Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

17 files changed, 704 insertions, 0 deletions

diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
new file mode 100644
index 000000000..e0b8ec9a9
--- /dev/null
+++ b/arch/mips/boot/compressed/Makefile
@@ -0,0 +1,213 @@
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.
+#
+# Adapted for MIPS Pete Popov, Dan Malek
+#
+# Copyright (C) 1994 by Linus Torvalds
+# Adapted for PowerPC by Gary Thomas
+# modified by Cort (cort@cs.nmt.edu)
+#
+# Copyright (C) 2009 Lemote Inc. & DSLab, Lanzhou University
+# Author: Wu Zhangjin <wuzhangjin@gmail.com>
+#
+
+include $(srctree)/arch/mips/Kbuild.platforms
+
+# set the default size of the mallocing area for decompressing
+BOOT_HEAP_SIZE := 0x400000
+
+# Disable Function Tracer
+KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_FTRACE), $(KBUILD_CFLAGS))
+
+KBUILD_CFLAGS := $(filter-out -fstack-protector, $(KBUILD_CFLAGS))
+
+# Disable lq/sq in zboot
+ifdef CONFIG_CPU_LOONGSON64
+KBUILD_CFLAGS := $(filter-out -march=loongson3a, $(KBUILD_CFLAGS)) -march=mips64r2
+endif
+
+KBUILD_CFLAGS := $(KBUILD_CFLAGS) -D__KERNEL__ -D__DISABLE_EXPORTS \
+	-DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE) -D"VMLINUX_LOAD_ADDRESS_ULL=$(VMLINUX_LOAD_ADDRESS)ull"
+
+KBUILD_AFLAGS := $(KBUILD_AFLAGS) -D__ASSEMBLY__ \
+	-DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE) \
+	-DKERNEL_ENTRY=$(VMLINUX_ENTRY_ADDRESS)
+
+# decompressor objects (linked with vmlinuz)
+vmlinuzobjs-y := $(obj)/head.o $(obj)/decompress.o $(obj)/string.o $(obj)/bswapsi.o
+
+ifdef CONFIG_DEBUG_ZBOOT
+vmlinuzobjs-$(CONFIG_DEBUG_ZBOOT)		   += $(obj)/dbg.o
+vmlinuzobjs-$(CONFIG_SYS_SUPPORTS_ZBOOT_UART16550) += $(obj)/uart-16550.o
+vmlinuzobjs-$(CONFIG_SYS_SUPPORTS_ZBOOT_UART_PROM) += $(obj)/uart-prom.o
+vmlinuzobjs-$(CONFIG_MIPS_ALCHEMY)		   += $(obj)/uart-alchemy.o
+vmlinuzobjs-$(CONFIG_ATH79)			   += $(obj)/uart-ath79.o
+endif
+
+vmlinuzobjs-$(CONFIG_KERNEL_XZ) += $(obj)/ashldi3.o
+
+vmlinuzobjs-$(CONFIG_KERNEL_ZSTD) += $(obj)/bswapdi.o $(obj)/ashldi3.o $(obj)/clz_ctz.o
+
+targets := $(notdir $(vmlinuzobjs-y))
+
+targets += vmlinux.bin
+
+OBJCOPYFLAGS_vmlinux.bin := $(OBJCOPYFLAGS) -O binary -R .comment -S
+
+$(obj)/vmlinux.bin: $(KBUILD_IMAGE) FORCE
+	$(call if_changed,objcopy)
+
+tool_$(CONFIG_KERNEL_GZIP)    = gzip
+tool_$(CONFIG_KERNEL_BZIP2)   = bzip2_with_size
+tool_$(CONFIG_KERNEL_LZ4)     = lz4_with_size
+tool_$(CONFIG_KERNEL_LZMA)    = lzma_with_size
+tool_$(CONFIG_KERNEL_LZO)     = lzo_with_size
+tool_$(CONFIG_KERNEL_XZ)      = xzkern_with_size
+tool_$(CONFIG_KERNEL_ZSTD)    = zstd22_with_size
+
+targets += vmlinux.bin.z
+
+$(obj)/vmlinux.bin.z: $(obj)/vmlinux.bin FORCE
+	$(call if_changed,$(tool_y))
+
+targets += piggy.o dummy.o
+
+OBJCOPYFLAGS_piggy.o := --add-section=.image=$(obj)/vmlinux.bin.z \
