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-rw-r--r--arch/arm/kernel/module.c537
1 files changed, 537 insertions, 0 deletions
diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c
new file mode 100644
index 0000000000..e74d84f58b
--- /dev/null
+++ b/arch/arm/kernel/module.c
@@ -0,0 +1,537 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/arch/arm/kernel/module.c
+ *
+ * Copyright (C) 2002 Russell King.
+ * Modified for nommu by Hyok S. Choi
+ *
+ * Module allocation method suggested by Andi Kleen.
+ */
+#include <linux/module.h>
+#include <linux/moduleloader.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/elf.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/gfp.h>
+
+#include <asm/sections.h>
+#include <asm/smp_plat.h>
+#include <asm/unwind.h>
+#include <asm/opcodes.h>
+
+#ifdef CONFIG_XIP_KERNEL
+/*
+ * The XIP kernel text is mapped in the module area for modules and
+ * some other stuff to work without any indirect relocations.
+ * MODULES_VADDR is redefined here and not in asm/memory.h to avoid
+ * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
+ */
+#undef MODULES_VADDR
+#define MODULES_VADDR (((unsigned long)_exiprom + ~PMD_MASK) & PMD_MASK)
+#endif
+
+#ifdef CONFIG_MMU
+void *module_alloc(unsigned long size)
+{
+ gfp_t gfp_mask = GFP_KERNEL;
+ void *p;
+
+ /* Silence the initial allocation */
+ if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS))
+ gfp_mask |= __GFP_NOWARN;
+
+ p = __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
+ gfp_mask, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
+ __builtin_return_address(0));
+ if (!IS_ENABLED(CONFIG_ARM_MODULE_PLTS) || p)
+ return p;
+ return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
+ GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
+ __builtin_return_address(0));
+}
+#endif
+
+bool module_init_section(const char *name)
+{
+ return strstarts(name, ".init") ||
+ strstarts(name, ".ARM.extab.init") ||
+ strstarts(name, ".ARM.exidx.init");
+}
+
+bool module_exit_section(const char *name)
+{
+ return strstarts(name, ".exit") ||
+ strstarts(name, ".ARM.extab.exit") ||
+ strstarts(name, ".ARM.exidx.exit");
+}
+
+#ifdef CONFIG_ARM_HAS_GROUP_RELOCS
+/*
+ * This implements the partitioning algorithm for group relocations as
+ * documented in the ARM AArch32 ELF psABI (IHI 0044).
+ *
+ * A single PC-relative symbol reference is divided in up to 3 add or subtract
+ * operations, where the final one could be incorporated into a load/store
+ * instruction with immediate offset. E.g.,
+ *
+ * ADD Rd, PC, #... or ADD Rd, PC, #...
+ * ADD Rd, Rd, #... ADD Rd, Rd, #...
+ * LDR Rd, [Rd, #...] ADD Rd, Rd, #...
+ *
+ * The latter has a guaranteed range of only 16 MiB (3x8 == 24 bits), so it is
+ * of limited use in the kernel. However, the ADD/ADD/LDR combo has a range of
+ * -/+ 256 MiB, (2x8 + 12 == 28 bits), which means it has sufficient range for
+ * any in-kernel symbol reference (unless module PLTs are being used).
+ *
+ * The main advantage of this approach over the typical pattern using a literal
+ * load is that literal loads may miss in the D-cache, and generally lead to
+ * lower cache efficiency for variables that are referenced often from many
+ * different places in the code.
