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mckernel_procfs_read(): fix buffer allocation, offset check and return code

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This commit is contained in:
Balazs Gerofi bgerofi@riken.jp
2014-12-05 16:27:48 +09:00
parent cc9d30efbf
commit 25f108bf78
1 changed files with 24 additions and 6 deletions
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30
executer/kernel/procfs.c
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@ -275,23 +275,38 @@ void procfs_answer(unsigned int arg, int err)
int mckernel_procfs_read(char *buffer, char **start, off_t offset,
int count, int *peof, void *dat)
{
char *kern_buffer;
int order = 0;
struct procfs_list_entry *e = dat;
volatile struct procfs_read *r;
struct ikc_scd_packet isp;
int ret, retrycount = 0;
unsigned long pbuf;
dprintk("mckernel_procfs_read: invoked for %s\n", e->fname);
dprintk("mckernel_procfs_read: invoked for %s, count: %d\n",
e->fname, count);
/* Starting from the middle of a proc file is not supported yet */
if (offset > 0) {
return 0;
}
if (count <= 0 || dat == NULL || offset < 0) {
return 0;
}
while ((1 << order) < count) ++order;
order -= 12;
pbuf = virt_to_phys(buffer);
if (pbuf / PAGE_SIZE != (pbuf + count - 1) / PAGE_SIZE) {
/* Truncate the read count upto the nearest page boundary */
count = ((pbuf + count - 1) / PAGE_SIZE) * PAGE_SIZE - pbuf;
/* NOTE: we need physically contigous memory to pass through IKC */
kern_buffer = (char *)__get_free_pages(GFP_KERNEL, order);
if (!kern_buffer) {
printk("mckernel_procfs_read(): ERROR: allocating kernel buffer\n");
return -ENOMEM;
}
pbuf = virt_to_phys(kern_buffer);
r = kmalloc(sizeof(struct procfs_read), GFP_KERNEL);
if (r == NULL) {
return -ENOMEM;
@ -339,9 +354,12 @@ retry:
dprintk("reached end of file.\n");
*peof = 1;
}
*start = buffer;
memcpy(buffer, kern_buffer, r->ret);
ret = r->ret;
out:
free_pages((uintptr_t)kern_buffer, order);
kfree((void *)r);
return ret;