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-rw-r--r--arch/x86/mm/fault.c28
-rw-r--r--arch/x86/mm/init_64.c9
-rw-r--r--arch/x86/mm/pageattr-test.c65
-rw-r--r--arch/x86/mm/pageattr.c14
4 files changed, 79 insertions, 37 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index ad8b9733d6b..621afb6343d 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -428,6 +428,16 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
}
#endif
+static int spurious_fault_check(unsigned long error_code, pte_t *pte)
+{
+ if ((error_code & PF_WRITE) && !pte_write(*pte))
+ return 0;
+ if ((error_code & PF_INSTR) && !pte_exec(*pte))
+ return 0;
+
+ return 1;
+}
+
/*
* Handle a spurious fault caused by a stale TLB entry. This allows
* us to lazily refresh the TLB when increasing the permissions of a
@@ -457,20 +467,21 @@ static int spurious_fault(unsigned long address,
if (!pud_present(*pud))
return 0;
+ if (pud_large(*pud))
+ return spurious_fault_check(error_code, (pte_t *) pud);
+
pmd = pmd_offset(pud, address);
if (!pmd_present(*pmd))
return 0;
+ if (pmd_large(*pmd))
+ return spurious_fault_check(error_code, (pte_t *) pmd);
+
pte = pte_offset_kernel(pmd, address);
if (!pte_present(*pte))
return 0;
- if ((error_code & PF_WRITE) && !pte_write(*pte))
- return 0;
- if ((error_code & PF_INSTR) && !pte_exec(*pte))
- return 0;
-
- return 1;
+ return spurious_fault_check(error_code, pte);
}
/*
@@ -947,11 +958,12 @@ void vmalloc_sync_all(void)
for (address = start; address <= VMALLOC_END; address += PGDIR_SIZE) {
if (!test_bit(pgd_index(address), insync)) {
const pgd_t *pgd_ref = pgd_offset_k(address);
+ unsigned long flags;
struct page *page;
if (pgd_none(*pgd_ref))
continue;
- spin_lock(&pgd_lock);
+ spin_lock_irqsave(&pgd_lock, flags);
list_for_each_entry(page, &pgd_list, lru) {
pgd_t *pgd;
pgd = (pgd_t *)page_address(page) + pgd_index(address);
@@ -960,7 +972,7 @@ void vmalloc_sync_all(void)
else
BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
}
- spin_unlock(&pgd_lock);
+ spin_unlock_irqrestore(&pgd_lock, flags);
set_bit(pgd_index(address), insync);
}
if (address == start)
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 3a98d6f724a..9b61c75a235 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -591,10 +591,17 @@ void mark_rodata_ro(void)
if (end <= start)
return;
- set_memory_ro(start, (end - start) >> PAGE_SHIFT);
printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
(end - start) >> 10);
+ set_memory_ro(start, (end - start) >> PAGE_SHIFT);
+
+ /*
+ * The rodata section (but not the kernel text!) should also be
+ * not-executable.
+ */
+ start = ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
+ set_memory_nx(start, (end - start) >> PAGE_SHIFT);
rodata_test();
diff --git a/arch/x86/mm/pageattr-test.c b/arch/x86/mm/pageattr-test.c
index 398f3a578dd..ed820160035 100644
--- a/arch/x86/mm/pageattr-test.c
+++ b/arch/x86/mm/pageattr-test.c
@@ -5,6 +5,7 @@
* and compares page tables forwards and afterwards.