+			--set-section-flags=.image=contents,alloc,load,readonly,data
+
+$(obj)/piggy.o: $(obj)/dummy.o $(obj)/vmlinux.bin.z FORCE
+	$(call if_changed,objcopy)
+
+HOSTCFLAGS_calc_vmlinuz_load_addr.o += $(LINUXINCLUDE)
+
+# Calculate the load address of the compressed kernel image
+hostprogs := calc_vmlinuz_load_addr
+
+ifneq (0x0,$(CONFIG_ZBOOT_LOAD_ADDRESS))
+zload-y	= $(CONFIG_ZBOOT_LOAD_ADDRESS)
+endif
+
+ifneq ($(zload-y),)
+VMLINUZ_LOAD_ADDRESS := $(zload-y)
+else
+VMLINUZ_LOAD_ADDRESS = $(shell $(obj)/calc_vmlinuz_load_addr \
+		$(obj)/vmlinux.bin $(LINKER_LOAD_ADDRESS))
+endif
+UIMAGE_LOADADDR = $(VMLINUZ_LOAD_ADDRESS)
+
+vmlinuzobjs-y += $(obj)/piggy.o
+
+targets += ../../../../vmlinuz
+
+quiet_cmd_zld = LD      $@
+      cmd_zld = $(LD) $(KBUILD_LDFLAGS) -Ttext $(VMLINUZ_LOAD_ADDRESS) -T $< $(vmlinuzobjs-y) -o $@
+quiet_cmd_strip = STRIP   $@
+      cmd_strip = $(STRIP) -s $@
+
+$(objtree)/vmlinuz: $(src)/ld.script $(vmlinuzobjs-y) $(obj)/calc_vmlinuz_load_addr
+	$(call cmd,zld)
+	$(call cmd,strip)
+
+objboot := $(objtree)/arch/mips/boot
+
+$(objboot)/vmlinuz: $(objtree)/vmlinuz FORCE
+
+#
+# Some DECstations need all possible sections of an ECOFF executable
+#
+ifdef CONFIG_MACH_DECSTATION
+  e2eflag := -a
+endif
+
+# elf2ecoff can only handle 32bit image
+hostprogs += ../elf2ecoff
+
+ifdef CONFIG_32BIT
+	VMLINUZ = $(objtree)/vmlinuz
+else
+	VMLINUZ = $(objboot)/vmlinuz.32
+endif
+
+targets += ../vmlinuz.32
+
+quiet_cmd_32 = OBJCOPY $@
+      cmd_32 = $(OBJCOPY) -O $(32bit-bfd) $(OBJCOPYFLAGS) $< $@
+
+$(objboot)/vmlinuz.32: $(objtree)/vmlinuz
+	$(call cmd,32)
+
+targets += ../vmlinuz.ecoff
+
+quiet_cmd_ecoff = ECOFF	  $@
+      cmd_ecoff = $< $(VMLINUZ) $@ $(e2eflag)
+
+$(objboot)/vmlinuz.ecoff: $(objboot)/elf2ecoff $(VMLINUZ)
+	$(call cmd,ecoff)
+
+targets += ../vmlinuz.bin
+
+OBJCOPYFLAGS_vmlinuz.bin := $(OBJCOPYFLAGS) -O binary
+
+$(objboot)/vmlinuz.bin: $(objtree)/vmlinuz
+	$(call cmd,objcopy)
+
+targets += ../vmlinuz.srec
+
+OBJCOPYFLAGS_vmlinuz.srec := $(OBJCOPYFLAGS) -S -O srec
+
+$(objboot)/vmlinuz.srec: $(objtree)/vmlinuz
+	$(call cmd,objcopy)
+
+targets += ../uzImage.bin
+
+$(objboot)/uzImage.bin: $(objboot)/vmlinuz.bin FORCE
+	$(call if_changed,uimage,none)
+
+#
+# Flattened Image Tree (.itb) image
+#
+
+ifeq ($(ADDR_BITS),32)
+itb_addr_cells = 1
+endif
+ifeq ($(ADDR_BITS),64)
+itb_addr_cells = 2
+endif
+
+targets += ../vmlinuz.its.S
+
+quiet_cmd_its_cat = CAT     $@
+      cmd_its_cat = cat $(real-prereqs) >$@
+
+$(objboot)/vmlinuz.its.S: $(addprefix $(srctree)/arch/mips/$(PLATFORM)/,$(ITS_INPUTS)) FORCE
+	$(call if_changed,its_cat)
+
+targets += ../vmlinuz.its
+
+quiet_cmd_cpp_its_S = ITS     $@
+      cmd_cpp_its_S = $(CPP) -P -C -o $@ $< \
+		        -DKERNEL_NAME="\"Linux $(KERNELRELEASE)\"" \
