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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/powerpc/kernel/module_64.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/kernel/module_64.c')
-rw-r--r--arch/powerpc/kernel/module_64.c1109
1 files changed, 1109 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
new file mode 100644
index 0000000000..7112adc597
--- /dev/null
+++ b/arch/powerpc/kernel/module_64.c
@@ -0,0 +1,1109 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Kernel module help for PPC64.
+ Copyright (C) 2001, 2003 Rusty Russell IBM Corporation.
+
+*/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/elf.h>
+#include <linux/moduleloader.h>
+#include <linux/err.h>
+#include <linux/vmalloc.h>
+#include <linux/ftrace.h>
+#include <linux/bug.h>
+#include <linux/uaccess.h>
+#include <linux/kernel.h>
+#include <asm/module.h>
+#include <asm/firmware.h>
+#include <asm/code-patching.h>
+#include <linux/sort.h>
+#include <asm/setup.h>
+#include <asm/sections.h>
+#include <asm/inst.h>
+
+/* FIXME: We don't do .init separately. To do this, we'd need to have
+ a separate r2 value in the init and core section, and stub between
+ them, too.
+
+ Using a magic allocator which places modules within 32MB solves
+ this, and makes other things simpler. Anton?
+ --RR. */
+
+bool module_elf_check_arch(Elf_Ehdr *hdr)
+{
+ unsigned long abi_level = hdr->e_flags & 0x3;
+
+ if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
+ return abi_level == 2;
+ else
+ return abi_level < 2;
+}
+
+#ifdef CONFIG_PPC64_ELF_ABI_V2
+
+static func_desc_t func_desc(unsigned long addr)
+{
+ func_desc_t desc = {
+ .addr = addr,
+ };
+
+ return desc;
+}
+
+/* PowerPC64 specific values for the Elf64_Sym st_other field. */
+#define STO_PPC64_LOCAL_BIT 5
+#define STO_PPC64_LOCAL_MASK (7 << STO_PPC64_LOCAL_BIT)
+#define PPC64_LOCAL_ENTRY_OFFSET(other) \
+ (((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2)
+
+static unsigned int local_entry_offset(const Elf64_Sym *sym)
+{
+ /* sym->st_other indicates offset to local entry point
+ * (otherwise it will assume r12 is the address of the start
+ * of function and try to derive r2 from it). */
+ return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);
+}
+#else
+
+static func_desc_t func_desc(unsigned long addr)
+{
+ return *(struct func_desc *)addr;
+}
+static unsigned int local_entry_offset(const Elf64_Sym *sym)
+{
+ return 0;
+}
+
+void *dereference_module_function_descriptor(struct module *mod, void *ptr)
+{
+ if (ptr < (void *)mod->arch.start_opd ||
+ ptr >= (void *)mod->arch.end_opd)
+ return ptr;
+
+ return dereference_function_descriptor(ptr);
+}
+#endif
+
+static unsigned long func_addr(unsigned long addr)
+{
+ return func_desc(addr).addr;
+}
+
+static unsigned long stub_func_addr(func_desc_t func)
+{
+ return func.addr;
+}
+
+#define STUB_MAGIC 0x73747562 /* stub */
+
+/* Like PPC32, we need little trampolines to do > 24-bit jumps (into
+ the kernel itself). But on PPC64, these need to be used for every
+ jump, actually, to reset r2 (TOC+0x8000). */
+struct ppc64_stub_entry {
+ /*
+ * 28 byte jump instruction sequence (7 instructions) that can
+ * hold ppc64_stub_insns or stub_insns. Must be 8-byte aligned
+ * with PCREL kernels that use prefix instructions in the stub.
+ */
+ u32 jump[7];
+ /* Used by ftrace to identify stubs */
+ u32 magic;
+ /* Data for the above code */
+ func_desc_t funcdata;
+} __aligned(8);
+
+struct ppc64_got_entry {
+ u64 addr;
+};
+
+/*
+ * PPC64 uses 24 bit jumps, but we need to jump into other modules or
+ * the kernel which may be further. So we jump to a stub.
+ *
+ * Target address and TOC are loaded from function descriptor in the
+ * ppc64_stub_entry.
+ *
+ * r12 is used to generate the target address, which is required for the
+ * ELFv2 global entry point calling convention.
+ *
+ * TOC handling:
+ * - PCREL does not have a TOC.
+ * - ELFv2 non-PCREL just has to save r2, the callee is responsible for
+ * setting its own TOC pointer at the global entry address.
+ * - ELFv1 must load the new TOC pointer from the function descriptor.
