ARM: move signal handlers into a vdso-like page
Move the signal handlers into a VDSO page rather than keeping them in
the vectors page. This allows us to place them randomly within this
page, and also map the page at a random location within userspace
further protecting these code fragments from ROP attacks. The new
VDSO page is also poisoned in the same way as the vector page.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/mmu.h b/arch/arm/include/asm/mmu.h
index e3d5554..7345e37 100644
--- a/arch/arm/include/asm/mmu.h
+++ b/arch/arm/include/asm/mmu.h
@@ -8,6 +8,7 @@
atomic64_t id;
#endif
unsigned int vmalloc_seq;
+ unsigned long sigpage;
} mm_context_t;
#ifdef CONFIG_CPU_HAS_ASID