@@ -222,6 +222,76 @@ static inline void log_cpu_exec(target_ulong pc, CPUState *cpu,
}
}
+static bool check_for_breakpoints(CPUState *cpu, target_ulong pc,
+ uint32_t *cflags)
+{
+ CPUBreakpoint *bp;
+ bool match_page = false;
+
+ if (likely(QTAILQ_EMPTY(&cpu->breakpoints))) {
+ return false;
+ }
+
+ /*
+ * Singlestep overrides breakpoints.
+ * This requirement is visible in the record-replay tests, where
+ * we would fail to make forward progress in reverse-continue.
+ *
+ * TODO: gdb singlestep should only override gdb breakpoints,
+ * so that one could (gdb) singlestep into the guest kernel's
+ * architectural breakpoint handler.
+ */
+ if (cpu->singlestep_enabled) {
+ return false;
+ }
+
+ QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {
+ /*
+ * If we have an exact pc match, trigger the breakpoint.
+ * Otherwise, note matches within the page.
+ */
+ if (pc == bp->pc) {
+ bool match_bp = false;
+
+ if (bp->flags & BP_GDB) {
+ match_bp = true;
+ } else if (bp->flags & BP_CPU) {
+#ifdef CONFIG_USER_ONLY
+ g_assert_not_reached();
+#else
+ CPUClass *cc = CPU_GET_CLASS(cpu);
+ assert(cc->tcg_ops->debug_check_breakpoint);
+ match_bp = cc->tcg_ops->debug_check_breakpoint(cpu);
+#endif
+ }
+
+ if (match_bp) {
+ cpu->exception_index = EXCP_DEBUG;
+ return true;
+ }
+ } else if (((pc ^ bp->pc) & TARGET_PAGE_MASK) == 0) {
+ match_page = true;
+ }
+ }
+
+ /*
+ * Within the same page as a breakpoint, single-step,
+ * returning to helper_lookup_tb_ptr after each insn looking
+ * for the actual breakpoint.
+ *
+ * TODO: Perhaps better to record all of the TBs associated
+ * with a given virtual page that contains a breakpoint, and
+ * then invalidate them when a new overlapping breakpoint is
+ * set on the page. Non-overlapping TBs would not be
+ * invalidated, nor would any TB need to be invalidated as
+ * breakpoints are removed.
+ */
+ if (match_page) {
+ *cflags = (*cflags & ~CF_COUNT_MASK) | CF_NO_GOTO_TB | 1;
+ }
+ return false;
+}
+
/**
* helper_lookup_tb_ptr: quick check for next tb
* @env: current cpu state
@@ -235,11 +305,16 @@ const void *HELPER(lookup_tb_ptr)(CPUArchState *env)
CPUState *cpu = env_cpu(env);
TranslationBlock *tb;
target_ulong cs_base, pc;
- uint32_t flags;
+ uint32_t flags, cflags;
cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
- tb = tb_lookup(cpu, pc, cs_base, flags, curr_cflags(cpu));
+ cflags = curr_cflags(cpu);
+ if (check_for_breakpoints(cpu, pc, &cflags)) {
+ cpu_loop_exit(cpu);
+ }
+
+ tb = tb_lookup(cpu, pc, cs_base, flags, cflags);
if (tb == NULL) {
return tcg_code_gen_epilogue;
}
@@ -346,6 +421,12 @@ void cpu_exec_step_atomic(CPUState *cpu)
cflags &= ~CF_PARALLEL;
/* After 1 insn, return and release the exclusive lock. */
cflags |= CF_NO_GOTO_TB | CF_NO_GOTO_PTR | 1;
+ /*
+ * No need to check_for_breakpoints here.
+ * We only arrive in cpu_exec_step_atomic after beginning execution
+ * of an insn that includes an atomic operation we can't handle.
+ * Any breakpoint for this insn will have been recognized earlier.
