1 files changed, 49 insertions, 33 deletions

diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index 21ab5df9fa76..65d81f965e74 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -35,6 +35,7 @@
 #include <asm/sections.h>
 #include <asm/smp.h>
 #include <asm/suspend.h>
+#include <asm/sysreg.h>
 #include <asm/virt.h>
 
 /*
@@ -217,12 +218,22 @@ static int create_safe_exec_page(void *src_start, size_t length,
         set_pte(pte, __pte(virt_to_phys((void *)dst) |
                          pgprot_val(PAGE_KERNEL_EXEC)));
 
-        /* Load our new page tables */
-        asm volatile("msr       ttbr0_el1, %0;"
-                     "isb;"
-                     "tlbi      vmalle1is;"
-                     "dsb       ish;"
-                     "isb" : : "r"(virt_to_phys(pgd)));
+        /*
+         * Load our new page tables. A strict BBM approach requires that we
+         * ensure that TLBs are free of any entries that may overlap with the
+         * global mappings we are about to install.
+         *
+         * For a real hibernate/resume cycle TTBR0 currently points to a zero
+         * page, but TLBs may contain stale ASID-tagged entries (e.g. for EFI
+         * runtime services), while for a userspace-driven test_resume cycle it
+         * points to userspace page tables (and we must point it at a zero page
+         * ourselves). Elsewhere we only (un)install the idmap with preemption
+         * disabled, so T0SZ should be as required regardless.
+         */
+        cpu_set_reserved_ttbr0();
+        local_flush_tlb_all();
+        write_sysreg(virt_to_phys(pgd), ttbr0_el1);
+        isb();
 
         *phys_dst_addr = virt_to_phys((void *)dst);
 
@@ -394,6 +405,38 @@ int swsusp_arch_resume(void)
                                           void *, phys_addr_t, phys_addr_t);
 
         /*
+         * Restoring the memory image will overwrite the ttbr1 page tables.
+         * Create a second copy of just the linear map, and use this when
+         * restoring.
+         */
+        tmp_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC);
+        if (!tmp_pg_dir) {
+                pr_err("Failed to allocate memory for temporary page tables.");
+                rc = -ENOMEM;
+                goto out;
+        }
+        rc = copy_page_tables(tmp_pg_dir, PAGE_OFFSET, 0);
+        if (rc)
+                goto out;
+
+        /*
+         * Since we only copied the linear map, we need to find restore_pblist's
+         * linear map address.
+         */
+        lm_restore_pblist = LMADDR(restore_pblist);
+
+        /*
+         * We need a zero page that is zero before & after resume in order to
+         * to break before make on the ttbr1 page tables.
+         */
+        zero_page = (void *)get_safe_page(GFP_ATOMIC);
+        if (!zero_page) {
+                pr_err("Failed to allocate zero page.");
+                rc = -ENOMEM;
+                goto out;
+        }
+
+        /*
          * Locate the exit code in the bottom-but-one page, so that *NULL
          * still has disastrous affects.
          */
@@ -419,27 +462,6 @@ int swsusp_arch_resume(void)
         __flush_dcache_area(hibernate_exit, exit_size);
 
         /*
-         * Restoring the memory image will overwrite the ttbr1 page tables.
-         * Create a second copy of just the linear map, and use this when
-         * restoring.
-         */
-        tmp_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC);
-        if (!tmp_pg_dir) {
-                pr_err("Failed to allocate memory for temporary page tables.");
-                rc = -ENOMEM;
-                goto out;
-        }
-        rc = copy_page_tables(tmp_pg_dir, PAGE_OFFSET, 0);
-        if (rc)
-                goto out;
-
-        /*
-         * Since we only copied the linear map, we need to find restore_pblist's
-         * linear map address.
-         */
-        lm_restore_pblist = LMADDR(restore_pblist);
-
-        /*
          * KASLR will cause the el2 vectors to be in a different location in
          * the resumed kernel. Load hibernate's temporary copy into el2.
          *
@@ -453,12 +475,6 @@ int swsusp_arch_resume(void)
                 __hyp_set_vectors(el2_vectors);
         }
 
-        /*
-         * We need a zero page that is zero before & after resume in order to
-         * to break before make on the ttbr1 page tables.
-         */
-        zero_page = (void *)get_safe_page(GFP_ATOMIC);
-
         hibernate_exit(virt_to_phys(tmp_pg_dir), resume_hdr.ttbr1_el1,
                        resume_hdr.reenter_kernel, lm_restore_pblist,
                        resume_hdr.__hyp_stub_vectors, virt_to_phys(zero_page));