From 8e30444e153008e8eb3e74cbcb7a865bfcfb04a0 Mon Sep 17 00:00:00 2001 From: Lan Tianyu Date: Thu, 18 Sep 2014 15:03:07 +0800 Subject: [PATCH 1/3] cpufreq: fix cpufreq suspend/resume for intel_pstate Cpufreq core introduces cpufreq_suspended flag to let cpufreq sysfs nodes across S2RAM/S2DISK. But the flag is only set in the cpufreq_suspend() for cpufreq drivers which have target or target_index callback. This skips intel_pstate driver. This patch is to set the flag before checking target or target_index callback. Fixes: 2f0aea936360 (cpufreq: suspend governors on system suspend/hibernate) Signed-off-by: Lan Tianyu Cc: 3.15+ # 3.15+ [rjw: Subject] Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cpufreq.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index d9fdeddcef96..eb9bb7848e50 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1656,6 +1656,8 @@ void cpufreq_suspend(void) if (!cpufreq_driver) return; + cpufreq_suspended = true; + if (!has_target()) return; @@ -1670,8 +1672,6 @@ void cpufreq_suspend(void) pr_err("%s: Failed to suspend driver: %p\n", __func__, policy); } - - cpufreq_suspended = true; } /** @@ -1687,13 +1687,13 @@ void cpufreq_resume(void) if (!cpufreq_driver) return; + cpufreq_suspended = false; + if (!has_target()) return; pr_debug("%s: Resuming Governors\n", __func__); - cpufreq_suspended = false; - list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) pr_err("%s: Failed to resume driver: %p\n", __func__, From 7106e02baed4a72fb23de56b02ad4d31daa74d95 Mon Sep 17 00:00:00 2001 From: Prarit Bhargava Date: Wed, 10 Sep 2014 10:12:08 -0400 Subject: [PATCH 2/3] cpufreq: release policy->rwsem on error While debugging a cpufreq-related hardware failure on a system I saw the following lockdep warning: ========================= [ BUG: held lock freed! ] 3.17.0-rc4+ #1 Tainted: G E ------------------------- insmod/2247 is freeing memory ffff88006e1b1400-ffff88006e1b17ff, with a lock still held there! (&policy->rwsem){+.+...}, at: [] __cpufreq_add_dev.isra.21+0x47d/0xb80 3 locks held by insmod/2247: #0: (subsys mutex#5){+.+.+.}, at: [] subsys_interface_register+0x69/0x120 #1: (cpufreq_rwsem){.+.+.+}, at: [] __cpufreq_add_dev.isra.21+0x73/0xb80 #2: (&policy->rwsem){+.+...}, at: [] __cpufreq_add_dev.isra.21+0x47d/0xb80 stack backtrace: CPU: 0 PID: 2247 Comm: insmod Tainted: G E 3.17.0-rc4+ #1 Hardware name: HP ProLiant MicroServer Gen8, BIOS J06 08/24/2013 0000000000000000 000000008f3063c4 ffff88006f87bb30 ffffffff8171b358 ffff88006bcf3750 ffff88006f87bb68 ffffffff810e09e1 ffff88006e1b1400 ffffea0001b86c00 ffffffff8156d327 ffff880073003500 0000000000000246 Call Trace: [] dump_stack+0x4d/0x66 [] debug_check_no_locks_freed+0x171/0x180 [] ? __cpufreq_add_dev.isra.21+0x427/0xb80 [] kfree+0xab/0x2b0 [] __cpufreq_add_dev.isra.21+0x427/0xb80 [] ? _raw_spin_unlock+0x27/0x40 [] ? pcc_cpufreq_do_osc+0x17f/0x17f [pcc_cpufreq] [] cpufreq_add_dev+0xe/0x10 [] subsys_interface_register+0xc1/0x120 [] cpufreq_register_driver+0x112/0x340 [] ? kfree+0xda/0x2b0 [] ? pcc_cpufreq_do_osc+0x17f/0x17f [pcc_cpufreq] [] pcc_cpufreq_init+0x4af/0xe81 [pcc_cpufreq] [] ? pcc_cpufreq_do_osc+0x17f/0x17f [pcc_cpufreq] [] do_one_initcall+0xd4/0x210 [] ? __vunmap+0xd2/0x120 [] load_module+0x1315/0x1b70 [] ? store_uevent+0x70/0x70 [] ? copy_module_from_fd.isra.44+0x129/0x180 [] SyS_finit_module+0xa6/0xd0 [] system_call_fastpath+0x16/0x1b cpufreq: __cpufreq_add_dev: ->get() failed insmod: ERROR: could not insert module pcc-cpufreq.ko: No such device The warning occurs in the __cpufreq_add_dev() code which does down_write(&policy->rwsem); ... if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { policy->cur = cpufreq_driver->get(policy->cpu); if (!policy->cur) { pr_err("%s: ->get() failed\n", __func__); goto err_get_freq; } If cpufreq_driver->get(policy->cpu) returns an error we execute the code at err_get_freq, which does not up the policy->rwsem. This causes the lockdep warning. Trivial patch to up the policy->rwsem in the error path. After the patch has been applied, and an error occurs in the cpufreq_driver->get(policy->cpu) call we will now see cpufreq: __cpufreq_add_dev: ->get() failed cpufreq: __cpufreq_add_dev: ->get() failed modprobe: ERROR: could not insert 'pcc_cpufreq': No such device Fixes: 4e97b631f24c (cpufreq: Initialize governor for a new policy under policy->rwsem) Signed-off-by: Prarit Bhargava Acked-by: Viresh Kumar Cc: 3.14+ # 3.14+ Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cpufreq.