[PATCH] EDAC: Fix lockdep splat
From: Borislav Petkov
Date: Fri Jul 12 2013 - 04:53:38 EST
Fix the following:
BUG: key ffff88043bdd0330 not in .data!
------------[ cut here ]------------
WARNING: at kernel/lockdep.c:2987 lockdep_init_map+0x565/0x5a0()
DEBUG_LOCKS_WARN_ON(1)
Modules linked in: glue_helper sb_edac(+) edac_core snd acpi_cpufreq lrw gf128mul ablk_helper iTCO_wdt evdev i2c_i801 dcdbas button cryptd pcspkr iTCO_vendor_support usb_common lpc_ich mfd_core soundcore mperf processor microcode
CPU: 2 PID: 599 Comm: modprobe Not tainted 3.10.0 #1
Hardware name: Dell Inc. Precision T3600/0PTTT9, BIOS A08 01/24/2013
0000000000000009 ffff880439a1d920 ffffffff8160a9a9 ffff880439a1d958
ffffffff8103d9e0 ffff88043af4a510 ffffffff81a16e11 0000000000000000
ffff88043bdd0330 0000000000000000 ffff880439a1d9b8 ffffffff8103dacc
Call Trace:
dump_stack
warn_slowpath_common
warn_slowpath_fmt
lockdep_init_map
? trace_hardirqs_on_caller
? trace_hardirqs_on
debug_mutex_init
__mutex_init
bus_register
edac_create_sysfs_mci_device
edac_mc_add_mc
sbridge_probe
pci_device_probe
driver_probe_device
__driver_attach
? driver_probe_device
bus_for_each_dev
driver_attach
bus_add_driver
driver_register
__pci_register_driver
? 0xffffffffa0010fff
sbridge_init
? 0xffffffffa0010fff
do_one_initcall
load_module
? unset_module_init_ro_nx
SyS_init_module
tracesys
---[ end trace d24a70b0d3ddf733 ]---
EDAC MC0: Giving out device to 'sbridge_edac.c' 'Sandy Bridge Socket#0': DEV 0000:3f:0e.0
EDAC sbridge: Driver loaded.
What happens is that bus_register needs a statically allocated lock_key
because it is handed in to lockdep. However, struct mem_ctl_info embeds
struct bus_type (the whole struct, not a pointer to it) which gets
dynamically allocated.
Fix this by using a statically allocated struct bus_type for the MC bus.
Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxx>
Cc: Markus Trippelsdorf <markus@xxxxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
drivers/edac/edac_mc.c | 6 ++++++
drivers/edac/edac_mc_sysfs.c | 28 +++++++++++++++-------------
drivers/edac/i5100_edac.c | 2 +-
include/linux/edac.h | 7 ++++++-
4 files changed, 28 insertions(+), 15 deletions(-)
diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index 27e86d938262..429e971e02d7 100644
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -48,6 +48,8 @@ static LIST_HEAD(mc_devices);
*/
static void const *edac_mc_owner;
+static struct bus_type mc_bus[EDAC_MAX_MCS];
+
unsigned edac_dimm_info_location(struct dimm_info *dimm, char *buf,
unsigned len)
{
@@ -762,6 +764,10 @@ int edac_mc_add_mc(struct mem_ctl_info *mci)
/* set load time so that error rate can be tracked */
mci->start_time = jiffies;
+ BUG_ON(mci->mc_idx >= EDAC_MAX_MCS);
+
+ mci->bus = &mc_bus[mci->mc_idx];
+
if (edac_create_sysfs_mci_device(mci)) {
edac_mc_printk(mci, KERN_WARNING,
"failed to create sysfs device\n");
diff --git a/drivers/edac/edac_mc_sysfs.c b/drivers/edac/edac_mc_sysfs.c
index ef15a7e613bc..e7c32c4f7837 100644
--- a/drivers/edac/edac_mc_sysfs.c
+++ b/drivers/edac/edac_mc_sysfs.c
@@ -370,7 +370,7 @@ static int edac_create_csrow_object(struct mem_ctl_info *mci,
return -ENODEV;
csrow->dev.type = &csrow_attr_type;
- csrow->dev.bus = &mci->bus;
+ csrow->dev.bus = mci->bus;
device_initialize(&csrow->dev);
csrow->dev.parent = &mci->dev;
csrow->mci = mci;
@@ -605,7 +605,7 @@ static int edac_create_dimm_object(struct mem_ctl_info *mci,
dimm->mci = mci;
dimm->dev.type = &dimm_attr_type;
- dimm->dev.bus = &mci->bus;
+ dimm->dev.bus = mci->bus;
device_initialize(&dimm->dev);
dimm->dev.parent = &mci->dev;
@@ -975,11 +975,13 @@ int edac_create_sysfs_mci_device(struct mem_ctl_info *mci)
* The memory controller needs its own bus, in order to avoid
* namespace conflicts at /sys/bus/edac.
