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-rw-r--r--arch/riscv/kernel/module-sections.c159
1 files changed, 159 insertions, 0 deletions
diff --git a/arch/riscv/kernel/module-sections.c b/arch/riscv/kernel/module-sections.c
new file mode 100644
index 0000000000..e264e59e59
--- /dev/null
+++ b/arch/riscv/kernel/module-sections.c
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2014-2017 Linaro Ltd. <ard.biesheuvel@linaro.org>
+ *
+ * Copyright (C) 2018 Andes Technology Corporation <zong@andestech.com>
+ */
+
+#include <linux/elf.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleloader.h>
+
+unsigned long module_emit_got_entry(struct module *mod, unsigned long val)
+{
+ struct mod_section *got_sec = &mod->arch.got;
+ int i = got_sec->num_entries;
+ struct got_entry *got = get_got_entry(val, got_sec);
+
+ if (got)
+ return (unsigned long)got;
+
+ /* There is no duplicate entry, create a new one */
+ got = (struct got_entry *)got_sec->shdr->sh_addr;
+ got[i] = emit_got_entry(val);
+
+ got_sec->num_entries++;
+ BUG_ON(got_sec->num_entries > got_sec->max_entries);
+
+ return (unsigned long)&got[i];
+}
+
+unsigned long module_emit_plt_entry(struct module *mod, unsigned long val)
+{
+ struct mod_section *got_plt_sec = &mod->arch.got_plt;
+ struct got_entry *got_plt;
+ struct mod_section *plt_sec = &mod->arch.plt;
+ struct plt_entry *plt = get_plt_entry(val, plt_sec, got_plt_sec);
+ int i = plt_sec->num_entries;
+
+ if (plt)
+ return (unsigned long)plt;
+
+ /* There is no duplicate entry, create a new one */
+ got_plt = (struct got_entry *)got_plt_sec->shdr->sh_addr;
+ got_plt[i] = emit_got_entry(val);
+ plt = (struct plt_entry *)plt_sec->shdr->sh_addr;
+ plt[i] = emit_plt_entry(val,
+ (unsigned long)&plt[i],
+ (unsigned long)&got_plt[i]);
+
+ plt_sec->num_entries++;
+ got_plt_sec->num_entries++;
+ BUG_ON(plt_sec->num_entries > plt_sec->max_entries);
+
+ return (unsigned long)&plt[i];
+}
+
+static int is_rela_equal(const Elf_Rela *x, const Elf_Rela *y)
+{
+ return x->r_info == y->r_info && x->r_addend == y->r_addend;
+}
+
+static bool duplicate_rela(const Elf_Rela *rela, int idx)
+{
+ int i;
+ for (i = 0; i < idx; i++) {
+ if (is_rela_equal(&rela[i], &rela[idx]))
+ return true;
+ }
+ return false;
+}
+
+static void count_max_entries(Elf_Rela *relas, int num,
+ unsigned int *plts, unsigned int *gots)
+{
+ unsigned int type, i;
+
+ for (i = 0; i < num; i++) {
+ type = ELF_RISCV_R_TYPE(relas[i].r_info);
+ if (type == R_RISCV_CALL_PLT) {
+ if (!duplicate_rela(relas, i))
+ (*plts)++;
+ } else if (type == R_RISCV_GOT_HI20) {
+ if (!duplicate_rela(relas, i))
+ (*gots)++;
+ }
+ }
+}
+
+int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
+ char *secstrings, struct module *mod)
+{
+ unsigned int num_plts = 0;
+ unsigned int num_gots = 0;
+ int i;
+
+ /*
+ * Find the empty .got and .plt sections.
+ */
+ for (i = 0; i < ehdr->e_shnum; i++) {
+ if (!strcmp(secstrings + sechdrs[i].sh_name, ".plt"))
+ mod->arch.plt.shdr = sechdrs + i;
+ else if (!strcmp(secstrings + sechdrs[i].sh_name, ".got"))
+ mod->arch.got.shdr = sechdrs + i;
+ else if (!strcmp(secstrings + sechdrs[i].sh_name, ".got.plt"))
+ mod->arch.got_plt.shdr = sechdrs + i;
+ }
+
+ if (!mod->arch.plt.shdr) {
+ pr_err("%s: module PLT section(s) missing\n", mod->name);
+ return -ENOEXEC;
+ }
+ if (!mod->arch.got.shdr) {
+ pr_err("%s: module GOT section(s) missing\n", mod->name);
+ return -ENOEXEC;
+ }
+ if (!mod->arch.got_plt.shdr) {
+ pr_err("%s: module GOT.PLT section(s) missing\n", mod->name);
+ return -ENOEXEC;
+ }
+
+ /* Calculate the maxinum number of entries */
+ for (i = 0; i < ehdr->e_shnum; i++) {
+ Elf_Rela *relas = (void *)ehdr + sechdrs[i].sh_offset;
+ int num_rela = sechdrs[i].sh_size / sizeof(Elf_Rela);
+ Elf_Shdr *dst_sec = sechdrs + sechdrs[i].sh_info;
+
+ if (sechdrs[i].sh_type != SHT_RELA)
+ continue;
+
+ /* ignore relocations that operate on non-exec sections */
+ if (!(dst_sec->sh_flags & SHF_EXECINSTR))
+ continue;
+
+ count_max_entries(relas, num_rela, &num_plts, &num_gots);
+ }
+
+ mod->arch.plt.shdr->sh_type = SHT_NOBITS;
+ mod->arch.plt.shdr->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
+ mod->arch.plt.shdr->sh_addralign = L1_CACHE_BYTES;
+ mod->arch.plt.shdr->sh_size = (num_plts + 1) * sizeof(struct plt_entry);
+ mod->arch.plt.num_entries = 0;
+ mod->arch.plt.max_entries = num_plts;
+
+ mod->arch.got.shdr->sh_type = SHT_NOBITS;
+ mod->arch.got.shdr->sh_flags = SHF_ALLOC;
+ mod->arch.got.shdr->sh_addralign = L1_CACHE_BYTES;
+ mod->arch.got.shdr->sh_size = (num_gots + 1) * sizeof(struct got_entry);
+ mod->arch.got.num_entries = 0;
+ mod->arch.got.max_entries = num_gots;
+
+ mod->arch.got_plt.shdr->sh_type = SHT_NOBITS;
+ mod->arch.got_plt.shdr->sh_flags = SHF_ALLOC;
+ mod->arch.got_plt.shdr->sh_addralign = L1_CACHE_BYTES;
+ mod->arch.got_plt.shdr->sh_size = (num_plts + 1) * sizeof(struct got_entry);
+ mod->arch.got_plt.num_entries = 0;
+ mod->arch.got_plt.max_entries = num_plts;
+ return 0;
+}