+ */
+static u32 ppc64_stub_insns[] = {
+#ifdef CONFIG_PPC_KERNEL_PCREL
+ /* pld r12,addr */
+ PPC_PREFIX_8LS | __PPC_PRFX_R(1),
+ PPC_INST_PLD | ___PPC_RT(_R12),
+#else
+ PPC_RAW_ADDIS(_R11, _R2, 0),
+ PPC_RAW_ADDI(_R11, _R11, 0),
+ /* Save current r2 value in magic place on the stack. */
+ PPC_RAW_STD(_R2, _R1, R2_STACK_OFFSET),
+ PPC_RAW_LD(_R12, _R11, 32),
+#ifdef CONFIG_PPC64_ELF_ABI_V1
+ /* Set up new r2 from function descriptor */
+ PPC_RAW_LD(_R2, _R11, 40),
+#endif
+#endif
+ PPC_RAW_MTCTR(_R12),
+ PPC_RAW_BCTR(),
+};
+
+/*
+ * Count how many different r_type relocations (different symbol,
+ * different addend).
+ */
+static unsigned int count_relocs(const Elf64_Rela *rela, unsigned int num,
+ unsigned long r_type)
+{
+ unsigned int i, r_info, r_addend, _count_relocs;
+
+ /* FIXME: Only count external ones --RR */
+ _count_relocs = 0;
+ r_info = 0;
+ r_addend = 0;
+ for (i = 0; i < num; i++)
+ /* Only count r_type relocs, others don't need stubs */
+ if (ELF64_R_TYPE(rela[i].r_info) == r_type &&
+ (r_info != ELF64_R_SYM(rela[i].r_info) ||
+ r_addend != rela[i].r_addend)) {
+ _count_relocs++;
+ r_info = ELF64_R_SYM(rela[i].r_info);
+ r_addend = rela[i].r_addend;
+ }
+
+ return _count_relocs;
+}
+
+static int relacmp(const void *_x, const void *_y)
+{
+ const Elf64_Rela *x, *y;
+
+ y = (Elf64_Rela *)_x;
+ x = (Elf64_Rela *)_y;
+
+ /* Compare the entire r_info (as opposed to ELF64_R_SYM(r_info) only) to
+ * make the comparison cheaper/faster. It won't affect the sorting or
+ * the counting algorithms' performance
+ */
+ if (x->r_info < y->r_info)
+ return -1;
+ else if (x->r_info > y->r_info)
+ return 1;
+ else if (x->r_addend < y->r_addend)
+ return -1;
+ else if (x->r_addend > y->r_addend)
+ return 1;
+ else
+ return 0;
+}
+
+/* Get size of potential trampolines required. */
+static unsigned long get_stubs_size(const Elf64_Ehdr *hdr,
+ const Elf64_Shdr *sechdrs)
+{
+ /* One extra reloc so it's always 0-addr terminated */
+ unsigned long relocs = 1;
+ unsigned i;
+
+ /* Every relocated section... */
+ for (i = 1; i < hdr->e_shnum; i++) {
+ if (sechdrs[i].sh_type == SHT_RELA) {
+ pr_debug("Found relocations in section %u\n", i);
+ pr_debug("Ptr: %p. Number: %Lu\n",
+ (void *)sechdrs[i].sh_addr,
+ sechdrs[i].sh_size / sizeof(Elf64_Rela));
+
+ /* Sort the relocation information based on a symbol and
+ * addend key. This is a stable O(n*log n) complexity
+ * algorithm but it will reduce the complexity of
+ * count_relocs() to linear complexity O(n)
+ */
+ sort((void *)sechdrs[i].sh_addr,
+ sechdrs[i].sh_size / sizeof(Elf64_Rela),
+ sizeof(Elf64_Rela), relacmp, NULL);
+
+ relocs += count_relocs((void *)sechdrs[i].sh_addr,
+ sechdrs[i].sh_size
+ / sizeof(Elf64_Rela),
+ R_PPC_REL24);
+#ifdef CONFIG_PPC_KERNEL_PCREL
+ relocs += count_relocs((void *)sechdrs[i].sh_addr,
+ sechdrs[i].sh_size
+ / sizeof(Elf64_Rela),
+ R_PPC64_REL24_NOTOC);
+#endif
+ }
+ }
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+ /* make the trampoline to the ftrace_caller */
+ relocs++;
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ /* an additional one for ftrace_regs_caller */
+ relocs++;
+#endif
+#endif
+
+ pr_debug("Looks like a total of %lu stubs, max\n", relocs);
+ return relocs * sizeof(struct ppc64_stub_entry);
+}
+
+#ifdef CONFIG_PPC_KERNEL_PCREL
+static int count_pcpu_relocs(const Elf64_Shdr *sechdrs,
+ const Elf64_Rela *rela, unsigned int num,
+ unsigned int symindex, unsigned int pcpu)
+{
+ unsigned int i, r_info, r_addend, _count_relocs;
+
+ _count_relocs = 0;
+ r_info = 0;
+ r_addend = 0;
+
+ for (i = 0; i < num; i++) {
+ Elf64_Sym *sym;
+
+ /* This is the symbol it is referring to */
+ sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
+ + ELF64_R_SYM(rela[i].r_info);
+
+ if (sym->st_shndx == pcpu &&
+ (r_info != ELF64_R_SYM(rela[i].r_info) ||
+ r_addend != rela[i].r_addend)) {
+ _count_relocs++;
+ r_info = ELF64_R_SYM(rela[i].r_info);
+ r_addend = rela[i].r_addend;
+ }
+ }
+
+ return _count_relocs;
+}
+
+/* Get size of potential GOT required. */
+static unsigned long get_got_size(const Elf64_Ehdr *hdr,
+ const Elf64_Shdr *sechdrs,
+ struct module *me)
