Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

 - fix EFI stub cache maintenance causing aborts during boot on certain
   platforms

 - handle byte stores in __clear_user without panicking

 - fix race condition in aarch64_insn_patch_text_sync() (instruction
   patching)

 - Couple of type fixes

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: ARCH_PFN_OFFSET should be unsigned long
  Correct the race condition in aarch64_insn_patch_text_sync()
  arm64: __clear_user: handle exceptions on strb
  arm64: Fix data type for physical address
  arm64: efi: Fix stub cache maintenance

5 files changed, 27 insertions, 11 deletions

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index ccc7087d3c4e..a62cd077457b 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -142,7 +142,7 @@ static inline void *phys_to_virt(phys_addr_t x)
  *  virt_to_page(k)     convert a _valid_ virtual address to struct page *
  *  virt_addr_valid(k)  indicates whether a virtual address is valid
  */
-#define ARCH_PFN_OFFSET         PHYS_PFN_OFFSET
+#define ARCH_PFN_OFFSET         ((unsigned long)PHYS_PFN_OFFSET)
 
 #define virt_to_page(kaddr)     pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
 #define virt_addr_valid(kaddr)  pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
diff --git a/arch/arm64/kernel/efi-entry.S b/arch/arm64/kernel/efi-entry.S
index 619b1dd7bcde..d18a44940968 100644
--- a/arch/arm64/kernel/efi-entry.S
+++ b/arch/arm64/kernel/efi-entry.S
@@ -54,18 +54,17 @@ ENTRY(efi_stub_entry)
         b.eq    efi_load_fail
 
         /*
-         * efi_entry() will have relocated the kernel image if necessary
-         * and we return here with device tree address in x0 and the kernel
-         * entry point stored at *image_addr. Save those values in registers
-         * which are callee preserved.
+         * efi_entry() will have copied the kernel image if necessary and we
+         * return here with device tree address in x0 and the kernel entry
+         * point stored at *image_addr. Save those values in registers which
+         * are callee preserved.
          */
         mov     x20, x0         // DTB address
         ldr     x0, [sp, #16]   // relocated _text address
         mov     x21, x0
 
         /*
-         * Flush dcache covering current runtime addresses
-         * of kernel text/data. Then flush all of icache.
+         * Calculate size of the kernel Image (same for original and copy).
          */
         adrp    x1, _text
         add     x1, x1, #:lo12:_text
@@ -73,9 +72,24 @@ ENTRY(efi_stub_entry)
         add     x2, x2, #:lo12:_edata
         sub     x1, x2, x1
 
+        /*
+         * Flush the copied Image to the PoC, and ensure it is not shadowed by
+         * stale icache entries from before relocation.
+         */
         bl      __flush_dcache_area
         ic      ialluis
 
+        /*
+         * Ensure that the rest of this function (in the original Image) is
+         * visible when the caches are disabled. The I-cache can't have stale
+         * entries for the VA range of the current image, so no maintenance is
+         * necessary.
+         */
+        adr     x0, efi_stub_entry
+        adr     x1, efi_stub_entry_end
+        sub     x1, x1, x0
+        bl      __flush_dcache_area
+
         /* Turn off Dcache and MMU */
         mrs     x0, CurrentEL
         cmp     x0, #CurrentEL_EL2
@@ -105,4 +119,5 @@ efi_load_fail:
         ldp     x29, x30, [sp], #32
         ret
 
+efi_stub_entry_end:
 ENDPROC(efi_stub_entry)
diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
index e007714ded04..8cd27fedc8b6 100644
--- a/arch/arm64/kernel/insn.c
+++ b/arch/arm64/kernel/insn.c
@@ -163,9 +163,10 @@ static int __kprobes aarch64_insn_patch_text_cb(void *arg)
                  * which ends with "dsb; isb" pair guaranteeing global
                  * visibility.
                  */
-                atomic_set(&pp->cpu_count, -1);
+                /* Notify other processors with an additional increment. */
+                atomic_inc(&pp->cpu_count);
         } else {
-                while (atomic_read(&pp->cpu_count) != -1)
+                while (atomic_read(&pp->cpu_count) <= num_online_cpus())
                         cpu_relax();
                 isb();
         }
diff --git a/arch/arm64/lib/clear_user.S b/arch/arm64/lib/clear_user.S
index 6e0ed93d51fe..c17967fdf5f6 100644
--- a/arch/arm64/lib/clear_user.S
+++ b/arch/arm64/lib/clear_user.S
@@ -46,7 +46,7 @@ USER(9f, strh	wzr, [x0], #2	)
         sub     x1, x1, #2
 4:      adds    x1, x1, #1
         b.mi    5f
-        strb    wzr, [x0]
+USER(9f, strb   wzr, [x0]       )
 5:      mov     x0, #0
         ret
 ENDPROC(__clear_user)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 0bf90d26e745..f4f8b500f74c 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -202,7 +202,7 @@ static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
 }
 
 static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
-                                  unsigned long end, unsigned long phys,
+                                  unsigned long end, phys_addr_t phys,
                                   int map_io)
 {
         pud_t *pud;