Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 1f5a5ff..9219389 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -101,6 +101,7 @@
 		$(libfdt) $(libfdt_hdrs) hyp-stub.S
 
 KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
+KBUILD_CFLAGS += $(DISABLE_ARM_SSP_PER_TASK_PLUGIN)
 
 ifeq ($(CONFIG_FUNCTION_TRACER),y)
 ORIG_CFLAGS := $(KBUILD_CFLAGS)
@@ -131,8 +132,6 @@
 ifeq ($(CONFIG_CPU_ENDIAN_BE8),y)
 LDFLAGS_vmlinux += --be8
 endif
-# ?
-LDFLAGS_vmlinux += -p
 # Report unresolved symbol references
 LDFLAGS_vmlinux += --no-undefined
 # Delete all temporary local symbols
@@ -169,7 +168,7 @@
 bad_syms=$$($(CROSS_COMPILE)nm $@ | sed -n 's/^.\{8\} [bc] \(.*\)/\1/p') && \
 [ -z "$$bad_syms" ] || \
   ( echo "following symbols must have non local/private scope:" >&2; \
-    echo "$$bad_syms" >&2; rm -f $@; false )
+    echo "$$bad_syms" >&2; false )
 
 check_for_multiple_zreladdr = \
 if [ $(words $(ZRELADDR)) -gt 1 -a "$(CONFIG_AUTO_ZRELADDR)" = "" ]; then \
diff --git a/arch/arm/boot/compressed/atags_to_fdt.c b/arch/arm/boot/compressed/atags_to_fdt.c
index 41fa731..330cd3c 100644
--- a/arch/arm/boot/compressed/atags_to_fdt.c
+++ b/arch/arm/boot/compressed/atags_to_fdt.c
@@ -98,6 +98,24 @@
 	setprop_string(fdt, "/chosen", "bootargs", cmdline);
 }
 
+static void hex_str(char *out, uint32_t value)
+{
+	uint32_t digit;
+	int idx;
+
+	for (idx = 7; idx >= 0; idx--) {
+		digit = value >> 28;
+		value <<= 4;
+		digit &= 0xf;
+		if (digit < 10)
+			digit += '0';
+		else
+			digit += 'A'-10;
+		*out++ = digit;
+	}
+	*out = '\0';
+}
+
 /*
  * Convert and fold provided ATAGs into the provided FDT.
  *
@@ -180,6 +198,11 @@
 					initrd_start);
 			setprop_cell(fdt, "/chosen", "linux,initrd-end",
 					initrd_start + initrd_size);
+		} else if (atag->hdr.tag == ATAG_SERIAL) {
+			char serno[16+2];
+			hex_str(serno, atag->u.serialnr.high);
+			hex_str(serno+8, atag->u.serialnr.low);
+			setprop_string(fdt, "/", "serial-number", serno);
 		}
 	}
 
diff --git a/arch/arm/boot/compressed/decompress.c b/arch/arm/boot/compressed/decompress.c
index c16c182..aa075d8 100644
--- a/arch/arm/boot/compressed/decompress.c
+++ b/arch/arm/boot/compressed/decompress.c
@@ -32,6 +32,7 @@
 extern char * strstr(const char * s1, const char *s2);
 extern size_t strlen(const char *s);
 extern int memcmp(const void *cs, const void *ct, size_t count);
+extern char * strchrnul(const char *, int);
 
 #ifdef CONFIG_KERNEL_GZIP
 #include "../../../../lib/decompress_inflate.c"
diff --git a/arch/arm/boot/compressed/efi-header.S b/arch/arm/boot/compressed/efi-header.S
index c94a88a..a598358 100644
--- a/arch/arm/boot/compressed/efi-header.S
+++ b/arch/arm/boot/compressed/efi-header.S
@@ -1,11 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Copyright (C) 2013-2017 Linaro Ltd
  * Authors: Roy Franz <roy.franz@linaro.org>
  *          Ard Biesheuvel <ard.biesheuvel@linaro.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
 #include <linux/pe.h>
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 517e0e1..93dffed 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -1,12 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  *  linux/arch/arm/boot/compressed/head.S
  *
  *  Copyright (C) 1996-2002 Russell King
  *  Copyright (C) 2004 Hyok S. Choi (MPU support)
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
@@ -114,6 +111,35 @@
 #endif
 		.endm
 
