summaryrefslogtreecommitdiffstats
path: root/arch/xtensa/kernel/module.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/xtensa/kernel/module.c')
-rw-r--r--arch/xtensa/kernel/module.c189
1 files changed, 189 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/module.c b/arch/xtensa/kernel/module.c
new file mode 100644
index 0000000000..902845ddac
--- /dev/null
+++ b/arch/xtensa/kernel/module.c
@@ -0,0 +1,189 @@
+/*
+ * arch/xtensa/kernel/module.c
+ *
+ * Module support.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2006 Tensilica Inc.
+ *
+ * Chris Zankel <chris@zankel.net>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/moduleloader.h>
+#include <linux/elf.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/cache.h>
+
+static int
+decode_calln_opcode (unsigned char *location)
+{
+#ifdef __XTENSA_EB__
+ return (location[0] & 0xf0) == 0x50;
+#endif
+#ifdef __XTENSA_EL__
+ return (location[0] & 0xf) == 0x5;
+#endif
+}
+
+static int
+decode_l32r_opcode (unsigned char *location)
+{
+#ifdef __XTENSA_EB__
+ return (location[0] & 0xf0) == 0x10;
+#endif
+#ifdef __XTENSA_EL__
+ return (location[0] & 0xf) == 0x1;
+#endif
+}
+
+int apply_relocate_add(Elf32_Shdr *sechdrs,
+ const char *strtab,
+ unsigned int symindex,
+ unsigned int relsec,
+ struct module *mod)
+{
+ unsigned int i;
+ Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
+ Elf32_Sym *sym;
+ unsigned char *location;
+ uint32_t value;
+
+ pr_debug("Applying relocate section %u to %u\n", relsec,
+ sechdrs[relsec].sh_info);
+
+ for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
+ location = (char *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ + rela[i].r_offset;
+ sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+ + ELF32_R_SYM(rela[i].r_info);
+ value = sym->st_value + rela[i].r_addend;
+
+ switch (ELF32_R_TYPE(rela[i].r_info)) {
+ case R_XTENSA_NONE:
+ case R_XTENSA_DIFF8:
+ case R_XTENSA_DIFF16:
+ case R_XTENSA_DIFF32:
+ case R_XTENSA_ASM_EXPAND:
+ break;
+
+ case R_XTENSA_32:
+ case R_XTENSA_PLT:
+ *(uint32_t *)location += value;
+ break;
+
+ case R_XTENSA_SLOT0_OP:
+ if (decode_calln_opcode(location)) {
+ value -= ((unsigned long)location & -4) + 4;
+ if ((value & 3) != 0 ||
+ ((value + (1 << 19)) >> 20) != 0) {
+ pr_err("%s: relocation out of range, "
+ "section %d reloc %d "
+ "sym '%s'\n",
+ mod->name, relsec, i,
+ strtab + sym->st_name);
+ return -ENOEXEC;
+ }
+ value = (signed int)value >> 2;
+#ifdef __XTENSA_EB__
+ location[0] = ((location[0] & ~0x3) |
+ ((value >> 16) & 0x3));
+ location[1] = (value >> 8) & 0xff;
+ location[2] = value & 0xff;
+#endif
+#ifdef __XTENSA_EL__
+ location[0] = ((location[0] & ~0xc0) |
+ ((value << 6) & 0xc0));
+ location[1] = (value >> 2) & 0xff;
+ location[2] = (value >> 10) & 0xff;
+#endif
+ } else if (decode_l32r_opcode(location)) {
+ value -= (((unsigned long)location + 3) & -4);
+ if ((value & 3) != 0 ||
+ (signed int)value >> 18 != -1) {
+ pr_err("%s: relocation out of range, "
+ "section %d reloc %d "
+ "sym '%s'\n",
+ mod->name, relsec, i,
+ strtab + sym->st_name);
+ return -ENOEXEC;
+ }
+ value = (signed int)value >> 2;
+
+#ifdef __XTENSA_EB__
+ location[1] = (value >> 8) & 0xff;
+ location[2] = value & 0xff;
+#endif
+#ifdef __XTENSA_EL__
+ location[1] = value & 0xff;
+ location[2] = (value >> 8) & 0xff;
+#endif
+ }
+ /* FIXME: Ignore any other opcodes. The Xtensa
+ assembler currently assumes that the linker will
+ always do relaxation and so all PC-relative
+ operands need relocations. (The assembler also
+ writes out the tentative PC-relative values,
+ assuming no link-time relaxation, so it is usually
+ safe to ignore the relocations.) If the
+ assembler's "--no-link-relax" flag can be made to
+ work, and if all kernel modules can be assembled
+ with that flag, then unexpected relocations could
+ be detected here. */
+ break;
+
+ case R_XTENSA_SLOT1_OP:
+ case R_XTENSA_SLOT2_OP:
+ case R_XTENSA_SLOT3_OP:
+ case R_XTENSA_SLOT4_OP:
+ case R_XTENSA_SLOT5_OP:
+ case R_XTENSA_SLOT6_OP:
+ case R_XTENSA_SLOT7_OP:
+ case R_XTENSA_SLOT8_OP:
+ case R_XTENSA_SLOT9_OP:
+ case R_XTENSA_SLOT10_OP:
+ case R_XTENSA_SLOT11_OP:
+ case R_XTENSA_SLOT12_OP:
+ case R_XTENSA_SLOT13_OP:
+ case R_XTENSA_SLOT14_OP:
+ pr_err("%s: unexpected FLIX relocation: %u\n",
+ mod->name,
+ ELF32_R_TYPE(rela[i].r_info));
+ return -ENOEXEC;
+
+ case R_XTENSA_SLOT0_ALT:
+ case R_XTENSA_SLOT1_ALT:
+ case R_XTENSA_SLOT2_ALT:
+ case R_XTENSA_SLOT3_ALT:
+ case R_XTENSA_SLOT4_ALT:
+ case R_XTENSA_SLOT5_ALT:
+ case R_XTENSA_SLOT6_ALT:
+ case R_XTENSA_SLOT7_ALT:
+ case R_XTENSA_SLOT8_ALT:
+ case R_XTENSA_SLOT9_ALT:
+ case R_XTENSA_SLOT10_ALT:
+ case R_XTENSA_SLOT11_ALT:
+ case R_XTENSA_SLOT12_ALT:
+ case R_XTENSA_SLOT13_ALT:
+ case R_XTENSA_SLOT14_ALT:
+ pr_err("%s: unexpected ALT relocation: %u\n",
+ mod->name,
+ ELF32_R_TYPE(rela[i].r_info));
+ return -ENOEXEC;
+
+ default:
+ pr_err("%s: unexpected relocation: %u\n",
+ mod->name,
+ ELF32_R_TYPE(rela[i].r_info));
+ return -ENOEXEC;
+ }
+ }
+ return 0;
+}