module: replace module_layout with module_memory

module_layout manages different types of memory (text, data, rodata, etc.)
in one allocation, which is problematic for some reasons:

1. It is hard to enable CONFIG_STRICT_MODULE_RWX.
2. It is hard to use huge pages in modules (and not break strict rwx).
3. Many archs uses module_layout for arch-specific data, but it is not
   obvious how these data are used (are they RO, RX, or RW?)

Improve the scenario by replacing 2 (or 3) module_layout per module with
up to 7 module_memory per module:

        MOD_TEXT,
        MOD_DATA,
        MOD_RODATA,
        MOD_RO_AFTER_INIT,
        MOD_INIT_TEXT,
        MOD_INIT_DATA,
        MOD_INIT_RODATA,

and allocating them separately. This adds slightly more entries to
mod_tree (from up to 3 entries per module, to up to 7 entries per
module). However, this at most adds a small constant overhead to
__module_address(), which is expected to be fast.

Various archs use module_layout for different data. These data are put
into different module_memory based on their location in module_layout.
IOW, data that used to go with text is allocated with MOD_MEM_TYPE_TEXT;
data that used to go with data is allocated with MOD_MEM_TYPE_DATA, etc.

module_memory simplifies quite some of the module code. For example,
ARCH_WANTS_MODULES_DATA_IN_VMALLOC is a lot cleaner, as it just uses a
different allocator for the data. kernel/module/strict_rwx.c is also
much cleaner with module_memory.

Signed-off-by: Song Liu <song@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

1 files changed, 17 insertions, 34 deletions

diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c
index 7df140545b22..f6e38c4d3904 100644
--- a/arch/parisc/kernel/module.c
+++ b/arch/parisc/kernel/module.c
@@ -27,9 +27,9 @@
  *      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->init_layout.base;
+ *				val -= (uint32_t)me->mem[MOD_INIT_TEXT].base;
  *			else
- *				val -= (uint32_t)me->core_layout.base;
+ *				val -= (uint32_t)me->mem[MOD_TEXT].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.
  *
@@ -76,25 +76,6 @@
  * allows us to allocate up to 4095 GOT entries. */
 #define MAX_GOTS	4095
 
-/* three functions to determine where in the module core
- * or init pieces the location is */
-static inline int in_init(struct module *me, void *loc)
-{
-	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->core_layout.base &&
-		loc <= (me->core_layout.base + me->core_layout.size));
-}
-
-static inline int in_local(struct module *me, void *loc)
-{
-	return in_init(me, loc) || in_core(me, loc);
-}
-
 #ifndef CONFIG_64BIT
 struct got_entry {
 	Elf32_Addr addr;
@@ -302,6 +283,7 @@ int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
 {
 	unsigned long gots = 0, fdescs = 0, len;
 	unsigned int i;
+	struct module_memory *mod_mem;
 
 	len = hdr->e_shnum * sizeof(me->arch.section[0]);
 	me->arch.section = kzalloc(len, GFP_KERNEL);
@@ -346,14 +328,15 @@ int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
 		me->arch.section[s].stub_entries += count;
 	}
 
+	mod_mem = &me->mem[MOD_TEXT];
 	/* align things a bit */
-	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);
+	mod_mem->size = ALIGN(mod_mem->size, 16);
+	me->arch.got_offset = mod_mem->size;
+	mod_mem->size += gots * sizeof(struct got_entry);
 
-	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);
+	mod_mem->size = ALIGN(mod_mem->size, 16);
+	me->arch.fdesc_offset = mod_mem->size;
+	mod_mem->size += fdescs * sizeof(Elf_Fdesc);
 
 	me->arch.got_max = gots;
 	me->arch.fdesc_max = fdescs;
@@ -371,7 +354,7 @@ static Elf64_Word get_got(struct module *me, unsigned long value, long addend)
 
 	BUG_ON(value == 0);
 
-	got = me->core_layout.base + me->arch.got_offset;
+	got = me->mem[MOD_TEXT].base + me->arch.got_offset;
 	for (i = 0; got[i].addr; i++)
 		if (got[i].addr == value)
 			goto out;
@@ -389,7 +372,7 @@ 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->core_layout.base + me->arch.fdesc_offset;
+	Elf_Fdesc *fdesc = me->mem[MOD_TEXT].base + me->arch.fdesc_offset;
 
 	if (!value) {
 		printk(KERN_ERR "%s: zero OPD requested!\n", me->name);
@@ -407,7 +390,7 @@ static Elf_Addr get_fdesc(struct module *me, unsigned long value)
 
 	/* Create new one */
 	fdesc->addr = value;
-	fdesc->gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;
+	fdesc->gp = (Elf_Addr)me->mem[MOD_TEXT].base + me->arch.got_offset;
 	return (Elf_Addr)fdesc;
 }
 #endif /* CONFIG_64BIT */
@@ -742,7 +725,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
 			       loc, val);
 			val += addend;
 			/* can we reach it locally? */
-			if (in_local(me, (void *)val)) {
+			if (within_module(val, me)) {
 				/* this is the case where the symbol is local
 				 * to the module, but in a different section,
 				 * so stub the jump in case it's more than 22
@@ -801,7 +784,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
 			break;
 		case R_PARISC_FPTR64:
 			/* 64-bit function address */
-			if(in_local(me, (void *)(val + addend))) {
+			if (within_module(val + addend, me)) {
 				*loc64 = get_fdesc(me, val+addend);
 				pr_debug("FDESC for %s at %llx points to %llx\n",
 				       strtab + sym->st_name, *loc64,
@@ -839,7 +822,7 @@ 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->core_layout.base + me->arch.got_offset;
+	gp = (Elf_Addr)me->mem[MOD_TEXT].base + me->arch.got_offset;
 
 	pr_debug("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
 	       me->arch.unwind_section, table, end, gp);
@@ -977,7 +960,7 @@ void module_arch_cleanup(struct module *mod)
 #ifdef CONFIG_64BIT
 void *dereference_module_function_descriptor(struct module *mod, void *ptr)
 {
-	unsigned long start_opd = (Elf64_Addr)mod->core_layout.base +
+	unsigned long start_opd = (Elf64_Addr)mod->mem[MOD_TEXT].base +
 				   mod->arch.fdesc_offset;
 	unsigned long end_opd = start_opd +
 				mod->arch.fdesc_count * sizeof(Elf64_Fdesc);