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.
>
> 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.
> 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".
> + 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.
> hw_breakpoint_remove(env, i);
> }
>
Jan
--
Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
Corporate Competence Center Embedded Linux
