diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c index 019669eb21d2..71c1262589fe 100644 --- a/arch/powerpc/platforms/powernv/memtrace.c +++ b/arch/powerpc/platforms/powernv/memtrace.c @@ -46,10 +46,26 @@ static ssize_t memtrace_read(struct file *filp, char __user *ubuf, return simple_read_from_buffer(ubuf, count, ppos, ent->mem, ent->size); } +static int memtrace_mmap(struct file *filp, struct vm_area_struct *vma) +{ + struct memtrace_entry *ent = filp->private_data; + + if (ent->size < vma->vm_end - vma->vm_start) + return -EINVAL; + + if (vma->vm_pgoff << PAGE_SHIFT >= ent->size) + return -EINVAL; + + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + return remap_pfn_range(vma, vma->vm_start, PHYS_PFN(ent->start) + vma->vm_pgoff, + vma->vm_end - vma->vm_start, vma->vm_page_prot); +} + static const struct file_operations memtrace_fops = { .llseek = default_llseek, .read = memtrace_read, .open = simple_open, + .mmap = memtrace_mmap, }; #define FLUSH_CHUNK_SIZE SZ_1G @@ -187,7 +203,7 @@ static int memtrace_init_debugfs(void) dir = debugfs_create_dir(ent->name, memtrace_debugfs_dir); ent->dir = dir; - debugfs_create_file("trace", 0400, dir, ent, &memtrace_fops); + debugfs_create_file_unsafe("trace", 0600, dir, ent, &memtrace_fops); debugfs_create_x64("start", 0400, dir, &ent->start); debugfs_create_x64("size", 0400, dir, &ent->size); }