+			-DVMLINUX_BINARY="\"$(2)\"" \
+			-DVMLINUX_COMPRESSION="\"none\"" \
+			-DVMLINUX_LOAD_ADDRESS=$(VMLINUZ_LOAD_ADDRESS) \
+			-DVMLINUX_ENTRY_ADDRESS=$(VMLINUZ_LOAD_ADDRESS) \
+			-DADDR_BITS=$(ADDR_BITS) \
+			-DADDR_CELLS=$(itb_addr_cells)
+
+$(objboot)/vmlinuz.its: $(objboot)/vmlinuz.its.S FORCE
+	$(call if_changed,cpp_its_S,vmlinuz.bin)
+
+targets += ../vmlinuz.itb
+
+quiet_cmd_itb-image = ITB     $@
+      cmd_itb-image = \
+		env PATH="$(objtree)/scripts/dtc:$(PATH)" \
+		$(BASH) $(MKIMAGE) \
+		-D "-I dts -O dtb -p 500 \
+			--include $(objtree)/arch/mips \
+			--warning no-unit_address_vs_reg" \
+		-f $(2) $@
+
+$(objboot)/vmlinuz.itb: $(objboot)/vmlinuz.its $(objboot)/vmlinuz.bin FORCE
+	$(call if_changed,itb-image,$<)
diff --git a/arch/mips/boot/compressed/ashldi3.c b/arch/mips/boot/compressed/ashldi3.c
new file mode 100644
index 000000000..f7bf6a7aa
--- /dev/null
+++ b/arch/mips/boot/compressed/ashldi3.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "../../../../lib/ashldi3.c"
diff --git a/arch/mips/boot/compressed/bswapdi.c b/arch/mips/boot/compressed/bswapdi.c
new file mode 100644
index 000000000..acb28aebb
--- /dev/null
+++ b/arch/mips/boot/compressed/bswapdi.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "../../lib/bswapdi.c"
diff --git a/arch/mips/boot/compressed/bswapsi.c b/arch/mips/boot/compressed/bswapsi.c
new file mode 100644
index 000000000..fdb9c6476
--- /dev/null
+++ b/arch/mips/boot/compressed/bswapsi.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "../../lib/bswapsi.c"
diff --git a/arch/mips/boot/compressed/calc_vmlinuz_load_addr.c b/arch/mips/boot/compressed/calc_vmlinuz_load_addr.c
new file mode 100644
index 000000000..080b926d2
--- /dev/null
+++ b/arch/mips/boot/compressed/calc_vmlinuz_load_addr.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2010 "Wu Zhangjin" <wuzhangjin@gmail.com>
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <linux/sizes.h>
+
+int main(int argc, char *argv[])
+{
+	unsigned long long vmlinux_size, vmlinux_load_addr, vmlinuz_load_addr;
+	struct stat sb;
+
+	if (argc != 3) {
+		fprintf(stderr, "Usage: %s <pathname> <vmlinux_load_addr>\n",
+				argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	if (stat(argv[1], &sb) == -1) {
+		perror("stat");
+		return EXIT_FAILURE;
+	}
+
+	/* Convert hex characters to dec number */
+	errno = 0;
+	if (sscanf(argv[2], "%llx", &vmlinux_load_addr) != 1) {
+		if (errno != 0)
+			perror("sscanf");
+		else
+			fprintf(stderr, "No matching characters\n");
+
+		return EXIT_FAILURE;
+	}
+
+	vmlinux_size = (uint64_t)sb.st_size;
+	vmlinuz_load_addr = vmlinux_load_addr + vmlinux_size;
+
+	/*
+	 * Align with 64KB: KEXEC needs load sections to be aligned to PAGE_SIZE,
+	 * which may be as large as 64KB depending on the kernel configuration.
