Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 185 insertions, 0 deletions

diff --git a/arch/loongarch/kernel/module-sections.c b/arch/loongarch/kernel/module-sections.c
new file mode 100644
index 0000000000..e2f30ff9af
--- /dev/null
+++ b/arch/loongarch/kernel/module-sections.c
@@ -0,0 +1,185 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#include <linux/elf.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleloader.h>
+#include <linux/ftrace.h>
+
+Elf_Addr module_emit_got_entry(struct module *mod, Elf_Shdr *sechdrs, Elf_Addr val)
+{
+	struct mod_section *got_sec = &mod->arch.got;
+	int i = got_sec->num_entries;
+	struct got_entry *got = get_got_entry(val, sechdrs, got_sec);
+
+	if (got)
+		return (Elf_Addr)got;
+
+	/* There is no GOT entry for val yet, create a new one. */
+	got = (struct got_entry *)sechdrs[got_sec->shndx].sh_addr;
+	got[i] = emit_got_entry(val);
+
+	got_sec->num_entries++;
+	if (got_sec->num_entries > got_sec->max_entries) {
+		/*
+		 * This may happen when the module contains a GOT_HI20 without
+		 * a paired GOT_LO12. Such a module is broken, reject it.
+		 */
+		pr_err("%s: module contains bad GOT relocation\n", mod->name);
+		return 0;
+	}
+
+	return (Elf_Addr)&got[i];
+}
+
+Elf_Addr module_emit_plt_entry(struct module *mod, Elf_Shdr *sechdrs, Elf_Addr val)
+{
+	int nr;
+	struct mod_section *plt_sec = &mod->arch.plt;
+	struct mod_section *plt_idx_sec = &mod->arch.plt_idx;
+	struct plt_entry *plt = get_plt_entry(val, sechdrs, plt_sec, plt_idx_sec);
+	struct plt_idx_entry *plt_idx;
+
+	if (plt)
+		return (Elf_Addr)plt;
+
+	nr = plt_sec->num_entries;
+
+	/* There is no duplicate entry, create a new one */
+	plt = (struct plt_entry *)sechdrs[plt_sec->shndx].sh_addr;
+	plt[nr] = emit_plt_entry(val);
+	plt_idx = (struct plt_idx_entry *)sechdrs[plt_idx_sec->shndx].sh_addr;
+	plt_idx[nr] = emit_plt_idx_entry(val);
+
+	plt_sec->num_entries++;
+	plt_idx_sec->num_entries++;
+	BUG_ON(plt_sec->num_entries > plt_sec->max_entries);
+
+	return (Elf_Addr)&plt[nr];
+}
+
+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 i, type;
+
+	for (i = 0; i < num; i++) {
+		type = ELF_R_TYPE(relas[i].r_info);
+		switch (type) {
+		case R_LARCH_SOP_PUSH_PLT_PCREL:
+		case R_LARCH_B26:
+			if (!duplicate_rela(relas, i))
+				(*plts)++;
+			break;
+		case R_LARCH_GOT_PC_HI20:
+			if (!duplicate_rela(relas, i))
+				(*gots)++;
+			break;
+		default:
+			break; /* Do nothing. */
+		}
+	}
+}
+
+int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
+			      char *secstrings, struct module *mod)
+{
+	unsigned int i, num_plts = 0, num_gots = 0;
+	Elf_Shdr *got_sec, *plt_sec, *plt_idx_sec, *tramp = NULL;
+
+	/*
+	 * Find the empty .plt sections.
+	 */
+	for (i = 0; i < ehdr->e_shnum; i++) {
+		if (!strcmp(secstrings + sechdrs[i].sh_name, ".got"))
+			mod->arch.got.shndx = i;
+		else if (!strcmp(secstrings + sechdrs[i].sh_name, ".plt"))
+			mod->arch.plt.shndx = i;
+		else if (!strcmp(secstrings + sechdrs[i].sh_name, ".plt.idx"))
+			mod->arch.plt_idx.shndx = i;
+		else if (!strcmp(secstrings + sechdrs[i].sh_name, ".ftrace_trampoline"))
+			tramp = sechdrs + i;
+	}
+
+	if (!mod->arch.got.shndx) {
+		pr_err("%s: module GOT section(s) missing\n", mod->name);
+		return -ENOEXEC;
+	}
+	if (!mod->arch.plt.shndx) {
+		pr_err("%s: module PLT section(s) missing\n", mod->name);
+		return -ENOEXEC;
+	}
+	if (!mod->arch.plt_idx.shndx) {
+		pr_err("%s: module PLT.IDX section(s) missing\n", mod->name);
+		return -ENOEXEC;
+	}
+
+	/* Calculate the maxinum number of entries */
+	for (i = 0; i < ehdr->e_shnum; i++) {
+		int num_rela = sechdrs[i].sh_size / sizeof(Elf_Rela);
+		Elf_Rela *relas = (void *)ehdr + sechdrs[i].sh_offset;
+		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);
+	}
+
+	got_sec = sechdrs + mod->arch.got.shndx;
+	got_sec->sh_type = SHT_NOBITS;
+	got_sec->sh_flags = SHF_ALLOC;
+	got_sec->sh_addralign = L1_CACHE_BYTES;
+	got_sec->sh_size = (num_gots + 1) * sizeof(struct got_entry);
+	mod->arch.got.num_entries = 0;
+	mod->arch.got.max_entries = num_gots;
+
+	plt_sec = sechdrs + mod->arch.plt.shndx;
+	plt_sec->sh_type = SHT_NOBITS;
+	plt_sec->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
+	plt_sec->sh_addralign = L1_CACHE_BYTES;
+	plt_sec->sh_size = (num_plts + 1) * sizeof(struct plt_entry);
+	mod->arch.plt.num_entries = 0;
+	mod->arch.plt.max_entries = num_plts;
+
+	plt_idx_sec = sechdrs + mod->arch.plt_idx.shndx;
+	plt_idx_sec->sh_type = SHT_NOBITS;
+	plt_idx_sec->sh_flags = SHF_ALLOC;
+	plt_idx_sec->sh_addralign = L1_CACHE_BYTES;
+	plt_idx_sec->sh_size = (num_plts + 1) * sizeof(struct plt_idx_entry);
+	mod->arch.plt_idx.num_entries = 0;
+	mod->arch.plt_idx.max_entries = num_plts;
+
+	if (tramp) {
+		tramp->sh_type = SHT_NOBITS;
+		tramp->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
+		tramp->sh_addralign = __alignof__(struct plt_entry);
+		tramp->sh_size = NR_FTRACE_PLTS * sizeof(struct plt_entry);
+	}
+
+	return 0;
+}