+{
+ /* One extra reloc so it's always 0-addr terminated */
+ unsigned long relocs = 1;
+ unsigned int i, symindex = 0;
+
+ for (i = 1; i < hdr->e_shnum; i++) {
+ if (sechdrs[i].sh_type == SHT_SYMTAB) {
+ symindex = i;
+ break;
+ }
+ }
+ WARN_ON_ONCE(!symindex);
+
+ /* Every relocated section... */
+ for (i = 1; i < hdr->e_shnum; i++) {
+ if (sechdrs[i].sh_type == SHT_RELA) {
+ pr_debug("Found relocations in section %u\n", i);
+ pr_debug("Ptr: %p. Number: %llu\n", (void *)sechdrs[i].sh_addr,
+ sechdrs[i].sh_size / sizeof(Elf64_Rela));
+
+ /*
+ * Sort the relocation information based on a symbol and
+ * addend key. This is a stable O(n*log n) complexity
+ * algorithm but it will reduce the complexity of
+ * count_relocs() to linear complexity O(n)
+ */
+ sort((void *)sechdrs[i].sh_addr,
+ sechdrs[i].sh_size / sizeof(Elf64_Rela),
+ sizeof(Elf64_Rela), relacmp, NULL);
+
+ relocs += count_relocs((void *)sechdrs[i].sh_addr,
+ sechdrs[i].sh_size
+ / sizeof(Elf64_Rela),
+ R_PPC64_GOT_PCREL34);
+
+ /*
+ * Percpu data access typically gets linked with
+ * REL34 relocations, but the percpu section gets
+ * moved at load time and requires that to be
+ * converted to GOT linkage.
+ */
+ if (IS_ENABLED(CONFIG_SMP) && symindex)
+ relocs += count_pcpu_relocs(sechdrs,
+ (void *)sechdrs[i].sh_addr,
+ sechdrs[i].sh_size
+ / sizeof(Elf64_Rela),
+ symindex, me->arch.pcpu_section);
+ }
+ }
+
+ pr_debug("Looks like a total of %lu GOT entries, max\n", relocs);
+ return relocs * sizeof(struct ppc64_got_entry);
+}
+#else /* CONFIG_PPC_KERNEL_PCREL */
+
+/* Still needed for ELFv2, for .TOC. */
+static void dedotify_versions(struct modversion_info *vers,
+ unsigned long size)
+{
+ struct modversion_info *end;
+
+ for (end = (void *)vers + size; vers < end; vers++)
+ if (vers->name[0] == '.') {
+ memmove(vers->name, vers->name+1, strlen(vers->name));
+ }
+}
+
+/*
+ * Undefined symbols which refer to .funcname, hack to funcname. Make .TOC.
+ * seem to be defined (value set later).
+ */
+static void dedotify(Elf64_Sym *syms, unsigned int numsyms, char *strtab)
+{
+ unsigned int i;
+
+ for (i = 1; i < numsyms; i++) {
+ if (syms[i].st_shndx == SHN_UNDEF) {
+ char *name = strtab + syms[i].st_name;
+ if (name[0] == '.') {
+ if (strcmp(name+1, "TOC.") == 0)
+ syms[i].st_shndx = SHN_ABS;
+ syms[i].st_name++;
+ }
+ }
+ }
+}
+
+static Elf64_Sym *find_dot_toc(Elf64_Shdr *sechdrs,
+ const char *strtab,
+ unsigned int symindex)
+{
+ unsigned int i, numsyms;
+ Elf64_Sym *syms;
+
+ syms = (Elf64_Sym *)sechdrs[symindex].sh_addr;
+ numsyms = sechdrs[symindex].sh_size / sizeof(Elf64_Sym);
+
+ for (i = 1; i < numsyms; i++) {
+ if (syms[i].st_shndx == SHN_ABS
+ && strcmp(strtab + syms[i].st_name, "TOC.") == 0)
+ return &syms[i];
+ }
+ return NULL;
+}
+#endif /* CONFIG_PPC_KERNEL_PCREL */
+
+bool module_init_section(const char *name)
+{
+ /* We don't handle .init for the moment: always return false. */
+ return false;
+}
+
+int module_frob_arch_sections(Elf64_Ehdr *hdr,
+ Elf64_Shdr *sechdrs,
+ char *secstrings,
+ struct module *me)
+{
+ unsigned int i;
+
+ /* Find .toc and .stubs sections, symtab and strtab */
+ for (i = 1; i < hdr->e_shnum; i++) {
+ if (strcmp(secstrings + sechdrs[i].sh_name, ".stubs") == 0)
+ me->arch.stubs_section = i;
+#ifdef CONFIG_PPC_KERNEL_PCREL
+ else if (strcmp(secstrings + sechdrs[i].sh_name, ".data..percpu") == 0)
+ me->arch.pcpu_section = i;
+ else if (strcmp(secstrings + sechdrs[i].sh_name, ".mygot") == 0) {
+ me->arch.got_section = i;
+ if (sechdrs[i].sh_addralign < 8)
+ sechdrs[i].sh_addralign = 8;
+ }
+#else
+ else if (strcmp(secstrings + sechdrs[i].sh_name, ".toc") == 0) {
+ me->arch.toc_section = i;
+ if (sechdrs[i].sh_addralign < 8)
+ sechdrs[i].sh_addralign = 8;
+ }
+ else if (strcmp(secstrings+sechdrs[i].sh_name,"__versions")==0)
+ dedotify_versions((void *)hdr + sechdrs[i].sh_offset,
+ sechdrs[i].sh_size);
+
+ if (sechdrs[i].sh_type == SHT_SYMTAB)
+ dedotify((void *)hdr + sechdrs[i].sh_offset,
+ sechdrs[i].sh_size / sizeof(Elf64_Sym),
+ (void *)hdr
+ + sechdrs[sechdrs[i].sh_link].sh_offset);
+#endif
+ }
+
+ if (!me->arch.stubs_section) {
