From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: [patch 02/10] cpu/hotplug: Prevent overwriting of callbacks
Date: Wed, 21 Dec 2016 20:19:49 +0100 [thread overview]
Message-ID: <20161221192111.675234535@linutronix.de> (raw)
In-Reply-To: 20161221191947.089046759@linutronix.de
[-- Attachment #1: cpu-hotplug--Prevent-overwriting-of-callbacks.patch --]
[-- Type: text/plain, Size: 2331 bytes --]
Developers manage to overwrite states blindly without thought. That's fatal
and hard to debug. Add sanity checks to make it fail.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/cpu.c | 33 +++++++++++++++++++++------------
1 file changed, 21 insertions(+), 12 deletions(-)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1432,23 +1432,29 @@ static int cpuhp_cb_check(enum cpuhp_sta
return 0;
}
-static void cpuhp_store_callbacks(enum cpuhp_state state,
- const char *name,
- int (*startup)(unsigned int cpu),
- int (*teardown)(unsigned int cpu),
- bool multi_instance)
+static int cpuhp_store_callbacks(enum cpuhp_state state, const char *name,
+ int (*startup)(unsigned int cpu),
+ int (*teardown)(unsigned int cpu),
+ bool multi_instance)
{
/* (Un)Install the callbacks for further cpu hotplug operations */
struct cpuhp_step *sp;
+ int ret = 0;
mutex_lock(&cpuhp_state_mutex);
sp = cpuhp_get_step(state);
+ if (name && sp->name) {
+ ret = -EBUSY;
+ goto out;
+ }
sp->startup.single = startup;
sp->teardown.single = teardown;
sp->name = name;
sp->multi_instance = multi_instance;
INIT_HLIST_HEAD(&sp->list);
+out:
mutex_unlock(&cpuhp_state_mutex);
+ return ret;
}
static void *cpuhp_get_teardown_cb(enum cpuhp_state state)
@@ -1580,11 +1586,13 @@ EXPORT_SYMBOL_GPL(__cpuhp_state_add_inst
/**
* __cpuhp_setup_state - Setup the callbacks for an hotplug machine state
- * @state: The state to setup
- * @invoke: If true, the startup function is invoked for cpus where
- * cpu state >= @state
- * @startup: startup callback function
- * @teardown: teardown callback function
+ * @state: The state to setup
+ * @invoke: If true, the startup function is invoked for cpus where
+ * cpu state >= @state
+ * @startup: startup callback function
+ * @teardown: teardown callback function
+ * @multi_instance: State is set up for multiple instances which get
+ * added afterwards.
*
* Returns:
* On success:
@@ -1615,9 +1623,10 @@ int __cpuhp_setup_state(enum cpuhp_state
state = ret;
}
- cpuhp_store_callbacks(state, name, startup, teardown, multi_instance);
+ ret = cpuhp_store_callbacks(state, name, startup, teardown,
+ multi_instance);
- if (!invoke || !startup)
+ if (ret || !invoke || !startup)
goto out;
/*
next prev parent reply other threads:[~2016-12-21 19:28 UTC|newest]
Thread overview: 105+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-21 19:19 [patch 00/10] cpu/hotplug: Final cleanup Thomas Gleixner
2016-12-21 19:19 ` [patch 01/10] ARM: imx: mmcd: Fix broken cpu hotplug handling Thomas Gleixner
2016-12-22 20:18 ` [tip:smp/urgent] ARM/imx/mmcd: " tip-bot for Thomas Gleixner
2016-12-25 10:02 ` tip-bot for Thomas Gleixner
2016-12-21 19:19 ` Thomas Gleixner [this message]
2016-12-22 11:07 ` [patch 02/10] cpu/hotplug: Prevent overwriting of callbacks Thomas Gleixner
2016-12-26 23:04 ` ojab
2016-12-26 23:12 ` ojab
