Revision eb35bdd7bca29a13c8ecd44e6fd747a84ce675db authored by Will Deacon on 11 September 2014, 13:38:16 UTC, committed by Will Deacon on 11 September 2014, 17:34:58 UTC
Nathan reports that we leak TLS information from the parent context during an exec, as we don't clear the TLS registers when flushing the thread state. This patch updates the flushing code so that we: (1) Unconditionally zero the tpidr_el0 register (since this is fully context switched for native tasks and zeroed for compat tasks) (2) Zero the tp_value state in thread_info before clearing the tpidrr0_el0 register for compat tasks (since this is only writable by the set_tls compat syscall and therefore not fully switched). A missing compiler barrier is also added to the compat set_tls syscall. Cc: <stable@vger.kernel.org> Acked-by: Nathan Lynch <Nathan_Lynch@mentor.com> Reported-by: Nathan Lynch <Nathan_Lynch@mentor.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
1 parent 3d8afe3
mkcompile_h
#!/bin/sh
TARGET=$1
ARCH=$2
SMP=$3
PREEMPT=$4
CC=$5
vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; }
# If compile.h exists already and we don't own autoconf.h
# (i.e. we're not the same user who did make *config), don't
# modify compile.h
# So "sudo make install" won't change the "compiled by <user>"
# do "compiled by root"
if [ -r $TARGET -a ! -O include/generated/autoconf.h ]; then
vecho " SKIPPED $TARGET"
exit 0
fi
# Do not expand names
set -f
# Fix the language to get consistent output
LC_ALL=C
export LC_ALL
if [ -z "$KBUILD_BUILD_VERSION" ]; then
if [ -r .version ]; then
VERSION=`cat .version`
else
VERSION=0
echo 0 > .version
fi
else
VERSION=$KBUILD_BUILD_VERSION
fi
if [ -z "$KBUILD_BUILD_TIMESTAMP" ]; then
TIMESTAMP=`date`
else
TIMESTAMP=$KBUILD_BUILD_TIMESTAMP
fi
if test -z "$KBUILD_BUILD_USER"; then
LINUX_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
else
LINUX_COMPILE_BY=$KBUILD_BUILD_USER
fi
if test -z "$KBUILD_BUILD_HOST"; then
LINUX_COMPILE_HOST=`hostname`
else
LINUX_COMPILE_HOST=$KBUILD_BUILD_HOST
fi
UTS_VERSION="#$VERSION"
CONFIG_FLAGS=""
if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi
if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi
UTS_VERSION="$UTS_VERSION $CONFIG_FLAGS $TIMESTAMP"
# Truncate to maximum length
UTS_LEN=64
UTS_TRUNCATE="cut -b -$UTS_LEN"
# Generate a temporary compile.h
( echo /\* This file is auto generated, version $VERSION \*/
if [ -n "$CONFIG_FLAGS" ] ; then echo "/* $CONFIG_FLAGS */"; fi
echo \#define UTS_MACHINE \"$ARCH\"
echo \#define UTS_VERSION \"`echo $UTS_VERSION | $UTS_TRUNCATE`\"
echo \#define LINUX_COMPILE_BY \"`echo $LINUX_COMPILE_BY | $UTS_TRUNCATE`\"
echo \#define LINUX_COMPILE_HOST \"`echo $LINUX_COMPILE_HOST | $UTS_TRUNCATE`\"
echo \#define LINUX_COMPILER \"`$CC -v 2>&1 | grep ' version '`\"
) > .tmpcompile
# Only replace the real compile.h if the new one is different,
# in order to preserve the timestamp and avoid unnecessary
# recompilations.
# We don't consider the file changed if only the date/time changed.
# A kernel config change will increase the generation number, thus
# causing compile.h to be updated (including date/time) due to the
# changed comment in the
# first line.
if [ -r $TARGET ] && \
grep -v 'UTS_VERSION' $TARGET > .tmpver.1 && \
grep -v 'UTS_VERSION' .tmpcompile > .tmpver.2 && \
cmp -s .tmpver.1 .tmpver.2; then
rm -f .tmpcompile
else
vecho " UPD $TARGET"
mv -f .tmpcompile $TARGET
fi
rm -f .tmpver.1 .tmpver.2
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