target/m68k: fix physical address translation in m68k_cpu_get_phys_page_debug()

The result of the get_physical_address() function should be combined with the
offset of the original page access before being returned. Otherwise the
m68k_cpu_get_phys_page_debug() function can round to the wrong page causing
incorrect lookups in gdbstub and various "Disassembler disagrees with
translator over instruction decoding" warnings to appear at translation time.

Fixes: 88b2fef ("target/m68k: add MC68040 MMU")
Signed-off-by: Mark Cave-Ayland <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Laurent Vivier <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Laurent Vivier <[email protected]>

Author: mcayland

target/m68k/helper.c

@@ -820,10 +820,14 @@ hwaddr m68k_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
     if (env->sr & SR_S) {
         access_type |= ACCESS_SUPER;
     }
+
     if (get_physical_address(env, &phys_addr, &prot,
                              addr, access_type, &page_size) != 0) {
         return -1;
     }
+
+    addr &= TARGET_PAGE_MASK;
+    phys_addr += addr & (page_size - 1);
     return phys_addr;
 }