From bf4b9d2fecd366336aa76ce26b5b38af7c3db4dc Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 12 Nov 2014 09:18:07 +0900 Subject: [PATCH] 3.10-stable patches added patches: i2c-at91-don-t-account-as-iowait.patch sysfs-driver-core-fix-glue-dir-race-condition-by-gdp_mutex.patch --- .../i2c-at91-don-t-account-as-iowait.patch | 32 ++++++ queue-3.10/series | 2 + ...glue-dir-race-condition-by-gdp_mutex.patch | 103 ++++++++++++++++++ 3 files changed, 137 insertions(+) create mode 100644 queue-3.10/i2c-at91-don-t-account-as-iowait.patch create mode 100644 queue-3.10/sysfs-driver-core-fix-glue-dir-race-condition-by-gdp_mutex.patch diff --git a/queue-3.10/i2c-at91-don-t-account-as-iowait.patch b/queue-3.10/i2c-at91-don-t-account-as-iowait.patch new file mode 100644 index 00000000000..65ec8631433 --- /dev/null +++ b/queue-3.10/i2c-at91-don-t-account-as-iowait.patch @@ -0,0 +1,32 @@ +From 11cfbfb098b22d3e57f1f2be217cad20e2d48463 Mon Sep 17 00:00:00 2001 +From: Wolfram Sang +Date: Mon, 3 Nov 2014 21:16:16 +0100 +Subject: i2c: at91: don't account as iowait + +From: Wolfram Sang + +commit 11cfbfb098b22d3e57f1f2be217cad20e2d48463 upstream. + +iowait is for blkio [1]. I2C shouldn't use it. + +[1] https://lkml.org/lkml/2014/11/3/317 + +Signed-off-by: Wolfram Sang +Acked-by: Ludovic Desroches +Signed-off-by: Greg Kroah-Hartman + +--- + drivers/i2c/busses/i2c-at91.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/drivers/i2c/busses/i2c-at91.c ++++ b/drivers/i2c/busses/i2c-at91.c +@@ -435,7 +435,7 @@ static int at91_do_twi_transfer(struct a + } + } + +- ret = wait_for_completion_io_timeout(&dev->cmd_complete, ++ ret = wait_for_completion_timeout(&dev->cmd_complete, + dev->adapter.timeout); + if (ret == 0) { + dev_err(dev->dev, "controller timed out\n"); diff --git a/queue-3.10/series b/queue-3.10/series index 42c1b7b818b..ecafe33c0c9 100644 --- a/queue-3.10/series +++ b/queue-3.10/series @@ -116,3 +116,5 @@ usb-gadget-udc-core-fix-kernel-oops-with-soft-connect.patch drm-radeon-remove-invalid-pci-id.patch rbd-fix-error-recovery-in-rbd_obj_read_sync.patch acer-wmi-add-acpi_backlight-video-quirk-for-the-acer-kav80.patch +i2c-at91-don-t-account-as-iowait.patch +sysfs-driver-core-fix-glue-dir-race-condition-by-gdp_mutex.patch diff --git a/queue-3.10/sysfs-driver-core-fix-glue-dir-race-condition-by-gdp_mutex.patch b/queue-3.10/sysfs-driver-core-fix-glue-dir-race-condition-by-gdp_mutex.patch new file mode 100644 index 00000000000..649b3cc18cc --- /dev/null +++ b/queue-3.10/sysfs-driver-core-fix-glue-dir-race-condition-by-gdp_mutex.patch @@ -0,0 +1,103 @@ +From e4a60d139060975eb956717e4f63ae348d4d8cc5 Mon Sep 17 00:00:00 2001 +From: Yijing Wang +Date: Fri, 7 Nov 2014 12:05:49 +0800 +Subject: sysfs: driver core: Fix glue dir race condition by gdp_mutex + +From: Yijing Wang + +commit e4a60d139060975eb956717e4f63ae348d4d8cc5 upstream. + +There is a race condition when removing glue directory. +It can be reproduced in following test: + +path 1: Add first child device +device_add() + get_device_parent() + /*find parent from glue_dirs.list*/ + list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry) + if (k->parent == parent_kobj) { + kobj = kobject_get(k); + break; + } + .... + class_dir_create_and_add() + +path2: Remove last child device under glue dir +device_del() + cleanup_device_parent() + cleanup_glue_dir() + kobject_put(glue_dir); + +If path2 has been called cleanup_glue_dir(), but not +call kobject_put(glue_dir), the glue dir is still +in parent's kset list. Meanwhile, path1 find the glue +dir from the glue_dirs.list. Path2 may release glue dir +before path1 call kobject_get(). So kernel will report +the warning and bug_on. + +This is a "classic" problem we have of a kref in a list +that can be found while the last instance could be removed +at the same time. + +This patch reuse gdp_mutex to fix this race condition. + +The following calltrace is captured in kernel 3.4, but +the latest kernel still has this bug. + +----------------------------------------------------- +<4>[ 3965.441471] WARNING: at ...include/linux/kref.h:41 kobject_get+0x33/0x40() +<4>[ 3965.441474] Hardware name: Romley +<4>[ 3965.441475] Modules linked in: isd_iop(O) isd_xda(O)... +... +<4>[ 3965.441605] Call Trace: +<4>[ 3965.441611] [] warn_slowpath_common+0x7a/0xb0 +<4>[ 3965.441615] [] warn_slowpath_null+0x15/0x20 +<4>[ 3965.441618] [] kobject_get+0x33/0x40 +<4>[ 3965.441624] [] get_device_parent.isra.11+0x135/0x1f0 +<4>[ 3965.441627] [] device_add+0xd4/0x6d0 +<4>[ 3965.441631] [] ? dev_set_name+0x3c/0x40 +.... +<2>[ 3965.441912] kernel BUG at ..../fs/sysfs/group.c:65! +<4>[ 3965.441915] invalid opcode: 0000 [#1] SMP +... +<4>[ 3965.686743] [] sysfs_create_group+0xe/0x10 +<4>[ 3965.686748] [] blk_trace_init_sysfs+0x14/0x20 +<4>[ 3965.686753] [] blk_register_queue+0x3b/0x120 +<4>[ 3965.686756] [] add_disk+0x1cc/0x490 +.... +------------------------------------------------------- + +Signed-off-by: Yijing Wang +Signed-off-by: Weng Meiling +Signed-off-by: Greg Kroah-Hartman + +--- + drivers/base/core.c | 4 +++- + 1 file changed, 3 insertions(+), 1 deletion(-) + +--- a/drivers/base/core.c ++++ b/drivers/base/core.c +@@ -765,12 +765,12 @@ class_dir_create_and_add(struct class *c + return &dir->kobj; + } + ++static DEFINE_MUTEX(gdp_mutex); + + static struct kobject *get_device_parent(struct device *dev, + struct device *parent) + { + if (dev->class) { +- static DEFINE_MUTEX(gdp_mutex); + struct kobject *kobj = NULL; + struct kobject *parent_kobj; + struct kobject *k; +@@ -834,7 +834,9 @@ static void cleanup_glue_dir(struct devi + glue_dir->kset != &dev->class->p->glue_dirs) + return; + ++ mutex_lock(&gdp_mutex); + kobject_put(glue_dir); ++ mutex_unlock(&gdp_mutex); + } + + static void cleanup_device_parent(struct device *dev) -- 2.47.3