+ pr_err("%s: doesn't contain .stubs.\n", me->name);
+ return -ENOEXEC;
+ }
+
+#ifdef CONFIG_PPC_KERNEL_PCREL
+ if (!me->arch.got_section) {
+ pr_err("%s: doesn't contain .mygot.\n", me->name);
+ return -ENOEXEC;
+ }
+
+ /* Override the got size */
+ sechdrs[me->arch.got_section].sh_size = get_got_size(hdr, sechdrs, me);
+#else
+ /* If we don't have a .toc, just use .stubs. We need to set r2
+ to some reasonable value in case the module calls out to
+ other functions via a stub, or if a function pointer escapes
+ the module by some means. */
+ if (!me->arch.toc_section)
+ me->arch.toc_section = me->arch.stubs_section;
+#endif
+
+ /* Override the stubs size */
+ sechdrs[me->arch.stubs_section].sh_size = get_stubs_size(hdr, sechdrs);
+
+ return 0;
+}
+
+#if defined(CONFIG_MPROFILE_KERNEL) || defined(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY)
+
+static u32 stub_insns[] = {
+#ifdef CONFIG_PPC_KERNEL_PCREL
+ PPC_RAW_LD(_R12, _R13, offsetof(struct paca_struct, kernelbase)),
+ PPC_RAW_NOP(), /* align the prefix insn */
+ /* paddi r12,r12,addr */
+ PPC_PREFIX_MLS | __PPC_PRFX_R(0),
+ PPC_INST_PADDI | ___PPC_RT(_R12) | ___PPC_RA(_R12),
+ PPC_RAW_MTCTR(_R12),
+ PPC_RAW_BCTR(),
+#else
+ PPC_RAW_LD(_R12, _R13, offsetof(struct paca_struct, kernel_toc)),
+ PPC_RAW_ADDIS(_R12, _R12, 0),
+ PPC_RAW_ADDI(_R12, _R12, 0),
+ PPC_RAW_MTCTR(_R12),
+ PPC_RAW_BCTR(),
+#endif
+};
+
+/*
+ * For mprofile-kernel we use a special stub for ftrace_caller() because we
+ * can't rely on r2 containing this module's TOC when we enter the stub.
+ *
+ * That can happen if the function calling us didn't need to use the toc. In
+ * that case it won't have setup r2, and the r2 value will be either the
+ * kernel's toc, or possibly another modules toc.
+ *
+ * To deal with that this stub uses the kernel toc, which is always accessible
+ * via the paca (in r13). The target (ftrace_caller()) is responsible for
+ * saving and restoring the toc before returning.
+ */
+static inline int create_ftrace_stub(struct ppc64_stub_entry *entry,
+ unsigned long addr,
+ struct module *me)
+{
+ long reladdr;
+
+ if ((unsigned long)entry->jump % 8 != 0) {
+ pr_err("%s: Address of stub entry is not 8-byte aligned\n", me->name);
+ return 0;
+ }
+
+ BUILD_BUG_ON(sizeof(stub_insns) > sizeof(entry->jump));
+ memcpy(entry->jump, stub_insns, sizeof(stub_insns));
+
+ if (IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) {
+ /* Stub uses address relative to kernel base (from the paca) */
+ reladdr = addr - local_paca->kernelbase;
+ if (reladdr > 0x1FFFFFFFFL || reladdr < -0x200000000L) {
+ pr_err("%s: Address of %ps out of range of 34-bit relative address.\n",
+ me->name, (void *)addr);
+ return 0;
+ }
+
+ entry->jump[2] |= IMM_H18(reladdr);
+ entry->jump[3] |= IMM_L(reladdr);
+ } else {
+ /* Stub uses address relative to kernel toc (from the paca) */
+ reladdr = addr - kernel_toc_addr();
+ if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
+ pr_err("%s: Address of %ps out of range of kernel_toc.\n",
+ me->name, (void *)addr);
+ return 0;
+ }
+
+ entry->jump[1] |= PPC_HA(reladdr);
+ entry->jump[2] |= PPC_LO(reladdr);
+ }
+
+ /* Even though we don't use funcdata in the stub, it's needed elsewhere. */
+ entry->funcdata = func_desc(addr);
+ entry->magic = STUB_MAGIC;
+
+ return 1;
+}
+
+static bool is_mprofile_ftrace_call(const char *name)
+{
+ if (!strcmp("_mcount", name))
+ return true;
+#ifdef CONFIG_DYNAMIC_FTRACE
+ if (!strcmp("ftrace_caller", name))
+ return true;
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ if (!strcmp("ftrace_regs_caller", name))
+ return true;
+#endif
+#endif
+
+ return false;
+}
+#else
+static inline int create_ftrace_stub(struct ppc64_stub_entry *entry,
+ unsigned long addr,
+ struct module *me)
+{
+ return 0;
+}
+
+static bool is_mprofile_ftrace_call(const char *name)
+{
+ return false;
+}
+#endif
+
+/*
+ * r2 is the TOC pointer: it actually points 0x8000 into the TOC (this gives the
+ * value maximum span in an instruction which uses a signed offset). Round down
+ * to a 256 byte boundary for the odd case where we are setting up r2 without a
+ * .toc section.
