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: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Nicholas Piggin 2017-05-12 03:40:38 +10:00 committed by Michael Ellerman
parent efe0160cfd
commit 4ea80652dc
2 changed files with 65 additions and 1 deletions

View File

@ -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

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@ -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