*/
- mci->bus.name = kasprintf(GFP_KERNEL, "mc%d", mci->mc_idx);
- if (!mci->bus.name)
+ mci->bus->name = kasprintf(GFP_KERNEL, "mc%d", mci->mc_idx);
+ if (!mci->bus->name)
return -ENOMEM;
- edac_dbg(0, "creating bus %s\n", mci->bus.name);
- err = bus_register(&mci->bus);
+
+ edac_dbg(0, "creating bus %s\n", mci->bus->name);
+
+ err = bus_register(mci->bus);
if (err < 0)
return err;
@@ -988,7 +990,7 @@ int edac_create_sysfs_mci_device(struct mem_ctl_info *mci)
device_initialize(&mci->dev);
mci->dev.parent = mci_pdev;
- mci->dev.bus = &mci->bus;
+ mci->dev.bus = mci->bus;
dev_set_name(&mci->dev, "mc%d", mci->mc_idx);
dev_set_drvdata(&mci->dev, mci);
pm_runtime_forbid(&mci->dev);
@@ -997,8 +999,8 @@ int edac_create_sysfs_mci_device(struct mem_ctl_info *mci)
err = device_add(&mci->dev);
if (err < 0) {
edac_dbg(1, "failure: create device %s\n", dev_name(&mci->dev));
- bus_unregister(&mci->bus);
- kfree(mci->bus.name);
+ bus_unregister(mci->bus);
+ kfree(mci->bus->name);
return err;
}
@@ -1064,8 +1066,8 @@ fail:
}
fail2:
device_unregister(&mci->dev);
- bus_unregister(&mci->bus);
- kfree(mci->bus.name);
+ bus_unregister(mci->bus);
+ kfree(mci->bus->name);
return err;
}
@@ -1098,8 +1100,8 @@ void edac_unregister_sysfs(struct mem_ctl_info *mci)
{
edac_dbg(1, "Unregistering device %s\n", dev_name(&mci->dev));
device_unregister(&mci->dev);
- bus_unregister(&mci->bus);
- kfree(mci->bus.name);
+ bus_unregister(mci->bus);
+ kfree(mci->bus->name);
}
static void mc_attr_release(struct device *dev)
diff --git a/drivers/edac/i5100_edac.c b/drivers/edac/i5100_edac.c
index 1b635178cc44..157b934e8ce3 100644
--- a/drivers/edac/i5100_edac.c
+++ b/drivers/edac/i5100_edac.c
@@ -974,7 +974,7 @@ static int i5100_setup_debugfs(struct mem_ctl_info *mci)
if (!i5100_debugfs)
return -ENODEV;
- priv->debugfs = debugfs_create_dir(mci->bus.name, i5100_debugfs);
+ priv->debugfs = debugfs_create_dir(mci->bus->name, i5100_debugfs);
if (!priv->debugfs)
return -ENOMEM;
diff --git a/include/linux/edac.h b/include/linux/edac.h
index 0b763276f619..5c6d7fbaf89e 100644
--- a/include/linux/edac.h
+++ b/include/linux/edac.h
@@ -622,7 +622,7 @@ struct edac_raw_error_desc {
*/
struct mem_ctl_info {
struct device dev;
- struct bus_type bus;
+ struct bus_type *bus;
struct list_head link; /* for global list of mem_ctl_info structs */
@@ -742,4 +742,9 @@ struct mem_ctl_info {
#endif
};
+/*
+ * Maximum number of memory controllers in the coherent fabric.
+ */
+#define EDAC_MAX_MCS 16
+
#endif
--
1.8.3
--
Regards/Gruss,
Boris.
Sent from a fat crate under my desk. Formatting is fine.
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