+ */
+static inline unsigned long my_r2(const Elf64_Shdr *sechdrs, struct module *me)
+{
+#ifndef CONFIG_PPC_KERNEL_PCREL
+ return (sechdrs[me->arch.toc_section].sh_addr & ~0xfful) + 0x8000;
+#else
+ return -1;
+#endif
+}
+
+/* Patch stub to reference function and correct r2 value. */
+static inline int create_stub(const Elf64_Shdr *sechdrs,
+ struct ppc64_stub_entry *entry,
+ unsigned long addr,
+ struct module *me,
+ const char *name)
+{
+ long reladdr;
+ func_desc_t desc;
+ int i;
+
+ if (is_mprofile_ftrace_call(name))
+ return create_ftrace_stub(entry, addr, me);
+
+ if ((unsigned long)entry->jump % 8 != 0) {
+ pr_err("%s: Address of stub entry is not 8-byte aligned\n", me->name);
+ return 0;
+ }
+
+ BUILD_BUG_ON(sizeof(ppc64_stub_insns) > sizeof(entry->jump));
+ for (i = 0; i < ARRAY_SIZE(ppc64_stub_insns); i++) {
+ if (patch_instruction(&entry->jump[i],
+ ppc_inst(ppc64_stub_insns[i])))
+ return 0;
+ }
+
+ if (IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) {
+ /* Stub uses address relative to itself! */
+ reladdr = 0 + offsetof(struct ppc64_stub_entry, funcdata);
+ BUILD_BUG_ON(reladdr != 32);
+ if (reladdr > 0x1FFFFFFFFL || reladdr < -0x200000000L) {
+ pr_err("%s: Address of %p out of range of 34-bit relative address.\n",
+ me->name, (void *)reladdr);
+ return 0;
+ }
+ pr_debug("Stub %p get data from reladdr %li\n", entry, reladdr);
+
+ /* May not even need this if we're relative to 0 */
+ if (patch_instruction(&entry->jump[0],
+ ppc_inst_prefix(entry->jump[0] | IMM_H18(reladdr),
+ entry->jump[1] | IMM_L(reladdr))))
+ return 0;
+
+ } else {
+ /* Stub uses address relative to r2. */
+ reladdr = (unsigned long)entry - my_r2(sechdrs, me);
+ if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
+ pr_err("%s: Address %p of stub out of range of %p.\n",
+ me->name, (void *)reladdr, (void *)my_r2);
+ return 0;
+ }
+ pr_debug("Stub %p get data from reladdr %li\n", entry, reladdr);
+
+ if (patch_instruction(&entry->jump[0],
+ ppc_inst(entry->jump[0] | PPC_HA(reladdr))))
+ return 0;
+
+ if (patch_instruction(&entry->jump[1],
+ ppc_inst(entry->jump[1] | PPC_LO(reladdr))))
+ return 0;
+ }
+
+ // func_desc_t is 8 bytes if ABIv2, else 16 bytes
+ desc = func_desc(addr);
+ for (i = 0; i < sizeof(func_desc_t) / sizeof(u32); i++) {
+ if (patch_instruction(((u32 *)&entry->funcdata) + i,
+ ppc_inst(((u32 *)(&desc))[i])))
+ return 0;
+ }
+
+ if (patch_instruction(&entry->magic, ppc_inst(STUB_MAGIC)))
+ return 0;
+
+ return 1;
+}
+
+/* Create stub to jump to function described in this OPD/ptr: we need the
+ stub to set up the TOC ptr (r2) for the function. */
+static unsigned long stub_for_addr(const Elf64_Shdr *sechdrs,
+ unsigned long addr,
+ struct module *me,
+ const char *name)
+{
+ struct ppc64_stub_entry *stubs;
+ unsigned int i, num_stubs;
+
+ num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*stubs);
+
+ /* Find this stub, or if that fails, the next avail. entry */
+ stubs = (void *)sechdrs[me->arch.stubs_section].sh_addr;
+ for (i = 0; stub_func_addr(stubs[i].funcdata); i++) {
+ if (WARN_ON(i >= num_stubs))
+ return 0;
+
+ if (stub_func_addr(stubs[i].funcdata) == func_addr(addr))
+ return (unsigned long)&stubs[i];
+ }
+
+ if (!create_stub(sechdrs, &stubs[i], addr, me, name))
+ return 0;
+
+ return (unsigned long)&stubs[i];
+}
+
+#ifdef CONFIG_PPC_KERNEL_PCREL
+/* Create GOT to load the location described in this ptr */