+	 */
+
+	vmlinuz_load_addr += (SZ_64K - vmlinux_size % SZ_64K);
+
+	printf("0x%llx\n", vmlinuz_load_addr);
+
+	return EXIT_SUCCESS;
+}
diff --git a/arch/mips/boot/compressed/clz_ctz.c b/arch/mips/boot/compressed/clz_ctz.c
new file mode 100644
index 000000000..b4a1b6eb2
--- /dev/null
+++ b/arch/mips/boot/compressed/clz_ctz.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "../../../../lib/clz_ctz.c"
diff --git a/arch/mips/boot/compressed/dbg.c b/arch/mips/boot/compressed/dbg.c
new file mode 100644
index 000000000..95405292a
--- /dev/null
+++ b/arch/mips/boot/compressed/dbg.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MIPS-specific debug support for pre-boot environment
+ *
+ * NOTE: putc() is board specific, if your board have a 16550 compatible uart,
+ * please select SYS_SUPPORTS_ZBOOT_UART16550 for your machine. otherwise, you
+ * need to implement your own putc().
+ */
+#include <linux/compiler.h>
+#include <linux/types.h>
+
+#include "decompress.h"
+
+void __weak putc(char c)
+{
+}
+
+void puts(const char *s)
+{
+	char c;
+	while ((c = *s++) != '\0') {
+		putc(c);
+		if (c == '\n')
+			putc('\r');
+	}
+}
+
+void puthex(unsigned long long val)
+{
+
+	unsigned char buf[10];
+	int i;
+	for (i = 7; i >= 0; i--) {
+		buf[i] = "0123456789ABCDEF"[val & 0x0F];
+		val >>= 4;
+	}
+	buf[8] = '\0';
+	puts(buf);
+}
diff --git a/arch/mips/boot/compressed/decompress.c b/arch/mips/boot/compressed/decompress.c
new file mode 100644
index 000000000..90021c6a8
--- /dev/null
+++ b/arch/mips/boot/compressed/decompress.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2001 MontaVista Software Inc.
+ * Author: Matt Porter <mporter@mvista.com>
+ *
+ * Copyright (C) 2009 Lemote, Inc.
