diff --git a/drivers/mfd/sec-core.c b/drivers/mfd/sec-core.c index 34c18fb8c089..54cc25546592 100644 --- a/drivers/mfd/sec-core.c +++ b/drivers/mfd/sec-core.c @@ -81,31 +81,31 @@ static struct of_device_id sec_dt_match[] = { int sec_reg_read(struct sec_pmic_dev *sec_pmic, u8 reg, void *dest) { - return regmap_read(sec_pmic->regmap, reg, dest); + return regmap_read(sec_pmic->regmap_pmic, reg, dest); } EXPORT_SYMBOL_GPL(sec_reg_read); int sec_bulk_read(struct sec_pmic_dev *sec_pmic, u8 reg, int count, u8 *buf) { - return regmap_bulk_read(sec_pmic->regmap, reg, buf, count); + return regmap_bulk_read(sec_pmic->regmap_pmic, reg, buf, count); } EXPORT_SYMBOL_GPL(sec_bulk_read); int sec_reg_write(struct sec_pmic_dev *sec_pmic, u8 reg, u8 value) { - return regmap_write(sec_pmic->regmap, reg, value); + return regmap_write(sec_pmic->regmap_pmic, reg, value); } EXPORT_SYMBOL_GPL(sec_reg_write); int sec_bulk_write(struct sec_pmic_dev *sec_pmic, u8 reg, int count, u8 *buf) { - return regmap_raw_write(sec_pmic->regmap, reg, buf, count); + return regmap_raw_write(sec_pmic->regmap_pmic, reg, buf, count); } EXPORT_SYMBOL_GPL(sec_bulk_write); int sec_reg_update(struct sec_pmic_dev *sec_pmic, u8 reg, u8 val, u8 mask) { - return regmap_update_bits(sec_pmic->regmap, reg, mask, val); + return regmap_update_bits(sec_pmic->regmap_pmic, reg, mask, val); } EXPORT_SYMBOL_GPL(sec_reg_update); @@ -166,6 +166,11 @@ static struct regmap_config s5m8767_regmap_config = { .cache_type = REGCACHE_FLAT, }; +static const struct regmap_config sec_rtc_regmap_config = { + .reg_bits = 8, + .val_bits = 8, +}; + #ifdef CONFIG_OF /* * Only the common platform data elements for s5m8767 are parsed here from the @@ -266,9 +271,9 @@ static int sec_pmic_probe(struct i2c_client *i2c, break; } - sec_pmic->regmap = devm_regmap_init_i2c(i2c, regmap); - if (IS_ERR(sec_pmic->regmap)) { - ret = PTR_ERR(sec_pmic->regmap); + sec_pmic->regmap_pmic = devm_regmap_init_i2c(i2c, regmap); + if (IS_ERR(sec_pmic->regmap_pmic)) { + ret = PTR_ERR(sec_pmic->regmap_pmic); dev_err(&i2c->dev, "Failed to allocate register map: %d\n", ret); return ret; @@ -277,6 +282,15 @@ static int sec_pmic_probe(struct i2c_client *i2c, sec_pmic->rtc = i2c_new_dummy(i2c->adapter, RTC_I2C_ADDR); i2c_set_clientdata(sec_pmic->rtc, sec_pmic); + sec_pmic->regmap_rtc = devm_regmap_init_i2c(sec_pmic->rtc, + &sec_rtc_regmap_config); + if (IS_ERR(sec_pmic->regmap_rtc)) { + ret = PTR_ERR(sec_pmic->regmap_rtc); + dev_err(&i2c->dev, "Failed to allocate RTC register map: %d\n", + ret); + return ret; + } + if (pdata && pdata->cfg_pmic_irq) pdata->cfg_pmic_irq(); diff --git a/drivers/mfd/sec-irq.c b/drivers/mfd/sec-irq.c index 0dd84e99081e..b441b1be27cb 100644 --- a/drivers/mfd/sec-irq.c +++ b/drivers/mfd/sec-irq.c @@ -280,19 +280,19 @@ int sec_irq_init(struct sec_pmic_dev *sec_pmic) switch (type) { case S5M8763X: - ret = regmap_add_irq_chip(sec_pmic->regmap, sec_pmic->irq, + ret = regmap_add_irq_chip(sec_pmic->regmap_pmic, sec_pmic->irq, IRQF_TRIGGER_FALLING | IRQF_ONESHOT, sec_pmic->irq_base, &s5m8763_irq_chip, &sec_pmic->irq_data); break; case S5M8767X: - ret = regmap_add_irq_chip(sec_pmic->regmap, sec_pmic->irq, + ret = regmap_add_irq_chip(sec_pmic->regmap_pmic, sec_pmic->irq, IRQF_TRIGGER_FALLING | IRQF_ONESHOT, sec_pmic->irq_base, &s5m8767_irq_chip, &sec_pmic->irq_data); break; case S2MPS11X: - ret = regmap_add_irq_chip(sec_pmic->regmap, sec_pmic->irq, + ret = regmap_add_irq_chip(sec_pmic->regmap_pmic, sec_pmic->irq, IRQF_TRIGGER_FALLING | IRQF_ONESHOT, sec_pmic->irq_base, &s2mps11_irq_chip, &sec_pmic->irq_data); diff --git a/drivers/regulator/s5m8767.c b/drivers/regulator/s5m8767.c index cbf91e25cf7f..aeb40aad0ae7 100644 --- a/drivers/regulator/s5m8767.c +++ b/drivers/regulator/s5m8767.c @@ -925,7 +925,7 @@ static int s5m8767_pmic_probe(struct platform_device *pdev) config.dev = s5m8767->dev; config.init_data = pdata->regulators[i].initdata; config.driver_data = s5m8767; - config.regmap = iodev->regmap; + config.regmap = iodev->regmap_pmic; config.of_node = pdata->regulators[i].reg_node; rdev[i] = devm_regulator_register(&pdev->dev, ®ulators[id], diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c index c0da95e95702..3281c90691c3 100644 --- a/drivers/rtc/rtc-at91rm9200.c +++ b/drivers/rtc/rtc-at91rm9200.c @@ -220,6 +220,8 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) at91_alarm_year = tm.tm_year; + tm.tm_mon = alrm->time.tm_mon; + tm.tm_mday = alrm->time.tm_mday; tm.tm_hour = alrm->time.tm_hour; tm.tm_min = alrm->time.tm_min; tm.tm_sec = alrm->time.tm_sec; diff --git a/drivers/rtc/rtc-s5m.c b/drivers/rtc/rtc-s5m.c index b7fd02bc0a14..ae8119dc2846 100644 --- a/drivers/rtc/rtc-s5m.c +++ b/drivers/rtc/rtc-s5m.c @@ -28,10 +28,20 @@ #include #include +/* + * Maximum number of retries for checking changes in UDR field + * of SEC_RTC_UDR_CON register (to limit possible endless loop). + * + * After writing to RTC registers (setting time or alarm) read the UDR field + * in SEC_RTC_UDR_CON register. UDR is auto-cleared when data have + * been transferred. + */ +#define UDR_READ_RETRY_CNT 5 + struct s5m_rtc_info { struct device *dev; struct sec_pmic_dev *s5m87xx; - struct regmap *rtc; + struct regmap *regmap; struct rtc_device *rtc_dev; int irq; int device_type; @@ -84,12 +94,31 @@ static int s5m8767_tm_to_data(struct rtc_time *tm, u8 *data) } } +/* + * Read RTC_UDR_CON register and wait till UDR field is cleared. + * This indicates that time/alarm update ended. + */ +static inline int s5m8767_wait_for_udr_update(struct s5m_rtc_info *info) +{ + int ret, retry = UDR_READ_RETRY_CNT; + unsigned int data; + + do { + ret = regmap_read(info->regmap, SEC_RTC_UDR_CON, &data); + } while (--retry && (data & RTC_UDR_MASK) && !ret); + + if (!retry) + dev_err(info->dev, "waiting for UDR update, reached max number of retries\n"); + + return ret; +} + static inline int s5m8767_rtc_set_time_reg(struct s5m_rtc_info *info) { int ret; unsigned int data; - ret = regmap_read(info->rtc, SEC_RTC_UDR_CON, &data); + ret = regmap_read(info->regmap, SEC_RTC_UDR_CON, &data); if (ret < 0) { dev_err(info->dev, "failed to read update reg(%d)\n", ret); return ret; @@ -98,15 +127,13 @@ static inline int s5m8767_rtc_set_time_reg(struct s5m_rtc_info *info) data |= RTC_TIME_EN_MASK; data |= RTC_UDR_MASK; - ret = regmap_write(info->rtc, SEC_RTC_UDR_CON, data); + ret = regmap_write(info->regmap, SEC_RTC_UDR_CON, data); if (ret < 0) { dev_err(info->dev, "failed