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Commit 4ea80652 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
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powerpc/64s: Tool to flag direct branches from unrelocated interrupt vectors 



Direct banches from code below __end_interrupts to code above
__end_interrupts when built with CONFIG_RELOCATABLE are disallowed
because they will break when the kernel is not located at 0.

Sample output:

    WARNING: Unrelocated relative branches
    c000000000000118 bl-> 0xc000000000038fb8 <pnv_restore_hyp_resource>
    c00000000000013c b-> 0xc0000000001068a4 <kvm_start_guest>
    c000000000000148 b-> 0xc00000000003919c <pnv_wakeup_loss>
    c00000000000014c b-> 0xc00000000003923c <pnv_wakeup_noloss>
    c0000000000005a4 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
    c000000000001af0 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
    c000000000001b24 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
    c000000000001b58 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>

Signed-off-by: default avatarBalbir Singh <bsingharora@gmail.com>
Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent efe0160c

arch/powerpc/Makefile.postlink

+8 −1
Original line number Diff line number Diff line
@@ -11,7 +11,14 @@ __archpost: 
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

arch/powerpc/tools/unrel_branch_check.sh

0 → 100755
+57 −0
Original line number Diff line number Diff line 
# 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