The TCG helpers were added inb92e5a22ecin softmmu_template.h. probe_write() was added in there in3b4afc9e75to be moved out to accel/tcg/cputlb.c in3b08f0a925, and was later refactored as probe_access() inc25c283df0. Since it is a TCG specific helper, add a stub to avoid failures when building without TCG, such: target/arm/helper.o: In function `probe_read': include/exec/exec-all.h:362: undefined reference to `probe_access' Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>