2006-11-03 Hollis Blanchard <hollis@penguinppc.org>

	* include/grub/elfload.h: New file.
	* kern/elf.c: Likewise.

diff --git a/include/grub/elfload.h b/include/grub/elfload.h
new file mode 100644 (file)
index 0000000..ad8c781
--- /dev/null
+++ b/include/grub/elfload.h
@@ -0,0 +1,55 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2003, 2004, 2005, 2006  Free Software Foundation, Inc.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of 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.
+ *
+ *  This program 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 a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef GRUB_ELFLOAD_HEADER
+#define GRUB_ELFLOAD_HEADER    1
+
+#include <grub/err.h>
+#include <grub/elf.h>
+#include <grub/file.h>
+#include <grub/symbol.h>
+#include <grub/types.h>
+
+struct grub_elf_file
+{
+  grub_file_t file;
+  union {
+    Elf64_Ehdr ehdr64;
+    Elf32_Ehdr ehdr32;
+  } ehdr;
+  void *phdrs;
+};
+typedef struct grub_elf_file *grub_elf_t;
+
+typedef int (*grub_elf32_load_hook_t) (Elf32_Phdr *phdr, grub_addr_t *addr);
+typedef int (*grub_elf64_load_hook_t) (Elf64_Phdr *phdr, grub_addr_t *addr);
+
+grub_elf_t grub_elf_open (const char *);
+grub_elf_t grub_elf_file (grub_file_t);
+grub_err_t grub_elf_close (grub_elf_t);
+
+int grub_elf_is_elf32 (grub_elf_t);
+grub_size_t grub_elf32_size (grub_elf_t);
+grub_err_t grub_elf32_load (grub_elf_t, grub_elf32_load_hook_t);
+
+int grub_elf_is_elf64 (grub_elf_t);
+grub_size_t grub_elf64_size (grub_elf_t);
+grub_err_t grub_elf64_load (grub_elf_t, grub_elf64_load_hook_t);
+
+#endif /* ! GRUB_ELFLOAD_HEADER */

diff --git a/kern/elf.c b/kern/elf.c
new file mode 100644 (file)
index 0000000..02619dd
--- /dev/null
+++ b/kern/elf.c
@@ -0,0 +1,387 @@
+/* elf.c - load ELF files */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2003, 2004, 2005, 2006  Free Software Foundation, Inc.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of 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.
+ *
+ *  This program 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 a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <grub/err.h>
+#include <grub/elf.h>
+#include <grub/elfload.h>
+#include <grub/file.h>
+#include <grub/gzio.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+
+/* Check if EHDR is a valid ELF header.  */
+static grub_err_t
+grub_elf_check_header (grub_elf_t elf)
+{
+  Elf32_Ehdr *e = &elf->ehdr.ehdr32;
+
+  if (e->e_ident[EI_MAG0] != ELFMAG0
+      || e->e_ident[EI_MAG1] != ELFMAG1
+      || e->e_ident[EI_MAG2] != ELFMAG2
+      || e->e_ident[EI_MAG3] != ELFMAG3
+      || e->e_ident[EI_VERSION] != EV_CURRENT
+      || e->e_version != EV_CURRENT)
+    return grub_error (GRUB_ERR_BAD_OS, "invalid arch independent ELF magic");
+
+  return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_elf_close (grub_elf_t elf)
+{
+  grub_file_t file = elf->file;
+
+  grub_free (elf->phdrs);
+  grub_free (elf);
+
+  if (file)
+    grub_file_close (file);
+
+  return grub_errno;
+}
+
+grub_elf_t
+grub_elf_file (grub_file_t file)
+{
+  grub_elf_t elf;
+
+  elf = grub_malloc (sizeof (*elf));
+  if (! elf)
+    return 0;
+
+  elf->file = file;
+  elf->phdrs = 0;
+
+  if (grub_file_read (elf->file, (char *) &elf->ehdr, sizeof (elf->ehdr))
+      != sizeof (elf->ehdr))
+    {
+      grub_error (GRUB_ERR_READ_ERROR, "Cannot read ELF header.");
+      goto fail;
+    }
+
+  if (grub_elf_check_header (elf))
+    goto fail;
+
+  return elf;
+
+fail:
+  grub_elf_close (elf);
+  return 0;
+}
+
+grub_elf_t
+grub_elf_open (const char *name)
+{
+  grub_file_t file;
+
+  file = grub_gzfile_open (name, 1);
+  if (! file)
+    return 0;
+
+  return grub_elf_file (file);
+}
+
+\f
+/* 32-bit */
+
+int
+grub_elf_is_elf32 (grub_elf_t elf)
+{
+  return elf->ehdr.ehdr32.e_ident[EI_CLASS] == ELFCLASS32;
+}
+
+static int
+grub_elf32_load_segment (grub_elf_t elf, Elf32_Phdr *phdr, void *hook)
+{
