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-rw-r--r--target/i386/bpt_helper.c328
1 files changed, 328 insertions, 0 deletions
diff --git a/target/i386/bpt_helper.c b/target/i386/bpt_helper.c
new file mode 100644
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--- /dev/null
+++ b/target/i386/bpt_helper.c
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+/*
+ * i386 breakpoint helpers
+ *
+ * Copyright (c) 2003 Fabrice Bellard
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/exec-all.h"
+#include "exec/helper-proto.h"
+
+
+#ifndef CONFIG_USER_ONLY
+static inline bool hw_local_breakpoint_enabled(unsigned long dr7, int index)
+{
+ return (dr7 >> (index * 2)) & 1;
+}
+
+static inline bool hw_global_breakpoint_enabled(unsigned long dr7, int index)
+{
+ return (dr7 >> (index * 2)) & 2;
+
+}
+static inline bool hw_breakpoint_enabled(unsigned long dr7, int index)
+{
+ return hw_global_breakpoint_enabled(dr7, index) ||
+ hw_local_breakpoint_enabled(dr7, index);
+}
+
+static inline int hw_breakpoint_type(unsigned long dr7, int index)
+{
+ return (dr7 >> (DR7_TYPE_SHIFT + (index * 4))) & 3;
+}
+
+static inline int hw_breakpoint_len(unsigned long dr7, int index)
+{
+ int len = ((dr7 >> (DR7_LEN_SHIFT + (index * 4))) & 3);
+ return (len == 2) ? 8 : len + 1;
+}
+
+static int hw_breakpoint_insert(CPUX86State *env, int index)
+{
+ CPUState *cs = CPU(x86_env_get_cpu(env));
+ target_ulong dr7 = env->dr[7];
+ target_ulong drN = env->dr[index];
+ int err = 0;
+
+ switch (hw_breakpoint_type(dr7, index)) {
+ case DR7_TYPE_BP_INST:
+ if (hw_breakpoint_enabled(dr7, index)) {
+ err = cpu_breakpoint_insert(cs, drN, BP_CPU,
+ &env->cpu_breakpoint[index]);
+ }
+ break;
+
+ case DR7_TYPE_IO_RW:
+ /* Notice when we should enable calls to bpt_io. */
+ return hw_breakpoint_enabled(env->dr[7], index)
+ ? HF_IOBPT_MASK : 0;
+
+ case DR7_TYPE_DATA_WR:
+ if (hw_breakpoint_enabled(dr7, index)) {
+ err = cpu_watchpoint_insert(cs, drN,
+ hw_breakpoint_len(dr7, index),
+ BP_CPU | BP_MEM_WRITE,
+ &env->cpu_watchpoint[index]);
+ }
+ break;
+
+ case DR7_TYPE_DATA_RW:
+ if (hw_breakpoint_enabled(dr7, index)) {
+ err = cpu_watchpoint_insert(cs, drN,
+ hw_breakpoint_len(dr7, index),
+ BP_CPU | BP_MEM_ACCESS,
+ &env->cpu_watchpoint[index]);
+ }
+ break;
+ }
+ if (err) {
+ env->cpu_breakpoint[index] = NULL;
+ }
+ return 0;
+}
+
+static void hw_breakpoint_remove(CPUX86State *env, int index)
+{
+ CPUState *cs = CPU(x86_env_get_cpu(env));
+
+ switch (hw_breakpoint_type(env->dr[7], index)) {
+ case DR7_TYPE_BP_INST:
+ if (env->cpu_breakpoint[index]) {
+ cpu_breakpoint_remove_by_ref(cs, env->cpu_breakpoint[index]);
+ env->cpu_breakpoint[index] = NULL;
+ }
+ break;
+
+ case DR7_TYPE_DATA_WR:
+ case DR7_TYPE_DATA_RW:
+ if (env->cpu_breakpoint[index]) {
+ cpu_watchpoint_remove_by_ref(cs, env->cpu_watchpoint[index]);
+ env->cpu_breakpoint[index] = NULL;
+ }
+ break;
+
+ case DR7_TYPE_IO_RW:
+ /* HF_IOBPT_MASK cleared elsewhere. */
+ break;
+ }
+}
+
+void cpu_x86_update_dr7(CPUX86State *env, uint32_t new_dr7)
+{
+ target_ulong old_dr7 = env->dr[7];
+ int iobpt = 0;
+ int i;
+
+ new_dr7 |= DR7_FIXED_1;
+
+ /* If nothing is changing except the global/local enable bits,
+ then we can make the change more efficient. */
+ if (((old_dr7 ^ new_dr7) & ~0xff) == 0) {
+ /* Fold the global and local enable bits together into the
+ global fields, then xor to show which registers have
+ changed collective enable state. */
+ int mod = ((old_dr7 | old_dr7 * 2) ^ (new_dr7 | new_dr7 * 2)) & 0xff;
+
+ for (i = 0; i < DR7_MAX_BP; i++) {
+ if ((mod & (2 << i * 2)) && !hw_breakpoint_enabled(new_dr7, i)) {
+ hw_breakpoint_remove(env, i);
+ }
+ }
+ env->dr[7] = new_dr7;
+ for (i = 0; i < DR7_MAX_BP; i++) {
+ if (mod & (2 << i * 2) && hw_breakpoint_enabled(new_dr7, i)) {
