Merge tag 'v4.13-rc1' into fixes

The fixes branch is based off a random pre-rc1 commit, because we had
some fixes that needed to go in before rc1 was released.

However we now need to fix some code that went in after that point, but
before rc1, so merge rc1 to get that code into fixes so we can fix it!

1 files changed, 167 insertions, 57 deletions

diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c
index 94627a3a6a0d..491605137b03 100644
--- a/arch/mips/kernel/module.c
+++ b/arch/mips/kernel/module.c
@@ -53,22 +53,25 @@ void *module_alloc(unsigned long size)
 }
 #endif
 
-int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_none(struct module *me, u32 *location,
+			     u32 base, Elf_Addr v, bool rela)
 {
 	return 0;
 }
 
-static int apply_r_mips_32_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_32(struct module *me, u32 *location,
+			   u32 base, Elf_Addr v, bool rela)
 {
-	*location += v;
+	*location = base + v;
 
 	return 0;
 }
 
-static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_26(struct module *me, u32 *location,
+			   u32 base, Elf_Addr v, bool rela)
 {
 	if (v % 4) {
-		pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
+		pr_err("module %s: dangerous R_MIPS_26 relocation\n",
 		       me->name);
 		return -ENOEXEC;
 	}
@@ -80,15 +83,22 @@ static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 	}
 
 	*location = (*location & ~0x03ffffff) |
-		    ((*location + (v >> 2)) & 0x03ffffff);
+		    ((base + (v >> 2)) & 0x03ffffff);
 
 	return 0;
 }
 
-static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_hi16(struct module *me, u32 *location,
+			     u32 base, Elf_Addr v, bool rela)
 {
 	struct mips_hi16 *n;
 
+	if (rela) {
+		*location = (*location & 0xffff0000) |
+			    ((((long long) v + 0x8000LL) >> 16) & 0xffff);
+		return 0;
+	}
+
 	/*
 	 * We cannot relocate this one now because we don't know the value of
 	 * the carry we need to add.  Save the information, and let LO16 do the
@@ -117,12 +127,18 @@ static void free_relocation_chain(struct mips_hi16 *l)
 	}
 }
 
-static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_lo16(struct module *me, u32 *location,
+			     u32 base, Elf_Addr v, bool rela)
 {
-	unsigned long insnlo = *location;
+	unsigned long insnlo = base;
 	struct mips_hi16 *l;
 	Elf_Addr val, vallo;
 
+	if (rela) {
+		*location = (*location & 0xffff0000) | (v & 0xffff);
+		return 0;
+	}
+
 	/* Sign extend the addend we extract from the lo insn.	*/
 	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
 
@@ -178,26 +194,26 @@ out_danger:
 	free_relocation_chain(l);
 	me->arch.r_mips_hi16_list = NULL;
 
-	pr_err("module %s: dangerous R_MIPS_LO16 REL relocation\n", me->name);
+	pr_err("module %s: dangerous R_MIPS_LO16 relocation\n", me->name);
 
 	return -ENOEXEC;
 }
 
-static int apply_r_mips_pc_rel(struct module *me, u32 *location, Elf_Addr v,
-			       unsigned bits)
+static int apply_r_mips_pc(struct module *me, u32 *location, u32 base,
+			   Elf_Addr v, unsigned int bits)
 {
 	unsigned long mask = GENMASK(bits - 1, 0);
 	unsigned long se_bits;
 	long offset;
 
 	if (v % 4) {
-		pr_err("module %s: dangerous R_MIPS_PC%u REL relocation\n",
+		pr_err("module %s: dangerous R_MIPS_PC%u relocation\n",
 		       me->name, bits);
 		return -ENOEXEC;
 	}
 
-	/* retrieve & sign extend implicit addend */
-	offset = *location & mask;
+	/* retrieve & sign extend implicit addend if any */
+	offset = base & mask;
 	offset |= (offset & BIT(bits - 1)) ? ~mask : 0;
 
 	offset += ((long)v - (long)location) >> 2;
@@ -214,99 +230,192 @@ static int apply_r_mips_pc_rel(struct module *me, u32 *location, Elf_Addr v,
 	return 0;
 }
 