+ */
+static u32 get_group_rem(u32 group, u32 *offset)
+{
+ u32 val = *offset;
+ u32 shift;
+ do {
+ shift = val ? (31 - __fls(val)) & ~1 : 32;
+ *offset = val;
+ if (!val)
+ break;
+ val &= 0xffffff >> shift;
+ } while (group--);
+ return shift;
+}
+#endif
+
+int
+apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
+ unsigned int relindex, struct module *module)
+{
+ Elf32_Shdr *symsec = sechdrs + symindex;
+ Elf32_Shdr *relsec = sechdrs + relindex;
+ Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
+ Elf32_Rel *rel = (void *)relsec->sh_addr;
+ unsigned int i;
+
+ for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) {
+ unsigned long loc;
+ Elf32_Sym *sym;
+ const char *symname;
+#ifdef CONFIG_ARM_HAS_GROUP_RELOCS
+ u32 shift, group = 1;
+#endif
+ s32 offset;
+ u32 tmp;
+#ifdef CONFIG_THUMB2_KERNEL
+ u32 upper, lower, sign, j1, j2;
+#endif
+
+ offset = ELF32_R_SYM(rel->r_info);
+ if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
+ pr_err("%s: section %u reloc %u: bad relocation sym offset\n",
+ module->name, relindex, i);
+ return -ENOEXEC;
+ }
+
+ sym = ((Elf32_Sym *)symsec->sh_addr) + offset;
+ symname = strtab + sym->st_name;
+
+ if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) {
+ pr_err("%s: section %u reloc %u sym '%s': out of bounds relocation, offset %d size %u\n",
+ module->name, relindex, i, symname,
+ rel->r_offset, dstsec->sh_size);
+ return -ENOEXEC;
+ }
+
+ loc = dstsec->sh_addr + rel->r_offset;
+
+ switch (ELF32_R_TYPE(rel->r_info)) {
+ case R_ARM_NONE:
+ /* ignore */
+ break;
+
+ case R_ARM_ABS32:
+ case R_ARM_TARGET1:
+ *(u32 *)loc += sym->st_value;
+ break;
+
+ case R_ARM_PC24:
+ case R_ARM_CALL:
+ case R_ARM_JUMP24:
+ if (sym->st_value & 3) {
+ pr_err("%s: section %u reloc %u sym '%s': unsupported interworking call (ARM -> Thumb)\n",
+ module->name, relindex, i, symname);
+ return -ENOEXEC;
+ }
+
+ offset = __mem_to_opcode_arm(*(u32 *)loc);
+ offset = (offset & 0x00ffffff) << 2;
+ offset = sign_extend32(offset, 25);
+
+ offset += sym->st_value - loc;
+
+ /*
+ * Route through a PLT entry if 'offset' exceeds the
+ * supported range. Note that 'offset + loc + 8'
+ * contains the absolute jump target, i.e.,
+ * @sym + addend, corrected for the +8 PC bias.
+ */
+ if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS) &&
+ (offset <= (s32)0xfe000000 ||
+ offset >= (s32)0x02000000))
+ offset = get_module_plt(module, loc,
+ offset + loc + 8)
+ - loc - 8;
+
+ if (offset <= (s32)0xfe000000 ||
+ offset >= (s32)0x02000000) {
+ pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n",
+ module->name, relindex, i, symname,
+ ELF32_R_TYPE(rel->r_info), loc,
+ sym->st_value);
+ return -ENOEXEC;
+ }
+
+ offset >>= 2;
+ offset &= 0x00ffffff;
+
+ *(u32 *)loc &= __opcode_to_mem_arm(0xff000000);
+ *(u32 *)loc |= __opcode_to_mem_arm(offset);
+ break;
+
+ case R_ARM_V4BX:
+ /* Preserve Rm and the condition code. Alter
+ * other bits to re-code instruction as
+ * MOV PC,Rm.
