From 8a84bf45143b6b3552a806ab73181d7c7b6020ff Mon Sep 17 00:00:00 2001 From: Arvind Yadav Date: Mon, 3 Jul 2017 08:31:05 +0100 Subject: [PATCH 1/6] bus: arm-ccn: constify attribute_group structures. attribute_groups are not supposed to change at runtime. All functions working with attribute_groups provided by work with const attribute_group. So mark the non-const structs as const. File size before: text data bss dec hex filename 9074 5592 416 15082 3aea drivers/bus/arm-ccn.o File size After adding 'const': text data bss dec hex filename 9327 5336 416 15079 3ae7 drivers/bus/arm-ccn.o Signed-off-by: Arvind Yadav Signed-off-by: Pawel Moll --- drivers/bus/arm-ccn.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c index 3063f5312397..7625bf762acb 100644 --- a/drivers/bus/arm-ccn.c +++ b/drivers/bus/arm-ccn.c @@ -262,7 +262,7 @@ static struct attribute *arm_ccn_pmu_format_attrs[] = { NULL }; -static struct attribute_group arm_ccn_pmu_format_attr_group = { +static const struct attribute_group arm_ccn_pmu_format_attr_group = { .name = "format", .attrs = arm_ccn_pmu_format_attrs, }; @@ -451,7 +451,7 @@ static struct arm_ccn_pmu_event arm_ccn_pmu_events[] = { static struct attribute *arm_ccn_pmu_events_attrs[ARRAY_SIZE(arm_ccn_pmu_events) + 1]; -static struct attribute_group arm_ccn_pmu_events_attr_group = { +static const struct attribute_group arm_ccn_pmu_events_attr_group = { .name = "events", .is_visible = arm_ccn_pmu_events_is_visible, .attrs = arm_ccn_pmu_events_attrs, @@ -548,7 +548,7 @@ static struct attribute *arm_ccn_pmu_cmp_mask_attrs[] = { NULL }; -static struct attribute_group arm_ccn_pmu_cmp_mask_attr_group = { +static const struct attribute_group arm_ccn_pmu_cmp_mask_attr_group = { .name = "cmp_mask", .attrs = arm_ccn_pmu_cmp_mask_attrs, }; @@ -569,7 +569,7 @@ static struct attribute *arm_ccn_pmu_cpumask_attrs[] = { NULL, }; -static struct attribute_group arm_ccn_pmu_cpumask_attr_group = { +static const struct attribute_group arm_ccn_pmu_cpumask_attr_group = { .attrs = arm_ccn_pmu_cpumask_attrs, }; From 24771179c5c138f0ea3ef88b7972979f62f2d5db Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Sun, 27 Aug 2017 11:06:50 +0100 Subject: [PATCH 2/6] bus: arm-ccn: Check memory allocation failure Check memory allocation failures and return -ENOMEM in such cases This avoids a potential NULL pointer dereference. Signed-off-by: Christophe JAILLET Acked-by: Scott Branden Cc: stable@vger.kernel.org # 3.17+ Signed-off-by: Pawel Moll --- drivers/bus/arm-ccn.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c index 7625bf762acb..a7951662f85b 100644 --- a/drivers/bus/arm-ccn.c +++ b/drivers/bus/arm-ccn.c @@ -1271,6 +1271,10 @@ static int arm_ccn_pmu_init(struct arm_ccn *ccn) int len = snprintf(NULL, 0, "ccn_%d", ccn->dt.id); name = devm_kzalloc(ccn->dev, len + 1, GFP_KERNEL); + if (!name) { + err = -ENOMEM; + goto error_choose_name; + } snprintf(name, len + 1, "ccn_%d", ccn->dt.id); } @@ -1319,6 +1323,7 @@ static int arm_ccn_pmu_init(struct arm_ccn *ccn) error_pmu_register: error_set_affinity: +error_choose_name: ida_simple_remove(&arm_ccn_pmu_ida, ccn->dt.id); for (i = 0; i < ccn->num_xps; i++) writel(0, ccn->xp[i].base + CCN_XP_DT_CONTROL); From 0f9afd36bac9543bc087b77016311c3394bd77c2 Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Sun, 27 Aug 2017 11:07:06 +0100 Subject: [PATCH 3/6] bus: arm-ccn: Simplify code Use 'devm_kasprintf()' to simplify the code. Signed-off-by: Christophe JAILLET Acked-by: Scott Branden Signed-off-by: Pawel Moll --- drivers/bus/arm-ccn.