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/x86/kernel/callthunks.c | 4 ++-- arch/x86/kernel/module.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/callthunks.c b/arch/x86/kernel/callthunks.c index ffea98f9064b..22ab13966427 100644 --- a/arch/x86/kernel/callthunks.c +++ b/arch/x86/kernel/callthunks.c @@ -330,8 +330,8 @@ void noinline callthunks_patch_module_calls(struct callthunk_sites *cs, struct module *mod) { struct core_text ct = { - .base = (unsigned long)mod->core_layout.base, - .end = (unsigned long)mod->core_layout.base + mod->core_layout.size, + .base = (unsigned long)mod->mem[MOD_TEXT].base, + .end = (unsigned long)mod->mem[MOD_TEXT].base + mod->mem[MOD_TEXT].size, .name = mod->name, }; diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c index 84ad0e61ba6e..b05f62ee2344 100644 --- a/arch/x86/kernel/module.c +++ b/arch/x86/kernel/module.c @@ -362,8 +362,8 @@ int module_finalize(const Elf_Ehdr *hdr, } if (locks) { void *lseg = (void *)locks->sh_addr; - void *text = me->core_layout.base; - void *text_end = text + me->core_layout.text_size; + void *text = me->mem[MOD_TEXT].base; + void *text_end = text + me->mem[MOD_TEXT].size; alternatives_smp_module_add(me, me->name, lseg, lseg + locks->sh_size, text, text_end); -- cgit v1.2.1 From 48380368dec14859723b9e3fbd43e042638d9a76 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 29 Mar 2023 12:14:42 +0200 Subject: Change DEFINE_SEMAPHORE() to take a number argument Fundamentally semaphores are a counted primitive, but DEFINE_SEMAPHORE() does not expose this and explicitly creates a binary semaphore. Change DEFINE_SEMAPHORE() to take a number argument and use that in the few places that open-coded it using __SEMAPHORE_INITIALIZER(). Signed-off-by: Peter Zijlstra (Intel) [mcgrof: add some tribal knowledge about why some folks prefer binary sempahores over mutexes] Reviewed-by: Sergey Senozhatsky Reviewed-by: Davidlohr Bueso Signed-off-by: Luis Chamberlain --- arch/x86/kernel/cpu/intel.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 291d4167fab8..12bad63822f0 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -1177,7 +1177,7 @@ static const struct { static struct ratelimit_state bld_ratelimit; static unsigned int sysctl_sld_mitigate = 1; -static DEFINE_SEMAPHORE(buslock_sem); +static DEFINE_SEMAPHORE(buslock_sem, 1); #ifdef CONFIG_PROC_SYSCTL static struct ctl_table sld_sysctls[] = { -- cgit v1.2.1