to write update reg(%d)\n", ret); return ret; } - do { - ret = regmap_read(info->rtc, SEC_RTC_UDR_CON, &data); - } while ((data & RTC_UDR_MASK) && !ret); + ret = s5m8767_wait_for_udr_update(info); return ret; } @@ -116,7 +143,7 @@ static inline int s5m8767_rtc_set_alarm_reg(struct s5m_rtc_info *info) int ret; unsigned int data; - ret = regmap_read(info->rtc, SEC_RTC_UDR_CON, &data); + ret = regmap_read(info->regmap, SEC_RTC_UDR_CON, &data); if (ret < 0) { dev_err(info->dev, "%s: fail to read update reg(%d)\n", __func__, ret); @@ -126,16 +153,14 @@ static inline int s5m8767_rtc_set_alarm_reg(struct s5m_rtc_info *info) data &= ~RTC_TIME_EN_MASK; data |= RTC_UDR_MASK; - ret = regmap_write(info->rtc, SEC_RTC_UDR_CON, data); + ret = regmap_write(info->regmap, SEC_RTC_UDR_CON, data); if (ret < 0) { dev_err(info->dev, "%s: fail to write update reg(%d)\n", __func__, ret); return ret; } - do { - ret = regmap_read(info->rtc, SEC_RTC_UDR_CON, &data); - } while ((data & RTC_UDR_MASK) && !ret); + ret = s5m8767_wait_for_udr_update(info); return ret; } @@ -178,7 +203,7 @@ static int s5m_rtc_read_time(struct device *dev, struct rtc_time *tm) u8 data[8]; int ret; - ret = regmap_bulk_read(info->rtc, SEC_RTC_SEC, data, 8); + ret = regmap_bulk_read(info->regmap, SEC_RTC_SEC, data, 8); if (ret < 0) return ret; @@ -226,7 +251,7 @@ static int s5m_rtc_set_time(struct device *dev, struct rtc_time *tm) 1900 + tm->tm_year, 1 + tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec, tm->tm_wday); - ret = regmap_raw_write(info->rtc, SEC_RTC_SEC, data, 8); + ret = regmap_raw_write(info->regmap, SEC_RTC_SEC, data, 8); if (ret < 0) return ret; @@ -242,20 +267,20 @@ static int s5m_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) unsigned int val; int ret, i; - ret = regmap_bulk_read(info->rtc, SEC_ALARM0_SEC, data, 8); + ret = regmap_bulk_read(info->regmap, SEC_ALARM0_SEC, data, 8); if (ret < 0) return ret; switch (info->device_type) { case S5M8763X: s5m8763_data_to_tm(data, &alrm->time); - ret = regmap_read(info->rtc, SEC_ALARM0_CONF, &val); + ret = regmap_read(info->regmap, SEC_ALARM0_CONF, &val); if (ret < 0) return ret; alrm->enabled = !!val; - ret = regmap_read(info->rtc, SEC_RTC_STATUS, &val); + ret = regmap_read(info->regmap, SEC_RTC_STATUS, &val); if (ret < 0) return ret; @@ -278,7 +303,7 @@ static int s5m_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) } alrm->pending = 0; - ret = regmap_read(info->rtc, SEC_RTC_STATUS, &val); + ret = regmap_read(info->regmap, SEC_RTC_STATUS, &val); if (ret < 0) return ret; break; @@ -301,7 +326,7 @@ static int s5m_rtc_stop_alarm(struct s5m_rtc_info *info) int ret, i; struct rtc_time tm; - ret = regmap_bulk_read(info->rtc, SEC_ALARM0_SEC, data, 8); + ret = regmap_bulk_read(info->regmap, SEC_ALARM0_SEC, data, 8); if (ret < 0) return ret; @@ -312,14 +337,14 @@ static int s5m_rtc_stop_alarm(struct s5m_rtc_info *info) switch (info->device_type) { case S5M8763X: - ret = regmap_write(info->rtc, SEC_ALARM0_CONF, 0); + ret = regmap_write(info->regmap, SEC_ALARM0_CONF, 0); break; case S5M8767X: for (i = 0; i < 7; i++) data[i] &= ~ALARM_ENABLE_MASK; - ret = regmap_raw_write(info->rtc, SEC_ALARM0_SEC, data, 8); + ret = regmap_raw_write(info->regmap, SEC_ALARM0_SEC, data, 8); if (ret < 0) return ret; @@ -341,7 +366,7 @@ static int s5m_rtc_start_alarm(struct s5m_rtc_info *info) u8 alarm0_conf; struct rtc_time tm; - ret = regmap_bulk_read(info->rtc, SEC_ALARM0_SEC, data, 8); + ret = regmap_bulk_read(info->regmap, SEC_ALARM0_SEC, data, 8); if (ret < 0) return ret; @@ -353,7 +378,7 @@ static int s5m_rtc_start_alarm(struct s5m_rtc_info *info) switch (info->device_type) { case S5M8763X: alarm0_conf = 0x77; - ret = regmap_write(info->rtc, SEC_ALARM0_CONF, alarm0_conf); + ret = regmap_write(info->regmap, SEC_ALARM0_CONF, alarm0_conf); break; case S5M8767X: @@ -368,7 +393,7 @@ static int s5m_rtc_start_alarm(struct s5m_rtc_info *info) if (data[RTC_YEAR1] & 0x7f) data[RTC_YEAR1] |= ALARM_ENABLE_MASK; - ret = regmap_raw_write(info->rtc, SEC_ALARM0_SEC, data, 8); + ret = regmap_raw_write(info->regmap, SEC_ALARM0_SEC, data, 8); if (ret < 0) return ret; ret = s5m8767_rtc_set_alarm_reg(info); @@ -410,7 +435,7 @@ static int s5m_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) if (ret < 0) return ret; - ret = regmap_raw_write(info->rtc, SEC_ALARM0_SEC, data, 8); + ret = regmap_raw_write(info->regmap, SEC_ALARM0_SEC, data, 8); if (ret < 0) return ret; @@ -455,7 +480,7 @@ static const struct rtc_class_ops s5m_rtc_ops = { static void s5m_rtc_enable_wtsr(struct s5m_rtc_info *info, bool enable) { int ret; - ret = regmap_update_bits(info->rtc, SEC_WTSR_SMPL_CNTL, + ret = regmap_update_bits(info->regmap, SEC_WTSR_SMPL_CNTL, WTSR_ENABLE_MASK, enable ? WTSR_ENABLE_MASK : 0); if (ret < 0) @@ -466,7 +491,7 @@ static void s5m_rtc_enable_wtsr(struct s5m_rtc_info *info, bool enable) static void s5m_rtc_enable_smpl(struct s5m_rtc_info *info, bool enable) { int ret; - ret = regmap_update_bits(info->rtc, SEC_WTSR_SMPL_CNTL, + ret = regmap_update_bits(info->regmap, SEC_WTSR_SMPL_CNTL, SMPL_ENABLE_MASK, enable ? SMPL_ENABLE_MASK : 0); if (ret < 0) @@ -481,7 +506,7 @@ static int s5m8767_rtc_init_reg(struct s5m_rtc_info *info) int ret; struct rtc_time tm; - ret = regmap_read(info->rtc, SEC_RTC_UDR_CON, &tp_read); + ret = regmap_read(info->regmap, SEC_RTC_UDR_CON, &tp_read); if (ret < 0) { dev_err(info->dev, "%s: fail to read control reg(%d)\n", __func__, ret); @@ -493,7 +518,7 @@ static int s5m8767_rtc_init_reg(struct s5m_rtc_info *info) data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT); info->rtc_24hr_mode = 1; - ret = regmap_raw_write(info->rtc, SEC_ALARM0_CONF, data, 2); + ret = regmap_raw_write(info->regmap, SEC_ALARM0_CONF, data, 2); if (ret < 0) { dev_err(info->dev, "%s: fail to write controlm reg(%d)\n", __func__, ret); @@ -515,7 +540,7 @@ static int s5m8767_rtc_init_reg(struct s5m_rtc_info *info) ret = s5m_rtc_set_time(info->dev, &tm); } - ret = regmap_update_bits(info->rtc, SEC_RTC_UDR_CON, + ret = regmap_update_bits(info->regmap, SEC_RTC_UDR_CON, RTC_TCON_MASK, tp_read | RTC_TCON_MASK); if (ret < 0) dev_err(info->dev, "%s: fail to update TCON reg(%d)\n", @@ -542,17 +567,19 @@ static int s5m_rtc_probe(struct platform_device *pdev) info->dev = &pdev->dev; info->s5m87xx = s5m87xx; - info->rtc = s5m87xx->rtc; + info->regmap = s5m87xx->regmap_rtc; info->device_type = s5m87xx->device_type; info->wtsr_smpl = s5m87xx->wtsr_smpl; switch (pdata->device_type) { case S5M8763X: - info->irq = s5m87xx->irq_base + S5M8763_IRQ_ALARM0; + info->irq = regmap_irq_get_virq(s5m87xx->irq_data, + S5M8763_IRQ_ALARM0); break; case S5M8767X: - info->irq = s5m87xx->irq_base + S5M8767_IRQ_RTCA1; + info->irq = regmap_irq_get_virq(s5m87xx->irq_data, + S5M8767_IRQ_RTCA1); break; default: @@ -596,7 +623,7 @@ static void s5m_rtc_shutdown(struct platform_device *pdev) if (info->wtsr_smpl) { for (i = 0; i < 3; i++) { s5m_rtc_enable_wtsr(info, false); - regmap_read(info->rtc, SEC_WTSR_SMPL_CNTL, &val); + regmap_read(info->regmap, SEC_WTSR_SMPL_CNTL, &val); pr_debug("%s: WTSR_SMPL reg(0x%02x)\n", __func__, val); if (val & WTSR_ENABLE_MASK) pr_emerg("%s: fail to disable WTSR\n", @@ -612,6 +639,30 @@ static void s5m_rtc_shutdown(struct platform_device *pdev) s5m_rtc_enable_smpl(info, false); } +static int s5m_rtc_resume(struct device *dev) +{ + struct s5m_rtc_info *info = dev_get_drvdata(dev); + int ret = 0; + + if (device_may_wakeup(dev)) + ret = disable_irq_wake(info->irq); + + return ret; +} + +static int s5m_rtc_suspend(struct device *dev) +{ + struct s5m_rtc_info *info = dev_get_drvdata(dev); + int ret = 0; + + if (device_may_wakeup(dev)) + ret = enable_irq_wake(info->irq); + + return ret; +} + +static SIMPLE_DEV_PM_OPS(s5m_rtc_pm_ops, s5m_rtc_suspend, s5m_rtc_resume); + static const struct platform_device_id s5m_rtc_id[] = { { "s5m-rtc", 0 }, }; @@ -620,6 +671,7 @@ static struct platform_driver s5m_rtc_driver = { .driver = { .name = "s5m-rtc", .owner = THIS_MODULE, + .pm = &s5m_rtc_pm_ops, }, .probe = s5m_rtc_probe, .shutdown = s5m_rtc_shutdown, diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 28955d4b7218..124fc43c7090 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -292,16 +292,20 @@ proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr, { struct proc_dir_entry *pde = PDE(file_inode(file)); unsigned long rv = -EIO; - unsigned long (*get_area)(struct file *, unsigned long, unsigned long, - unsigned long, unsigned long) = NULL; + if (use_pde(pde)) { + typeof(proc_reg_get_unmapped_area) *get_area; + + get_area = pde->proc_fops->get_unmapped_area; #ifdef CONFIG_MMU - get_area = current->mm->get_unmapped_area; + if (!get_area) + get_area = current->mm->get_unmapped_area; #endif - if (pde->proc_fops->get_unmapped_area) - get_area = pde->proc_fops->get_unmapped_area; + if (get_area) rv = get_area(file, orig_addr, len, pgoff, flags); + else + rv = orig_addr; unuse_pde(pde); } return rv; diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 9649ff0c63f8..bd7e98752222 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -142,7 +142,10 @@ static inline int dequeue_hwpoisoned_huge_page(struct page *page) return 0; } -#define isolate_huge_page(p, l) false +static inline bool isolate_huge_page(struct page *page, struct list_head *list) +{ + return false; +} #define putback_active_hugepage(p) do {} while (0) #define is_hugepage_active(x) false diff --git a/include/linux/kernel.h b/include/linux/kernel.h index d4e98d13eff4..ecb87544cc5d 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -193,7 +193,8 @@ extern int _cond_resched(void); (__x < 0) ? -__x : __x; \ }) -#if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP) +#if