+ */
+ *(u32 *)loc &= __opcode_to_mem_arm(0xf000000f);
+ *(u32 *)loc |= __opcode_to_mem_arm(0x01a0f000);
+ break;
+
+ case R_ARM_PREL31:
+ offset = (*(s32 *)loc << 1) >> 1; /* sign extend */
+ offset += sym->st_value - loc;
+ if (offset >= 0x40000000 || offset < -0x40000000) {
+ pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n",
+ module->name, relindex, i, symname,
+ ELF32_R_TYPE(rel->r_info), loc,
+ sym->st_value);
+ return -ENOEXEC;
+ }
+ *(u32 *)loc &= 0x80000000;
+ *(u32 *)loc |= offset & 0x7fffffff;
+ break;
+
+ case R_ARM_REL32:
+ *(u32 *)loc += sym->st_value - loc;
+ break;
+
+ case R_ARM_MOVW_ABS_NC:
+ case R_ARM_MOVT_ABS:
+ case R_ARM_MOVW_PREL_NC:
+ case R_ARM_MOVT_PREL:
+ offset = tmp = __mem_to_opcode_arm(*(u32 *)loc);
+ offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff);
+ offset = sign_extend32(offset, 15);
+
+ offset += sym->st_value;
+ if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_PREL ||
+ ELF32_R_TYPE(rel->r_info) == R_ARM_MOVW_PREL_NC)
+ offset -= loc;
+ if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS ||
+ ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_PREL)
+ offset >>= 16;
+
+ tmp &= 0xfff0f000;
+ tmp |= ((offset & 0xf000) << 4) |
+ (offset & 0x0fff);
+
+ *(u32 *)loc = __opcode_to_mem_arm(tmp);
+ break;
+
+#ifdef CONFIG_ARM_HAS_GROUP_RELOCS
+ case R_ARM_ALU_PC_G0_NC:
+ group = 0;
+ fallthrough;
+ case R_ARM_ALU_PC_G1_NC:
+ tmp = __mem_to_opcode_arm(*(u32 *)loc);
+ offset = ror32(tmp & 0xff, (tmp & 0xf00) >> 7);
+ if (tmp & BIT(22))
+ offset = -offset;
+ offset += sym->st_value - loc;
+ if (offset < 0) {
+ offset = -offset;
+ tmp = (tmp & ~BIT(23)) | BIT(22); // SUB opcode
+ } else {
+ tmp = (tmp & ~BIT(22)) | BIT(23); // ADD opcode
+ }
+
+ shift = get_group_rem(group, &offset);
+ if (shift < 24) {
+ offset >>= 24 - shift;
+ offset |= (shift + 8) << 7;
+ }
+ *(u32 *)loc = __opcode_to_mem_arm((tmp & ~0xfff) | offset);
+ break;
+
+ case R_ARM_LDR_PC_G2:
+ tmp = __mem_to_opcode_arm(*(u32 *)loc);
+ offset = tmp & 0xfff;
+ if (~tmp & BIT(23)) // U bit cleared?
+ offset = -offset;
+ offset += sym->st_value - loc;
+ if (offset < 0) {
+ offset = -offset;
+ tmp &= ~BIT(23); // clear U bit
+ } else {
+ tmp |= BIT(23); // set U bit
+ }
+ get_group_rem(2, &offset);
+
+ if (offset > 0xfff) {
+ pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n",
+ module->name, relindex, i, symname,
+ ELF32_R_TYPE(rel->r_info), loc,
+ sym->st_value);
+ return -ENOEXEC;
+ }
+ *(u32 *)loc = __opcode_to_mem_arm((tmp & ~0xfff) | offset);
+ break;
+#endif
+#ifdef CONFIG_THUMB2_KERNEL
+ case R_ARM_THM_CALL:
+ case R_ARM_THM_JUMP24:
+ /*
+ * For function symbols, only Thumb addresses are
+ * allowed (no interworking).
+ *
+ * For non-function symbols, the destination
+ * has no specific ARM/Thumb disposition, so
+ * the branch is resolved under the assumption
+ * that interworking is not required.
