ARM updates for v6.4-rc1

Fixes for v6.4-rc1:
 - fix unwinder for uleb128 case
 - fix kernel-doc warnings for HP Jornada 7xx
 - fix unbalanced stack on vfp success path
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Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM fixes from Russell King:

 - fix unwinder for uleb128 case

 - fix kernel-doc warnings for HP Jornada 7xx

 - fix unbalanced stack on vfp success path

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 9297/1: vfp: avoid unbalanced stack on 'success' return path
  ARM: 9296/1: HP Jornada 7XX: fix kernel-doc warnings
  ARM: 9295/1: unwind:fix unwind abort for uleb128 case

arch/arm/kernel/unwind.c

@@ -308,6 +308,29 @@ static int unwind_exec_pop_subset_r0_to_r3(struct unwind_ctrl_block *ctrl,
 	return URC_OK;
 }
 
+static unsigned long unwind_decode_uleb128(struct unwind_ctrl_block *ctrl)
+{
+	unsigned long bytes = 0;
+	unsigned long insn;
+	unsigned long result = 0;
+
+	/*
+	 * unwind_get_byte() will advance `ctrl` one instruction at a time, so
+	 * loop until we get an instruction byte where bit 7 is not set.
+	 *
+	 * Note: This decodes a maximum of 4 bytes to output 28 bits data where
+	 * max is 0xfffffff: that will cover a vsp increment of 1073742336, hence
+	 * it is sufficient for unwinding the stack.
+	 */
+	do {
+		insn = unwind_get_byte(ctrl);
+		result |= (insn & 0x7f) << (bytes * 7);
+		bytes++;
+	} while (!!(insn & 0x80) && (bytes != sizeof(result)));
+
+	return result;
+}
+
 /*
  * Execute the current unwind instruction.
  */
@@ -361,7 +384,7 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl)
 		if (ret)
 			goto error;
 	} else if (insn == 0xb2) {
-		unsigned long uleb128 = unwind_get_byte(ctrl);
+		unsigned long uleb128 = unwind_decode_uleb128(ctrl);
 
 		ctrl->vrs[SP] += 0x204 + (uleb128 << 2);
 	} else {

arch/arm/mach-sa1100/jornada720_ssp.c

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
-/**
+/*
  *  arch/arm/mac-sa1100/jornada720_ssp.c
  *
  *  Copyright (C) 2006/2007 Kristoffer Ericson <Kristoffer.Ericson@gmail.com>
@@ -26,6 +26,7 @@ static unsigned long jornada_ssp_flags;
 
 /**
  * jornada_ssp_reverse - reverses input byte
+ * @byte: input byte to reverse
  *
  * we need to reverse all data we receive from the mcu due to its physical location
  * returns : 01110111 -> 11101110
@@ -46,6 +47,7 @@ EXPORT_SYMBOL(jornada_ssp_reverse);
 
 /**
  * jornada_ssp_byte - waits for ready ssp bus and sends byte
+ * @byte: input byte to transmit
  *
  * waits for fifo buffer to clear and then transmits, if it doesn't then we will
  * timeout after <timeout> rounds. Needs mcu running before its called.
@@ -77,6 +79,7 @@ EXPORT_SYMBOL(jornada_ssp_byte);
 
 /**
  * jornada_ssp_inout - decide if input is command or trading byte
+ * @byte: input byte to send (may be %TXDUMMY)
  *
  * returns : (jornada_ssp_byte(byte)) on success
  *         : %-ETIMEDOUT on timeout failure

arch/arm/vfp/entry.S

@@ -23,6 +23,9 @@
 @
 ENTRY(do_vfp)
 	mov	r1, r10
-	mov	r3, r9
+	str	lr, [sp, #-8]!
-	b	vfp_entry
+	add	r3, sp, #4
+	str	r9, [r3]
+	bl	vfp_entry
+	ldr	pc, [sp], #8
 ENDPROC(do_vfp)

arch/arm/vfp/vfphw.S

@@ -172,13 +172,14 @@ vfp_hw_state_valid:
 					@ out before setting an FPEXC that
 					@ stops us reading stuff
 	VFPFMXR	FPEXC, r1		@ Restore FPEXC last
+	mov	sp, r3			@ we think we have handled things
+	pop	{lr}
 	sub	r2, r2, #4		@ Retry current instruction - if Thumb
 	str	r2, [sp, #S_PC]		@ mode it's two 16-bit instructions,
 					@ else it's one 32-bit instruction, so
 					@ always subtract 4 from the following
 					@ instruction address.
 
-	mov	lr, r3			@ we think we have handled things
 local_bh_enable_and_ret:
 	adr	r0, .
 	mov	r1, #SOFTIRQ_DISABLE_OFFSET
@@ -209,8 +210,9 @@ skip:
 
 process_exception:
 	DBGSTR	"bounce"
+	mov	sp, r3			@ setup for a return to the user code.
+	pop	{lr}
 	mov	r2, sp			@ nothing stacked - regdump is at TOS
-	mov	lr, r3			@ setup for a return to the user code.
 
 	@ Now call the C code to package up the bounce to the support code
 	@   r0 holds the trigger instruction