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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/arc/kernel/module.c
Initial import
Diffstat (limited to 'arch/arc/kernel/module.c')
-rw-r--r--arch/arc/kernel/module.c145
1 files changed, 145 insertions, 0 deletions
diff --git a/arch/arc/kernel/module.c b/arch/arc/kernel/module.c
new file mode 100644
index 000000000..376e04622
--- /dev/null
+++ b/arch/arc/kernel/module.c
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleloader.h>
+#include <linux/kernel.h>
+#include <linux/elf.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <asm/unwind.h>
+
+static inline void arc_write_me(unsigned short *addr, unsigned long value)
+{
+ *addr = (value & 0xffff0000) >> 16;
+ *(addr + 1) = (value & 0xffff);
+}
+
+/* ARC specific section quirks - before relocation loop in generic loader
+ *
+ * For dwarf unwinding out of modules, this needs to
+ * 1. Ensure the .debug_frame is allocatable (ARC Linker bug: despite
+ * -fasynchronous-unwind-tables it doesn't).
+ * 2. Since we are iterating thru sec hdr tbl anyways, make a note of
+ * the exact section index, for later use.
+ */
+int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+ char *secstr, struct module *mod)
+{
+#ifdef CONFIG_ARC_DW2_UNWIND
+ int i;
+
+ mod->arch.unw_sec_idx = 0;
+ mod->arch.unw_info = NULL;
+
+ for (i = 1; i < hdr->e_shnum; i++) {
+ if (strcmp(secstr+sechdrs[i].sh_name, ".debug_frame") == 0) {
+ sechdrs[i].sh_flags |= SHF_ALLOC;
+ mod->arch.unw_sec_idx = i;
+ break;
+ }
+ }
+#endif
+ return 0;
+}
+
+void module_arch_cleanup(struct module *mod)
+{
+#ifdef CONFIG_ARC_DW2_UNWIND
+ if (mod->arch.unw_info)
+ unwind_remove_table(mod->arch.unw_info, 0);
+#endif
+}
+
+int apply_relocate_add(Elf32_Shdr *sechdrs,
+ const char *strtab,
+ unsigned int symindex, /* sec index for sym tbl */
+ unsigned int relsec, /* sec index for relo sec */
+ struct module *module)
+{
+ int i, n;
+ Elf32_Rela *rel_entry = (void *)sechdrs[relsec].sh_addr;
+ Elf32_Sym *sym_entry, *sym_sec;
+ Elf32_Addr relocation;
+ Elf32_Addr location;
+ Elf32_Addr sec_to_patch;
+ int relo_type;
+
+ sec_to_patch = sechdrs[sechdrs[relsec].sh_info].sh_addr;
+ sym_sec = (Elf32_Sym *) sechdrs[symindex].sh_addr;
+ n = sechdrs[relsec].sh_size / sizeof(*rel_entry);
+
+ pr_debug("\n========== Module Sym reloc ===========================\n");
+ pr_debug("Section to fixup %x\n", sec_to_patch);
+ pr_debug("=========================================================\n");
+ pr_debug("rela->r_off | rela->addend | sym->st_value | ADDR | VALUE\n");
+ pr_debug("=========================================================\n");
+
+ /* Loop thru entries in relocation section */
+ for (i = 0; i < n; i++) {
+
+ /* This is where to make the change */
+ location = sec_to_patch + rel_entry[i].r_offset;
+
+ /* This is the symbol it is referring to. Note that all
+ undefined symbols have been resolved. */
+ sym_entry = sym_sec + ELF32_R_SYM(rel_entry[i].r_info);
+
+ relocation = sym_entry->st_value + rel_entry[i].r_addend;
+
+ pr_debug("\t%x\t\t%x\t\t%x %x %x [%s]\n",
+ rel_entry[i].r_offset, rel_entry[i].r_addend,
+ sym_entry->st_value, location, relocation,
+ strtab + sym_entry->st_name);
+
+ /* This assumes modules are built with -mlong-calls
+ * so any branches/jumps are absolute 32 bit jmps
+ * global data access again is abs 32 bit.
+ * Both of these are handled by same relocation type
+ */
+ relo_type = ELF32_R_TYPE(rel_entry[i].r_info);
+
+ if (likely(R_ARC_32_ME == relo_type))
+ arc_write_me((unsigned short *)location, relocation);
+ else if (R_ARC_32 == relo_type)
+ *((Elf32_Addr *) location) = relocation;
+ else
+ goto relo_err;
+
+ }
+ return 0;
+
+relo_err:
+ pr_err("%s: unknown relocation: %u\n",
+ module->name, ELF32_R_TYPE(rel_entry[i].r_info));
+ return -ENOEXEC;
+
+}
+
+/* Just before lift off: After sections have been relocated, we add the
+ * dwarf section to unwinder table pool
+ * This couldn't be done in module_frob_arch_sections() because
+ * relocations had not been applied by then
+ */
+int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
+ struct module *mod)
+{
+#ifdef CONFIG_ARC_DW2_UNWIND
+ void *unw;
+ int unwsec = mod->arch.unw_sec_idx;
+
+ if (unwsec) {
+ unw = unwind_add_table(mod, (void *)sechdrs[unwsec].sh_addr,
+ sechdrs[unwsec].sh_size);
+ mod->arch.unw_info = unw;
+ }
+#endif
+ return 0;
+}