module: use a structure to encapsulate layout.

Makes it easier to handle init vs core cleanly, though the change is
fairly invasive across random architectures.

It simplifies the rbtree code immediately, however, while keeping the
core data together in the same cachline (now iff the rbtree code is
enabled).
Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

arch/alpha/kernel/module.c

@@ -160,7 +160,7 @@ apply_relocate_add(Elf64_Shdr *sechdrs, const char *strtab,
 
 	/* The small sections were sorted to the end of the segment.
 	   The following should definitely cover them.  */
-	gp = (u64)me->module_core + me->core_size - 0x8000;
+	gp = (u64)me->core_layout.base + me->core_layout.size - 0x8000;
 	got = sechdrs[me->arch.gotsecindex].sh_addr;
 
 	for (i = 0; i < n; i++) {

arch/arc/kernel/unwind.c

@@ -372,8 +372,8 @@ void *unwind_add_table(struct module *module, const void *table_start,
 		return NULL;
 
 	init_unwind_table(table, module->name,
-			  module->module_core, module->core_size,
-			  module->module_init, module->init_size,
+			  module->core_layout.base, module->core_layout.size,
+			  module->init_layout.base, module->init_layout.size,
 			  table_start, table_size,
 			  NULL, 0);
 

arch/arm/kernel/module-plts.c

@@ -32,7 +32,7 @@ struct plt_entries {
 
 static bool in_init(const struct module *mod, u32 addr)
 {
-	return addr - (u32)mod->module_init < mod->init_size;
+	return addr - (u32)mod->init_layout.base < mod->init_layout.size;
 }
 
 u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val)

arch/avr32/kernel/module.c

@@ -118,9 +118,9 @@ int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
 	 * Increase core size to make room for GOT and set start
 	 * offset for GOT.
 	 */
-	module->core_size = ALIGN(module->core_size, 4);
-	module->arch.got_offset = module->core_size;
-	module->core_size += module->arch.got_size;
+	module->core_layout.size = ALIGN(module->core_layout.size, 4);
+	module->arch.got_offset = module->core_layout.size;
+	module->core_layout.size += module->arch.got_size;
 
 	return 0;
 
@@ -177,7 +177,7 @@ int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
 			if (!info->got_initialized) {
 				Elf32_Addr *gotent;
 
-				gotent = (module->module_core
+				gotent = (module->core_layout.base
 					  + module->arch.got_offset
 					  + info->got_offset);
 				*gotent = relocation;
@@ -255,8 +255,8 @@ int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
 			 */
 			pr_debug("GOTPC: PC=0x%x, got_offset=0x%lx, core=0x%p\n",
 				 relocation, module->arch.got_offset,
-				 module->module_core);
-			relocation -= ((unsigned long)module->module_core
+				 module->core_layout.base);
+			relocation -= ((unsigned long)module->core_layout.base
 				       + module->arch.got_offset);
 			*location = relocation;
 			break;

arch/ia64/kernel/module.c

@@ -486,13 +486,13 @@ module_frob_arch_sections (Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings,
 static inline int
 in_init (const struct module *mod, uint64_t addr)
 {
-	return addr - (uint64_t) mod->module_init < mod->init_size;
+	return addr - (uint64_t) mod->init_layout.base < mod->init_layout.size;
 }
 
 static inline int
 in_core (const struct module *mod, uint64_t addr)
 {
-	return addr - (uint64_t) mod->module_core < mod->core_size;
+	return addr - (uint64_t) mod->core_layout.base < mod->core_layout.size;
 }
 
 static inline int
@@ -675,7 +675,7 @@ do_reloc (struct module *mod, uint8_t r_type, Elf64_Sym *sym, uint64_t addend,
 		break;
 
 	      case RV_BDREL:
-		val -= (uint64_t) (in_init(mod, val) ? mod->module_init : mod->module_core);
+		val -= (uint64_t) (in_init(mod, val) ? mod->init_layout.base : mod->core_layout.base);
 		break;
 