defined(CONFIG_MMU) && \ + (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)) void might_fault(void); #else static inline void might_fault(void) { } diff --git a/include/linux/mfd/samsung/core.h b/include/linux/mfd/samsung/core.h index 2d0c9071bcfb..cab2dd279076 100644 --- a/include/linux/mfd/samsung/core.h +++ b/include/linux/mfd/samsung/core.h @@ -39,7 +39,8 @@ enum sec_device_type { struct sec_pmic_dev { struct device *dev; struct sec_platform_data *pdata; - struct regmap *regmap; + struct regmap *regmap_pmic; + struct regmap *regmap_rtc; struct i2c_client *i2c; struct i2c_client *rtc; diff --git a/mm/huge_memory.c b/mm/huge_memory.c index bccd5a628ea6..33a5dc492810 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1481,8 +1481,18 @@ int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma, pmd = pmdp_get_and_clear(mm, old_addr, old_pmd); VM_BUG_ON(!pmd_none(*new_pmd)); set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd)); - if (new_ptl != old_ptl) + if (new_ptl != old_ptl) { + pgtable_t pgtable; + + /* + * Move preallocated PTE page table if new_pmd is on + * different PMD page table. + */ + pgtable = pgtable_trans_huge_withdraw(mm, old_pmd); + pgtable_trans_huge_deposit(mm, new_pmd, pgtable); + spin_unlock(new_ptl); + } spin_unlock(old_ptl); } out: diff --git a/mm/memcontrol.c b/mm/memcontrol.c index f1a0ae6e11b8..bf5e89457149 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2694,7 +2694,10 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm, goto bypass; if (unlikely(task_in_memcg_oom(current))) - goto bypass; + goto nomem; + + if (gfp_mask & __GFP_NOFAIL) + oom = false; /* * We always charge the cgroup the mm_struct belongs to. @@ -6352,6 +6355,42 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) static void mem_cgroup_css_free(struct cgroup_subsys_state *css) { struct mem_cgroup *memcg = mem_cgroup_from_css(css); + /* + * XXX: css_offline() would be where we should reparent all + * memory to prepare the cgroup for destruction. However, + * memcg does not do css_tryget() and res_counter charging + * under the same RCU lock region, which means that charging + * could race with offlining. Offlining only happens to + * cgroups with no tasks in them but charges can show up + * without any tasks from the swapin path when the target + * memcg is looked up from the swapout record and not from the + * current task as it usually is. A race like this can leak + * charges and put pages with stale cgroup pointers into + * circulation: + * + * #0 #1 + * lookup_swap_cgroup_id() + * rcu_read_lock() + * mem_cgroup_lookup() + * css_tryget() + * rcu_read_unlock() + * disable css_tryget() + * call_rcu() + * offline_css() + * reparent_charges() + * res_counter_charge() + * css_put() + * css_free() + * pc->mem_cgroup = dead memcg + * add page to lru + * + * The bulk of the charges are still moved in offline_css() to + * avoid pinning a lot of pages in case a long-term reference + * like a swapout record is deferring the css_free() to long + * after offlining. But this makes sure we catch any charges + * made after offlining: + */ + mem_cgroup_reparent_charges(memcg); memcg_destroy_kmem(memcg); __mem_cgroup_free(memcg);