[PATCH] ipmi: proper spinlocks initializations

From: Eric Dumazet
Date: Tue Oct 19 2010 - 10:38:11 EST


Unloading ipmi module can trigger following error.
(if CONFIG_DEBUG_SPINLOCK=y)

[ 9633.779590] BUG: spinlock bad magic on CPU#1, rmmod/7170
[ 9633.779606] lock: f41f5414, .magic: 00000000, .owner:
<none>/-1, .owner_cpu: 0
[ 9633.779626] Pid: 7170, comm: rmmod Not tainted
2.6.36-rc7-11474-gb71eb1e-dirty #328
[ 9633.779644] Call Trace:
[ 9633.779657] [<c13921cc>] ? printk+0x18/0x1c
[ 9633.779672] [<c11a1f33>] spin_bug+0xa3/0xf0
[ 9633.779685] [<c11a1ffd>] do_raw_spin_lock+0x7d/0x160
[ 9633.779702] [<c1131537>] ? release_sysfs_dirent+0x47/0xb0
[ 9633.779718] [<c1131b78>] ? sysfs_addrm_finish+0xa8/0xd0
[ 9633.779734] [<c1394bac>] _raw_spin_lock_irqsave+0xc/0x20
[ 9633.779752] [<f99d93da>] cleanup_one_si+0x6a/0x200 [ipmi_si]
[ 9633.779768] [<c11305b2>] ? sysfs_hash_and_remove+0x72/0x80
[ 9633.779786] [<f99dcf26>] ipmi_pnp_remove+0xd/0xf [ipmi_si]
[ 9633.779802] [<c11f622b>] pnp_device_remove+0x1b/0x40

Fix this by initializing spinlocks in a smi_info_alloc() helper
function, right after memory allocation and clearing.

Signed-off-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
CC: David Miller <davem@xxxxxxxxxxxxx>
CC: Yinghai Lu <yinghai@xxxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
CC David since I caught this error on net-next-2.6 tree ;)

drivers/char/ipmi/ipmi_si_intf.c | 30 ++++++++++++++++++-----------
1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 7bd7c45..501f115 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -1665,6 +1665,17 @@ static int check_hotmod_int_op(const char *curr, const char *option,
return 0;
}

+static struct smi_info *smi_info_alloc(void)
+{
+ struct smi_info *info = kzalloc(sizeof(*info), GFP_KERNEL);
+
+ if (info) {
+ spin_lock_init(&info->si_lock);
+ spin_lock_init(&info->msg_lock);
+ }
+ return info;
+}
+
static int hotmod_handler(const char *val, struct kernel_param *kp)
{
char *str = kstrdup(val, GFP_KERNEL);
@@ -1779,7 +1790,7 @@ static int hotmod_handler(const char *val, struct kernel_param *kp)
}

if (op == HM_ADD) {
- info = kzalloc(sizeof(*info), GFP_KERNEL);
+ info = smi_info_alloc();
if (!info) {
rv = -ENOMEM;
goto out;
@@ -1844,7 +1855,7 @@ static __devinit void hardcode_find_bmc(void)
if (!ports[i] && !addrs[i])
continue;

- info = kzalloc(sizeof(*info), GFP_KERNEL);
+ info = smi_info_alloc();
if (!info)
return;

@@ -2028,7 +2039,7 @@ static __devinit int try_init_spmi(struct SPMITable *spmi)
return -ENODEV;
}

- info = kzalloc(sizeof(*info), GFP_KERNEL);
+ info = smi_info_alloc();
if (!info) {
printk(KERN_ERR PFX "Could not allocate SI data (3)\n");
return -ENOMEM;
@@ -2138,7 +2149,7 @@ static int __devinit ipmi_pnp_probe(struct pnp_dev *dev,
if (!acpi_dev)
return -ENODEV;

- info = kzalloc(sizeof(*info), GFP_KERNEL);
+ info = smi_info_alloc();
if (!info)
return -ENOMEM;

@@ -2319,7 +2330,7 @@ static __devinit void try_init_dmi(struct dmi_ipmi_data *ipmi_data)
{
struct smi_info *info;

- info = kzalloc(sizeof(*info), GFP_KERNEL);
+ info = smi_info_alloc();
if (!info) {
printk(KERN_ERR PFX "Could not allocate SI data\n");
return;
@@ -2426,7 +2437,7 @@ static int __devinit ipmi_pci_probe(struct pci_dev *pdev,
int class_type = pdev->class & PCI_ERMC_CLASSCODE_TYPE_MASK;
struct smi_info *info;

- info = kzalloc(sizeof(*info), GFP_KERNEL);
+ info = smi_info_alloc();
if (!info)
return -ENOMEM;

@@ -2567,7 +2578,7 @@ static int __devinit ipmi_of_probe(struct platform_device *dev,
return -EINVAL;
}

- info = kzalloc(sizeof(*info), GFP_KERNEL);
+ info = smi_info_alloc();

if (!info) {
dev_err(&dev->dev,
@@ -3014,7 +3025,7 @@ static __devinit void default_find_bmc(void)
if (check_legacy_ioport(ipmi_defaults[i].port))
continue;
#endif
- info = kzalloc(sizeof(*info), GFP_KERNEL);
+ info = smi_info_alloc();
if (!info)
return;

@@ -3139,9 +3150,6 @@ static int try_smi_init(struct smi_info *new_smi)
goto out_err;
}

- spin_lock_init(&(new_smi->si_lock));
- spin_lock_init(&(new_smi->msg_lock));
-
/* Do low-level detection first. */
if (new_smi->handlers->detect(new_smi->si_sm)) {
if (new_smi->addr_source)


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