+ */
tb = tb_lookup(cpu, pc, cs_base, flags, cflags);
if (tb == NULL) {
@@ -837,6 +918,8 @@ int cpu_exec(CPUState *cpu)
target_ulong cs_base, pc;
uint32_t flags, cflags;
+ cpu_get_tb_cpu_state(cpu->env_ptr, &pc, &cs_base, &flags);
+
/*
* When requested, use an exact setting for cflags for the next
* execution. This is used for icount, precise smc, and stop-
@@ -851,7 +934,9 @@ int cpu_exec(CPUState *cpu)
cpu->cflags_next_tb = -1;
}
- cpu_get_tb_cpu_state(cpu->env_ptr, &pc, &cs_base, &flags);
+ if (check_for_breakpoints(cpu, pc, &cflags)) {
+ break;
+ }
tb = tb_lookup(cpu, pc, cs_base, flags, cflags);
if (tb == NULL) {
@@ -50,7 +50,6 @@ bool translator_use_goto_tb(DisasContextBase *db, target_ulong dest)
void translator_loop(const TranslatorOps *ops, DisasContextBase *db,
CPUState *cpu, TranslationBlock *tb, int max_insns)
{
- int bp_insn = 0;
bool plugin_enabled;
/* Initialize DisasContext */
@@ -85,27 +84,6 @@ void translator_loop(const TranslatorOps *ops, DisasContextBase *db,
plugin_gen_insn_start(cpu, db);
}
- /* Pass breakpoint hits to target for further processing */
- if (!db->singlestep_enabled
- && unlikely(!QTAILQ_EMPTY(&cpu->breakpoints))) {
- CPUBreakpoint *bp;
- QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {
- if (bp->pc == db->pc_next) {
- if (ops->breakpoint_check(db, cpu, bp)) {
- bp_insn = 1;
- break;
- }
- }
- }
- /* The breakpoint_check hook may use DISAS_TOO_MANY to indicate
- that only one more instruction is to be executed. Otherwise
- it should use DISAS_NORETURN when generating an exception,
- but may use a DISAS_TARGET_* value for Something Else. */
- if (db->is_jmp > DISAS_TOO_MANY) {
- break;
- }
- }
-
/* Disassemble one instruction. The translate_insn hook should
update db->pc_next and db->is_jmp to indicate what should be
done next -- either exiting this loop or locate the start of
@@ -144,7 +122,7 @@ void translator_loop(const TranslatorOps *ops, DisasContextBase *db,
/* Emit code to exit the TB, as indicated by db->is_jmp. */
ops->tb_stop(db, cpu);
- gen_tb_end(db->tb, db->num_insns - bp_insn);
+ gen_tb_end(db->tb, db->num_insns);
if (plugin_enabled) {
plugin_gen_tb_end(cpu);
@@ -225,11 +225,6 @@ void tb_invalidate_phys_addr(target_ulong addr)
tb_invalidate_phys_page_range(addr, addr + 1);
mmap_unlock();
}
-
-static void breakpoint_invalidate(CPUState *cpu, target_ulong pc)
-{
- tb_invalidate_phys_addr(pc);
-}
#else
void tb_invalidate_phys_addr(AddressSpace *as, hwaddr addr, MemTxAttrs attrs)
{
@@ -250,17 +245,6 @@ void tb_invalidate_phys_addr(AddressSpace *as, hwaddr addr, MemTxAttrs attrs)
ram_addr = memory_region_get_ram_addr(mr) + addr;
tb_invalidate_phys_page_range(ram_addr, ram_addr + 1);
}
-
-static void breakpoint_invalidate(CPUState *cpu, target_ulong pc)
-{
- /*
- * There may not be a virtual to physical translation for the pc
- * right now, but there may exist cached TB for this pc.
- * Flush the whole TB cache to force re-translation of such TBs.
- * This is heavyweight, but we're debugging anyway.
- */
- tb_flush(cpu);
-}
#endif
/* Add a breakpoint. */
@@ -286,8 +270,6 @@ int cpu_breakpoint_insert(CPUState *cpu, vaddr pc, int flags,
QTAILQ_INSERT_TAIL(&cpu->breakpoints, bp, entry);
}
- breakpoint_invalidate(cpu, pc);
-
if (breakpoint) {
*breakpoint = bp;
}
@@ -320,8 +302,6 @@ void cpu_breakpoint_remove_by_ref(CPUState *cpu, CPUBreakpoint *bp)
{
QTAILQ_REMOVE(&cpu->breakpoints, bp, entry);
- breakpoint_invalidate(cpu, bp->pc);
-
trace_breakpoint_remove(cpu->cpu_index, bp->pc, bp->flags);
g_free(bp);
}