+static unsigned long got_for_addr(const Elf64_Shdr *sechdrs,
+ unsigned long addr,
+ struct module *me,
+ const char *name)
+{
+ struct ppc64_got_entry *got;
+ unsigned int i, num_got;
+
+ if (!IS_ENABLED(CONFIG_PPC_KERNEL_PCREL))
+ return addr;
+
+ num_got = sechdrs[me->arch.got_section].sh_size / sizeof(*got);
+
+ /* Find this stub, or if that fails, the next avail. entry */
+ got = (void *)sechdrs[me->arch.got_section].sh_addr;
+ for (i = 0; got[i].addr; i++) {
+ if (WARN_ON(i >= num_got))
+ return 0;
+
+ if (got[i].addr == addr)
+ return (unsigned long)&got[i];
+ }
+
+ got[i].addr = addr;
+
+ return (unsigned long)&got[i];
+}
+#endif
+
+/* We expect a noop next: if it is, replace it with instruction to
+ restore r2. */
+static int restore_r2(const char *name, u32 *instruction, struct module *me)
+{
+ u32 *prev_insn = instruction - 1;
+ u32 insn_val = *instruction;
+
+ if (IS_ENABLED(CONFIG_PPC_KERNEL_PCREL))
+ return 0;
+
+ if (is_mprofile_ftrace_call(name))
+ return 0;
+
+ /*
+ * Make sure the branch isn't a sibling call. Sibling calls aren't
+ * "link" branches and they don't return, so they don't need the r2
+ * restore afterwards.
+ */
+ if (!instr_is_relative_link_branch(ppc_inst(*prev_insn)))
+ return 0;
+
+ /*
+ * For livepatch, the restore r2 instruction might have already been
+ * written previously, if the referenced symbol is in a previously
+ * unloaded module which is now being loaded again. In that case, skip
+ * the warning and the instruction write.
+ */
+ if (insn_val == PPC_INST_LD_TOC)
+ return 0;
+
+ if (insn_val != PPC_RAW_NOP()) {
+ pr_err("%s: Expected nop after call, got %08x at %pS\n",
+ me->name, insn_val, instruction);
+ return -ENOEXEC;
+ }
+
+ /* ld r2,R2_STACK_OFFSET(r1) */
+ return patch_instruction(instruction, ppc_inst(PPC_INST_LD_TOC));
+}
+
+int apply_relocate_add(Elf64_Shdr *sechdrs,
+ const char *strtab,
+ unsigned int symindex,
+ unsigned int relsec,
+ struct module *me)
+{
+ unsigned int i;
+ Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
+ Elf64_Sym *sym;
+ unsigned long *location;
+ unsigned long value;
+
+ pr_debug("Applying ADD relocate section %u to %u\n", relsec,
+ sechdrs[relsec].sh_info);
+
+#ifndef CONFIG_PPC_KERNEL_PCREL
+ /* First time we're called, we can fix up .TOC. */
+ if (!me->arch.toc_fixed) {
+ sym = find_dot_toc(sechdrs, strtab, symindex);
+ /* It's theoretically possible that a module doesn't want a
+ * .TOC. so don't fail it just for that. */
+ if (sym)
+ sym->st_value = my_r2(sechdrs, me);
+ me->arch.toc_fixed = true;
+ }
+#endif
+ for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
+ /* This is where to make the change */
+ location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ + rela[i].r_offset;
+ /* This is the symbol it is referring to */
+ sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
+ + ELF64_R_SYM(rela[i].r_info);
+
+ pr_debug("RELOC at %p: %li-type as %s (0x%lx) + %li\n",
+ location, (long)ELF64_R_TYPE(rela[i].r_info),
+ strtab + sym->st_name, (unsigned long)sym->st_value,
+ (long)rela[i].r_addend);
+
+ /* `Everything is relative'. */
+ value = sym->st_value + rela[i].r_addend;
+
+ switch (ELF64_R_TYPE(rela[i].r_info)) {
+ case R_PPC64_ADDR32:
+ /* Simply set it */
+ *(u32 *)location = value;
+ break;
+
+ case R_PPC64_ADDR64:
+ /* Simply set it */
+ *(unsigned long *)location = value;