2016-12-22 20:21 ` [tip:smp/urgent] " tip-bot for Thomas Gleixner
2016-12-25 10:04 ` tip-bot for Thomas Gleixner
2016-12-21 19:19 ` [patch 03/10] scsi/bnx2fc: Convert to hotplug state machine Thomas Gleixner
2016-12-22 20:21 ` [tip:smp/urgent] " tip-bot for Sebastian Andrzej Siewior
2016-12-25 10:05 ` tip-bot for Sebastian Andrzej Siewior
2016-12-21 19:19 ` [patch 04/10] scsi/bnx2i: " Thomas Gleixner
2016-12-22 20:22 ` [tip:smp/urgent] " tip-bot for Sebastian Andrzej Siewior
2016-12-25 10:05 ` tip-bot for Sebastian Andrzej Siewior
2016-12-21 19:19 ` [patch 05/10] staging/lustre/libcfs: " Thomas Gleixner
2016-12-22 20:22 ` [tip:smp/urgent] " tip-bot for Anna-Maria Gleixner
2016-12-25 10:06 ` tip-bot for Anna-Maria Gleixner
2016-12-21 19:19 ` [patch 06/10] cpu/hotplug: Remove obsolete cpu hotplug register/unregister functions Thomas Gleixner
2016-12-22 20:23 ` [tip:smp/urgent] " tip-bot for Thomas Gleixner
2016-12-25 10:06 ` tip-bot for Thomas Gleixner
2016-12-21 19:19 ` [patch 07/10] cpu/hotplug: Cleanup state names Thomas Gleixner
2016-12-22 20:23 ` [tip:smp/urgent] " tip-bot for Thomas Gleixner
2016-12-25 10:07 ` tip-bot for Thomas Gleixner
2016-12-21 19:19 ` [patch 08/10] coresight: etm3/4x: Consolidate hotplug state space Thomas Gleixner
2016-12-22 16:30 ` Mathieu Poirier
2016-12-22 20:24 ` [tip:smp/urgent] coresight/etm3/4x: " tip-bot for Thomas Gleixner
2016-12-25 10:07 ` tip-bot for Thomas Gleixner
2016-12-21 19:19 ` [patch 09/10] irqchip/gic: " Thomas Gleixner
2016-12-22 20:24 ` [tip:smp/urgent] " tip-bot for Thomas Gleixner
2016-12-25 10:08 ` tip-bot for Thomas Gleixner
2016-12-21 19:19 ` [patch 10/10] irqchip/armada-xp: " Thomas Gleixner
2016-12-21 20:22 ` Thomas Petazzoni
2016-12-21 20:27 ` Thomas Gleixner
2016-12-22 20:25 ` [tip:smp/urgent] " tip-bot for Thomas Gleixner
2016-12-25 10:08 ` tip-bot for Thomas Gleixner
2016-12-22 17:59 ` [patch 00/10] cpu/hotplug: Final cleanup Sam Ravnborg
2016-12-27 11:17 ` Thomas Gleixner
2016-12-27 19:41 ` Sam Ravnborg
-- strict thread matches above, loose matches on Subject: below --
2016-11-26 23:13 cpu hotplug: convert more drivers (batch #6 and last) Sebastian Andrzej Siewior
2016-11-26 23:13 ` [PATCH 01/22] cpufreq/acpi-cpufreq: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-28 5:15 ` Viresh Kumar
2016-11-28 9:49 ` Sebastian Andrzej Siewior
2016-11-28 9:51 ` [PATCH 01/22 v2] " Sebastian Andrzej Siewior
2016-11-28 9:54 ` Viresh Kumar
2016-11-28 12:46 ` Rafael J. Wysocki
2016-11-26 23:13 ` [PATCH 02/22] cpufreq/acpi-cpufreq: drop rdmsr_on_cpus() usage Sebastian Andrzej Siewior
2016-11-28 9:52 ` [PATCH 02/22 v2] " Sebastian Andrzej Siewior
2016-11-28 9:54 ` Viresh Kumar
2016-11-26 23:13 ` [PATCH 03/22] idle/intel: Remove superfluous SMP fuction call Sebastian Andrzej Siewior
2016-11-26 23:13 ` [PATCH 04/22] idle/intel: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-28 17:29 ` Thomas Gleixner
2016-11-29 9:40 ` Sebastian Andrzej Siewior
2016-11-29 9:51 ` [PATCH 04/22 v2] " Sebastian Andrzej Siewior
2016-11-26 23:13 ` [PATCH 05/22] oprofile/nmi timer: " Sebastian Andrzej Siewior
2016-12-02 0:09 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-26 23:13 ` [PATCH 06/22] tracing/rb: " Sebastian Andrzej Siewior