 	      case RV_LTV:
@@ -810,15 +810,15 @@ apply_relocate_add (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symind
 		 *     addresses have been selected...
 		 */
 		uint64_t gp;
-		if (mod->core_size > MAX_LTOFF)
+		if (mod->core_layout.size > MAX_LTOFF)
 			/*
 			 * This takes advantage of fact that SHF_ARCH_SMALL gets allocated
 			 * at the end of the module.
 			 */
-			gp = mod->core_size - MAX_LTOFF / 2;
+			gp = mod->core_layout.size - MAX_LTOFF / 2;
 		else
-			gp = mod->core_size / 2;
-		gp = (uint64_t) mod->module_core + ((gp + 7) & -8);
+			gp = mod->core_layout.size / 2;
+		gp = (uint64_t) mod->core_layout.base + ((gp + 7) & -8);
 		mod->arch.gp = gp;
 		DEBUGP("%s: placing gp at 0x%lx\n", __func__, gp);
 	}

arch/metag/kernel/module.c

@@ -176,8 +176,8 @@ static uint32_t do_plt_call(void *location, Elf32_Addr val,
 	tramp[1] = 0xac000001 | ((val & 0x0000ffff) << 3);
 
 	/* Init, or core PLT? */
-	if (location >= mod->module_core
-	    && location < mod->module_core + mod->core_size)
+	if (location >= mod->core_layout.base
+	    && location < mod->core_layout.base + mod->core_layout.size)
 		entry = (void *)sechdrs[mod->arch.core_plt_section].sh_addr;
 	else
 		entry = (void *)sechdrs[mod->arch.init_plt_section].sh_addr;

arch/mips/kernel/vpe.c

@@ -205,11 +205,11 @@ static void layout_sections(struct module *mod, const Elf_Ehdr *hdr,
 			    || s->sh_entsize != ~0UL)
 				continue;
 			s->sh_entsize =
-				get_offset((unsigned long *)&mod->core_size, s);
+				get_offset((unsigned long *)&mod->core_layout.size, s);
 		}
 
 		if (m == 0)
-			mod->core_text_size = mod->core_size;
+			mod->core_layout.text_size = mod->core_layout.size;
 
 	}
 }
@@ -641,7 +641,7 @@ static int vpe_elfload(struct vpe *v)
 		layout_sections(&mod, hdr, sechdrs, secstrings);
 	}
 
-	v->load_addr = alloc_progmem(mod.core_size);
+	v->load_addr = alloc_progmem(mod.core_layout.size);
 	if (!v->load_addr)
 		return -ENOMEM;
 

arch/parisc/kernel/module.c

@@ -42,9 +42,9 @@
  *      We are not doing SEGREL32 handling correctly. According to the ABI, we
  *      should do a value offset, like this:
  *			if (in_init(me, (void *)val))
- *				val -= (uint32_t)me->module_init;
+ *				val -= (uint32_t)me->init_layout.base;
  *			else
- *				val -= (uint32_t)me->module_core;
+ *				val -= (uint32_t)me->core_layout.base;
  *	However, SEGREL32 is used only for PARISC unwind entries, and we want
  *	those entries to have an absolute address, and not just an offset.
  *
@@ -100,14 +100,14 @@
  * or init pieces the location is */
 static inline int in_init(struct module *me, void *loc)
 {
-	return (loc >= me->module_init &&
-		loc <= (me->module_init + me->init_size));
+	return (loc >= me->init_layout.base &&
+		loc <= (me->init_layout.base + me->init_layout.size));
 }
 
 static inline int in_core(struct module *me, void *loc)
 {
-	return (loc >= me->module_core &&
-		loc <= (me->module_core + me->core_size));
+	return (loc >= me->core_layout.base &&
+		loc <= (me->core_layout.base + me->core_layout.size));
 }
 
 static inline int in_local(struct module *me, void *loc)
@@ -367,13 +367,13 @@ int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
 	}
 
