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, 3 insertions, 4 deletions

diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
index ea6536171778..816a63fd71fb 100644
--- a/arch/powerpc/kernel/module_32.c
+++ b/arch/powerpc/kernel/module_32.c
@@ -163,8 +163,7 @@ 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->core_layout.base
-	    && location < mod->core_layout.base + mod->core_layout.size)
+	if (within_module_core((unsigned long)location, mod))
 		entry = (void *)sechdrs[mod->arch.core_plt_section].sh_addr;
 	else
 		entry = (void *)sechdrs[mod->arch.init_plt_section].sh_addr;
@@ -322,14 +321,14 @@ notrace int module_trampoline_target(struct module *mod, unsigned long addr,
 
 int module_finalize_ftrace(struct module *module, const Elf_Shdr *sechdrs)
 {
-	module->arch.tramp = do_plt_call(module->core_layout.base,
+	module->arch.tramp = do_plt_call(module->mem[MOD_TEXT].base,
 					 (unsigned long)ftrace_caller,
 					 sechdrs, module);
 	if (!module->arch.tramp)
 		return -ENOENT;
 
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	module->arch.tramp_regs = do_plt_call(module->core_layout.base,
+	module->arch.tramp_regs = do_plt_call(module->mem[MOD_TEXT].base,
 					      (unsigned long)ftrace_regs_caller,
 					      sechdrs, module);
 	if (!module->arch.tramp_regs)