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-rw-r--r--arch/riscv/kernel/module.c179
1 files changed, 173 insertions, 6 deletions
diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
index e0f05034fc21..5dddba301d0a 100644
--- a/arch/riscv/kernel/module.c
+++ b/arch/riscv/kernel/module.c
@@ -49,6 +49,39 @@ static int apply_r_riscv_jal_rela(struct module *me, u32 *location,
return 0;
}
+static int apply_r_riscv_rcv_branch_rela(struct module *me, u32 *location,
+ Elf_Addr v)
+{
+ s64 offset = (void *)v - (void *)location;
+ u16 imm8 = (offset & 0x100) << (12 - 8);
+ u16 imm7_6 = (offset & 0xc0) >> (6 - 5);
+ u16 imm5 = (offset & 0x20) >> (5 - 2);
+ u16 imm4_3 = (offset & 0x18) << (12 - 5);
+ u16 imm2_1 = (offset & 0x6) << (12 - 10);
+
+ *(u16 *)location = (*(u16 *)location & 0xe383) |
+ imm8 | imm7_6 | imm5 | imm4_3 | imm2_1;
+ return 0;
+}
+
+static int apply_r_riscv_rvc_jump_rela(struct module *me, u32 *location,
+ Elf_Addr v)
+{
+ s64 offset = (void *)v - (void *)location;
+ u16 imm11 = (offset & 0x800) << (12 - 11);
+ u16 imm10 = (offset & 0x400) >> (10 - 8);
+ u16 imm9_8 = (offset & 0x300) << (12 - 11);
+ u16 imm7 = (offset & 0x80) >> (7 - 6);
+ u16 imm6 = (offset & 0x40) << (12 - 11);
+ u16 imm5 = (offset & 0x20) >> (5 - 2);
+ u16 imm4 = (offset & 0x10) << (12 - 5);
+ u16 imm3_1 = (offset & 0xe) << (12 - 10);
+
+ *(u16 *)location = (*(u16 *)location & 0xe003) |
+ imm11 | imm10 | imm9_8 | imm7 | imm6 | imm5 | imm4 | imm3_1;
+ return 0;
+}
+
static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location,
Elf_Addr v)
{
@@ -92,6 +125,67 @@ static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location,
return 0;
}
+static int apply_r_riscv_hi20_rela(struct module *me, u32 *location,
+ Elf_Addr v)
+{
+ s32 hi20;
+
+ if (IS_ENABLED(CMODEL_MEDLOW)) {
+ pr_err(
+ "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
+ me->name, v, location);
+ return -EINVAL;
+ }
+
+ hi20 = ((s32)v + 0x800) & 0xfffff000;
+ *location = (*location & 0xfff) | hi20;
+ return 0;
+}
+
+static int apply_r_riscv_lo12_i_rela(struct module *me, u32 *location,
+ Elf_Addr v)
+{
+ /* Skip medlow checking because of filtering by HI20 already */
+ s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
+ s32 lo12 = ((s32)v - hi20);
+ *location = (*location & 0xfffff) | ((lo12 & 0xfff) << 20);
+ return 0;
+}
+
+static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location,
+ Elf_Addr v)
+{
+ /* Skip medlow checking because of filtering by HI20 already */
+ s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
+ s32 lo12 = ((s32)v - hi20);
+ u32 imm11_5 = (lo12 & 0xfe0) << (31 - 11);
+ u32 imm4_0 = (lo12 & 0x1f) << (11 - 4);
+ *location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
+ return 0;
+}
+
+static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location,
+ Elf_Addr v)
+{
+ s64 offset = (void *)v - (void *)location;
+ s32 hi20;
+
+ /* Always emit the got entry */
+ if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
+ offset = module_emit_got_entry(me, v);
+ offset = (void *)offset - (void *)location;
+ } else {
+ pr_err(
+ "%s: can not generate the GOT entry for symbol = %016llx from PC = %p\n",
+ me->name, v, location);
+ return -EINVAL;
+ }
+
+ hi20 = (offset + 0x800) & 0xfffff000;
+ *location = (*location & 0xfff) | hi20;
+ return 0;
+}
+
static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location,
Elf_Addr v)
{
@@ -100,6 +194,33 @@ static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location,
u32 hi20, lo12;
if (offset != fill_v) {
+ /* Only emit the plt entry if offset over 32-bit range */
+ if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) {
