* Ren, Qiaowei <qiaowei....@intel.com> wrote:
> The size of one bound table is 4M bytes for 64bit, and 16K bytes for
> 32bit. It can not be accessed by user-space, and it will be accessed
> automatically by hardware.
So, here's the bound-table allocation AFAICS:
+static bool allocate_bt(unsigned long bd_entry)
+{
+ unsigned long bt_size = 1UL << (MPX_L2_BITS+MPX_L2_SHIFT);
+ unsigned long bt_addr, old_val = 0;
+
+ bt_addr = sys_mmap_pgoff(0, bt_size, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE | MAP_POPULATE, -1, 0);
What ensures that user-space cannot access (and in particular, modify)
the pages at bt_addr? It's a read-write anonymous mapping AFAICS.
Thanks,
Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
