Merge tag 'powerpc-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Add support for building the kernel using PC-relative addressing on
   Power10.

 - Allow HV KVM guests on Power10 to use prefixed instructions.

 - Unify support for the P2020 CPU (85xx) into a single machine
   description.

 - Always build the 64-bit kernel with 128-bit long double.

 - Drop support for several obsolete 2000's era development boards as
   identified by Paul Gortmaker.

 - A series fixing VFIO on Power since some generic changes.

 - Various other small features and fixes.

Thanks to Alexey Kardashevskiy, Andrew Donnellan, Benjamin Gray, Bo Liu,
Christophe Leroy, Dan Carpenter, David Binderman, Ira Weiny, Joel
Stanley, Kajol Jain, Kautuk Consul, Liang He, Luis Chamberlain, Masahiro
Yamada, Michael Neuling, Nathan Chancellor, Nathan Lynch, Nicholas
Miehlbradt, Nicholas Piggin, Nick Desaulniers, Nysal Jan K.A, Pali
Rohár, Paul Gortmaker, Paul Mackerras, Petr Vaněk, Randy Dunlap, Rob
Herring, Sachin Sant, Sean Christopherson, Segher Boessenkool, and
Timothy Pearson.

* tag 'powerpc-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (156 commits)
  powerpc/64s: Disable pcrel code model on Clang
  powerpc: Fix merge conflict between pcrel and copy_thread changes
  powerpc/configs/powernv: Add IGB=y
  powerpc/configs/64s: Drop JFS Filesystem
  powerpc/configs/64s: Use EXT4 to mount EXT2 filesystems
  powerpc/configs: Make pseries_defconfig an alias for ppc64le_guest
  powerpc/configs: Make pseries_le an alias for ppc64le_guest
  powerpc/configs: Incorporate generic kvm_guest.config into guest configs
  powerpc/configs: Add IBMVETH=y and IBMVNIC=y to guest configs
  powerpc/configs/64s: Enable Device Mapper options
  powerpc/configs/64s: Enable PSTORE
  powerpc/configs/64s: Enable VLAN support
  powerpc/configs/64s: Enable BLK_DEV_NVME
  powerpc/configs/64s: Drop REISERFS
  powerpc/configs/64s: Use SHA512 for module signatures
  powerpc/configs/64s: Enable IO_STRICT_DEVMEM
  powerpc/configs/64s: Enable SCHEDSTATS
  powerpc/configs/64s: Enable DEBUG_VM & other options
  powerpc/configs/64s: Enable EMULATED_STATS
  powerpc/configs/64s: Enable KUNIT and most tests
  ...

1 files changed, 40 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index af58f1ed3952..bf5dde1a4114 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -45,6 +45,7 @@
 #include <linux/cache.h>
 #include <asm/processor.h>
 #include <asm/accounting.h>
+#include <asm/ppc_asm.h>
 
 #define SLB_PRELOAD_NR	16U
 /*
@@ -175,9 +176,11 @@ static inline bool test_thread_local_flags(unsigned int flags)
 #ifdef CONFIG_COMPAT
 #define is_32bit_task()	(test_thread_flag(TIF_32BIT))
 #define is_tsk_32bit_task(tsk)	(test_tsk_thread_flag(tsk, TIF_32BIT))
+#define clear_tsk_compat_task(tsk) (clear_tsk_thread_flag(p, TIF_32BIT))
 #else
 #define is_32bit_task()	(IS_ENABLED(CONFIG_PPC32))
 #define is_tsk_32bit_task(tsk)	(IS_ENABLED(CONFIG_PPC32))
+#define clear_tsk_compat_task(tsk) do { } while (0)
 #endif
 
 #if defined(CONFIG_PPC64)
@@ -186,6 +189,43 @@ static inline bool test_thread_local_flags(unsigned int flags)
 #define is_elf2_task() (0)
 #endif
 
+/*
+ * Walks up the stack frames to make sure that the specified object is
+ * entirely contained by a single stack frame.
+ *
+ * Returns:
+ *	GOOD_FRAME	if within a frame
+ *	BAD_STACK	if placed across a frame boundary (or outside stack)
+ */
+static inline int arch_within_stack_frames(const void * const stack,
+					   const void * const stackend,
+					   const void *obj, unsigned long len)
+{
+	const void *params;
+	const void *frame;
+
+	params = *(const void * const *)current_stack_pointer + STACK_FRAME_PARAMS;
+	frame = **(const void * const * const *)current_stack_pointer;
+
+	/*
+	 * low -----------------------------------------------------------> high
+	 * [backchain][metadata][params][local vars][saved registers][backchain]
+	 *                      ^------------------------------------^
+	 *                      |  allows copies only in this region |
+	 *                      |                                    |
+	 *                    params                               frame
+	 * The metadata region contains the saved LR, CR etc.
+	 */
+	while (stack <= frame && frame < stackend) {
+		if (obj + len <= frame)
+			return obj >= params ? GOOD_FRAME : BAD_STACK;
+		params = frame + STACK_FRAME_PARAMS;
+		frame = *(const void * const *)frame;
+	}
+
+	return BAD_STACK;
+}
+
 #endif	/* !__ASSEMBLY__ */
 
 #endif /* __KERNEL__ */