mprotect04: fix powerpc crash when copying exec_func
Testcase tried to copy page size area starting at &exec_func.
This results in crash on powerpc, because &exec_func is too close
to end of page and subsequent page is not mapped:
10000000-10010000 r-xp 00000000 fd:00 402855 mprotect04
10010000-10020000 rw-p 00000000 fd:00 402855 mprotect04
806a410000-806a440000 r-xp 00000000 fd:00 2097827 /lib64/ld-2.12.so
where &exec_func == 0x100199c0, and page_size == 65536.
It's also worth noting, that function ptr does not reside in .text,
but in .opd section. That shouldn't matter for this testcase as long
as it doesn't try to copy non-existent pages.
This patch is changing copy function to try copy 2 whole aligned pages.
Both pages are checked to be present in memory before memcpy is
attempted. First is the page which contains &exec_func, and 2nd is the
subsequent page - for the case &exec_func is too close to page boundary.
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>
1 file changed