Bug 42967

Hi,

kmalloc_node crashes when it tries to allocate memory on a node that doesn't have memory.
Below is a simple kernel module that illustrates the problem:
It crashes when the core parameter is out of range (for example if we use 1 when there is memory only on node 0). The log crash is attached.
A better behaviour would be to return a NULL pointer that could be checked and handled by the module.


#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>

static char* ptr = NULL;
static int core = 0;
module_param(core, int, S_IRUSR);


static int __init mymodule_init(void)
{
    printk("Using core affinity %d\n", core);
    ptr = kmalloc_node(GFP_KERNEL, 128, core);
    printk ("My module worked! ptr = %p\n", ptr);
    return 0;
}

static void __exit mymodule_exit(void)
{
    kfree(ptr);
    printk ("Unloading my module.\n");
    return;
}

module_init(mymodule_init);
module_exit(mymodule_exit);

MODULE_LICENSE("GPL");