The functions it guards are dead code. Worse, while intended to exist in
debug builds only, as of commit bacbf0cb7349 ("build: convert debug to
Kconfig") they also get compiled in release builds.The remaining uses in show_stack_overflow() aren't really related to any memory guarding anymore - with CET-SS support the stacks now get set up the same in debug and release builds. Use CONFIG_DEBUG there instead. Signed-off-by: Jan Beulich <[email protected]> --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -6109,36 +6109,6 @@ void free_perdomain_mappings(struct doma d->arch.perdomain_l3_pg = NULL; } -#ifdef MEMORY_GUARD - -static void __memguard_change_range(void *p, unsigned long l, int guard) -{ - unsigned long _p = (unsigned long)p; - unsigned long _l = (unsigned long)l; - unsigned int flags = __PAGE_HYPERVISOR_RW | MAP_SMALL_PAGES; - - /* Ensure we are dealing with a page-aligned whole number of pages. */ - ASSERT(IS_ALIGNED(_p, PAGE_SIZE)); - ASSERT(IS_ALIGNED(_l, PAGE_SIZE)); - - if ( guard ) - flags &= ~_PAGE_PRESENT; - - map_pages_to_xen(_p, virt_to_mfn(p), PFN_DOWN(_l), flags); -} - -void memguard_guard_range(void *p, unsigned long l) -{ - __memguard_change_range(p, l, 1); -} - -void memguard_unguard_range(void *p, unsigned long l) -{ - __memguard_change_range(p, l, 0); -} - -#endif - static void write_sss_token(unsigned long *ptr) { /* --- a/xen/arch/x86/traps.c +++ b/xen/arch/x86/traps.c @@ -642,7 +642,7 @@ void show_stack_overflow(unsigned int cp { unsigned long esp = regs->rsp; unsigned long curr_stack_base = esp & ~(STACK_SIZE - 1); -#ifdef MEMORY_GUARD +#ifdef CONFIG_DEBUG unsigned long esp_top, esp_bottom; #endif @@ -650,7 +650,7 @@ void show_stack_overflow(unsigned int cp printk("Current stack base %p differs from expected %p\n", _p(curr_stack_base), stack_base[cpu]); -#ifdef MEMORY_GUARD +#ifdef CONFIG_DEBUG esp_bottom = (esp | (STACK_SIZE - 1)) + 1; esp_top = esp_bottom - PRIMARY_STACK_SIZE; --- a/xen/include/asm-x86/config.h +++ b/xen/include/asm-x86/config.h @@ -57,10 +57,6 @@ #define NR_hypercalls 64 -#ifndef NDEBUG -#define MEMORY_GUARD -#endif - #define STACK_ORDER 3 #define STACK_SIZE (PAGE_SIZE << STACK_ORDER) --- a/xen/include/asm-x86/mm.h +++ b/xen/include/asm-x86/mm.h @@ -530,14 +530,6 @@ extern struct rangeset *mmio_ro_ranges; #define compat_pfn_to_cr3(pfn) (((unsigned)(pfn) << 12) | ((unsigned)(pfn) >> 20)) #define compat_cr3_to_pfn(cr3) (((unsigned)(cr3) >> 12) | ((unsigned)(cr3) << 20)) -#ifdef MEMORY_GUARD -void memguard_guard_range(void *p, unsigned long l); -void memguard_unguard_range(void *p, unsigned long l); -#else -#define memguard_guard_range(_p,_l) ((void)0) -#define memguard_unguard_range(_p,_l) ((void)0) -#endif - void memguard_guard_stack(void *p); void memguard_unguard_stack(void *p);