 	/* align things a bit */
-	me->core_size = ALIGN(me->core_size, 16);
-	me->arch.got_offset = me->core_size;
-	me->core_size += gots * sizeof(struct got_entry);
+	me->core_layout.size = ALIGN(me->core_layout.size, 16);
+	me->arch.got_offset = me->core_layout.size;
+	me->core_layout.size += gots * sizeof(struct got_entry);
 
-	me->core_size = ALIGN(me->core_size, 16);
-	me->arch.fdesc_offset = me->core_size;
-	me->core_size += fdescs * sizeof(Elf_Fdesc);
+	me->core_layout.size = ALIGN(me->core_layout.size, 16);
+	me->arch.fdesc_offset = me->core_layout.size;
+	me->core_layout.size += fdescs * sizeof(Elf_Fdesc);
 
 	me->arch.got_max = gots;
 	me->arch.fdesc_max = fdescs;
@@ -391,7 +391,7 @@ static Elf64_Word get_got(struct module *me, unsigned long value, long addend)
 
 	BUG_ON(value == 0);
 
-	got = me->module_core + me->arch.got_offset;
+	got = me->core_layout.base + me->arch.got_offset;
 	for (i = 0; got[i].addr; i++)
 		if (got[i].addr == value)
 			goto out;
@@ -409,7 +409,7 @@ static Elf64_Word get_got(struct module *me, unsigned long value, long addend)
 #ifdef CONFIG_64BIT
 static Elf_Addr get_fdesc(struct module *me, unsigned long value)
 {
-	Elf_Fdesc *fdesc = me->module_core + me->arch.fdesc_offset;
+	Elf_Fdesc *fdesc = me->core_layout.base + me->arch.fdesc_offset;
 
 	if (!value) {
 		printk(KERN_ERR "%s: zero OPD requested!\n", me->name);
@@ -427,7 +427,7 @@ static Elf_Addr get_fdesc(struct module *me, unsigned long value)
 
 	/* Create new one */
 	fdesc->addr = value;
-	fdesc->gp = (Elf_Addr)me->module_core + me->arch.got_offset;
+	fdesc->gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;
 	return (Elf_Addr)fdesc;
 }
 #endif /* CONFIG_64BIT */
@@ -839,7 +839,7 @@ register_unwind_table(struct module *me,
 
 	table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr;
 	end = table + sechdrs[me->arch.unwind_section].sh_size;
-	gp = (Elf_Addr)me->module_core + me->arch.got_offset;
+	gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;
 
 	DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
 	       me->arch.unwind_section, table, end, gp);

arch/powerpc/kernel/module_32.c

@@ -188,8 +188,8 @@ static uint32_t do_plt_call(void *location,
 
 	pr_debug("Doing plt for call to 0x%x at 0x%x\n", val, (unsigned int)location);
 	/* Init, or core PLT? */
-	if (location >= mod->module_core
-	    && location < mod->module_core + mod->core_size)
+	if (location >= mod->core_layout.base
+	    && location < mod->core_layout.base + mod->core_layout.size)
 		entry = (void *)sechdrs[mod->arch.core_plt_section].sh_addr;
 	else
 		entry = (void *)sechdrs[mod->arch.init_plt_section].sh_addr;
@@ -296,7 +296,7 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
 	}
 #ifdef CONFIG_DYNAMIC_FTRACE
 	module->arch.tramp =
-		do_plt_call(module->module_core,
+		do_plt_call(module->core_layout.base,
 			    (unsigned long)ftrace_caller,
 			    sechdrs, module);
 #endif

arch/s390/kernel/module.c

@@ -159,11 +159,11 @@ int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
 
 	/* Increase core size by size of got & plt and set start
 	   offsets for got and plt. */
-	me->core_size = ALIGN(me->core_size, 4);
-	me->arch.got_offset = me->core_size;
-	me->core_size += me->arch.got_size;
-	me->arch.plt_offset = me->core_size;
-	me->core_size += me->arch.plt_size;
+	me->core_layout.size = ALIGN(me->core_layout.size, 4);
+	me->arch.got_offset = me->core_layout.size;
+	me->core_layout.size += me->arch.got_size;
+	me->arch.plt_offset = me->core_layout.size;
+	me->core_layout.size += me->arch.plt_size;
 	return 0;
 }
 