+ */
+ if (ELF32_ST_TYPE(sym->st_info) == STT_FUNC &&
+ !(sym->st_value & 1)) {
+ pr_err("%s: section %u reloc %u sym '%s': unsupported interworking call (Thumb -> ARM)\n",
+ module->name, relindex, i, symname);
+ return -ENOEXEC;
+ }
+
+ upper = __mem_to_opcode_thumb16(*(u16 *)loc);
+ lower = __mem_to_opcode_thumb16(*(u16 *)(loc + 2));
+
+ /*
+ * 25 bit signed address range (Thumb-2 BL and B.W
+ * instructions):
+ * S:I1:I2:imm10:imm11:0
+ * where:
+ * S = upper[10] = offset[24]
+ * I1 = ~(J1 ^ S) = offset[23]
+ * I2 = ~(J2 ^ S) = offset[22]
+ * imm10 = upper[9:0] = offset[21:12]
+ * imm11 = lower[10:0] = offset[11:1]
+ * J1 = lower[13]
+ * J2 = lower[11]
+ */
+ sign = (upper >> 10) & 1;
+ j1 = (lower >> 13) & 1;
+ j2 = (lower >> 11) & 1;
+ offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) |
+ ((~(j2 ^ sign) & 1) << 22) |
+ ((upper & 0x03ff) << 12) |
+ ((lower & 0x07ff) << 1);
+ offset = sign_extend32(offset, 24);
+ offset += sym->st_value - loc;
+
+ /*
+ * Route through a PLT entry if 'offset' exceeds the
+ * supported range.
+ */
+ if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS) &&
+ (offset <= (s32)0xff000000 ||
+ offset >= (s32)0x01000000))
+ offset = get_module_plt(module, loc,
+ offset + loc + 4)
+ - loc - 4;
+
+ if (offset <= (s32)0xff000000 ||
+ offset >= (s32)0x01000000) {
+ pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n",
+ module->name, relindex, i, symname,
+ ELF32_R_TYPE(rel->r_info), loc,
+ sym->st_value);
+ return -ENOEXEC;
+ }
+
+ sign = (offset >> 24) & 1;
+ j1 = sign ^ (~(offset >> 23) & 1);
+ j2 = sign ^ (~(offset >> 22) & 1);
+ upper = (u16)((upper & 0xf800) | (sign << 10) |
+ ((offset >> 12) & 0x03ff));
+ lower = (u16)((lower & 0xd000) |
+ (j1 << 13) | (j2 << 11) |
+ ((offset >> 1) & 0x07ff));
+
+ *(u16 *)loc = __opcode_to_mem_thumb16(upper);
+ *(u16 *)(loc + 2) = __opcode_to_mem_thumb16(lower);
+ break;
+
+ case R_ARM_THM_MOVW_ABS_NC:
+ case R_ARM_THM_MOVT_ABS:
+ case R_ARM_THM_MOVW_PREL_NC:
+ case R_ARM_THM_MOVT_PREL:
+ upper = __mem_to_opcode_thumb16(*(u16 *)loc);
+ lower = __mem_to_opcode_thumb16(*(u16 *)(loc + 2));
+
+ /*
+ * MOVT/MOVW instructions encoding in Thumb-2:
+ *
+ * i = upper[10]
+ * imm4 = upper[3:0]
+ * imm3 = lower[14:12]
+ * imm8 = lower[7:0]
+ *
+ * imm16 = imm4:i:imm3:imm8
+ */
+ offset = ((upper & 0x000f) << 12) |
+ ((upper & 0x0400) << 1) |
+ ((lower & 0x7000) >> 4) | (lower & 0x00ff);
+ offset = sign_extend32(offset, 15);
+ offset += sym->st_value;
+
+ if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_PREL ||
+ ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVW_PREL_NC)
+ offset -= loc;
+ if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS ||
+ ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_PREL)
+ offset >>= 16;
+
+ upper = (u16)((upper & 0xfbf0) |
+ ((offset & 0xf000) >> 12) |
+ ((offset & 0x0800) >> 1));
+ lower = (u16)((lower & 0x8f00) |
+ ((offset & 0x0700) << 4) |
