On 30.08.2024 11:08, Ayan Kumar Halder wrote: > From: Penny Zheng <[email protected]> > > Introduce CONFIG_HAS_VMAP which is selected by the architectures that > use MMU. vm_init() does not do anything if CONFIG_HAS_VMAP is not > enabled. > > HAS_VMAP is widely used in ALTERNATIVE feature to remap a range of > memory with new memory attributes. Since this is highly dependent on > virtual address translation, we choose to make HAS_VMAP selected by > MMU. And ALTERNATIVE depends on HAS_VMAP. > > At the moment, the users of HARDEN_BRANCH_PREDICTOR requires to use the > vmap() to update the exceptions vectors. While it might be possible to > rework the code, it is believed that speculative attackes would be > difficult to exploit on non-MMU because the software is tightly > controlled. So for now make HARDEN_BRANCH_PREDICTOR to depend on the > MMU. > > Also took the opportunity to remove "#ifdef VMAP_VIRT_START .. endif" > from vmap.c. Instead vmap.c is compiled when HAS_VMAP is enabled. Thus, > HAS_VMAP is now enabled from x86, ppc and riscv architectures as all of > them use MMU and has VMAP_VIRT_START defined. > > Signed-off-by: Penny Zheng <[email protected]> > Signed-off-by: Wei Chen <[email protected]> > Signed-off-by: Ayan Kumar Halder <[email protected]> > Acked-by: Julien Grall <[email protected]>
Acked-by: Jan Beulich <[email protected]>