+ offset = module_emit_plt_entry(me, v);
+ offset = (void *)offset - (void *)location;
+ } else {
+ pr_err(
+ "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
+ me->name, v, location);
+ return -EINVAL;
+ }
+ }
+
+ hi20 = (offset + 0x800) & 0xfffff000;
+ lo12 = (offset - hi20) & 0xfff;
+ *location = (*location & 0xfff) | hi20;
+ *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
+ return 0;
+}
+
+static int apply_r_riscv_call_rela(struct module *me, u32 *location,
+ Elf_Addr v)
+{
+ s64 offset = (void *)v - (void *)location;
+ s32 fill_v = offset;
+ u32 hi20, lo12;
+
+ if (offset != fill_v) {
pr_err(
"%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
me->name, v, location);
@@ -119,16 +240,49 @@ static int apply_r_riscv_relax_rela(struct module *me, u32 *location,
return 0;
}
+static int apply_r_riscv_align_rela(struct module *me, u32 *location,
+ Elf_Addr v)
+{
+ pr_err(
+ "%s: The unexpected relocation type 'R_RISCV_ALIGN' from PC = %p\n",
+ me->name, location);
+ return -EINVAL;
+}
+
+static int apply_r_riscv_add32_rela(struct module *me, u32 *location,
+ Elf_Addr v)
+{
+ *(u32 *)location += (*(u32 *)v);
+ return 0;
+}
+
+static int apply_r_riscv_sub32_rela(struct module *me, u32 *location,
+ Elf_Addr v)
+{
+ *(u32 *)location -= (*(u32 *)v);
+ return 0;
+}
+
static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
Elf_Addr v) = {
[R_RISCV_64] = apply_r_riscv_64_rela,
[R_RISCV_BRANCH] = apply_r_riscv_branch_rela,
[R_RISCV_JAL] = apply_r_riscv_jal_rela,
+ [R_RISCV_RVC_BRANCH] = apply_r_riscv_rcv_branch_rela,
+ [R_RISCV_RVC_JUMP] = apply_r_riscv_rvc_jump_rela,
[R_RISCV_PCREL_HI20] = apply_r_riscv_pcrel_hi20_rela,
[R_RISCV_PCREL_LO12_I] = apply_r_riscv_pcrel_lo12_i_rela,
[R_RISCV_PCREL_LO12_S] = apply_r_riscv_pcrel_lo12_s_rela,
+ [R_RISCV_HI20] = apply_r_riscv_hi20_rela,
+ [R_RISCV_LO12_I] = apply_r_riscv_lo12_i_rela,
+ [R_RISCV_LO12_S] = apply_r_riscv_lo12_s_rela,
+ [R_RISCV_GOT_HI20] = apply_r_riscv_got_hi20_rela,
[R_RISCV_CALL_PLT] = apply_r_riscv_call_plt_rela,
+ [R_RISCV_CALL] = apply_r_riscv_call_rela,
[R_RISCV_RELAX] = apply_r_riscv_relax_rela,
+ [R_RISCV_ALIGN] = apply_r_riscv_align_rela,
+ [R_RISCV_ADD32] = apply_r_riscv_add32_rela,
+ [R_RISCV_SUB32] = apply_r_riscv_sub32_rela,
};
int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
@@ -184,25 +338,38 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
u64 hi20_loc =
sechdrs[sechdrs[relsec].sh_info].sh_addr
+ rel[j].r_offset;
- /* Find the corresponding HI20 PC-relative relocation entry */
- if (hi20_loc == sym->st_value) {
+ u32 hi20_type = ELF_RISCV_R_TYPE(rel[j].r_info);
+
+ /* Find the corresponding HI20 relocation entry */
+ if (hi20_loc == sym->st_value
+ && (hi20_type == R_RISCV_PCREL_HI20
+ || hi20_type == R_RISCV_GOT_HI20)) {
+ s32 hi20, lo12;
Elf_Sym *hi20_sym =
(Elf_Sym *)sechdrs[symindex].sh_addr
+ ELF_RISCV_R_SYM(rel[j].r_info);
u64 hi20_sym_val =
hi20_sym->st_value
+ rel[j].r_addend;
+
/* Calculate lo12 */
- s64 offset = hi20_sym_val - hi20_loc;
- s32 hi20 = (offset + 0x800) & 0xfffff000;
- s32 lo12 = offset - hi20;
+ u64 offset = hi20_sym_val - hi20_loc;
+ if (IS_ENABLED(CONFIG_MODULE_SECTIONS)
+ && hi20_type == R_RISCV_GOT_HI20) {
+ offset = module_emit_got_entry(
+ me, hi20_sym_val);
+ offset = offset - hi20_loc;
+ }
+ hi20 = (offset + 0x800) & 0xfffff000;
+ lo12 = offset - hi20;
v = lo12;
+
break;
}
}
if (j == sechdrs[relsec].sh_size / sizeof(*rel)) {
pr_err(
- "%s: Can not find HI20 PC-relative relocation information\n",
+ "%s: Can not find HI20 relocation information\n",
me->name);
return -EINVAL;
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.