在 2012-12-03一的 10:43 +0100，Jan Kiszka写道：
> On 2012-12-03 04:07, liguang wrote:
> > 1. define names of breakpoints in dr7
> > 2. slightly refactor bits field of breakpoint
> > related functions.
>
> Two topics, (at least) two patches, please. The code is hairy - not your
> fault, you actually try to improve it. But splitting up makes review
> easier. Thanks in advance.
OK, I'll split this patch.
>
> >
> > Signed-off-by: liguang <lig.f...@cn.fujitsu.com>
> > ---
> > target-i386/cpu.h | 6 ++++
> > target-i386/helper.c | 59
> > ++++++++++++++++++++++++++++----------------
> > target-i386/machine.c | 2 +-
> > target-i386/misc_helper.c | 4 +-
> > target-i386/seg_helper.c | 4 +-
> > 5 files changed, 48 insertions(+), 27 deletions(-)
> >
> > diff --git a/target-i386/cpu.h b/target-i386/cpu.h
> > index 90ef1ff..2da6ea0 100644
> > --- a/target-i386/cpu.h
> > +++ b/target-i386/cpu.h
> > @@ -231,6 +231,12 @@
> > #define DR7_TYPE_SHIFT 16
> > #define DR7_LEN_SHIFT 18
> > #define DR7_FIXED_1 0x00000400
> > +#define DR7_L0_3 0x55
>
> DR7_LOCAL_BP_MASK or so.
>
> > +#define DR7_MAX_BP 4
> > +#define DR7_BP_INST 0x0
> > +#define DR7_DATA_WR 0x1
> > +#define DR7_IO_RW 0x2
> > +#define DR7_DATA_RW 0x3
> >
> > #define PG_PRESENT_BIT 0
> > #define PG_RW_BIT 1
> > diff --git a/target-i386/helper.c b/target-i386/helper.c
> > index bf206cf..54d6712 100644
> > --- a/target-i386/helper.c
> > +++ b/target-i386/helper.c
> > @@ -966,27 +966,26 @@ hwaddr cpu_get_phys_page_debug(CPUX86State *env,
> > target_ulong addr)
> >
> > void hw_breakpoint_insert(CPUX86State *env, int index)
> > {
> > - int type, err = 0;
> > + int type = 0, err = 0;
> >
> > switch (hw_breakpoint_type(env->dr[7], index)) {
> > - case 0:
> > + case DR7_BP_INST:
> > if (hw_breakpoint_enabled(env->dr[7], index))
> > err = cpu_breakpoint_insert(env, env->dr[index], BP_CPU,
> > &env->cpu_breakpoint[index]);
> > break;
> > - case 1:
> > + case DR7_DATA_WR:
> > type = BP_CPU | BP_MEM_WRITE;
> > - goto insert_wp;
> > - case 2:
> > - /* No support for I/O watchpoints yet */
> > - break;
> > - case 3:
> > - type = BP_CPU | BP_MEM_ACCESS;
> > - insert_wp:
> > + case DR7_DATA_RW:
> > + if (!type)
> > + type = BP_CPU | BP_MEM_ACCESS;
>
> Coding style.
>
> But, to be honest, I find the goto approach cleaner. Alternatively, test
> for "type" (or "wp_type") != 0 outside the switch, moving the
> cpu_watchpoint_insert there.
okay.
>
> > err = cpu_watchpoint_insert(env, env->dr[index],
> > hw_breakpoint_len(env->dr[7], index),
> > type, &env->cpu_watchpoint[index]);
> > break;
> > + case DR7_IO_RW:
> > + /* No support for I/O watchpoints yet */
> > + break;
> > }
> > if (err)
> > env->cpu_breakpoint[index] = NULL;
> > @@ -997,15 +996,15 @@ void hw_breakpoint_remove(CPUX86State *env, int index)
> > if (!env->cpu_breakpoint[index])
> > return;
> > switch (hw_breakpoint_type(env->dr[7], index)) {
> > - case 0:
> > + case DR7_BP_INST:
> > if (hw_breakpoint_enabled(env->dr[7], index))
> > cpu_breakpoint_remove_by_ref(env, env->cpu_breakpoint[index]);
> > break;
> > - case 1:
> > - case 3:
> > + case DR7_DATA_WR:
> > + case DR7_DATA_RW:
> > cpu_watchpoint_remove_by_ref(env, env->cpu_watchpoint[index]);
> > break;
> > - case 2:
> > + case DR7_IO_RW:
> > /* No support for I/O watchpoints yet */
> > break;
> > }
> > @@ -1014,22 +1013,38 @@ void hw_breakpoint_remove(CPUX86State *env, int
> > index)
> > int check_hw_breakpoints(CPUX86State *env, int force_dr6_update)
> > {
> > target_ulong dr6;
> > - int reg, type;
> > + int index, type = 0;
> > int hit_enabled = 0;
> >
> > dr6 = env->dr[6] & ~0xf;
> > - for (reg = 0; reg < 4; reg++) {
> > - type = hw_breakpoint_type(env->dr[7], reg);
> > - if ((type == 0 && env->dr[reg] == env->eip) ||
> > - ((type & 1) && env->cpu_watchpoint[reg] &&
> > - (env->cpu_watchpoint[reg]->flags & BP_WATCHPOINT_HIT))) {
> > - dr6 |= 1 << reg;
> > - if (hw_breakpoint_enabled(env->dr[7], reg))
> > + for (index = 0; index < DR7_MAX_BP; index++) {
> > + switch (hw_breakpoint_type(env->dr[7], index)) {
> > + case DR7_BP_INST:
> > + if (env->dr[index] != env->eip)
> > + break;
> > + type = 1;
>
> "type" is not very telling as it is used here. Either continue to assign
> it to hw_breakpoint_type and clear it on DR7_IO_RW, or rename it to a
> boolean like "bp_match".
