Question

1. kmalloc()
   • Can be used by regular processes as a faster, lower-level version of malloc
   • Allocates memory in the kernel with different priorities
   • Only accepts allocation requests that are evenly divisible by the page size
   • Returns the physical address of allocated memory
   • All of the above
2. If the kernel makes use of a userspace pointer as if it was a regular pointer, the kernel could
   • return confidential kernel data to a process
   • overwrite kernel data it shouldn't
   • attempt to write to memory that isn't writable
   • attempt to read memory that isn't readable
   • all of the above
3. When you stat a file, you are getting the contents of
   • a directory entry
   • an inode
   • a file's page table
   • a block on disk
4. Changing the return value of getdents() involves
   • changing file permissions
   • allocating kernel memory statically
   • traversing a set of fixed-length records
   • parsing filenames
   • all of the above

Answer 1

Ans - 1.

Kmalloc is the normal method which allo to allocate memory for objects smaller then the page size in kernel.

So option b is coorect which says that kmalloc() allocates memory in the kernel with different priorities.

Ans - 2.

If kernel makes uses use of userspace pointer as if it was a regular pointer the kernel could

Option (e) that is all of the above.

Ans - 3.

When you state a file you are getting the contents of

Option (b) an inode.