From ac3b43283923440900b4f36ca5f9f0b1ca43b70e Mon Sep 17 00:00:00 2001 From: Song Liu Date: Mon, 6 Feb 2023 16:28:02 -0800 Subject: 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 Cc: Luis Chamberlain Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Guenter Roeck Cc: Christophe Leroy Reviewed-by: Thomas Gleixner Reviewed-by: Christophe Leroy Reviewed-by: Luis Chamberlain Signed-off-by: Luis Chamberlain --- arch/arm/kernel/module-plts.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/module-plts.c b/arch/arm/kernel/module-plts.c index af7c322ebed6..f5a43fd8c163 100644 --- a/arch/arm/kernel/module-plts.c +++ b/arch/arm/kernel/module-plts.c @@ -28,11 +28,6 @@ static const u32 fixed_plts[] = { #endif }; -static bool in_init(const struct module *mod, unsigned long loc) -{ - return loc - (u32)mod->init_layout.base < mod->init_layout.size; -} - static void prealloc_fixed(struct mod_plt_sec *pltsec, struct plt_entries *plt) { int i; @@ -50,8 +45,8 @@ static void prealloc_fixed(struct mod_plt_sec *pltsec, struct plt_entries *plt) u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val) { - struct mod_plt_sec *pltsec = !in_init(mod, loc) ? &mod->arch.core : - &mod->arch.init; + struct mod_plt_sec *pltsec = !within_module_init(loc, mod) ? + &mod->arch.core : &mod->arch.init; struct plt_entries *plt; int idx; -- cgit