+ break;
+
+#ifndef CONFIG_PPC_KERNEL_PCREL
+ case R_PPC64_TOC:
+ *(unsigned long *)location = my_r2(sechdrs, me);
+ break;
+
+ case R_PPC64_TOC16:
+ /* Subtract TOC pointer */
+ value -= my_r2(sechdrs, me);
+ if (value + 0x8000 > 0xffff) {
+ pr_err("%s: bad TOC16 relocation (0x%lx)\n",
+ me->name, value);
+ return -ENOEXEC;
+ }
+ *((uint16_t *) location)
+ = (*((uint16_t *) location) & ~0xffff)
+ | (value & 0xffff);
+ break;
+
+ case R_PPC64_TOC16_LO:
+ /* Subtract TOC pointer */
+ value -= my_r2(sechdrs, me);
+ *((uint16_t *) location)
+ = (*((uint16_t *) location) & ~0xffff)
+ | (value & 0xffff);
+ break;
+
+ case R_PPC64_TOC16_DS:
+ /* Subtract TOC pointer */
+ value -= my_r2(sechdrs, me);
+ if ((value & 3) != 0 || value + 0x8000 > 0xffff) {
+ pr_err("%s: bad TOC16_DS relocation (0x%lx)\n",
+ me->name, value);
+ return -ENOEXEC;
+ }
+ *((uint16_t *) location)
+ = (*((uint16_t *) location) & ~0xfffc)
+ | (value & 0xfffc);
+ break;
+
+ case R_PPC64_TOC16_LO_DS:
+ /* Subtract TOC pointer */
+ value -= my_r2(sechdrs, me);
+ if ((value & 3) != 0) {
+ pr_err("%s: bad TOC16_LO_DS relocation (0x%lx)\n",
+ me->name, value);
+ return -ENOEXEC;
+ }
+ *((uint16_t *) location)
+ = (*((uint16_t *) location) & ~0xfffc)
+ | (value & 0xfffc);
+ break;
+
+ case R_PPC64_TOC16_HA:
+ /* Subtract TOC pointer */
+ value -= my_r2(sechdrs, me);
+ value = ((value + 0x8000) >> 16);
+ *((uint16_t *) location)
+ = (*((uint16_t *) location) & ~0xffff)
+ | (value & 0xffff);
+ break;
+#endif
+
+ case R_PPC_REL24:
+#ifdef CONFIG_PPC_KERNEL_PCREL
+ /* PCREL still generates REL24 for mcount */
+ case R_PPC64_REL24_NOTOC:
+#endif
+ /* FIXME: Handle weak symbols here --RR */
+ if (sym->st_shndx == SHN_UNDEF ||
+ sym->st_shndx == SHN_LIVEPATCH) {
+ /* External: go via stub */
+ value = stub_for_addr(sechdrs, value, me,
+ strtab + sym->st_name);
+ if (!value)
+ return -ENOENT;
+ if (restore_r2(strtab + sym->st_name,
+ (u32 *)location + 1, me))
+ return -ENOEXEC;
+ } else
+ value += local_entry_offset(sym);
+
+ /* Convert value to relative */
+ value -= (unsigned long)location;
+ if (value + 0x2000000 > 0x3ffffff || (value & 3) != 0){
+ pr_err("%s: REL24 %li out of range!\n",
+ me->name, (long int)value);
+ return -ENOEXEC;
+ }
+
+ /* Only replace bits 2 through 26 */
+ value = (*(uint32_t *)location & ~PPC_LI_MASK) | PPC_LI(value);
+
+ if (patch_instruction((u32 *)location, ppc_inst(value)))
+ return -EFAULT;
+
+ break;
+
+ case R_PPC64_REL64:
+ /* 64 bits relative (used by features fixups) */
+ *location = value - (unsigned long)location;
+ break;
+
+ case R_PPC64_REL32:
+ /* 32 bits relative (used by relative exception tables) */
+ /* Convert value to relative */
+ value -= (unsigned long)location;
+ if (value + 0x80000000 > 0xffffffff) {
+ pr_err("%s: REL32 %li out of range!\n",
+ me->name, (long int)value);
+ return -ENOEXEC;
+ }
+ *(u32 *)location = value;
+ break;
+
+#ifdef CONFIG_PPC_KERNEL_PCREL
+ case R_PPC64_PCREL34: {
+ unsigned long absvalue = value;
+
+ /* Convert value to relative */
+ value -= (unsigned long)location;
+
+ if (value + 0x200000000 > 0x3ffffffff) {
+ if (sym->st_shndx != me->arch.pcpu_section) {
+ pr_err("%s: REL34 %li out of range!\n",
+ me->name, (long)value);
+ return -ENOEXEC;
+ }
+
+ /*
+ * per-cpu section is special cased because
+ * it is moved during loading, so has to be
+ * converted to use GOT.