+ iobpt |= hw_breakpoint_insert(env, i);
+ } else if (hw_breakpoint_type(new_dr7, i) == DR7_TYPE_IO_RW
+ && hw_breakpoint_enabled(new_dr7, i)) {
+ iobpt |= HF_IOBPT_MASK;
+ }
+ }
+ } else {
+ for (i = 0; i < DR7_MAX_BP; i++) {
+ hw_breakpoint_remove(env, i);
+ }
+ env->dr[7] = new_dr7;
+ for (i = 0; i < DR7_MAX_BP; i++) {
+ iobpt |= hw_breakpoint_insert(env, i);
+ }
+ }
+
+ env->hflags = (env->hflags & ~HF_IOBPT_MASK) | iobpt;
+}
+
+static bool check_hw_breakpoints(CPUX86State *env, bool force_dr6_update)
+{
+ target_ulong dr6;
+ int reg;
+ bool hit_enabled = false;
+
+ dr6 = env->dr[6] & ~0xf;
+ for (reg = 0; reg < DR7_MAX_BP; reg++) {
+ bool bp_match = false;
+ bool wp_match = false;
+
+ switch (hw_breakpoint_type(env->dr[7], reg)) {
+ case DR7_TYPE_BP_INST:
+ if (env->dr[reg] == env->eip) {
+ bp_match = true;
+ }
+ break;
+ case DR7_TYPE_DATA_WR:
+ case DR7_TYPE_DATA_RW:
+ if (env->cpu_watchpoint[reg] &&
+ env->cpu_watchpoint[reg]->flags & BP_WATCHPOINT_HIT) {
+ wp_match = true;
+ }
+ break;
+ case DR7_TYPE_IO_RW:
+ break;
+ }
+ if (bp_match || wp_match) {
+ dr6 |= 1 << reg;
+ if (hw_breakpoint_enabled(env->dr[7], reg)) {
+ hit_enabled = true;
+ }
+ }
+ }
+
+ if (hit_enabled || force_dr6_update) {
+ env->dr[6] = dr6;
+ }
+
+ return hit_enabled;
+}
+
+void breakpoint_handler(CPUState *cs)
+{
+ X86CPU *cpu = X86_CPU(cs);
+ CPUX86State *env = &cpu->env;
+ CPUBreakpoint *bp;
+
+ if (cs->watchpoint_hit) {
+ if (cs->watchpoint_hit->flags & BP_CPU) {
+ cs->watchpoint_hit = NULL;
+ if (check_hw_breakpoints(env, false)) {
+ raise_exception(env, EXCP01_DB);
+ } else {
+ cpu_loop_exit_noexc(cs);
+ }
+ }
+ } else {
+ QTAILQ_FOREACH(bp, &cs->breakpoints, entry) {
+ if (bp->pc == env->eip) {
+ if (bp->flags & BP_CPU) {
+ check_hw_breakpoints(env, true);
+ raise_exception(env, EXCP01_DB);
+ }
+ break;
+ }
+ }
+ }
+}
+#endif
+
+void helper_single_step(CPUX86State *env)
+{
+#ifndef CONFIG_USER_ONLY
+ check_hw_breakpoints(env, true);
+ env->dr[6] |= DR6_BS;
+#endif
+ raise_exception(env, EXCP01_DB);
+}
+
+void helper_set_dr(CPUX86State *env, int reg, target_ulong t0)
+{
+#ifndef CONFIG_USER_ONLY
+ switch (reg) {
+ case 0: case 1: case 2: case 3:
+ if (hw_breakpoint_enabled(env->dr[7], reg)
+ && hw_breakpoint_type(env->dr[7], reg) != DR7_TYPE_IO_RW) {
+ hw_breakpoint_remove(env, reg);
+ env->dr[reg] = t0;
+ hw_breakpoint_insert(env, reg);
+ } else {
+ env->dr[reg] = t0;
+ }
+ return;
+ case 4:
+ if (env->cr[4] & CR4_DE_MASK) {
+ break;
+ }
+ /* fallthru */
+ case 6:
+ env->dr[6] = t0 | DR6_FIXED_1;
+ return;
+ case 5:
+ if (env->cr[4] & CR4_DE_MASK) {
+ break;
+ }
+ /* fallthru */
+ case 7:
+ cpu_x86_update_dr7(env, t0);
+ return;
+ }
+ raise_exception_err_ra(env, EXCP06_ILLOP, 0, GETPC());
+#endif
+}
+
+target_ulong helper_get_dr(CPUX86State *env, int reg)
+{
+ switch (reg) {
+ case 0: case 1: case 2: case 3: case 6: case 7:
+ return env->dr[reg];
+ case 4:
+ if (env->cr[4] & CR4_DE_MASK) {
+ break;
+ } else {
+ return env->dr[6];
+ }
+ case 5:
+ if (env->cr[4] & CR4_DE_MASK) {
+ break;
+ } else {
+ return env->dr[7];
+ }
+ }
+ raise_exception_err_ra(env, EXCP06_ILLOP, 0, GETPC());
+}
+
+/* Check if Port I/O is trapped by a breakpoint. */
+void helper_bpt_io(CPUX86State *env, uint32_t port,
+ uint32_t size, target_ulong next_eip)
+{
+#ifndef CONFIG_USER_ONLY
+ target_ulong dr7 = env->dr[7];
+ int i, hit = 0;
+
+ for (i = 0; i < DR7_MAX_BP; ++i) {
+ if (hw_breakpoint_type(dr7, i) == DR7_TYPE_IO_RW
+ && hw_breakpoint_enabled(dr7, i)) {
+ int bpt_len = hw_breakpoint_len(dr7, i);
+ if (port + size - 1 >= env->dr[i]
+ && port <= env->dr[i] + bpt_len - 1) {
+ hit |= 1 << i;
+ }
+ }
+ }
+
+ if (hit) {
+ env->dr[6] = (env->dr[6] & ~0xf) | hit;
+ env->eip = next_eip;
+ raise_exception(env, EXCP01_DB);
+ }
+#endif
+}
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