4.4-stable patches

added patches:
	x86-build-build-compressed-x86-kernels-as-pie.patch

diff --git a/queue-4.4/series b/queue-4.4/series
new file mode 100644 (file)
index 0000000..a131add
--- /dev/null
+++ b/queue-4.4/series
@@ -0,0 +1 @@
+x86-build-build-compressed-x86-kernels-as-pie.patch

diff --git a/queue-4.4/x86-build-build-compressed-x86-kernels-as-pie.patch b/queue-4.4/x86-build-build-compressed-x86-kernels-as-pie.patch
new file mode 100644 (file)
index 0000000..424f555
--- /dev/null
+++ b/queue-4.4/x86-build-build-compressed-x86-kernels-as-pie.patch
@@ -0,0 +1,157 @@
+From 6d92bc9d483aa1751755a66fee8fb39dffb088c0 Mon Sep 17 00:00:00 2001
+From: "H.J. Lu" <hjl.tools@gmail.com>
+Date: Wed, 16 Mar 2016 20:04:35 -0700
+Subject: x86/build: Build compressed x86 kernels as PIE
+
+From: H.J. Lu <hjl.tools@gmail.com>
+
+commit 6d92bc9d483aa1751755a66fee8fb39dffb088c0 upstream.
+
+The 32-bit x86 assembler in binutils 2.26 will generate R_386_GOT32X
+relocation to get the symbol address in PIC.  When the compressed x86
+kernel isn't built as PIC, the linker optimizes R_386_GOT32X relocations
+to their fixed symbol addresses.  However, when the compressed x86
+kernel is loaded at a different address, it leads to the following
+load failure:
+
+  Failed to allocate space for phdrs
+
+during the decompression stage.
+
+If the compressed x86 kernel is relocatable at run-time, it should be
+compiled with -fPIE, instead of -fPIC, if possible and should be built as
+Position Independent Executable (PIE) so that linker won't optimize
+R_386_GOT32X relocation to its fixed symbol address.
+
+Older linkers generate R_386_32 relocations against locally defined
+symbols, _bss, _ebss, _got and _egot, in PIE.  It isn't wrong, just less
+optimal than R_386_RELATIVE.  But the x86 kernel fails to properly handle
+R_386_32 relocations when relocating the kernel.  To generate
+R_386_RELATIVE relocations, we mark _bss, _ebss, _got and _egot as
+hidden in both 32-bit and 64-bit x86 kernels.
+
+To build a 64-bit compressed x86 kernel as PIE, we need to disable the
+relocation overflow check to avoid relocation overflow errors. We do
+this with a new linker command-line option, -z noreloc-overflow, which
+got added recently:
+
+ commit 4c10bbaa0912742322f10d9d5bb630ba4e15dfa7
+ Author: H.J. Lu <hjl.tools@gmail.com>
+ Date:   Tue Mar 15 11:07:06 2016 -0700
+
+    Add -z noreloc-overflow option to x86-64 ld
+
+    Add -z noreloc-overflow command-line option to the x86-64 ELF linker to
+    disable relocation overflow check.  This can be used to avoid relocation
+    overflow check if there will be no dynamic relocation overflow at
+    run-time.
+
+The 64-bit compressed x86 kernel is built as PIE only if the linker supports
+-z noreloc-overflow.  So far 64-bit relocatable compressed x86 kernel
+boots fine even when it is built as a normal executable.
+
+Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
+Cc: Andy Lutomirski <luto@amacapital.net>
+Cc: Borislav Petkov <bp@alien8.de>
+Cc: Brian Gerst <brgerst@gmail.com>
+Cc: Denys Vlasenko <dvlasenk@redhat.com>
+Cc: H. Peter Anvin <hpa@zytor.com>
+Cc: Linus Torvalds <torvalds@linux-foundation.org>
+Cc: Peter Zijlstra <peterz@infradead.org>
+Cc: Thomas Gleixner <tglx@linutronix.de>
+Cc: linux-kernel@vger.kernel.org
+[ Edited the changelog and comments. ]
+Signed-off-by: Ingo Molnar <mingo@kernel.org>