+ * Author: Wu Zhangjin <wuzhangjin@gmail.com>
+ */
+
+#define DISABLE_BRANCH_PROFILING
+
+#define __NO_FORTIFY
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/libfdt.h>
+
+#include <asm/addrspace.h>
+#include <linux/unaligned.h>
+#include <asm-generic/vmlinux.lds.h>
+
+#include "decompress.h"
+
+/*
+ * These two variables specify the free mem region
+ * that can be used for temporary malloc area
+ */
+unsigned long free_mem_ptr;
+unsigned long free_mem_end_ptr;
+
+void error(char *x)
+{
+	puts("\n\n");
+	puts(x);
+	puts("\n\n -- System halted");
+
+	while (1)
+		;	/* Halt */
+}
+
+/* activate the code for pre-boot environment */
+#define STATIC static
+
+#ifdef CONFIG_KERNEL_GZIP
+#include "../../../../lib/decompress_inflate.c"
+#endif
+
+#ifdef CONFIG_KERNEL_BZIP2
+#include "../../../../lib/decompress_bunzip2.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZ4
+#include "../../../../lib/decompress_unlz4.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZMA
+#include "../../../../lib/decompress_unlzma.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZO
+#include "../../../../lib/decompress_unlzo.c"
+#endif
+
+#ifdef CONFIG_KERNEL_XZ
+#include "../../../../lib/decompress_unxz.c"
+#endif
+
+#ifdef CONFIG_KERNEL_ZSTD
+#include "../../../../lib/decompress_unzstd.c"
+#endif
+
+const unsigned long __stack_chk_guard = 0x000a0dff;
+
+void __stack_chk_fail(void)
+{
+	error("stack-protector: Kernel stack is corrupted\n");
+}
+
+void decompress_kernel(unsigned long boot_heap_start)
+{
+	unsigned long zimage_start, zimage_size;
+
+	zimage_start = (unsigned long)(__image_begin);
+	zimage_size = (unsigned long)(__image_end) -
+	    (unsigned long)(__image_begin);
+
+	puts("zimage at:     ");
+	puthex(zimage_start);
+	puts(" ");
+	puthex(zimage_size + zimage_start);
+	puts("\n");
+
+	/* This area are prepared for mallocing when decompressing */
+	free_mem_ptr = boot_heap_start;
+	free_mem_end_ptr = boot_heap_start + BOOT_HEAP_SIZE;
+
+	/* Display standard Linux/MIPS boot prompt */
+	puts("Uncompressing Linux at load address ");
+	puthex(VMLINUX_LOAD_ADDRESS_ULL);
+	puts("\n");
+
+	/* Decompress the kernel with according algorithm */
+	__decompress((char *)zimage_start, zimage_size, 0, 0,
+		   (void *)VMLINUX_LOAD_ADDRESS_ULL, 0, 0, error);
+
+	if (IS_ENABLED(CONFIG_MIPS_RAW_APPENDED_DTB) &&
+	    fdt_magic((void *)&__appended_dtb) == FDT_MAGIC) {
+		unsigned int image_size, dtb_size;
+
+		dtb_size = fdt_totalsize((void *)&__appended_dtb);
+
+		/* last four bytes is always image size in little endian */
+		image_size = get_unaligned_le32((void *)__image_end - 4);
+
+		/* The device tree's address must be properly aligned  */
+		image_size = ALIGN(image_size, STRUCT_ALIGNMENT);
+
+		puts("Copy device tree to address  ");
+		puthex(VMLINUX_LOAD_ADDRESS_ULL + image_size);
+		puts("\n");
+
+		/* copy dtb to where the booted kernel will expect it */
+		memcpy((void *)VMLINUX_LOAD_ADDRESS_ULL + image_size,
+		       __appended_dtb, dtb_size);
+	}
+
+	/* FIXME: should we flush cache here? */
+	puts("Now, booting the kernel...\n");
+}
diff --git a/arch/mips/boot/compressed/decompress.h b/arch/mips/boot/compressed/decompress.h
new file mode 100644
index 000000000..073b64593
--- /dev/null
+++ b/arch/mips/boot/compressed/decompress.h
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef _DECOMPRESSOR_H
+#define _DECOMPRESSOR_H
+
+/* The linker tells us where the image is. */
+extern unsigned char __image_begin[], __image_end[];
+
+/* debug interfaces  */
+#ifdef CONFIG_DEBUG_ZBOOT
+extern void putc(char c);
+extern void puts(const char *s);
+extern void puthex(unsigned long long val);
+#else
+#define putc(s) do {} while (0)
+#define puts(s) do {} while (0)
+#define puthex(val) do {} while (0)
+#endif
+
+extern char __appended_dtb[];
+
+void error(char *x);
+void decompress_kernel(unsigned long boot_heap_start);
+
+#endif
diff --git a/arch/mips/boot/compressed/dummy.c b/arch/mips/boot/compressed/dummy.c
new file mode 100644
index 000000000..31dbf45bf
--- /dev/null
+++ b/arch/mips/boot/compressed/dummy.c
@@ -0,0 +1,4 @@
+int main(void)
+{
+	return 0;
+}
diff --git a/arch/mips/boot/compressed/head.S b/arch/mips/boot/compressed/head.S
new file mode 100644
index 000000000..d237a834b
--- /dev/null
+++ b/arch/mips/boot/compressed/head.S
@@ -0,0 +1,52 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1994, 1995 Waldorf Electronics
+ * Written by Ralf Baechle and Andreas Busse
+ * Copyright (C) 1995 - 1999 Ralf Baechle
+ * Copyright (C) 1996 Paul M. Antoine
+ * Modified for DECStation and hence R3000 support by Paul M. Antoine
+ * Further modifications by David S. Miller and Harald Koerfgen
+ * Copyright (C) 1999 Silicon Graphics, Inc.
