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

Pull arm64 fixes from Catalin Marinas:

 - ZONE_DMA32 initialisation fix when memblocks fall entirely within the
   first GB (used by ZONE_DMA in 5.5 for Raspberry Pi 4).

 - Couple of ftrace fixes following the FTRACE_WITH_REGS patchset.

 - access_ok() fix for the Tagged Address ABI when called from from a
   kernel thread (asynchronous I/O): the kthread does not have the TIF
   flags of the mm owner, so untag the user address unconditionally.

 - KVM compute_layout() called before the alternatives code patching.

 - Minor clean-ups.

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: entry: refine comment of stack overflow check
  arm64: ftrace: fix ifdeffery
  arm64: KVM: Invoke compute_layout() before alternatives are applied
  arm64: Validate tagged addresses in access_ok() called from kernel threads
  arm64: mm: Fix column alignment for UXN in kernel_page_tables
  arm64: insn: consistently handle exit text
  arm64: mm: Fix initialisation of DMA zones on non-NUMA systems

1 files changed, 6 insertions, 1 deletions

diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 127712b0b970..32fc8061aa76 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -62,8 +62,13 @@ static inline unsigned long __range_ok(const void __user *addr, unsigned long si
 {
 	unsigned long ret, limit = current_thread_info()->addr_limit;
 
+	/*
+	 * Asynchronous I/O running in a kernel thread does not have the
+	 * TIF_TAGGED_ADDR flag of the process owning the mm, so always untag
+	 * the user address before checking.
+	 */
 	if (IS_ENABLED(CONFIG_ARM64_TAGGED_ADDR_ABI) &&
-	    test_thread_flag(TIF_TAGGED_ADDR))
+	    (current->flags & PF_KTHREAD || test_thread_flag(TIF_TAGGED_ADDR)))
 		addr = untagged_addr(addr);
 
 	__chk_user_ptr(addr);