patch_instructions() introduces new behaviour with a couple of
variations. Test each case of
* a repeated 32-bit instruction,
* a repeated 64-bit instruction (ppc64), and
* a copied sequence of instructions
for both on a single page and when it crosses a page boundary.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240325052815.854044-1-bgray@linux.ibm.com
The purpose of selftests is to check that instructions are
properly formed. Not to check that they properly run.
For that test it uses normal memory, not special test
memory.
In preparation of a future patch enforcing patch_instruction()
to be used only on valid text areas, implement a ppc_inst_write()
instruction which is the complement of ppc_inst_read(). This
new function writes the formated instruction in valid kernel
memory and doesn't bother about icache.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7cf5335cc07ca9b6f8cdaa20ca9887fce4df3bea.1638446239.git.christophe.leroy@csgroup.eu