+ */
+
+#include <asm/asm.h>
+#include <asm/regdef.h>
+
+	LEAF(start)
+	/* Save boot rom start args */
+	move	s0, a0
+	move	s1, a1
+	move	s2, a2
+	move	s3, a3
+
+	/* Clear BSS */
+	PTR_LA	a0, _edata
+	PTR_LA	a2, _end
+1:	PTR_S	zero, 0(a0)
+	PTR_ADDIU a0, a0, PTRSIZE
+	bne	a2, a0, 1b
+
+	PTR_LA	a0, (.heap)	     /* heap address */
+	PTR_LA	sp, (.stack + 8192)  /* stack address */
+
+	PTR_LA	t9, decompress_kernel
+	jalr	t9
+
+2:
+	move	a0, s0
+	move	a1, s1
+	move	a2, s2
+	move	a3, s3
+	PTR_LI	t9, KERNEL_ENTRY
+	jalr	t9
+
+3:
+	b	3b
+
+	END(start)
+
+	.comm .heap,BOOT_HEAP_SIZE,4
+	.comm .stack,4096*2,4
diff --git a/arch/mips/boot/compressed/ld.script b/arch/mips/boot/compressed/ld.script
new file mode 100644
index 000000000..0ebb66727
--- /dev/null
+++ b/arch/mips/boot/compressed/ld.script
@@ -0,0 +1,60 @@
+/*
+ * ld.script for compressed kernel support of MIPS
+ *
+ * Copyright (C) 2009 Lemote Inc.
+ * Author: Wu Zhangjin <wuzhanjing@gmail.com>
+ * Copyright (C) 2010 "Wu Zhangjin" <wuzhanjing@gmail.com>
+ */
+
+OUTPUT_ARCH(mips)
+ENTRY(start)
+PHDRS {
+	text PT_LOAD FLAGS(7); /* RWX */
+}
+SECTIONS
+{
+	/* Text and read-only data */
+	/* . = VMLINUZ_LOAD_ADDRESS; */
+	.text : {
+		*(.text)
+		*(.rodata)
+	}: text
+	/* End of text section */
+
+	/* Writable data */
+	.data : {
+		*(.data)
+		/* Put the compressed image here */
+		__image_begin = .;
+		*(.image)
+		__image_end = .;
+		CONSTRUCTORS
+		. = ALIGN(16);
+	}
+
+	.appended_dtb : {
+		__appended_dtb = .;
+		/* leave space for appended DTB */
+		. += 0x100000;
+	}
+
+	_edata = .;
+	/* End of data section */
+
+	/* BSS */
+	.bss : {
+		*(.bss)
+	}
+	. = ALIGN(16);
+	_end = .;
+
+	/* Sections to be discarded */
+	/DISCARD/ : {
+		*(.MIPS.options)
+		*(.options)
+		*(.pdr)
+		*(.reginfo)
+		*(.comment)
+		*(.note)
+	}
+}
diff --git a/arch/mips/boot/compressed/string.c b/arch/mips/boot/compressed/string.c
new file mode 100644
index 000000000..f0eb251e4
--- /dev/null
+++ b/arch/mips/boot/compressed/string.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/mips/boot/compressed/string.c
+ *
+ * Very small subset of simple string routines
+ */
+
+#include <linux/compiler_attributes.h>
+#include <linux/types.h>
+#include <asm/string.h>
+
+void *memcpy(void *dest, const void *src, size_t n)
+{
+	int i;
+	const char *s = src;
+	char *d = dest;
+
+	for (i = 0; i < n; i++)
+		d[i] = s[i];
+	return dest;
+}
+
+void *memset(void *s, int c, size_t n)
+{
+	int i;
+	char *ss = s;
+
+	for (i = 0; i < n; i++)
+		ss[i] = c;
+	return s;
+}
+
+void * __weak memmove(void *dest, const void *src, size_t n)
+{
+	unsigned int i;
+	const char *s = src;
+	char *d = dest;
