From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- tools/testing/selftests/cpu-hotplug/Makefile | 11 + .../selftests/cpu-hotplug/cpu-on-off-test.sh | 225 +++++++++++++++++++++ 2 files changed, 236 insertions(+) create mode 100644 tools/testing/selftests/cpu-hotplug/Makefile create mode 100755 tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh (limited to 'tools/testing/selftests/cpu-hotplug') diff --git a/tools/testing/selftests/cpu-hotplug/Makefile b/tools/testing/selftests/cpu-hotplug/Makefile new file mode 100644 index 000000000..8b66c4738 --- /dev/null +++ b/tools/testing/selftests/cpu-hotplug/Makefile @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0 +all: + +TEST_PROGS := cpu-on-off-test.sh + +include ../lib.mk + +run_full_test: + @/bin/bash ./cpu-on-off-test.sh -a && echo "cpu-hotplug selftests: [PASS]" || echo "cpu-hotplug selftests: [FAIL]" + +clean: diff --git a/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh b/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh new file mode 100755 index 000000000..287cfd580 --- /dev/null +++ b/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh @@ -0,0 +1,225 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 + +SYSFS= +# Kselftest framework requirement - SKIP code is 4. +ksft_skip=4 +retval=0 + +prerequisite() +{ + msg="skip all tests:" + + if [ $UID != 0 ]; then + echo $msg must be run as root >&2 + exit $ksft_skip + fi + + taskset -p 01 $$ + + SYSFS=`mount -t sysfs | head -1 | awk '{ print $3 }'` + + if [ ! -d "$SYSFS" ]; then + echo $msg sysfs is not mounted >&2 + exit $ksft_skip + fi + + if ! ls $SYSFS/devices/system/cpu/cpu*/online > /dev/null 2>&1; then + echo $msg cpu hotplug is not supported >&2 + exit $ksft_skip + fi + + echo "CPU online/offline summary:" + online_cpus=`cat $SYSFS/devices/system/cpu/online` + online_max=${online_cpus##*-} + + if [[ "$online_cpus" = "$online_max" ]]; then + echo "$msg: since there is only one cpu: $online_cpus" + exit $ksft_skip + fi + + present_cpus=`cat $SYSFS/devices/system/cpu/present` + present_max=${present_cpus##*-} + echo "present_cpus = $present_cpus present_max = $present_max" + + echo -e "\t Cpus in online state: $online_cpus" + + offline_cpus=`cat $SYSFS/devices/system/cpu/offline` + if [[ "a$offline_cpus" = "a" ]]; then + offline_cpus=0 + else + offline_max=${offline_cpus##*-} + fi + echo -e "\t Cpus in offline state: $offline_cpus" +} + +# +# list all hot-pluggable CPUs +# +hotpluggable_cpus() +{ + local state=${1:-.\*} + + for cpu in $SYSFS/devices/system/cpu/cpu*; do + if [ -f $cpu/online ] && grep -q $state $cpu/online; then + echo ${cpu##/*/cpu} + fi + done +} + +hotpluggable_offline_cpus() +{ + hotpluggable_cpus 0 +} + +hotpluggable_online_cpus() +{ + hotpluggable_cpus 1 +} + +cpu_is_online() +{ + grep -q 1 $SYSFS/devices/system/cpu/cpu$1/online +} + +cpu_is_offline() +{ + grep -q 0 $SYSFS/devices/system/cpu/cpu$1/online +} + +online_cpu() +{ + echo 1 > $SYSFS/devices/system/cpu/cpu$1/online +} + +offline_cpu() +{ + echo 0 > $SYSFS/devices/system/cpu/cpu$1/online +} + +online_cpu_expect_success() +{ + local cpu=$1 + + if ! online_cpu $cpu; then + echo $FUNCNAME $cpu: unexpected fail >&2 + retval=1 + elif ! cpu_is_online $cpu; then + echo $FUNCNAME $cpu: unexpected offline >&2 + retval=1 + fi +} + +online_cpu_expect_fail() +{ + local cpu=$1 + + if online_cpu $cpu 2> /dev/null; then + echo $FUNCNAME $cpu: unexpected success >&2 + retval=1 + elif ! cpu_is_offline $cpu; then + echo $FUNCNAME $cpu: unexpected online >&2 + retval=1 + fi +} + +offline_cpu_expect_success() +{ + local cpu=$1 + + if ! offline_cpu $cpu; then + echo $FUNCNAME $cpu: unexpected fail >&2 + retval=1 + elif ! cpu_is_offline $cpu; then + echo $FUNCNAME $cpu: unexpected offline >&2 + retval=1 + fi +} + +offline_cpu_expect_fail() +{ + local cpu=$1 + + if offline_cpu $cpu 2> /dev/null; then + echo $FUNCNAME $cpu: unexpected success >&2 + retval=1 + elif ! cpu_is_online $cpu; then + echo $FUNCNAME $cpu: unexpected offline >&2 + retval=1 + fi +} + +online_all_hot_pluggable_cpus() +{ + for cpu in `hotpluggable_offline_cpus`; do + online_cpu_expect_success $cpu + done +} + +offline_all_hot_pluggable_cpus() +{ + local reserve_cpu=$online_max + for cpu in `hotpluggable_online_cpus`; do + # Reserve one cpu oneline at least. + if [ $cpu -eq $reserve_cpu ];then + continue + fi + offline_cpu_expect_success $cpu + done +} + +allcpus=0 +online_cpus=0 +online_max=0 +offline_cpus=0 +offline_max=0 +present_cpus=0 +present_max=0 + +while getopts ah opt; do + case $opt in + a) + allcpus=1 + ;; + h) + echo "Usage $0 [ -a ]" + echo -e "\t default offline one cpu" + echo -e "\t run with -a option to offline all cpus" + exit + ;; + esac +done + +prerequisite + +# +# Safe test (default) - offline and online one cpu +# +if [ $allcpus -eq 0 ]; then + echo "Limited scope test: one hotplug cpu" + echo -e "\t (leaves cpu in the original state):" + echo -e "\t online to offline to online: cpu $online_max" + offline_cpu_expect_success $online_max + online_cpu_expect_success $online_max + + if [[ $offline_cpus -gt 0 ]]; then + echo -e "\t online to offline to online: cpu $present_max" + online_cpu_expect_success $present_max + offline_cpu_expect_success $present_max + online_cpu $present_max + fi + exit $retval +else + echo "Full scope test: all hotplug cpus" + echo -e "\t online all offline cpus" + echo -e "\t offline all online cpus" + echo -e "\t online all offline cpus" +fi + +online_all_hot_pluggable_cpus + +offline_all_hot_pluggable_cpus + +online_all_hot_pluggable_cpus + +exit $retval -- cgit v1.3.1