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/arc/kernel/unwind.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'arch/arc') diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c index 200270a94558..9270d0a713c3 100644 --- a/arch/arc/kernel/unwind.c +++ b/arch/arc/kernel/unwind.c @@ -369,6 +369,8 @@ void *unwind_add_table(struct module *module, const void *table_start, unsigned long table_size) { struct unwind_table *table; + struct module_memory *core_text; + struct module_memory *init_text; if (table_size <= 0) return NULL; @@ -377,11 +379,11 @@ void *unwind_add_table(struct module *module, const void *table_start, if (!table) return NULL; - init_unwind_table(table, module->name, - module->core_layout.base, module->core_layout.size, - module->init_layout.base, module->init_layout.size, - table_start, table_size, - NULL, 0); + core_text = &module->mem[MOD_TEXT]; + init_text = &module->mem[MOD_INIT_TEXT]; + + init_unwind_table(table, module->name, core_text->base, core_text->size, + init_text->base, init_text->size, table_start, table_size, NULL, 0); init_unwind_hdr(table, unw_hdr_alloc); -- cgit v1.2.3