bp_match is a nicer name, thanks!
>
> > + break;
> > + case DR7_DATA_WR:
> > + case DR7_DATA_RW:
> > + if (!env->cpu_watchpoint[index])
> > + break;
> > + if (!(env->cpu_watchpoint[index]->flags & BP_WATCHPOINT_HIT))
> > + break;
>
> Let's fold these two into one.
>
> In general: coding style.
>
> > + type = 1;
> > + break;
> > + case DR7_IO_RW:
> > + break;
> > + }
> > + if (type) {
> > + dr6 |= 1 << index;
> > + if (hw_breakpoint_enabled(env->dr[7], index))
> > hit_enabled = 1;
> > + type = 0;
>
> If you go for "wp_match", just set to false under DR7_IO_RW.
>
> > }
> > }
> > if (hit_enabled || force_dr6_update)
> > env->dr[6] = dr6;
> > +
> > return hit_enabled;
> > }
> >
> > diff --git a/target-i386/machine.c b/target-i386/machine.c
> > index 4771508..a4b1a1e 100644
> > --- a/target-i386/machine.c
> > +++ b/target-i386/machine.c
> > @@ -265,7 +265,7 @@ static int cpu_post_load(void *opaque, int version_id)
> >
> > cpu_breakpoint_remove_all(env, BP_CPU);
> > cpu_watchpoint_remove_all(env, BP_CPU);
> > - for (i = 0; i < 4; i++)
> > + for (i = 0; i < DR7_MAX_BP; i++)
>
> If touching the line, please fix the coding style as well.
>
> > hw_breakpoint_insert(env, i);
> >
> > tlb_flush(env, 1);
> > diff --git a/target-i386/misc_helper.c b/target-i386/misc_helper.c
> > index a020379..5ee0863 100644
> > --- a/target-i386/misc_helper.c
> > +++ b/target-i386/misc_helper.c
> > @@ -197,11 +197,11 @@ void helper_movl_drN_T0(CPUX86State *env, int reg,
> > target_ulong t0)
> > env->dr[reg] = t0;
> > hw_breakpoint_insert(env, reg);
> > } else if (reg == 7) {
> > - for (i = 0; i < 4; i++) {
> > + for (i = 0; i < DR7_MAX_BP; i++) {
> > hw_breakpoint_remove(env, i);
> > }
> > env->dr[7] = t0;
> > - for (i = 0; i < 4; i++) {
> > + for (i = 0; i < DR7_MAX_BP; i++) {
> > hw_breakpoint_insert(env, i);
> > }
> > } else {
> > diff --git a/target-i386/seg_helper.c b/target-i386/seg_helper.c
> > index ff93374..317187b 100644
> > --- a/target-i386/seg_helper.c
> > +++ b/target-i386/seg_helper.c
> > @@ -465,8 +465,8 @@ static void switch_tss(CPUX86State *env, int
> > tss_selector,
> >
> > #ifndef CONFIG_USER_ONLY
> > /* reset local breakpoints */
> > - if (env->dr[7] & 0x55) {
> > - for (i = 0; i < 4; i++) {
> > + if (env->dr[7] & DR7_L0_3) {
> > + for (i = 0; i < DR7_MAX_BP; i++) {
> > if (hw_breakpoint_enabled(env->dr[7], i) == 0x1) {
>
> There is a magic value remaining here. You probably want defines for the
> local vs. global enable bits as well.
okay.
Thanks!
>
> > hw_breakpoint_remove(env, i);
> > }
> >
>
> Jan
>
--
regards!
li guang