+
+	if ((uintptr_t)dest < (uintptr_t)src) {
+		for (i = 0; i < n; i++)
+			d[i] = s[i];
+	} else {
+		for (i = n; i > 0; i--)
+			d[i - 1] = s[i - 1];
+	}
+	return dest;
+}
diff --git a/arch/mips/boot/compressed/uart-16550.c b/arch/mips/boot/compressed/uart-16550.c
new file mode 100644
index 000000000..529e77a64
--- /dev/null
+++ b/arch/mips/boot/compressed/uart-16550.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 16550 compatible uart based serial debug support for zboot
+ */
+
+#include <linux/types.h>
+#include <linux/serial_reg.h>
+
+#include <asm/addrspace.h>
+
+#include "decompress.h"
+
+#if defined(CONFIG_MACH_LOONGSON64) || defined(CONFIG_MIPS_MALTA)
+#define UART_BASE 0x1fd003f8
+#define PORT(offset) (CKSEG1ADDR(UART_BASE) + (offset))
+#endif
+
+#ifdef CONFIG_MACH_INGENIC
+#define INGENIC_UART_BASE_ADDR	(0x10030000 + 0x1000 * CONFIG_ZBOOT_INGENIC_UART)
+#define PORT(offset) (CKSEG1ADDR(INGENIC_UART_BASE_ADDR) + (4 * offset))
+#endif
+
+#ifdef CONFIG_ECONET
+#define EN75_UART_BASE	0x1fbf0003
+#define PORT(offset)	(CKSEG1ADDR(EN75_UART_BASE) + (4 * (offset)))
+#endif
+
+#ifndef IOTYPE
+#define IOTYPE char
+#endif
+
+#ifndef PORT
+#error please define the serial port address for your own machine
+#endif
+
+static inline unsigned int serial_in(int offset)
+{
+	return *((volatile IOTYPE *)PORT(offset)) & 0xFF;
+}
+
+static inline void serial_out(int offset, int value)
+{
+	*((volatile IOTYPE *)PORT(offset)) = value & 0xFF;
+}
+
+void putc(char c)
+{
+	int timeout = 1000000;
+
+	while (((serial_in(UART_LSR) & UART_LSR_THRE) == 0) && (timeout-- > 0))
+		;
+
+	serial_out(UART_TX, c);
+}
diff --git a/arch/mips/boot/compressed/uart-alchemy.c b/arch/mips/boot/compressed/uart-alchemy.c
new file mode 100644
index 000000000..003967c08
--- /dev/null
+++ b/arch/mips/boot/compressed/uart-alchemy.c
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <asm/mach-au1x00/au1000.h>
+
+#include "decompress.h"
+
+void putc(char c)
+{
+	alchemy_uart_putchar(AU1000_UART0_PHYS_ADDR, c);
+}
diff --git a/arch/mips/boot/compressed/uart-ath79.c b/arch/mips/boot/compressed/uart-ath79.c
new file mode 100644
index 000000000..d68682092
--- /dev/null
+++ b/arch/mips/boot/compressed/uart-ath79.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "../../ath79/early_printk.c"
diff --git a/arch/mips/boot/compressed/uart-prom.c b/arch/mips/boot/compressed/uart-prom.c
new file mode 100644
index 000000000..5fa3b9945
--- /dev/null
+++ b/arch/mips/boot/compressed/uart-prom.c
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <asm/setup.h>
+
+#include "decompress.h"
+
+void putc(char c)
+{
+	prom_putchar(c);
+}