-static int apply_r_mips_pc16_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_pc16(struct module *me, u32 *location,
+			     u32 base, Elf_Addr v, bool rela)
+{
+	return apply_r_mips_pc(me, location, base, v, 16);
+}
+
+static int apply_r_mips_pc21(struct module *me, u32 *location,
+			     u32 base, Elf_Addr v, bool rela)
+{
+	return apply_r_mips_pc(me, location, base, v, 21);
+}
+
+static int apply_r_mips_pc26(struct module *me, u32 *location,
+			     u32 base, Elf_Addr v, bool rela)
+{
+	return apply_r_mips_pc(me, location, base, v, 26);
+}
+
+static int apply_r_mips_64(struct module *me, u32 *location,
+			   u32 base, Elf_Addr v, bool rela)
 {
-	return apply_r_mips_pc_rel(me, location, v, 16);
+	if (WARN_ON(!rela))
+		return -EINVAL;
+
+	*(Elf_Addr *)location = v;
+
+	return 0;
 }
 
-static int apply_r_mips_pc21_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_higher(struct module *me, u32 *location,
+			       u32 base, Elf_Addr v, bool rela)
 {
-	return apply_r_mips_pc_rel(me, location, v, 21);
+	if (WARN_ON(!rela))
+		return -EINVAL;
+
+	*location = (*location & 0xffff0000) |
+		    ((((long long)v + 0x80008000LL) >> 32) & 0xffff);
+
+	return 0;
 }
 
-static int apply_r_mips_pc26_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_highest(struct module *me, u32 *location,
+				u32 base, Elf_Addr v, bool rela)
 {
-	return apply_r_mips_pc_rel(me, location, v, 26);
+	if (WARN_ON(!rela))
+		return -EINVAL;
+
+	*location = (*location & 0xffff0000) |
+		    ((((long long)v + 0x800080008000LL) >> 48) & 0xffff);
+
+	return 0;
 }
 
-static int (*reloc_handlers_rel[]) (struct module *me, u32 *location,
-				Elf_Addr v) = {
+/**
+ * reloc_handler() - Apply a particular relocation to a module
+ * @me: the module to apply the reloc to
+ * @location: the address at which the reloc is to be applied
+ * @base: the existing value at location for REL-style; 0 for RELA-style
+ * @v: the value of the reloc, with addend for RELA-style
+ *
+ * Each implemented reloc_handler function applies a particular type of
+ * relocation to the module @me. Relocs that may be found in either REL or RELA
+ * variants can be handled by making use of the @base & @v parameters which are
+ * set to values which abstract the difference away from the particular reloc
+ * implementations.
+ *
+ * Return: 0 upon success, else -ERRNO
+ */
+typedef int (*reloc_handler)(struct module *me, u32 *location,
+			     u32 base, Elf_Addr v, bool rela);
+
+/* The handlers for known reloc types */
+static reloc_handler reloc_handlers[] = {
 	[R_MIPS_NONE]		= apply_r_mips_none,
-	[R_MIPS_32]		= apply_r_mips_32_rel,
-	[R_MIPS_26]		= apply_r_mips_26_rel,
-	[R_MIPS_HI16]		= apply_r_mips_hi16_rel,
-	[R_MIPS_LO16]		= apply_r_mips_lo16_rel,
-	[R_MIPS_PC16]		= apply_r_mips_pc16_rel,
-	[R_MIPS_PC21_S2]	= apply_r_mips_pc21_rel,
-	[R_MIPS_PC26_S2]	= apply_r_mips_pc26_rel,
+	[R_MIPS_32]		= apply_r_mips_32,
+	[R_MIPS_26]		= apply_r_mips_26,
+	[R_MIPS_HI16]		= apply_r_mips_hi16,
+	[R_MIPS_LO16]		= apply_r_mips_lo16,
+	[R_MIPS_PC16]		= apply_r_mips_pc16,
+	[R_MIPS_64]		= apply_r_mips_64,
+	[R_MIPS_HIGHER]		= apply_r_mips_higher,
+	[R_MIPS_HIGHEST]	= apply_r_mips_highest,
+	[R_MIPS_PC21_S2]	= apply_r_mips_pc21,
+	[R_MIPS_PC26_S2]	= apply_r_mips_pc26,
 };
 
-int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
-		   unsigned int symindex, unsigned int relsec,
-		   struct module *me)
+static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
+			    unsigned int symindex, unsigned int relsec,
+			    struct module *me, bool rela)
 {
-	Elf_Mips_Rel *rel = (void *) sechdrs[relsec].sh_addr;
-	int (*handler)(struct module *me, u32 *location, Elf_Addr v);
+	union {
+		Elf_Mips_Rel *rel;
+		Elf_Mips_Rela *rela;
+	} r;
+	reloc_handler handler;
 	Elf_Sym *sym;
-	u32 *location;
+	u32 *location, base;
 	unsigned int i, type;
 	Elf_Addr v;
-	int res;
+	int err = 0;
+	size_t reloc_sz;
 
 	pr_debug("Applying relocate section %u to %u\n", relsec,
 	       sechdrs[relsec].sh_info);
 