+ */
+ value = got_for_addr(sechdrs, absvalue, me,
+ strtab + sym->st_name);
+ if (!value)
+ return -ENOENT;
+ value -= (unsigned long)location;
+
+ /* Turn pla into pld */
+ if (patch_instruction((u32 *)location,
+ ppc_inst_prefix((*(u32 *)location & ~0x02000000),
+ (*((u32 *)location + 1) & ~0xf8000000) | 0xe4000000)))
+ return -EFAULT;
+ }
+
+ if (patch_instruction((u32 *)location,
+ ppc_inst_prefix((*(u32 *)location & ~0x3ffff) | IMM_H18(value),
+ (*((u32 *)location + 1) & ~0xffff) | IMM_L(value))))
+ return -EFAULT;
+
+ break;
+ }
+
+#else
+ case R_PPC64_TOCSAVE:
+ /*
+ * Marker reloc indicates we don't have to save r2.
+ * That would only save us one instruction, so ignore
+ * it.
+ */
+ break;
+#endif
+
+ case R_PPC64_ENTRY:
+ if (IS_ENABLED(CONFIG_PPC_KERNEL_PCREL))
+ break;
+
+ /*
+ * Optimize ELFv2 large code model entry point if
+ * the TOC is within 2GB range of current location.
+ */
+ value = my_r2(sechdrs, me) - (unsigned long)location;
+ if (value + 0x80008000 > 0xffffffff)
+ break;
+ /*
+ * Check for the large code model prolog sequence:
+ * ld r2, ...(r12)
+ * add r2, r2, r12
+ */
+ if ((((uint32_t *)location)[0] & ~0xfffc) != PPC_RAW_LD(_R2, _R12, 0))
+ break;
+ if (((uint32_t *)location)[1] != PPC_RAW_ADD(_R2, _R2, _R12))
+ break;
+ /*
+ * If found, replace it with:
+ * addis r2, r12, (.TOC.-func)@ha
+ * addi r2, r2, (.TOC.-func)@l
+ */
+ ((uint32_t *)location)[0] = PPC_RAW_ADDIS(_R2, _R12, PPC_HA(value));
+ ((uint32_t *)location)[1] = PPC_RAW_ADDI(_R2, _R2, PPC_LO(value));
+ break;
+
+ case R_PPC64_REL16_HA:
+ /* Subtract location pointer */
+ value -= (unsigned long)location;
+ value = ((value + 0x8000) >> 16);
+ *((uint16_t *) location)
+ = (*((uint16_t *) location) & ~0xffff)
+ | (value & 0xffff);
+ break;
+
+ case R_PPC64_REL16_LO:
+ /* Subtract location pointer */
+ value -= (unsigned long)location;
+ *((uint16_t *) location)
+ = (*((uint16_t *) location) & ~0xffff)
+ | (value & 0xffff);
+ break;
+
+#ifdef CONFIG_PPC_KERNEL_PCREL
+ case R_PPC64_GOT_PCREL34:
+ value = got_for_addr(sechdrs, value, me,
+ strtab + sym->st_name);
+ if (!value)
+ return -ENOENT;
+ value -= (unsigned long)location;
+ ((uint32_t *)location)[0] = (((uint32_t *)location)[0] & ~0x3ffff) |
+ ((value >> 16) & 0x3ffff);
+ ((uint32_t *)location)[1] = (((uint32_t *)location)[1] & ~0xffff) |
+ (value & 0xffff);
+ break;
+#endif
+
+ default:
+ pr_err("%s: Unknown ADD relocation: %lu\n",
+ me->name,
+ (unsigned long)ELF64_R_TYPE(rela[i].r_info));
+ return -ENOEXEC;
+ }
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+int module_trampoline_target(struct module *mod, unsigned long addr,
+ unsigned long *target)
+{
+ struct ppc64_stub_entry *stub;
+ func_desc_t funcdata;
+ u32 magic;
+
+ if (!within_module_core(addr, mod)) {
+ pr_err("%s: stub %lx not in module %s\n", __func__, addr, mod->name);
+ return -EFAULT;
+ }
+
+ stub = (struct ppc64_stub_entry *)addr;
+
+ if (copy_from_kernel_nofault(&magic, &stub->magic,
+ sizeof(magic))) {
+ pr_err("%s: fault reading magic for stub %lx for %s\n", __func__, addr, mod->name);
+ return -EFAULT;
+ }
+
+ if (magic != STUB_MAGIC) {
+ pr_err("%s: bad magic for stub %lx for %s\n", __func__, addr, mod->name);
+ return -EFAULT;
+ }
+
+ if (copy_from_kernel_nofault(&funcdata, &stub->funcdata,
+ sizeof(funcdata))) {
+ pr_err("%s: fault reading funcdata for stub %lx for %s\n", __func__, addr, mod->name);
+ return -EFAULT;
+ }
+
+ *target = stub_func_addr(funcdata);
+
+ return 0;
+}
+
+int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs)
+{
+ mod->arch.tramp = stub_for_addr(sechdrs,
+ (unsigned long)ftrace_caller,
+ mod,
+ "ftrace_caller");
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ mod->arch.tramp_regs = stub_for_addr(sechdrs,
+ (unsigned long)ftrace_regs_caller,
+ mod,
+ "ftrace_regs_caller");
+ if (!mod->arch.tramp_regs)
+ return -ENOENT;
+#endif
+
+ if (!mod->arch.tramp)
+ return -ENOENT;
+
+ return 0;
+}
+#endif