Re: [PATCH] ipmi: proper spinlocks initializations

[Corey Minyard <minyard@acm.org>]

Looks good to me.

Acked-by: Corey Minyard <cminyard@mvista.com>

On 10/19/2010 09:37 AM, Eric Dumazet wrote:
> 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@gmail.com>
> CC: David Miller<davem@davemloft.net>
> CC: Yinghai Lu<yinghai@kernel.org>
> CC: Andrew Morton<akpm@linux-foundation.org>
> ---
> 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)
>
>
>