+		/*
+		 * Debug kernel copy by printing the memory addresses involved
+		 */
+		.macro dbgkc, begin, end, cbegin, cend
+#ifdef DEBUG
+		kputc   #'\n'
+		kputc   #'C'
+		kputc   #':'
+		kputc   #'0'
+		kputc   #'x'
+		kphex   \begin, 8	/* Start of compressed kernel */
+		kputc	#'-'
+		kputc	#'0'
+		kputc	#'x'
+		kphex	\end, 8		/* End of compressed kernel */
+		kputc	#'-'
+		kputc	#'>'
+		kputc   #'0'
+		kputc   #'x'
+		kphex   \cbegin, 8	/* Start of kernel copy */
+		kputc	#'-'
+		kputc	#'0'
+		kputc	#'x'
+		kphex	\cend, 8	/* End of kernel copy */
+		kputc	#'\n'
+		kputc	#'\r'
+#endif
+		.endm
+
 		.section ".start", #alloc, #execinstr
 /*
  * sort out different calling conventions
@@ -127,11 +153,23 @@
  AR_CLASS(	.arm	)
 start:
 		.type	start,#function
+		/*
+		 * These 7 nops along with the 1 nop immediately below for
+		 * !THUMB2 form 8 nops that make the compressed kernel bootable
+		 * on legacy ARM systems that were assuming the kernel in a.out
+		 * binary format. The boot loaders on these systems would
+		 * jump 32 bytes into the image to skip the a.out header.
+		 * with these 8 nops filling exactly 32 bytes, things still
+		 * work as expected on these legacy systems. Thumb2 mode keeps
+		 * 7 of the nops as it turns out that some boot loaders
+		 * were patching the initial instructions of the kernel, i.e
+		 * had started to exploit this "patch area".
+		 */
 		.rept	7
 		__nop
 		.endr
 #ifndef CONFIG_THUMB2_KERNEL
-		mov	r0, r0
+		__nop
 #else
  AR_CLASS(	sub	pc, pc, #3	)	@ A/R: switch to Thumb2 mode
   M_CLASS(	nop.w			)	@ M: already in Thumb2 mode
@@ -450,6 +488,20 @@
 		add	r6, r9, r5
 		add	r9, r9, r10
 
+#ifdef DEBUG
+		sub     r10, r6, r5
+		sub     r10, r9, r10
+		/*
+		 * We are about to copy the kernel to a new memory area.
+		 * The boundaries of the new memory area can be found in
+		 * r10 and r9, whilst r5 and r6 contain the boundaries
+		 * of the memory we are going to copy.
+		 * Calling dbgkc will help with the printing of this
+		 * information.
+		 */
+		dbgkc	r5, r6, r10, r9
+#endif
+
 1:		ldmdb	r6!, {r0 - r3, r10 - r12, lr}
 		cmp	r6, r5
 		stmdb	r9!, {r0 - r3, r10 - r12, lr}
@@ -1395,7 +1447,21 @@
 
 		@ Preserve return value of efi_entry() in r4
 		mov	r4, r0
-		bl	cache_clean_flush
+
+		@ our cache maintenance code relies on CP15 barrier instructions
+		@ but since we arrived here with the MMU and caches configured
+		@ by UEFI, we must check that the CP15BEN bit is set in SCTLR.
+		@ Note that this bit is RAO/WI on v6 and earlier, so the ISB in
+		@ the enable path will be executed on v7+ only.
+		mrc	p15, 0, r1, c1, c0, 0	@ read SCTLR
+		tst	r1, #(1 << 5)		@ CP15BEN bit set?
+		bne	0f
+		orr	r1, r1, #(1 << 5)	@ CP15 barrier instructions
+		mcr	p15, 0, r1, c1, c0, 0	@ write SCTLR
+ ARM(		.inst	0xf57ff06f		@ v7+ isb	)
+ THUMB(		isb						)
+
+0:		bl	cache_clean_flush
 		bl	cache_off
 
 		@ Set parameters for booting zImage according to boot protocol
diff --git a/arch/arm/boot/compressed/libfdt_env.h b/arch/arm/boot/compressed/libfdt_env.h
index 0743781..b36c028 100644
--- a/arch/arm/boot/compressed/libfdt_env.h
+++ b/arch/arm/boot/compressed/libfdt_env.h
@@ -6,6 +6,8 @@
 #include <linux/string.h>
 #include <asm/byteorder.h>
 
+#define INT_MAX			((int)(~0U>>1))
+
 typedef __be16 fdt16_t;
 typedef __be32 fdt32_t;
 typedef __be64 fdt64_t;
diff --git a/arch/arm/boot/compressed/ll_char_wr.S b/arch/arm/boot/compressed/ll_char_wr.S
index 8517c86..1ec8cb2 100644
--- a/arch/arm/boot/compressed/ll_char_wr.S
+++ b/arch/arm/boot/compressed/ll_char_wr.S
@@ -1,12 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  *  linux/arch/arm/lib/ll_char_wr.S
  *
  *  Copyright (C) 1995, 1996 Russell King.
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
  *  Speedups & 1bpp code (C) 1996 Philip Blundell & Russell King.
  *
  *  10-04-96	RMK	Various cleanups & reduced register usage.
@@ -75,7 +72,7 @@
 	tst	r1, #7				@ avoid using r7 directly after
 	str	r7, [r0, -r5]!
 	subne	r1, r1, #1
-	ldrneb	r7, [r6, r1]
+	ldrbne	r7, [r6, r1]
 	bne	Lrow4bpplp
 	ldmfd	sp!, {r4 - r7, pc}
 
@@ -103,7 +100,7 @@
 	sub	r0, r0, r5			@ avoid ip
 	stmia	r0, {r4, ip}
 	subne	r1, r1, #1
-	ldrneb	r7, [r6, r1]
+	ldrbne	r7, [r6, r1]
 	bne	Lrow8bpplp
 	ldmfd	sp!, {r4 - r7, pc}
 
diff --git a/arch/arm/boot/compressed/vmlinux.lds.S b/arch/arm/boot/compressed/vmlinux.lds.S
index 2b963d8..fc7ed03 100644
--- a/arch/arm/boot/compressed/vmlinux.lds.S
+++ b/arch/arm/boot/compressed/vmlinux.lds.S
@@ -1,9 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  *  Copyright (C) 2000 Russell King
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
 #ifdef CONFIG_CPU_ENDIAN_BE8