*/
#include <linux/bootmem.h>
+#include <linux/kthread.h>
#include <linux/random.h>
#include <linux/kernel.h>
#include <linux/init.h>
@@ -14,8 +15,13 @@
#include <asm/pgtable.h>
#include <asm/kdebug.h>
+/*
+ * Only print the results of the first pass:
+ */
+static __read_mostly int print = 1;
+
enum {
- NTEST = 4000,
+ NTEST = 400,
#ifdef CONFIG_X86_64
LPS = (1 << PMD_SHIFT),
#elif defined(CONFIG_X86_PAE)
@@ -31,7 +37,7 @@ struct split_state {
long min_exec, max_exec;
};
-static __init int print_split(struct split_state *s)
+static int print_split(struct split_state *s)
{
long i, expected, missed = 0;
int printed = 0;
@@ -82,10 +88,13 @@ static __init int print_split(struct split_state *s)
s->max_exec = addr;
}
}
- printk(KERN_INFO
- "CPA mapping 4k %lu large %lu gb %lu x %lu[%lx-%lx] miss %lu\n",
- s->spg, s->lpg, s->gpg, s->exec,
- s->min_exec != ~0UL ? s->min_exec : 0, s->max_exec, missed);
+ if (print) {
+ printk(KERN_INFO
+ " 4k %lu large %lu gb %lu x %lu[%lx-%lx] miss %lu\n",
+ s->spg, s->lpg, s->gpg, s->exec,
+ s->min_exec != ~0UL ? s->min_exec : 0,
+ s->max_exec, missed);
+ }
expected = (s->gpg*GPS + s->lpg*LPS)/PAGE_SIZE + s->spg + missed;
if (expected != i) {
@@ -96,11 +105,11 @@ static __init int print_split(struct split_state *s)
return err;
}
-static unsigned long __initdata addr[NTEST];
-static unsigned int __initdata len[NTEST];
+static unsigned long addr[NTEST];
+static unsigned int len[NTEST];
/* Change the global bit on random pages in the direct mapping */
-static __init int exercise_pageattr(void)
+static int pageattr_test(void)
{
struct split_state sa, sb, sc;
unsigned long *bm;
@@ -110,7 +119,8 @@ static __init int exercise_pageattr(void)
int i, k;
int err;
- printk(KERN_INFO "CPA exercising pageattr\n");
+ if (print)
+ printk(KERN_INFO "CPA self-test:\n");
bm = vmalloc((max_pfn_mapped + 7) / 8);
if (!bm) {
@@ -186,7 +196,6 @@ static __init int exercise_pageattr(void)
failed += print_split(&sb);
- printk(KERN_INFO "CPA reverting everything\n");
for (i = 0; i < NTEST; i++) {
if (!addr[i])
continue;
@@ -214,12 +223,40 @@ static __init int exercise_pageattr(void)
failed += print_split(&sc);
if (failed) {
- printk(KERN_ERR "CPA selftests NOT PASSED. Please report.\n");
+ printk(KERN_ERR "NOT PASSED. Please report.\n");
WARN_ON(1);
+ return -EINVAL;
} else {
- printk(KERN_INFO "CPA selftests PASSED\n");
+ if (print)
+ printk(KERN_INFO "ok.\n");
}
return 0;
}
-module_init(exercise_pageattr);
+
+static int do_pageattr_test(void *__unused)
+{
+ while (!kthread_should_stop()) {
+ schedule_timeout_interruptible(HZ*30);
+ if (pageattr_test() < 0)
+ break;
+ if (print)
+ print--;
+ }
+ return 0;
+}
+
+static int start_pageattr_test(void)
+{
+ struct task_struct *p;
+
+ p = kthread_create(do_pageattr_test, NULL, "pageattr-test");
+ if (!IS_ERR(p))
+ wake_up_process(p);
+ else
+ WARN_ON(1);
+
+ return 0;
+}
+
+module_init(start_pageattr_test);
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 16ce841f08d..8493c855582 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -167,8 +167,6 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address)
if (within(address, virt_to_highmap(_text), virt_to_highmap(_etext)))
pgprot_val(forbidden) |= _PAGE_NX;
-
-#ifdef CONFIG_DEBUG_RODATA
/* The .rodata section needs to be read-only */
if (within(address, (unsigned long)__start_rodata,
(unsigned long)__end_rodata))
@@ -179,7 +177,6 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address)
if (within(address, virt_to_highmap(__start_rodata),
virt_to_highmap(__end_rodata)))
pgprot_val(forbidden) |= _PAGE_RW;
-#endif
prot = __pgprot(pgprot_val(prot) & ~pgprot_val(forbidden));
@@ -260,17 +257,6 @@ try_preserve_large_page(pte_t *kpte, unsigned long address,
pgprot_t old_prot, new_prot;
int level, do_split = 1;
- /*
- * An Athlon 64 X2 showed hard hangs if we tried to preserve
- * largepages and changed the PSE entry from RW to RO.
- *
- * As AMD CPUs have a long series of erratas in this area,
- * (and none of the known ones seem to explain this hang),
- * disable this code until the hang can be debugged:
- */
- if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
- return 1;
-
spin_lock_irqsave(&pgd_lock, flags);
/*
* Check for races, another CPU might have split this page
generated by cgit (git 2.34.1) at 2025-01-25 19:07:08 +0000