+	r.rel = (void *)sechdrs[relsec].sh_addr;
+	reloc_sz = rela ? sizeof(*r.rela) : sizeof(*r.rel);
 	me->arch.r_mips_hi16_list = NULL;
-	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+	for (i = 0; i < sechdrs[relsec].sh_size / reloc_sz; i++) {
 		/* This is where to make the change */
 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
-			+ rel[i].r_offset;
+			+ r.rel->r_offset;
 		/* This is the symbol it is referring to */
 		sym = (Elf_Sym *)sechdrs[symindex].sh_addr
-			+ ELF_MIPS_R_SYM(rel[i]);
+			+ ELF_MIPS_R_SYM(*r.rel);
 		if (sym->st_value >= -MAX_ERRNO) {
 			/* Ignore unresolved weak symbol */
 			if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
 				continue;
 			pr_warn("%s: Unknown symbol %s\n",
 				me->name, strtab + sym->st_name);
-			return -ENOENT;
+			err = -ENOENT;
+			goto out;
 		}
 
-		type = ELF_MIPS_R_TYPE(rel[i]);
-
-		if (type < ARRAY_SIZE(reloc_handlers_rel))
-			handler = reloc_handlers_rel[type];
+		type = ELF_MIPS_R_TYPE(*r.rel);
+		if (type < ARRAY_SIZE(reloc_handlers))
+			handler = reloc_handlers[type];
 		else
 			handler = NULL;
 
 		if (!handler) {
 			pr_err("%s: Unknown relocation type %u\n",
 			       me->name, type);
-			return -EINVAL;
+			err = -EINVAL;
+			goto out;
 		}
 
-		v = sym->st_value;
-		res = handler(me, location, v);
-		if (res)
-			return res;
+		if (rela) {
+			v = sym->st_value + r.rela->r_addend;
+			base = 0;
+			r.rela = &r.rela[1];
+		} else {
+			v = sym->st_value;
+			base = *location;
+			r.rel = &r.rel[1];
+		}
+
+		err = handler(me, location, base, v, rela);
+		if (err)
+			goto out;
 	}
 
+out:
 	/*
-	 * Normally the hi16 list should be deallocated at this point.	A
+	 * Normally the hi16 list should be deallocated at this point. A
 	 * malformed binary however could contain a series of R_MIPS_HI16
-	 * relocations not followed by a R_MIPS_LO16 relocation.  In that
-	 * case, free up the list and return an error.
+	 * relocations not followed by a R_MIPS_LO16 relocation, or if we hit
+	 * an error processing a reloc we might have gotten here before
+	 * reaching the R_MIPS_LO16. In either case, free up the list and
+	 * return an error.
 	 */
 	if (me->arch.r_mips_hi16_list) {
 		free_relocation_chain(me->arch.r_mips_hi16_list);
 		me->arch.r_mips_hi16_list = NULL;
-
-		return -ENOEXEC;
+		err = err ?: -ENOEXEC;
 	}
 
-	return 0;
+	return err;
+}
+
+int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
+		   unsigned int symindex, unsigned int relsec,
+		   struct module *me)
+{
+	return __apply_relocate(sechdrs, strtab, symindex, relsec, me, false);
+}
+
+#ifdef CONFIG_MODULES_USE_ELF_RELA
+int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
+		       unsigned int symindex, unsigned int relsec,
+		       struct module *me)
+{
+	return __apply_relocate(sechdrs, strtab, symindex, relsec, me, true);
 }
+#endif /* CONFIG_MODULES_USE_ELF_RELA */
 
 /* Given an address, look for it in the module exception tables. */
 const struct exception_table_entry *search_module_dbetables(unsigned long addr)
@@ -317,7 +426,8 @@ const struct exception_table_entry *search_module_dbetables(unsigned long addr)
 
 	spin_lock_irqsave(&dbe_lock, flags);
 	list_for_each_entry(dbe, &dbe_list, dbe_list) {
-		e = search_extable(dbe->dbe_start, dbe->dbe_end - 1, addr);
+		e = search_extable(dbe->dbe_start,
+				   dbe->dbe_end - dbe->dbe_start, addr);
 		if (e)
 			break;
 	}