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c index a7951662f85b..bbc1a2ef9639 100644 --- a/drivers/bus/arm-ccn.c +++ b/drivers/bus/arm-ccn.c @@ -1268,14 +1268,12 @@ static int arm_ccn_pmu_init(struct arm_ccn *ccn) if (ccn->dt.id == 0) { name = "ccn"; } else { - int len = snprintf(NULL, 0, "ccn_%d", ccn->dt.id); - - name = devm_kzalloc(ccn->dev, len + 1, GFP_KERNEL); + name = devm_kasprintf(ccn->dev, GFP_KERNEL, "ccn_%d", + ccn->dt.id); if (!name) { err = -ENOMEM; goto error_choose_name; } - snprintf(name, len + 1, "ccn_%d", ccn->dt.id); } /* Perf driver registration */ From b18c2b9487d8e797fc0a757e57ac3645348c5fba Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 3 Oct 2017 18:14:12 +0100 Subject: [PATCH 4/6] bus: arm-ccn: Fix use of smp_processor_id() in preemptible context Booting a DEBUG_PREEMPT enabled kernel on a CCN-based system results in the following splat: [...] arm-ccn e8000000.ccn: No access to interrupts, using timer. BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1 caller is debug_smp_processor_id+0x1c/0x28 CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.13.0 #6111 Hardware name: AMD Seattle/Seattle, BIOS 17:08:23 Jun 26 2017 Call trace: [] dump_backtrace+0x0/0x278 [] show_stack+0x24/0x30 [] dump_stack+0x8c/0xb0 [] check_preemption_disabled+0xfc/0x100 [] debug_smp_processor_id+0x1c/0x28 [] arm_ccn_probe+0x358/0x4f0 [...] as we use smp_processor_id() in the wrong context. Turn this into a get_cpu()/put_cpu() that extends over the CPU hotplug registration, making sure that we don't race against a CPU down operation. Signed-off-by: Marc Zyngier Acked-by: Mark Rutland Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: Pawel Moll --- drivers/bus/arm-ccn.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c index bbc1a2ef9639..508a1a389b7e 100644 --- a/drivers/bus/arm-ccn.c +++ b/drivers/bus/arm-ccn.c @@ -1300,7 +1300,7 @@ static int arm_ccn_pmu_init(struct arm_ccn *ccn) } /* Pick one CPU which we will use to collect data from CCN... */ - cpumask_set_cpu(smp_processor_id(), &ccn->dt.cpu); + cpumask_set_cpu(get_cpu(), &ccn->dt.cpu); /* Also make sure that the overflow interrupt is handled by this CPU */ if (ccn->irq) { @@ -1317,10 +1317,12 @@ static int arm_ccn_pmu_init(struct arm_ccn *ccn) cpuhp_state_add_instance_nocalls(CPUHP_AP_PERF_ARM_CCN_ONLINE, &ccn->dt.node); + put_cpu(); return 0; error_pmu_register: error_set_affinity: + put_cpu(); error_choose_name: ida_simple_remove(&arm_ccn_pmu_ida, ccn->dt.id); for (i = 0; i < ccn->num_xps; i++) From 4608af8aa53e7f3922ddee695d023b7bcd5cb35b Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 3 Oct 