cputlb: Pass retaddr to tb_check_watchpoint

Fixes the previous TLB_WATCHPOINT patches because we are currently
failing to set cpu->mem_io_pc with the call to cpu_check_watchpoint.
Pass down the retaddr directly because it's readily available.

Fixes: 50b107c5Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NRichard Henderson <richard.henderson@linaro.org>

accel/tcg/translate-all.c

@@ -2142,16 +2142,16 @@ static bool tb_invalidate_phys_page(tb_page_addr_t addr, uintptr_t pc)
 #endif
 
 /* user-mode: call with mmap_lock held */
-void tb_check_watchpoint(CPUState *cpu)
+void tb_check_watchpoint(CPUState *cpu, uintptr_t retaddr)
 {
     TranslationBlock *tb;
 
     assert_memory_lock();
 
-    tb = tcg_tb_lookup(cpu->mem_io_pc);
+    tb = tcg_tb_lookup(retaddr);
     if (tb) {
         /* We can use retranslation to find the PC.  */
-        cpu_restore_state_from_tb(cpu, tb, cpu->mem_io_pc, true);
+        cpu_restore_state_from_tb(cpu, tb, retaddr, true);
         tb_phys_invalidate(tb, -1);
     } else {
         /* The exception probably happened in a helper.  The CPU state should

accel/tcg/translate-all.h

@@ -30,7 +30,7 @@ void tb_invalidate_phys_page_fast(struct page_collection *pages,
                                   tb_page_addr_t start, int len,
                                   uintptr_t retaddr);
 void tb_invalidate_phys_page_range(tb_page_addr_t start, tb_page_addr_t end);
-void tb_check_watchpoint(CPUState *cpu);
+void tb_check_watchpoint(CPUState *cpu, uintptr_t retaddr);
 
 #ifdef CONFIG_USER_ONLY
 int page_unprotect(target_ulong address, uintptr_t pc);

exec.c

@@ -2758,7 +2758,7 @@ void cpu_check_watchpoint(CPUState *cpu, vaddr addr, vaddr len,
                 cpu->watchpoint_hit = wp;
 
                 mmap_lock();
-                tb_check_watchpoint(cpu);
+                tb_check_watchpoint(cpu, ra);
                 if (wp->flags & BP_STOP_BEFORE_ACCESS) {
                     cpu->exception_index = EXCP_DEBUG;
                     mmap_unlock();