From c83b99f415afae51fdb46ca6699615985fa7ae76 Mon Sep 17 00:00:00 2001 From: Zheng Zucheng Date: Mon, 30 Sep 2024 09:21:29 +0000 Subject: [PATCH 1/3] sched: Revert fix unbalance sched_smt_present dec/inc hulk inclusion category: other bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAOXYI CVE: CVE-2024-44958 -------------------------------- The solution has been fixed in the community. So revert "[Huawei] sched/smt: fix unbalance sched_smt_present dec/inc" This reverts commit 0a948df174ce31f30a70c3a2adc668e23262b063. Conflicts: kernel/sched/core.c [Some contexts around sched_cpu_deactivate different. No functional impact.] Signed-off-by: Zheng Zucheng --- kernel/sched/core.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e37428598155..23065b5d515c 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5899,10 +5899,6 @@ int sched_cpu_deactivate(unsigned int cpu) ret = cpuset_cpu_inactive(cpu); if (ret) { -#ifdef CONFIG_SCHED_SMT - if (cpumask_weight(cpu_smt_mask(cpu)) == 2) - static_branch_inc_cpuslocked(&sched_smt_present); -#endif set_cpu_active(cpu, true); return ret; } -- Gitee From 9be7a8ee0ab338fd30d8afa0662bc2678cccc81f Mon Sep 17 00:00:00 2001 From: Yang Yingliang Date: Mon, 30 Sep 2024 09:21:30 +0000 Subject: [PATCH 2/3] sched/smt: Introduce sched_smt_present_inc/dec() helper mainline inclusion from mainline-v6.11-rc1 commit 31b164e2e4af84d08d2498083676e7eeaa102493 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAOXYI CVE: CVE-2024-44958 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=31b164e2e4af84d08d2498083676e7eeaa102493 -------------------------------- Introduce sched_smt_present_inc/dec() helper, so it can be called in normal or error path simply. No functional changed. Cc: stable@kernel.org Signed-off-by: Yang Yingliang Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20240703031610.587047-2-yangyingliang@huaweicloud.com Conflicts: kernel/sched/core.c [Some contexts around sched_cpu_deactivate different. No functional impact.] Signed-off-by: Zheng Zucheng --- kernel/sched/core.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 23065b5d515c..f62fd30cfd8f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5831,18 +5831,31 @@ static int cpuset_cpu_inactive(unsigned int cpu) return 0; } +static inline void sched_smt_present_inc(int cpu) +{ +#ifdef CONFIG_SCHED_SMT + if (cpumask_weight(cpu_smt_mask(cpu)) == 2) + static_branch_inc_cpuslocked(&sched_smt_present); +#endif +} + +static inline void sched_smt_present_dec(int cpu) +{ +#ifdef CONFIG_SCHED_SMT + if (cpumask_weight(cpu_smt_mask(cpu)) == 2) + static_branch_dec_cpuslocked(&sched_smt_present); +#endif +} + int sched_cpu_activate(unsigned int cpu) { struct rq *rq = cpu_rq(cpu); struct rq_flags rf; -#ifdef CONFIG_SCHED_SMT /* * When going up, increment the number of cores with SMT present. */ - if (cpumask_weight(cpu_smt_mask(cpu)) == 2) - static_branch_inc_cpuslocked(&sched_smt_present); -#endif + sched_smt_present_inc(cpu); set_cpu_active(cpu, true); tg_update_affinity_domains(cpu, 1); @@ -5886,13 +5899,10 @@ int sched_cpu_deactivate(unsigned int cpu) */ synchronize_rcu_mult(call_rcu, call_rcu_sched); -#ifdef CONFIG_SCHED_SMT /* * When going down, decrement the number of cores with SMT present. */ - if (cpumask_weight(cpu_smt_mask(cpu)) == 2) - static_branch_dec_cpuslocked(&sched_smt_present); -#endif + sched_smt_present_dec(cpu); if (!sched_smp_initialized) return 0; -- Gitee From 7d01838c8ac7de99f9a36cfe17034c14189289c2 Mon Sep 17 00:00:00 2001 From: Yang Yingliang Date: Mon, 30 Sep 2024 09:21:31 +0000 Subject: [PATCH 3/3] sched/smt: Fix unbalance sched_smt_present dec/inc mainline inclusion from mainline-v6.11-rc1 commit e22f910a26cc2a3ac9c66b8e935ef2a7dd881117 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAOXYI CVE: CVE-2024-44958 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e22f910a26cc2a3ac9c66b8e935ef2a7dd881117 -------------------------------- I got the following warn report while doing stress test: jump label: negative count! WARNING: CPU: 3 PID: 38 at kernel/jump_label.c:263 static_key_slow_try_dec+0x9d/0xb0 Call Trace: __static_key_slow_dec_cpuslocked+0x16/0x70 sched_cpu_deactivate+0x26e/0x2a0 cpuhp_invoke_callback+0x3ad/0x10d0 cpuhp_thread_fun+0x3f5/0x680 smpboot_thread_fn+0x56d/0x8d0 kthread+0x309/0x400 ret_from_fork+0x41/0x70 ret_from_fork_asm+0x1b/0x30 Because when cpuset_cpu_inactive() fails in sched_cpu_deactivate(), the cpu offline failed, but sched_smt_present is decremented before calling sched_cpu_deactivate(), it leads to unbalanced dec/inc, so fix it by incrementing sched_smt_present in the error path. Fixes: c5511d03ec09 ("sched/smt: Make sched_smt_present track topology") Cc: stable@kernel.org Signed-off-by: Yang Yingliang Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Chen Yu Reviewed-by: Tim Chen Link: https://lore.kernel.org/r/20240703031610.587047-3-yangyingliang@huaweicloud.com Conflicts: kernel/sched/core.c [Some contexts around sched_cpu_deactivate different. No functional impact.] Signed-off-by: Zheng Zucheng --- kernel/sched/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f62fd30cfd8f..ee191af83fd0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5909,6 +5909,7 @@ int sched_cpu_deactivate(unsigned int cpu) ret = cpuset_cpu_inactive(cpu); if (ret) { + sched_smt_present_inc(cpu); set_cpu_active(cpu, true); return ret; } -- Gitee