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index eb9bb7848e50..6e93e7f98358 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1289,6 +1289,8 @@ err_get_freq: per_cpu(cpufreq_cpu_data, j) = NULL; write_unlock_irqrestore(&cpufreq_driver_lock, flags); + up_write(&policy->rwsem); + if (cpufreq_driver->exit) cpufreq_driver->exit(policy); err_set_policy_cpu: From 5c4dd348af35a6f6db97b4f2401f74c71f7f3c7d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 25 Sep 2014 00:53:44 +0200 Subject: [PATCH 3/3] Revert "PM / Hibernate: Iterate over set bits instead of PFNs in swsusp_free()" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Revert commit 6efde38f0769 (PM / Hibernate: Iterate over set bits instead of PFNs in swsusp_free()) that introduced a NULL pointer dereference during system resume from hibernation: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] swsusp_free+0x21/0x190 PGD b39c2067 PUD b39c1067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: CPU: 1 PID: 4898 Comm: s2disk Tainted: G C 3.17-rc5-amd64 #1 Debian 3.17~rc5-1~exp1 Hardware name: LENOVO 2776LEG/2776LEG, BIOS 6EET55WW (3.15 ) 12/19/2011 task: ffff88023155ea40 ti: ffff8800b3b14000 task.ti: ffff8800b3b14000 RIP: 0010:[] [] swsusp_free+0x21/0x190 RSP: 0018:ffff8800b3b17ea8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8800b39bab00 RCX: 0000000000000001 RDX: ffff8800b39bab10 RSI: ffff8800b39bab00 RDI: 0000000000000000 RBP: 0000000000000010 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8800b39bab10 R11: 0000000000000246 R12: ffffea0000000000 R13: ffff880232f485a0 R14: ffff88023ac27cd8 R15: ffff880232927590 FS: 00007f406d83b700(0000) GS:ffff88023bc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 00000000b3a62000 CR4: 00000000000007e0 Stack: ffff8800b39bab00 0000000000000010 ffff880232927590 ffffffff810acb4a ffff8800b39bab00 ffffffff811a955a ffff8800b39bab10 0000000000000000 ffff88023155f098 ffffffff81a6b8c0 ffff88023155ea40 0000000000000007 Call Trace: [] ? snapshot_release+0x2a/0xb0 [] ? __fput+0xca/0x1d0 [] ? task_work_run+0x97/0xd0 [] ? do_notify_resume+0x69/0xa0 [] ? int_signal+0x12/0x17 Code: 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 41 54 48 8b 05 ba 62 9c 00 49 bc 00 00 00 00 00 ea ff ff 48 8b 3d a1 62 9c 00 55 53 <48> 8b 10 48 89 50 18 48 8b 52 20 48 c7 40 28 00 00 00 00 c7 40 RIP [] swsusp_free+0x21/0x190 RSP CR2: 0000000000000000 ---[ end trace f02be86a1ec0cccb ]--- due to forbidden_pages_map being NULL in swsusp_free(). Fixes: 6efde38f0769 "PM / Hibernate: Iterate over set bits instead of PFNs in swsusp_free()" Reported-by: Bjørn Mork Signed-off-by: Rafael J. Wysocki --- kernel/power/snapshot.c | 48 ++++++++++++----------------------------- 1 file changed, 14 insertions(+), 34 deletions(-) diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index c4b8093c80b3..f1604d8cf489 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -725,14 +725,6 @@ static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn) clear_bit(bit, addr); } -static void memory_bm_clear_current(struct memory_bitmap *bm) -{ - int bit; - - bit = max(bm->cur.node_bit - 1, 0); - clear_bit(bit, bm->cur.node->data); -} - static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn) { void *addr; @@ -1341,35 +1333,23 @@ static struct memory_bitmap copy_bm; void swsusp_free(void) { - unsigned long fb_pfn, fr_pfn; + struct zone *zone; + unsigned long pfn, max_zone_pfn; - memory_bm_position_reset(forbidden_pages_map); - memory_bm_position_reset(free_pages_map); + for_each_populated_zone(zone) { + max_zone_pfn = zone_end_pfn(zone); + for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) + if (pfn_valid(pfn)) { + struct page *page = pfn_to_page(pfn); -loop: - fr_pfn = memory_bm_next_pfn(free_pages_map); - fb_pfn = memory_bm_next_pfn(forbidden_pages_map); - - /* - * Find the next bit set in both bitmaps. This is guaranteed to - * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP. - */ - do { - if (fb_pfn < fr_pfn) - fb_pfn = memory_bm_next_pfn(forbidden_pages_map); - if (fr_pfn < fb_pfn) - fr_pfn = memory_bm_next_pfn(free_pages_map); - } while (fb_pfn != fr_pfn); - - if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) { - struct page *page = pfn_to_page(fr_pfn); - - memory_bm_clear_current(forbidden_pages_map); - memory_bm_clear_current(free_pages_map); - __free_page(page); - goto loop; + if (swsusp_page_is_forbidden(page) && + swsusp_page_is_free(page)) { + swsusp_unset_page_forbidden(page); + swsusp_unset_page_free(page); + __free_page(page); + } + } } - nr_copy_pages = 0; nr_meta_pages = 0; restore_pblist = NULL;