@@ -279,7 +279,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
 		if (info->got_initialized == 0) {
 			Elf_Addr *gotent;
 
-			gotent = me->module_core + me->arch.got_offset +
+			gotent = me->core_layout.base + me->arch.got_offset +
 				info->got_offset;
 			*gotent = val;
 			info->got_initialized = 1;
@@ -302,7 +302,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
 			rc = apply_rela_bits(loc, val, 0, 64, 0);
 		else if (r_type == R_390_GOTENT ||
 			 r_type == R_390_GOTPLTENT) {
-			val += (Elf_Addr) me->module_core - loc;
+			val += (Elf_Addr) me->core_layout.base - loc;
 			rc = apply_rela_bits(loc, val, 1, 32, 1);
 		}
 		break;
@@ -315,7 +315,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
 	case R_390_PLTOFF64:	/* 16 bit offset from GOT to PLT. */
 		if (info->plt_initialized == 0) {
 			unsigned int *ip;
-			ip = me->module_core + me->arch.plt_offset +
+			ip = me->core_layout.base + me->arch.plt_offset +
 				info->plt_offset;
 			ip[0] = 0x0d10e310; /* basr 1,0; lg 1,10(1); br 1 */
 			ip[1] = 0x100a0004;
@@ -334,7 +334,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
 			       val - loc + 0xffffUL < 0x1ffffeUL) ||
 			      (r_type == R_390_PLT32DBL &&
 			       val - loc + 0xffffffffULL < 0x1fffffffeULL)))
-				val = (Elf_Addr) me->module_core +
+				val = (Elf_Addr) me->core_layout.base +
 					me->arch.plt_offset +
 					info->plt_offset;
 			val += rela->r_addend - loc;
@@ -356,7 +356,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
 	case R_390_GOTOFF32:	/* 32 bit offset to GOT.  */
 	case R_390_GOTOFF64:	/* 64 bit offset to GOT. */
 		val = val + rela->r_addend -
-			((Elf_Addr) me->module_core + me->arch.got_offset);
+			((Elf_Addr) me->core_layout.base + me->arch.got_offset);
 		if (r_type == R_390_GOTOFF16)
 			rc = apply_rela_bits(loc, val, 0, 16, 0);
 		else if (r_type == R_390_GOTOFF32)
@@ -366,7 +366,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
 		break;
 	case R_390_GOTPC:	/* 32 bit PC relative offset to GOT. */
 	case R_390_GOTPCDBL:	/* 32 bit PC rel. off. to GOT shifted by 1. */
-		val = (Elf_Addr) me->module_core + me->arch.got_offset +
+		val = (Elf_Addr) me->core_layout.base + me->arch.got_offset +
 			rela->r_addend - loc;
 		if (r_type == R_390_GOTPC)
 			rc = apply_rela_bits(loc, val, 1, 32, 0);

arch/x86/kernel/livepatch.c

@@ -41,8 +41,8 @@ int klp_write_module_reloc(struct module *mod, unsigned long type,
 	int ret, numpages, size = 4;
 	bool readonly;
 	unsigned long val;
-	unsigned long core = (unsigned long)mod->module_core;
-	unsigned long core_size = mod->core_size;
+	unsigned long core = (unsigned long)mod->core_layout.base;
+	unsigned long core_size = mod->core_layout.size;
 
 	switch (type) {
 	case R_X86_64_NONE:
@@ -72,7 +72,7 @@ int klp_write_module_reloc(struct module *mod, unsigned long type,
 	readonly = false;
 
 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
-	if (loc < core + mod->core_ro_size)
+	if (loc < core + mod->core_layout.ro_size)
 		readonly = true;
 #endif
 

include/linux/module.h

@@ -302,6 +302,28 @@ struct mod_tree_node {
 	struct latch_tree_node node;
 };
 