+  grub_elf32_load_hook_t load_hook = (grub_elf32_load_hook_t) hook;
+  grub_addr_t load_addr;
+
+  if (phdr->p_type != PT_LOAD)
+    return 0;
+
+  load_addr = phdr->p_paddr;
+  if (load_hook && load_hook (phdr, &load_addr))
+    return 1;
+
+  grub_dprintf ("elf", "Loading segment at %llx, size 0x%llx\n",
+               (unsigned long long) load_addr,
+               (unsigned long long) phdr->p_filesz);
+
+  if (grub_file_seek (elf->file, phdr->p_offset) == (grub_off_t) -1)
+    {
+      return grub_error (GRUB_ERR_BAD_OS, "Invalid offset in program header");
+    }
+
+  if (grub_file_read (elf->file, (void *) load_addr, phdr->p_filesz)
+      != (grub_ssize_t) phdr->p_filesz)
+    {
+      return grub_error (GRUB_ERR_BAD_OS, "Couldn't load segment");
+    }
+
+  if (phdr->p_filesz < phdr->p_memsz)
+    grub_memset ((void *) (long) (load_addr + phdr->p_filesz),
+                0, phdr->p_memsz - phdr->p_filesz);
+
+  return 0;
+}
+
+static grub_err_t
+grub_elf32_load_phdrs (grub_elf_t elf)
+{
+  grub_ssize_t phdrs_size;
+
+  phdrs_size = elf->ehdr.ehdr32.e_phnum * elf->ehdr.ehdr32.e_phentsize;
+
+  grub_dprintf ("elf", "Loading program headers at 0x%llx, size 0x%x.\n",
+               (unsigned long long) elf->ehdr.ehdr32.e_phoff,
+               phdrs_size);
+
+  elf->phdrs = grub_malloc (phdrs_size);
+  if (! elf->phdrs)
+    return grub_errno;
+
+  if ((grub_file_seek (elf->file, elf->ehdr.ehdr32.e_phoff) == (grub_off_t) -1)
+      || (grub_file_read (elf->file, elf->phdrs, phdrs_size) != phdrs_size))
+    return grub_error (GRUB_ERR_READ_ERROR, "Cannot read program headers");
+
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_elf32_phdr_iterate (grub_elf_t elf,
+                        int (*hook) (grub_elf_t, Elf32_Phdr *, void *),
+                        void *hook_arg)
+{
+  Elf32_Phdr *phdrs;
+  unsigned int i;
+
+  if (! elf->phdrs)
+    if (grub_elf32_load_phdrs (elf))
+      return grub_errno;
+  phdrs = elf->phdrs;
+
+  for (i = 0; i < elf->ehdr.ehdr32.e_phnum; i++)
+    {
+      Elf32_Phdr *phdr = phdrs + i;
+      grub_dprintf ("elf", "Segment %u: type 0x%x paddr 0x%lx memsz 0x%lx.\n",
+                   i, phdr->p_type,
+                   (unsigned long) phdr->p_paddr,
+                   (unsigned long) phdr->p_memsz);
+      if (hook (elf, phdr, hook_arg))
+       break;
+    }
+
+  return grub_errno;
+}
+
+/* Calculate the amount of memory spanned by the segments.  */
+grub_size_t
+grub_elf32_size (grub_elf_t elf)
+{
+  Elf32_Addr segments_start = (Elf32_Addr) -1;
+  Elf32_Addr segments_end = 0;
+  int nr_phdrs = 0;
+
+  /* Run through the program headers to calculate the total memory size we
+   * should claim.  */
+  auto int calcsize (grub_elf_t _elf, Elf32_Phdr *phdr, void *_arg);
+  int calcsize (grub_elf_t __unused _elf, Elf32_Phdr *phdr, void __unused *_arg)
+    {
+      /* Only consider loadable segments.  */
+      if (phdr->p_type != PT_LOAD)
+       return 0;
+      nr_phdrs++;
+      if (phdr->p_paddr < segments_start)
+       segments_start = phdr->p_paddr;
+      if (phdr->p_paddr + phdr->p_memsz > segments_end)
+       segments_end = phdr->p_paddr + phdr->p_memsz;
+      return 0;
+    }
+
+  grub_elf32_phdr_iterate (elf, calcsize, 0);
+
+  if (nr_phdrs == 0)
+    {
+      grub_error (GRUB_ERR_BAD_OS, "No program headers present");
+      return 0;
+    }
+
+  if (segments_end < segments_start)
+    {
+      /* Very bad addresses.  */
+      grub_error (GRUB_ERR_BAD_OS, "Bad program header load addresses");
+      return 0;
+    }
+
+  return segments_end - segments_start;
+}
+
+
+/* Load every loadable segment into memory specified by `load_hook'.  */
+grub_err_t
+grub_elf32_load (grub_elf_t elf, grub_elf32_load_hook_t load_hook)
+{
+  return grub_elf32_phdr_iterate (elf, grub_elf32_load_segment, load_hook);
+}
+
+
+\f
+/* 64-bit */
+
+int
+grub_elf_is_elf64 (grub_elf_t elf)
+{
+  return elf->ehdr.ehdr64.e_ident[EI_CLASS] == ELFCLASS64;
