[PATCH 0/4] resend build sanity checking additions

@@ -270,17 +270,6 @@ PHONY += $(BOOT_TARGETS1) $(BOOT_TARGETS2)
 
 boot := arch/$(ARCH)/boot
 
-ifeq ($(CONFIG_RELOCATABLE),y)
-quiet_cmd_relocs_check = CALL    $<
-      cmd_relocs_check = $(CONFIG_SHELL) $< "$(OBJDUMP)" "$(obj)/vmlinux"
-
-PHONY += relocs_check
-relocs_check: arch/powerpc/relocs_check.sh vmlinux
-	$(call cmd,relocs_check)
-
-zImage: relocs_check
-endif
-
 $(BOOT_TARGETS1): vmlinux
 	$(Q)$(MAKE) ARCH=ppc64 $(build)=$(boot) $(patsubst %,$(boot)/%,$@)
 $(BOOT_TARGETS2): vmlinux

@@ -0,0 +1,34 @@
+# ===========================================================================
+# Post-link powerpc pass
+# ===========================================================================
+#
+# 1. Check that vmlinux relocations look sane
+
+PHONY := __archpost
+__archpost:
+
+include include/config/auto.conf
+include scripts/Kbuild.include
+
+quiet_cmd_relocs_check = CHKREL  $@
+      cmd_relocs_check = $(CONFIG_SHELL) $(srctree)/arch/powerpc/relocs_check.sh "$(OBJDUMP)" "$@"
+
+# `@true` prevents complaint when there is nothing to be done
+
+vmlinux: FORCE
+	@true
+ifdef CONFIG_RELOCATABLE
+	$(call if_changed,relocs_check)
+endif
+
+%.ko: FORCE
+	@true
+
+clean:
+	@true
+
+PHONY += FORCE clean
+
+FORCE:
+
+.PHONY: $(PHONY)

@@ -133,7 +133,7 @@ CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=powerpc64
 endif
 
 ifdef CONFIG_MPROFILE_KERNEL
-    ifeq ($(shell $(srctree)/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh $(CC) -I$(srctree)/include -D__KERNEL__),OK)
+    ifeq ($(shell $(srctree)/arch/powerpc/tools/gcc-check-mprofile-kernel.sh $(CC) -I$(srctree)/include -D__KERNEL__),OK)
         CC_FLAGS_FTRACE := -pg -mprofile-kernel
         KBUILD_CPPFLAGS += -DCC_USING_MPROFILE_KERNEL
     else

@@ -11,7 +11,7 @@ include include/config/auto.conf
 include scripts/Kbuild.include
 
 quiet_cmd_relocs_check = CHKREL  $@
-      cmd_relocs_check = $(CONFIG_SHELL) $(srctree)/arch/powerpc/relocs_check.sh "$(OBJDUMP)" "$@"
+      cmd_relocs_check = $(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/relocs_check.sh "$(OBJDUMP)" "$@"
 
 # `@true` prevents complaint when there is nothing to be done
 

@@ -11,7 +11,14 @@ include include/config/auto.conf
 include scripts/Kbuild.include
 
 quiet_cmd_relocs_check = CHKREL  $@
-      cmd_relocs_check = $(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/relocs_check.sh "$(OBJDUMP)" "$@"
+ifdef CONFIG_PPC_BOOK3S_64
+      cmd_relocs_check =						\
+	$(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/relocs_check.sh "$(OBJDUMP)" "$@" ; \
+	$(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/unrel_branch_check.sh "$(OBJDUMP)" "$@"
+else
+      cmd_relocs_check =						\
+	$(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/relocs_check.sh "$(OBJDUMP)" "$@"
+endif
 