+ (offset & 0x00ff));
+ *(u16 *)loc = __opcode_to_mem_thumb16(upper);
+ *(u16 *)(loc + 2) = __opcode_to_mem_thumb16(lower);
+ break;
+#endif
+
+ default:
+ pr_err("%s: unknown relocation: %u\n",
+ module->name, ELF32_R_TYPE(rel->r_info));
+ return -ENOEXEC;
+ }
+ }
+ return 0;
+}
+
+struct mod_unwind_map {
+ const Elf_Shdr *unw_sec;
+ const Elf_Shdr *txt_sec;
+};
+
+static const Elf_Shdr *find_mod_section(const Elf32_Ehdr *hdr,
+ const Elf_Shdr *sechdrs, const char *name)
+{
+ const Elf_Shdr *s, *se;
+ const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+
+ for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++)
+ if (strcmp(name, secstrs + s->sh_name) == 0)
+ return s;
+
+ return NULL;
+}
+
+extern void fixup_pv_table(const void *, unsigned long);
+extern void fixup_smp(const void *, unsigned long);
+
+int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
+ struct module *mod)
+{
+ const Elf_Shdr *s = NULL;
+#ifdef CONFIG_ARM_UNWIND
+ const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+ const Elf_Shdr *sechdrs_end = sechdrs + hdr->e_shnum;
+ struct list_head *unwind_list = &mod->arch.unwind_list;
+
+ INIT_LIST_HEAD(unwind_list);
+ mod->arch.init_table = NULL;
+
+ for (s = sechdrs; s < sechdrs_end; s++) {
+ const char *secname = secstrs + s->sh_name;
+ const char *txtname;
+ const Elf_Shdr *txt_sec;
+
+ if (!(s->sh_flags & SHF_ALLOC) ||
+ s->sh_type != ELF_SECTION_UNWIND)
+ continue;
+
+ if (!strcmp(".ARM.exidx", secname))
+ txtname = ".text";
+ else
+ txtname = secname + strlen(".ARM.exidx");
+ txt_sec = find_mod_section(hdr, sechdrs, txtname);
+
+ if (txt_sec) {
+ struct unwind_table *table =
+ unwind_table_add(s->sh_addr,
+ s->sh_size,
+ txt_sec->sh_addr,
+ txt_sec->sh_size);
+
+ list_add(&table->mod_list, unwind_list);
+
+ /* save init table for module_arch_freeing_init */
+ if (strcmp(".ARM.exidx.init.text", secname) == 0)
+ mod->arch.init_table = table;
+ }
+ }
+#endif
+#ifdef CONFIG_ARM_PATCH_PHYS_VIRT
+ s = find_mod_section(hdr, sechdrs, ".pv_table");
+ if (s)
+ fixup_pv_table((void *)s->sh_addr, s->sh_size);
+#endif
+ s = find_mod_section(hdr, sechdrs, ".alt.smp.init");
+ if (s && !is_smp())
+#ifdef CONFIG_SMP_ON_UP
+ fixup_smp((void *)s->sh_addr, s->sh_size);
+#else
+ return -EINVAL;
+#endif
+ return 0;
+}
+
+void
+module_arch_cleanup(struct module *mod)
+{
+#ifdef CONFIG_ARM_UNWIND
+ struct unwind_table *tmp;
+ struct unwind_table *n;
+
+ list_for_each_entry_safe(tmp, n,
+ &mod->arch.unwind_list, mod_list) {
+ list_del(&tmp->mod_list);
+ unwind_table_del(tmp);
+ }
+ mod->arch.init_table = NULL;
+#endif
+}
+
+void __weak module_arch_freeing_init(struct module *mod)
+{
+#ifdef CONFIG_ARM_UNWIND
+ struct unwind_table *init = mod->arch.init_table;
+
+ if (init) {
+ mod->arch.init_table = NULL;
+ list_del(&init->mod_list);
+ unwind_table_del(init);
+ }
+#endif
+}
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