[xen staging] x86: drop MEMORY_GUARD

[patchbot@xxxxxxx]

commit fdf01494560219d10f92ce3419a5551e3ce5fe4f
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Wed Dec 15 10:23:51 2021 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Dec 15 10:23:51 2021 +0100

    x86: drop MEMORY_GUARD
    
    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. Drop them as well; there's no harm
    providing the information there in all cases.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/include/asm/config.h |  4 ----
 xen/arch/x86/include/asm/mm.h     |  8 --------
 xen/arch/x86/mm.c                 | 30 ------------------------------
 xen/arch/x86/traps.c              |  4 ----
 4 files changed, 46 deletions(-)

diff --git a/xen/arch/x86/include/asm/config.h 
b/xen/arch/x86/include/asm/config.h
index 883c2ef0df..de20642524 100644
--- a/xen/arch/x86/include/asm/config.h
+++ b/xen/arch/x86/include/asm/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)
 
diff --git a/xen/arch/x86/include/asm/mm.h b/xen/arch/x86/include/asm/mm.h
index cb90527499..5dbcee8696 100644
--- a/xen/arch/x86/include/asm/mm.h
+++ b/xen/arch/x86/include/asm/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);
 
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 4a9ac8d5e6..1397f83e41 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -6109,36 +6109,6 @@ void free_perdomain_mappings(struct domain *d)
     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)
 {
     /*
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 2ddcd95dce..df7ffc448b 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -642,15 +642,12 @@ void show_stack_overflow(unsigned int cpu, const struct 
cpu_user_regs *regs)
 {
     unsigned long esp = regs->rsp;
     unsigned long curr_stack_base = esp & ~(STACK_SIZE - 1);
-#ifdef MEMORY_GUARD
     unsigned long esp_top, esp_bottom;
-#endif
 
     if ( _p(curr_stack_base) != stack_base[cpu] )
         printk("Current stack base %p differs from expected %p\n",
                _p(curr_stack_base), stack_base[cpu]);
 
-#ifdef MEMORY_GUARD
     esp_bottom = (esp | (STACK_SIZE - 1)) + 1;
     esp_top    = esp_bottom - PRIMARY_STACK_SIZE;
 
@@ -678,7 +675,6 @@ void show_stack_overflow(unsigned int cpu, const struct 
cpu_user_regs *regs)
     _show_trace(esp, regs->rbp);
 
     printk("\n");
-#endif
 }
 
 void show_execution_state(const struct cpu_user_regs *regs)
--
generated by git-patchbot for /home/xen/git/xen.git#staging