 # `@true` prevents complaint when there is nothing to be done
 

@@ -0,0 +1,57 @@
+# Copyright © 2016 IBM Corporation
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version
+# 2 of the License, or (at your option) any later version.
+#
+# This script checks the relocations of a vmlinux for "suspicious"
+# branches from unrelocated code (head_64.S code).
+
+# Turn this on if you want more debug output:
+# set -x
+
+# Have Kbuild supply the path to objdump so we handle cross compilation.
+objdump="$1"
+vmlinux="$2"
+
+#__end_interrupts should be located within the first 64K
+
+end_intr=0x$(
+"$objdump" -R "$vmlinux" -d --start-address=0xc000000000000000		\
+		 --stop-address=0xc000000000010000 |
+grep '\<__end_interrupts>:' |
+awk '{print $1}'
+)
+
+BRANCHES=$(
+"$objdump" -R "$vmlinux" -D --start-address=0xc000000000000000		\
+		--stop-address=${end_intr} |
+grep -e "^c[0-9a-f]*:[[:space:]]*\([0-9a-f][0-9a-f][[:space:]]\)\{4\}[[:space:]]*b" |
+grep -v '\<__start_initialization_multiplatform>' |
+grep -v -e 'b.\?.\?ctr' |
+grep -v -e 'b.\?.\?lr' |
+sed 's/://' |
+awk '{ print $1 ":" $6 ":0x" $7 ":" $8 " "}'
+)
+
+for tuple in $BRANCHES
+do
+	from=`echo $tuple | cut -d':' -f1`
+	branch=`echo $tuple | cut -d':' -f2`
+	to=`echo $tuple | cut -d':' -f3 | sed 's/cr[0-7],//'`
+	sym=`echo $tuple | cut -d':' -f4`
+
+	if (( $to > $end_intr ))
+	then
+		if [ -z "$bad_branches" ]; then
+			echo "WARNING: Unrelocated relative branches"
+			bad_branches="yes"
+		fi
+		echo "$from $branch-> $to $sym"
+	fi
+done
+
+if [ -z "$bad_branches" ]; then
+	exit 0
+fi

@@ -10,6 +10,9 @@ __archpost:
 include include/config/auto.conf
 include scripts/Kbuild.include
 
+quiet_cmd_head_check = CHKHEAD $@
+      cmd_head_check = $(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/head_check.sh "$(NM)" "$@"
+
 quiet_cmd_relocs_check = CHKREL  $@
 ifdef CONFIG_PPC_BOOK3S_64
       cmd_relocs_check =						\

@@ -24,6 +27,9 @@ endif
 
 vmlinux: FORCE
 	@true
+ifdef CONFIG_PPC64
+	$(call cmd,head_check)
+endif
 ifdef CONFIG_RELOCATABLE
 	$(call if_changed,relocs_check)
 endif

@@ -32,7 +38,7 @@ endif
 	@true
 
 clean:
-	@true
+	rm -f .tmp_symbols.txt
 
 PHONY += FORCE clean
 

@@ -49,8 +49,8 @@
  *   CLOSE_FIXED_SECTION() or elsewhere, there may be something
  *   unexpected being added there. Remove the '. = x_len' line, rebuild, and
  *   check what is pushing the section down.
- * - If the build dies in linking, check arch/powerpc/kernel/vmlinux.lds.S
- *   for instructions.
+ * - If the build dies in linking, check arch/powerpc/tools/head_check.sh
+ *   comments.
  * - If the kernel crashes or hangs in very early boot, it could be linker
  *   stubs at the start of the main text.
  */

@@ -58,7 +58,6 @@ SECTIONS
 #ifdef CONFIG_PPC64
 		KEEP(*(.head.text.first_256B));
 #ifdef CONFIG_PPC_BOOK3E
-# define END_FIXED	0x100
 #else
 		KEEP(*(.head.text.real_vectors));
 		*(.head.text.real_trampolines);

@@ -66,34 +65,13 @@ SECTIONS
 		*(.head.text.virt_trampolines);
 # if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
 		KEEP(*(.head.data.fwnmi_page));
-#  define END_FIXED	0x8000
-# else
-#  define END_FIXED	0x7000
 # endif
 #endif
-		ASSERT((. == END_FIXED), "vmlinux.lds.S: fixed section overflow error");
 #else /* !CONFIG_PPC64 */
 		HEAD_TEXT
 #endif
 	} :kernel
 
