Re: [PATCH 4/5] kernel handling of memory DLPAR

[Andrey Panin]

On 254, 09 11, 2009 at 04:14:35PM -0500, Nathan Fontenot wrote:
> This adds the capability to DLPAR add and remove memory from the kernel.  The
> patch extends the powerpc handling of memory_add_physaddr_to_nid(), which is
> called from the sysfs memory 'probe' file to first ensure that the memory
> has been added to the system.  This is done by creating a platform specific
> callout from the routine.  The pseries implementation of this handles the
> DLPAR work to add the memory to the system and update the device tree.
> 
> The patch also creates a pseries only 'release' sys file,
> /sys/devices/system/memory/release.  This file handles the DLPAR
> release of
> memory back to firmware and updating of the device-tree.
> 
> Signed-off-by: Nathan Fontenot 

> +static struct property *clone_property(struct property *old_prop)
> +{
> + struct property *new_prop;
> +
> + new_prop = kzalloc((sizeof *new_prop), GFP_KERNEL);
> + if (!new_prop)
> + return NULL;
> +
> + new_prop->name = kzalloc(strlen(old_prop->name) + 1, GFP_KERNEL);
> + new_prop->value = kzalloc(old_prop->length + 1, GFP_KERNEL);

Memory leak here. What if one kzalloc() succeeded and another failed ?

> + if (!new_prop->name || !new_prop->value) {
> + free_property(new_prop);
> + return NULL;
> + }
> +
> + strcpy(new_prop->name, old_prop->name);
> + memcpy(new_prop->value, old_prop->value, old_prop->length);
> + new_prop->length = old_prop->length;
> +
> + return new_prop;
> +}
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Re: [PATCH 5/5] kernel handling of CPU DLPAR

[Andrey Panin]

On 254, 09 11, 2009 at 04:15:33PM -0500, Nathan Fontenot wrote:
> This adds the capability to DLPAR add and remove CPUs from the kernel. The
> creates two new files /sys/devices/system/cpu/probe and
> /sys/devices/system/cpu/release to handle the DLPAR addition and
> removal of
> CPUs respectively.
> 
> CPU DLPAR add is accomplished by writing the drc-index of the CPU to the
> probe file, and removal is done by writing the device-tree path of the cpu
> to the release file.
> 
> Signed-off-by: Nathan Fontenot 

> +static ssize_t cpu_probe_store(struct class *class, const char *buf,
> +size_t count)
> +{
> + struct device_node *dn;
> + u32 drc_index;
> + char *cpu_name;
> + int rc;
> +
> + drc_index = simple_strtoull(buf, NULL, 0);
> + if (!drc_index)
> + return -EINVAL;
> +
> + rc = acquire_drc(drc_index);
> + if (rc)
> + return rc;
> +
> + dn = configure_connector(drc_index);
> + if (!dn) {
> + release_drc(drc_index);
> + return rc;
> + }
> +
> + /* fixup dn name */
> + cpu_name = kzalloc(strlen(dn->full_name) + strlen("/cpus/") + 1,
> +GFP_KERNEL);

Unchecked memory allocation with immediate crash in case of failure.

> + sprintf(cpu_name, "/cpus/%s", dn->full_name);
> + kfree(dn->full_name);
> + dn->full_name = cpu_name;
> +
> + rc = add_device_tree_nodes(dn);
> + if (rc)
> + release_drc(drc_index);
> +
> + return rc ? rc : count;
> +}
> +
> +static ssize_t cpu_release_store(struct class *class, const char *buf,
> +  size_t count)
> +{
> + struct device_node *dn;
> + u32 *drc_index;
> + int rc;
> +
> + dn = of_find_node_by_path(buf);
> + if (!dn)
> + return -EINVAL;
> +
> + drc_index = (u32 *)of_get_property(dn, "ibm,my-drc-index", NULL);
> + if (!drc_index) {
> + of_node_put(dn);
> + return -EINVAL;
> + }
> +
> + rc = release_drc(*drc_index);
> + if (rc) {
> + of_node_put(dn);
> + return rc;
> + }
> +
> + rc = remove_device_tree_nodes(dn);
> + if (rc)
> + acquire_drc(*drc_index);
> +
> + of_node_put(dn);
> + return rc? rc : count;
> +}
> +
> static struct class_attribute class_attr_mem_release =
>   __ATTR(release, S_IWUSR, NULL, memory_release_store);
> +static struct class_attribute class_attr_cpu_probe =
> + __ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
> +static struct class_attribute class_attr_cpu_release =
> + __ATTR(release, S_IWUSR, NULL, cpu_release_store);
> 
> static int pseries_dlpar_init(void)
> {
> @@ -576,6 +648,18 @@
>   printk(KERN_INFO "DLPAR: Could not create sysfs memory "
>  "release file\n");
> 
> + rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
> +&class_attr_cpu_probe.attr);
> + if (rc)
> + printk(KERN_INFO "DLPAR: Could not create sysfs cpu "
> +"probe file\n");
> +
> + rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
> +&class_attr_cpu_release.attr);
> + if (rc)
> + printk(KERN_INFO "DLPAR: Could not create sysfs cpu "
> +"release file\n");
> +
>   return 0;
> }
> __initcall(pseries_dlpar_init);
> --
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