+struct module_layout {
+	/* The actual code + data. */
+	void *base;
+	/* Total size. */
+	unsigned int size;
+	/* The size of the executable code.  */
+	unsigned int text_size;
+	/* Size of RO section of the module (text+rodata) */
+	unsigned int ro_size;
+
+#ifdef CONFIG_MODULES_TREE_LOOKUP
+	struct mod_tree_node mtn;
+#endif
+};
+
+#ifdef CONFIG_MODULES_TREE_LOOKUP
+/* Only touch one cacheline for common rbtree-for-core-layout case. */
+#define __module_layout_align ____cacheline_aligned
+#else
+#define __module_layout_align
+#endif
+
 struct module {
 	enum module_state state;
 
@@ -366,37 +388,9 @@ struct module {
 	/* Startup function. */
 	int (*init)(void);
 
-	/*
-	 * If this is non-NULL, vfree() after init() returns.
-	 *
-	 * Cacheline align here, such that:
-	 *   module_init, module_core, init_size, core_size,
-	 *   init_text_size, core_text_size and mtn_core::{mod,node[0]}
-	 * are on the same cacheline.
-	 */
-	void *module_init	____cacheline_aligned;
-
-	/* Here is the actual code + data, vfree'd on unload. */
-	void *module_core;
-
-	/* Here are the sizes of the init and core sections */
-	unsigned int init_size, core_size;
-
-	/* The size of the executable code in each section.  */
-	unsigned int init_text_size, core_text_size;
-
-#ifdef CONFIG_MODULES_TREE_LOOKUP
-	/*
-	 * We want mtn_core::{mod,node[0]} to be in the same cacheline as the
-	 * above entries such that a regular lookup will only touch one
-	 * cacheline.
-	 */
-	struct mod_tree_node	mtn_core;
-	struct mod_tree_node	mtn_init;
-#endif
-
-	/* Size of RO sections of the module (text+rodata) */
-	unsigned int init_ro_size, core_ro_size;
+	/* Core layout: rbtree is accessed frequently, so keep together. */
+	struct module_layout core_layout __module_layout_align;
+	struct module_layout init_layout;
 
 	/* Arch-specific module values */
 	struct mod_arch_specific arch;
@@ -505,15 +499,15 @@ bool is_module_text_address(unsigned long addr);
 static inline bool within_module_core(unsigned long addr,
 				      const struct module *mod)
 {
-	return (unsigned long)mod->module_core <= addr &&
-	       addr < (unsigned long)mod->module_core + mod->core_size;
+	return (unsigned long)mod->core_layout.base <= addr &&
+	       addr < (unsigned long)mod->core_layout.base + mod->core_layout.size;
 }
 
 static inline bool within_module_init(unsigned long addr,
 				      const struct module *mod)
 {
-	return (unsigned long)mod->module_init <= addr &&
-	       addr < (unsigned long)mod->module_init + mod->init_size;
+	return (unsigned long)mod->init_layout.base <= addr &&
+	       addr < (unsigned long)mod->init_layout.base + mod->init_layout.size;
 }
 
 static inline bool within_module(unsigned long addr, const struct module *mod)

kernel/debug/kdb/kdb_main.c

@@ -2021,7 +2021,7 @@ static int kdb_lsmod(int argc, const char **argv)
 			continue;
 
 		kdb_printf("%-20s%8u  0x%p ", mod->name,
-			   mod->core_size, (void *)mod);
+			   mod->core_layout.size, (void *)mod);
 #ifdef CONFIG_MODULE_UNLOAD
 		kdb_printf("%4d ", module_refcount(mod));
 #endif
@@ -2031,7 +2031,7 @@ static int kdb_lsmod(int argc, const char **argv)
 			kdb_printf(" (Loading)");
 		else
 			kdb_printf(" (Live)");
-		kdb_printf(" 0x%p", mod->module_core);
+		kdb_printf(" 0x%p", mod->core_layout.base);
 
 #ifdef CONFIG_MODULE_UNLOAD
 		{