-	/*
-	 * If the build dies here, it's likely code in head_64.S is referencing
-	 * labels it can't reach, and the linker inserting stubs without the
-	 * assembler's knowledge. To debug, remove the above assert and
-	 * rebuild. Look for branch stubs in the fixed section region.
-	 *
-	 * Linker stub generation could be allowed in "trampoline"
-	 * sections if absolutely necessary, but this would require
-	 * some rework of the fixed sections. Before resorting to this,
-	 * consider references that have sufficient addressing range,
-	 * (e.g., hand coded trampolines) so the linker does not have
-	 * to add stubs.
-	 *
-	 * Linker stubs at the top of the main text section are currently not
-	 * detected, and will result in a crash at boot due to offsets being
-	 * wrong.
-	 */
 #ifdef CONFIG_PPC64
 	/*
 	 * BLOCK(0) overrides the default output section alignment because

@@ -0,0 +1,70 @@
+# Copyright © 2016 IBM Corporation
+
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version
+# 2 of the License, or (at your option) any later version.
+
+# This script checks the head of a vmlinux for linker stubs that
+# break our placement of fixed-location code for 64-bit.
+
+# based on relocs_check.pl
+# Copyright © 2009 IBM Corporation
+
+# READ THIS
+#
+# If the build dies here, it's likely code in head_64.S or nearby is
+# referencing labels it can't reach, which results in the linker inserting
+# stubs without the assembler's knowledge. This can move code around in ways
+# that break the fixed location placement stuff (head-64.h). To debug,
+# disassemble the vmlinux and look for branch stubs (long_branch, plt_branch
+# etc) in the fixed section region (0 - 0x8000ish). Check what places are
+# calling those stubs.
+#
+# Linker stubs use the TOC pointer, so even if fixed section code could
+# tolerate them being inserted into head code, they can't be allowed in low
+# level entry code (boot, interrupt vectors, etc) until r2 is set up. This
+# could cause the kernel to die in early boot.
+
+# Turn this on if you want more debug output:
+# set -x
+
+if [ $# -lt 2 ]; then
+	echo "$0 [path to nm] [path to vmlinux]" 1>&2
+	exit 1
+fi
+
+# Have Kbuild supply the path to nm so we handle cross compilation.
+nm="$1"
+vmlinux="$2"
+
+$nm "$vmlinux" | grep -e " T _stext$" -e " t start_first_256B$" -e " a text_start$" -e " t start_text$" -m4 > .tmp_symbols.txt
+
+
+vma=$(cat .tmp_symbols.txt | grep " T _stext$" | cut -d' ' -f1)
+
+expected_start_head_addr=$vma
+
+start_head_addr=$(cat .tmp_symbols.txt | grep " t start_first_256B$" | cut -d' ' -f1)
+
+if [ "$start_head_addr" != "$expected_start_head_addr" ]; then
+	echo "ERROR: head code starts at $start_head_addr, should be 0"
+	echo "ERROR: see comments in arch/powerpc/tools/head_check.sh"
+
+	exit 1
+fi
+
+top_vma=$(echo $vma | cut -d'0' -f1)
+
+expected_start_text_addr=$(cat .tmp_symbols.txt | grep " a text_start$" | cut -d' ' -f1 | sed "s/^0/$top_vma/")
+
+start_text_addr=$(cat .tmp_symbols.txt | grep " t start_text$" | cut -d' ' -f1)
+
+if [ "$start_text_addr" != "$expected_start_text_addr" ]; then
+	echo "ERROR: start_text address is $start_text_addr, should be $expected_start_text_addr"
+	echo "ERROR: see comments in arch/powerpc/tools/head_check.sh"
+
+	exit 1
+fi
+
+rm .tmp_symbols.txt