+}
+
+static int
+grub_elf64_load_segment (grub_elf_t elf, Elf64_Phdr *phdr, void *hook)
+{
+  grub_elf64_load_hook_t load_hook = (grub_elf64_load_hook_t) hook;
+  grub_addr_t load_addr;
+
+  if (phdr->p_type != PT_LOAD)
+    return 0;
+
+  load_addr = phdr->p_paddr;
+  if (load_hook && load_hook (phdr, &load_addr))
+    return 1;
+
+  grub_dprintf ("elf", "Loading segment at %llx, size 0x%llx\n",
+               (unsigned long long) load_addr,
+               (unsigned long long) phdr->p_filesz);
+
+  if (grub_file_seek (elf->file, phdr->p_offset) == (grub_off_t) -1)
+    {
+      return grub_error (GRUB_ERR_BAD_OS, "Invalid offset in program header");
+    }
+
+  if (grub_file_read (elf->file, (void *) load_addr, phdr->p_filesz)
+      != (grub_ssize_t) phdr->p_filesz)
+    {
+      return grub_error (GRUB_ERR_BAD_OS, "Couldn't load segment");
+    }
+
+  if (phdr->p_filesz < phdr->p_memsz)
+    grub_memset ((void *) (long) (load_addr + phdr->p_filesz),
+                0, phdr->p_memsz - phdr->p_filesz);
+
+  return 0;
+}
+
+static grub_err_t
+grub_elf64_load_phdrs (grub_elf_t elf)
+{
+  grub_ssize_t phdrs_size;
+
+  phdrs_size = elf->ehdr.ehdr64.e_phnum * elf->ehdr.ehdr64.e_phentsize;
+
+  grub_dprintf ("elf", "Loading program headers at 0x%llx, size 0x%x.\n",
+               (unsigned long long) elf->ehdr.ehdr64.e_phoff,
+               phdrs_size);
+
+  elf->phdrs = grub_malloc (phdrs_size);
+  if (! elf->phdrs)
+    return grub_errno;
+
+  if ((grub_file_seek (elf->file, elf->ehdr.ehdr64.e_phoff) == (grub_off_t) -1)
+      || (grub_file_read (elf->file, elf->phdrs, phdrs_size) != phdrs_size))
+    return grub_error (GRUB_ERR_READ_ERROR, "Cannot read program headers");
+
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_elf64_phdr_iterate (grub_elf_t elf,
+                        int (*hook) (grub_elf_t, Elf64_Phdr *, void *),
+                        void *hook_arg)
+{
+  Elf64_Phdr *phdrs;
+  unsigned int i;
+
+  if (! elf->phdrs)
+    if (grub_elf64_load_phdrs (elf))
+      return grub_errno;
+  phdrs = elf->phdrs;
+
+  for (i = 0; i < elf->ehdr.ehdr64.e_phnum; i++)
+    {
+      Elf64_Phdr *phdr = phdrs + i;
+      grub_dprintf ("elf", "Segment %u: type 0x%x paddr 0x%lx memsz 0x%lx.\n",
+                   i, phdr->p_type,
+                   (unsigned long) phdr->p_paddr,
+                   (unsigned long) phdr->p_memsz);
+      if (hook (elf, phdr, hook_arg))
+       break;
+    }
+
+  return grub_errno;
+}
+
+/* Calculate the amount of memory spanned by the segments.  */
+grub_size_t
+grub_elf64_size (grub_elf_t elf)
+{
+  Elf64_Addr segments_start = (Elf64_Addr) -1;
+  Elf64_Addr segments_end = 0;
+  int nr_phdrs = 0;
+
+  /* Run through the program headers to calculate the total memory size we
+   * should claim.  */
+  auto int calcsize (grub_elf_t _elf, Elf64_Phdr *phdr, void *_arg);
+  int calcsize (grub_elf_t __unused _elf, Elf64_Phdr *phdr, void __unused *_arg)
+    {
+      /* Only consider loadable segments.  */
+      if (phdr->p_type != PT_LOAD)
+       return 0;
+      nr_phdrs++;
+      if (phdr->p_paddr < segments_start)
+       segments_start = phdr->p_paddr;
+      if (phdr->p_paddr + phdr->p_memsz > segments_end)
+       segments_end = phdr->p_paddr + phdr->p_memsz;
+      return 0;
+    }
+
+  grub_elf64_phdr_iterate (elf, calcsize, 0);
+
+  if (nr_phdrs == 0)
+    {
+      grub_error (GRUB_ERR_BAD_OS, "No program headers present");
+      return 0;
+    }
+
+  if (segments_end < segments_start)
+    {
+      /* Very bad addresses.  */
+      grub_error (GRUB_ERR_BAD_OS, "Bad program header load addresses");
+      return 0;
+    }
+
+  return segments_end - segments_start;
+}
+
+
+/* Load every loadable segment into memory specified by `load_hook'.  */
+grub_err_t
+grub_elf64_load (grub_elf_t elf, grub_elf64_load_hook_t load_hook)
+{
+  return grub_elf64_phdr_iterate (elf, grub_elf64_load_segment, load_hook);
+}
+