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 ccc7087..a62cd07 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 619b1dd..d18a449 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 e007714..8cd27fe 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 6e0ed93..c17967f 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 0bf90d2..f4f8b50 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;