2017 18:14:13 +0100 Subject: [PATCH 5/6] bus: arm-cci: Fix use of smp_processor_id() in preemptible context The ARM CCI driver seem to be using smp_processor_id() in a preemptible context, which is likely to make a DEBUG_PREMPT kernel scream at boot time. Turn this into a get_cpu()/put_cpu() that extends over the CPU hotplug registration, making sure that we don't race against a CPU down operation. Signed-off-by: Marc Zyngier Acked-by: Mark Rutland Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: Pawel Moll --- drivers/bus/arm-cci.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c index 3c29d36702a8..5426c04fe24b 100644 --- a/drivers/bus/arm-cci.c +++ b/drivers/bus/arm-cci.c @@ -1755,14 +1755,17 @@ static int cci_pmu_probe(struct platform_device *pdev) raw_spin_lock_init(&cci_pmu->hw_events.pmu_lock); mutex_init(&cci_pmu->reserve_mutex); atomic_set(&cci_pmu->active_events, 0); - cpumask_set_cpu(smp_processor_id(), &cci_pmu->cpus); + cpumask_set_cpu(get_cpu(), &cci_pmu->cpus); ret = cci_pmu_init(cci_pmu, pdev); - if (ret) + if (ret) { + put_cpu(); return ret; + } cpuhp_state_add_instance_nocalls(CPUHP_AP_PERF_ARM_CCI_ONLINE, &cci_pmu->node); + put_cpu(); pr_info("ARM %s PMU driver probed", cci_pmu->model->name); return 0; } From b69f63ebf553504739cc8534cbed31bd530c6f0b Mon Sep 17 00:00:00 2001 From: Kim Phillips Date: Wed, 11 Oct 2017 22:33:24 +0100 Subject: [PATCH 6/6] bus: arm-ccn: fix module unloading Error: Removing state 147 which has instances left. Unregistering the driver before calling cpuhp_remove_multi_state() removes any remaining hotplug cpu instances so __cpuhp_remove_state_cpuslocked() doesn't emit this warning: [ 268.748362] Error: Removing state 147 which has instances left. [ 268.748373] ------------[ cut here ]------------ [ 268.748386] WARNING: CPU: 2 PID: 5476 at kernel/cpu.c:1734 __cpuhp_remove_state_cpuslocked+0x454/0x4f0 [ 268.748389] Modules linked in: arm_ccn(-) [last unloaded: arm_ccn] [ 268.748403] CPU: 2 PID: 5476 Comm: rmmod Tainted: G W 4.14.0-rc4+ #3 [ 268.748406] Hardware name: AMD Seattle/Seattle, BIOS 10:18:39 Dec 8 2016 [ 268.748410] task: ffff8001a18ca000 task.stack: ffff80019c120000 [ 268.748416] PC is at __cpuhp_remove_state_cpuslocked+0x454/0x4f0 [ 268.748421] LR is at __cpuhp_remove_state_cpuslocked+0x448/0x4f0 [ 268.748425] pc : [] lr : [] pstate: 60000145 [ 268.748427] sp : ffff80019c127d30 [ 268.748430] x29: ffff80019c127d30 x28: ffff8001a18ca000 [ 268.748437] x27: ffff20000c2cb000 x26: 1fffe4000042d490 [ 268.748443] x25: ffff20000216a480 x24: 0000000000000000 [ 268.748449] x23: ffff20000b08e000 x22: 0000000000000001 [ 268.748455] x21: 0000000000000093 x20: 00000000000016f8 [ 268.748460] x19: ffff20000c2cbb80 x18: 0000ffffb5fe7c58 [ 268.748466] x17: 00000000004402d0 x16: 1fffe40001864f01 [ 268.748472] x15: ffff20000c4bf8b0 x14: 0000000000000000 [ 268.748477] x13: 0000000000007032 x12: ffff20000829ae48 [ 268.748483] x11: ffff20000c4bf000 x10: 0000000000000004 [ 268.748488] x9 : 0000000000006fbc x8 : ffff20000c318a40 [ 268.748494] x7 : 0000000000000000 x6 : ffff040001864f02 [ 