# # Common functions used by pktgen scripts # - Depending on bash 3 (or higher) syntax # # Author: Jesper Dangaaard Brouer # License: GPL ## -- General shell logging cmds -- function err() { local exitcode=$1 shift echo "ERROR: $@" >&2 exit $exitcode } function warn() { echo "WARN : $@" >&2 } function info() { if [[ -n "$VERBOSE" ]]; then echo "INFO : $@" >&2 fi } ## -- Pktgen proc config commands -- ## export PROC_DIR=/proc/net/pktgen # # Three different shell functions for configuring the different # components of pktgen: # pg_ctrl(), pg_thread() and pg_set(). # # These functions correspond to pktgens different components. # * pg_ctrl() control "pgctrl" (/proc/net/pktgen/pgctrl) # * pg_thread() control the kernel threads and binding to devices # * pg_set() control setup of individual devices function pg_ctrl() { local proc_file="pgctrl" proc_cmd ${proc_file} "$@" } function pg_thread() { local thread=$1 local proc_file="kpktgend_${thread}" shift proc_cmd ${proc_file} "$@" } function pg_set() { local dev=$1 local proc_file="$dev" shift proc_cmd ${proc_file} "$@" } # More generic replacement for pgset(), that does not depend on global # variable for proc file. function proc_cmd() { local result local proc_file=$1 # after shift, the remaining args are contained in $@ shift local proc_ctrl=${PROC_DIR}/$proc_file if [[ ! -e "$proc_ctrl" ]]; then err 3 "proc file:$proc_ctrl does not exists (dev added to thread?)" else if [[ ! -w "$proc_ctrl" ]]; then err 4 "proc file:$proc_ctrl not writable, not root?!" fi fi if [[ "$DEBUG" == "yes" ]]; then echo "cmd: $@ > $proc_ctrl" fi # Quoting of "$@" is important for space expansion echo "$@" > "$proc_ctrl" local status=$? result=$(grep "Result: OK:" $proc_ctrl) # Due to pgctrl, cannot use exit code $? from grep if [[ "$result" == "" ]]; then grep "Result:" $proc_ctrl >&2 fi if (( $status != 0 )); then err 5 "Write error($status) occurred cmd: \"$@ > $proc_ctrl\"" fi } # Old obsolete "pgset" function, with slightly improved err handling function pgset() { local result if [[ "$DEBUG" == "yes" ]]; then echo "cmd: $1 > $PGDEV" fi echo $1 > $PGDEV local status=$? result=`cat $PGDEV | fgrep "Result: OK:"` if [[ "$result" == "" ]]; then cat $PGDEV | fgrep Result: fi if (( $status != 0 )); then err 5 "Write error($status) occurred cmd: \"$1 > $PGDEV\"" fi } ## -- General shell tricks -- function root_check_run_with_sudo() { # Trick so, program can be run as normal user, will just use "sudo" # call as root_check_run_as_sudo "$@" if [ "$EUID" -ne 0 ]; then if [ -x $0 ]; then # Directly executable use sudo info "Not root, running with sudo" sudo "$0" "$@" exit $? fi err 4 "cannot perform sudo run of $0" fi } mmit/tools?id=966d2b04e070bc040319aaebfec09e0144dc3341'>tools/build/feature/test-libbabeltrace.c
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authorDouglas Miller <dougmill@linux.vnet.ibm.com>2017-01-28 06:42:20 -0600
committerTejun Heo <tj@kernel.org>2017-01-28 07:49:42 -0500
commit966d2b04e070bc040319aaebfec09e0144dc3341 (patch)
tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /tools/build/feature/test-libbabeltrace.c
parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'tools/build/feature/test-libbabeltrace.c')