word p_memsz;
+};
+
+struct elf32_fdpic_loadmap {
+ /* Protocol version number, must be zero. */
+ Elf32_Half version;
+ /* Number of segments in this map. */
+ Elf32_Half nsegs;
+ /* The actual memory map. */
+ struct elf32_fdpic_loadseg segs[/*nsegs*/];
+};
+
+struct elf32_fdpic_loadaddr {
+ struct elf32_fdpic_loadmap *map;
+ void *got_value;
+};
+
+/* Map a pointer's VMA to its corresponding address according to the
+ load map. */
+static __always_inline void *
+__reloc_pointer (void *p,
+ const struct elf32_fdpic_loadmap *map)
+{
+ int c;
+
+#if 0
+ if (map->version != 0)
+ /* Crash. */
+ ((void(*)())0)();
+#endif
+
+ /* No special provision is made for NULL. We don't want NULL
+ addresses to go through relocation, so they shouldn't be in
+ .rofixup sections, and, if they're present in dynamic
+ relocations, they shall be mapped to the NULL address without
+ undergoing relocations. */
+
+ for (c = 0;
+ /* Take advantage of the fact that the loadmap is ordered by
+ virtual addresses. In general there will only be 2 entries,
+ so it's not profitable to do a binary search. */
+ c < map->nsegs && p >= (void*)map->segs[c].p_vaddr;
+ c++)
+ {
+ /* This should be computed as part of the pointer comparison
+ above, but we want to use the carry in the comparison, so we
+ can't convert it to an integer type beforehand. */
+ unsigned long offset = p - (void*)map->segs[c].p_vaddr;
+ /* We only check for one-past-the-end for the last segment,
+ assumed to be the data segment, because other cases are
+ ambiguous in the absence of padding between segments, and
+ rofixup already serves as padding between text and data.
+ Unfortunately, unless we special-case the last segment, we
+ fail to relocate the _end symbol. */
+ if (offset < map->segs[c].p_memsz
+ || (offset == map->segs[c].p_memsz && c + 1 == map->nsegs))
+ return (char*)map->segs[c].addr + offset;
+ }
+
+ /* We might want to crash instead. */
+ return (void*)-1;
+}
+
+# define __RELOC_POINTER(ptr, loadaddr) \
+ (__reloc_pointer ((void*)(ptr), \
+ (loadaddr).map))
+
+#endif /* _BITS_ELF_FDPIC_H */