268.748500] x5 : 0000000000000000 x4 : 0000000000000000 [ 268.748505] x3 : 0000000000000007 x2 : dfff200000000000 [ 268.748510] x1 : 000000000000ad3d x0 : 00000000000001f0 [ 268.748516] Call trace: [ 268.748521] Exception stack(0xffff80019c127bf0 to 0xffff80019c127d30) [ 268.748526] 7be0: 00000000000001f0 000000000000ad3d [ 268.748531] 7c00: dfff200000000000 0000000000000007 0000000000000000 0000000000000000 [ 268.748535] 7c20: ffff040001864f02 0000000000000000 ffff20000c318a40 0000000000006fbc [ 268.748539] 7c40: 0000000000000004 ffff20000c4bf000 ffff20000829ae48 0000000000007032 [ 268.748544] 7c60: 0000000000000000 ffff20000c4bf8b0 1fffe40001864f01 00000000004402d0 [ 268.748548] 7c80: 0000ffffb5fe7c58 ffff20000c2cbb80 00000000000016f8 0000000000000093 [ 268.748553] 7ca0: 0000000000000001 ffff20000b08e000 0000000000000000 ffff20000216a480 [ 268.748557] 7cc0: 1fffe4000042d490 ffff20000c2cb000 ffff8001a18ca000 ffff80019c127d30 [ 268.748562] 7ce0: ffff2000081729e0 ffff80019c127d30 ffff2000081729ec 0000000060000145 [ 268.748566] 7d00: 00000000000001f0 0000000000000000 0001000000000000 0000000000000000 [ 268.748569] 7d20: ffff80019c127d30 ffff2000081729ec [ 268.748575] [] __cpuhp_remove_state_cpuslocked+0x454/0x4f0 [ 268.748580] [] __cpuhp_remove_state+0x54/0x80 [ 268.748597] [] arm_ccn_exit+0x2c/0x70 [arm_ccn] [ 268.748604] [] SyS_delete_module+0x5a4/0x708 [ 268.748607] Exception stack(0xffff80019c127ec0 to 0xffff80019c128000) [ 268.748612] 7ec0: 0000000019bb7258 0000000000000800 ba64d0fb3d26a800 00000000000000da [ 268.748616] 7ee0: 0000ffffb6144e28 0000ffffcd95b409 fefefefefefefeff 7f7f7f7f7f7f7f7f [ 268.748621] 7f00: 000000000000006a 1999999999999999 0000ffffb6179000 0000000000bbcc6d [ 268.748625] 7f20: 0000ffffb6176b98 0000ffffcd95c2d0 0000ffffb5fe7b58 0000ffffb6163000 [ 268.748630] 7f40: 0000ffffb60ad3e0 00000000004402d0 0000ffffb5fe7c58 0000000019bb71f0 [ 268.748634] 7f60: 0000ffffcd95c740 0000000000000000 0000000019bb71f0 0000000000416700 [ 268.748639] 7f80: 0000000000000000 00000000004402e8 0000000019bb6010 0000ffffcd95c748 [ 268.748643] 7fa0: 0000000000000000 0000ffffcd95c460 00000000004113a8 0000ffffcd95c460 [ 268.748648] 7fc0: 0000ffffb60ad3e8 0000000080000000 0000000019bb7258 000000000000006a [ 268.748652] 7fe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 268.748657] [] __sys_trace_return+0x0/0x4 [ 268.748661] ---[ end trace a996d358dcaa7f9c ]--- Fixes: 8df038725ad5 ("bus/arm-ccn: Use cpu-hp's multi instance support instead custom list") Signed-off-by: Kim Phillips Acked-by: Sebastian Andrzej Siewior Cc: stable@vger.kernel.org # 4.8+ Signed-off-by: Pawel Moll --- drivers/bus/arm-ccn.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c index 508a1a389b7e..b52332e52ca5 100644 --- a/drivers/bus/arm-ccn.c +++ b/drivers/bus/arm-ccn.c @@ -1586,8 +1586,8 @@ static int __init arm_ccn_init(void) static void __exit arm_ccn_exit(void) { - cpuhp_remove_multi_state(CPUHP_AP_PERF_ARM_CCN_ONLINE); platform_driver_unregister(&arm_ccn_driver); + cpuhp_remove_multi_state(CPUHP_AP_PERF_ARM_CCN_ONLINE); } module_init(arm_ccn_init);