+Cc: Paul Bolle <pebolle@tiscali.nl>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/x86/boot/compressed/Makefile  |   14 +++++++++++++-
+ arch/x86/boot/compressed/head_32.S |   28 ++++++++++++++++++++++++++++
+ arch/x86/boot/compressed/head_64.S |    8 ++++++++
+ 3 files changed, 49 insertions(+), 1 deletion(-)
+
+--- a/arch/x86/boot/compressed/Makefile
++++ b/arch/x86/boot/compressed/Makefile
+@@ -22,7 +22,7 @@ targets := vmlinux vmlinux.bin vmlinux.b
+       vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4
+ 
+ KBUILD_CFLAGS := -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2
+-KBUILD_CFLAGS += -fno-strict-aliasing -fPIC
++KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC)
+ KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
+ cflags-$(CONFIG_X86_32) := -march=i386
+ cflags-$(CONFIG_X86_64) := -mcmodel=small
+@@ -35,6 +35,18 @@ KBUILD_AFLAGS  := $(KBUILD_CFLAGS) -D__A
+ GCOV_PROFILE := n
+ 
+ LDFLAGS := -m elf_$(UTS_MACHINE)
++ifeq ($(CONFIG_RELOCATABLE),y)
++# If kernel is relocatable, build compressed kernel as PIE.
++ifeq ($(CONFIG_X86_32),y)
++LDFLAGS += $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker)
++else
++# To build 64-bit compressed kernel as PIE, we disable relocation
++# overflow check to avoid relocation overflow error with a new linker
++# command-line option, -z noreloc-overflow.
++LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \
++      && echo "-z noreloc-overflow -pie --no-dynamic-linker")
++endif
++endif
+ LDFLAGS_vmlinux := -T
+ 
+ hostprogs-y   := mkpiggy
+--- a/arch/x86/boot/compressed/head_32.S
++++ b/arch/x86/boot/compressed/head_32.S
+@@ -31,6 +31,34 @@
+ #include <asm/asm-offsets.h>
+ #include <asm/bootparam.h>
+ 
++/*
++ * The 32-bit x86 assembler in binutils 2.26 will generate R_386_GOT32X
++ * relocation to get the symbol address in PIC.  When the compressed x86
++ * kernel isn't built as PIC, the linker optimizes R_386_GOT32X
++ * relocations to their fixed symbol addresses.  However, when the
++ * compressed x86 kernel is loaded at a different address, it leads
++ * to the following load failure:
++ *
++ *   Failed to allocate space for phdrs
++ *
++ * during the decompression stage.
++ *
++ * If the compressed x86 kernel is relocatable at run-time, it should be
++ * compiled with -fPIE, instead of -fPIC, if possible and should be built as
++ * Position Independent Executable (PIE) so that linker won't optimize
++ * R_386_GOT32X relocation to its fixed symbol address.  Older
++ * linkers generate R_386_32 relocations against locally defined symbols,
++ * _bss, _ebss, _got and _egot, in PIE.  It isn't wrong, just less
++ * optimal than R_386_RELATIVE.  But the x86 kernel fails to properly handle
++ * R_386_32 relocations when relocating the kernel.  To generate
++ * R_386_RELATIVE relocations, we mark _bss, _ebss, _got and _egot as
++ * hidden:
++ */
++      .hidden _bss
++      .hidden _ebss
++      .hidden _got
++      .hidden _egot
++
+       __HEAD
+ ENTRY(startup_32)
+ #ifdef CONFIG_EFI_STUB
+--- a/arch/x86/boot/compressed/head_64.S
++++ b/arch/x86/boot/compressed/head_64.S
+@@ -33,6 +33,14 @@
+ #include <asm/asm-offsets.h>
+ #include <asm/bootparam.h>
+ 
++/*
++ * Locally defined symbols should be marked hidden:
++ */
++      .hidden _bss
++      .hidden _ebss
++      .hidden _got
++      .hidden _egot
++
+       __HEAD
+       .code32
+ ENTRY(startup_32)