2016-12-02 0:10 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-12-07 11:15 ` [linux-next] tracing/rb: NULL pointer dereference at trace_rb_cpu_prepare() Tetsuo Handa
2016-12-07 13:31 ` [PATCH] tracing/rb: init the CPU mask on allocation Sebastian Andrzej Siewior
2016-12-07 13:43 ` [tip:smp/hotplug] tracing/rb: Init " tip-bot for Sebastian Andrzej Siewior
2016-12-07 14:33 ` [PATCH] tracing/rb: init " Tetsuo Handa
2016-11-26 23:13 ` [PATCH 07/22] mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead() Sebastian Andrzej Siewior
2016-11-28 9:24 ` Michal Hocko
2016-12-02 0:10 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-26 23:13 ` [PATCH 08/22] mm/vmstat: Avoid on each online CPU loops Sebastian Andrzej Siewior
2016-11-28 9:28 ` Michal Hocko
2016-11-29 14:08 ` Thomas Gleixner
2016-11-29 14:44 ` Michal Hocko
2016-11-29 14:51 ` [PATCH 08/22 v2] " Sebastian Andrzej Siewior
2016-11-29 15:20 ` Michal Hocko
2016-12-02 0:11 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-26 23:13 ` [PATCH 09/22] mm/vmstat: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-29 14:52 ` [PATCH 09/22 v2] " Sebastian Andrzej Siewior
2016-12-02 0:11 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-26 23:13 ` [PATCH 10/22] mm/zsmalloc: " Sebastian Andrzej Siewior
2016-12-02 0:12 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-26 23:13 ` [PATCH 11/22] mm/zswap: Convert dst-mem " Sebastian Andrzej Siewior
2016-12-02 0:12 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-26 23:13 ` [PATCH 12/22] mm/zswap: Convert pool " Sebastian Andrzej Siewior
2016-12-02 0:13 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-26 23:13 ` [PATCH 13/22] iommu/vt-d: Convert " Sebastian Andrzej Siewior
2016-12-02 0:13 ` [tip:smp/hotplug] " tip-bot for Anna-Maria Gleixner
2016-11-26 23:13 ` [PATCH 14/22] mm/compaction: " Sebastian Andrzej Siewior
2016-12-02 0:14 ` [tip:smp/hotplug] " tip-bot for Anna-Maria Gleixner
2016-11-26 23:13 ` [PATCH 15/22] arm64/cpuinfo: Make hotplug notifier symmetric Sebastian Andrzej Siewior
2016-11-29 17:22 ` Suzuki K Poulose
2016-12-02 0:14 ` [tip:smp/hotplug] " tip-bot for Anna-Maria Gleixner
2016-11-26 23:13 ` [PATCH 16/22] arm64/cpuinfo: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-11-29 17:26 ` Suzuki K Poulose
2016-12-02 0:15 ` [tip:smp/hotplug] " tip-bot for Anna-Maria Gleixner
2016-11-26 23:13 ` [PATCH 17/22] KVM/PPC/Book3S HV: " Sebastian Andrzej Siewior
2016-12-02 0:15 ` [tip:smp/hotplug] " tip-bot for Anna-Maria Gleixner
2016-11-26 23:13 ` [PATCH 18/22] zram: " Sebastian Andrzej Siewior
2016-12-02 0:16 ` [tip:smp/hotplug] " tip-bot for Anna-Maria Gleixner
2016-11-26 23:13 ` [PATCH 19/22] soc/fsl/qbman: " Sebastian Andrzej Siewior
2016-12-02 0:16 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-26 23:13 ` [PATCH 20/22] " Sebastian Andrzej Siewior
2016-12-02 0:17 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-11-26 23:13 ` [PATCH 21/22] staging/lustre/libcfs: " Sebastian Andrzej Siewior
2016-12-02 10:18 ` [PATCH 21/22 v2] " Sebastian Andrzej Siewior
2016-12-02 10:42 ` Greg Kroah-Hartman
2016-12-02 11:00 ` [PATCH 21/22 v3] " Sebastian Andrzej Siewior
2016-11-26 23:13 ` [PATCH 22/22] Remove obsolete cpu hotplug register / unregister functions Sebastian Andrzej Siewior
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