diff options
Diffstat (limited to 'target/i386/tcg/system/bpt_helper.c')
| -rw-r--r-- | target/i386/tcg/system/bpt_helper.c | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/target/i386/tcg/system/bpt_helper.c b/target/i386/tcg/system/bpt_helper.c new file mode 100644 index 0000000..be232c1 --- /dev/null +++ b/target/i386/tcg/system/bpt_helper.c @@ -0,0 +1,316 @@ +/* + * i386 breakpoint helpers - system code + * + * 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 2.1 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" +#include "tcg/helper-tcg.h" + + +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 = env_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 = env_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_watchpoint[index]) { + cpu_watchpoint_remove_by_ref(cs, env->cpu_watchpoint[index]); + env->cpu_watchpoint[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; +} + +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; + + if (cs->watchpoint_hit) { + if (cs->watchpoint_hit->flags & BP_CPU) { + cs->watchpoint_hit = NULL; + if (check_hw_breakpoints(env, false)) { + /* + * FIXME: #DB should be delayed by one instruction if + * INHIBIT_IRQ is set (STI cannot trigger a watchpoint). + * The delayed #DB should also fuse with one generated + * by ICEBP (aka INT1). + */ + raise_exception(env, EXCP01_DB); + } else { + cpu_loop_exit_noexc(cs); + } + } + } else { + if (cpu_breakpoint_test(cs, env->eip, BP_CPU)) { + check_hw_breakpoints(env, true); + raise_exception(env, EXCP01_DB); + } + } +} + +target_ulong helper_get_dr(CPUX86State *env, int reg) +{ + if (reg >= 4 && reg < 6) { + if (env->cr[4] & CR4_DE_MASK) { + raise_exception_ra(env, EXCP06_ILLOP, GETPC()); + } else { + reg += 2; + } + } + + if (env->dr[7] & DR7_GD) { + env->dr[7] &= ~DR7_GD; + env->dr[6] |= DR6_BD; + raise_exception_ra(env, EXCP01_DB, GETPC()); + } + + return env->dr[reg]; +} + +void helper_set_dr(CPUX86State *env, int reg, target_ulong t0) +{ + if (reg >= 4 && reg < 6) { + if (env->cr[4] & CR4_DE_MASK) { + raise_exception_ra(env, EXCP06_ILLOP, GETPC()); + } else { + reg += 2; + } + } + + if (env->dr[7] & DR7_GD) { + env->dr[7] &= ~DR7_GD; + env->dr[6] |= DR6_BD; + raise_exception_ra(env, EXCP01_DB, GETPC()); + } + + if (reg < 4) { + 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; + } + } else { + if (t0 & DR_RESERVED_MASK) { + raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC()); + } + if (reg == 6) { + env->dr[6] = t0 | DR6_FIXED_1; + } else { + cpu_x86_update_dr7(env, t0); + } + } +} + +/* 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) +{ + 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); + } +} |