[PATCH for-5.0? v2] target/xtensa: Statically allocate xtensa_insnbufs in DisasContext

[PATCH for-5.0? v2] target/xtensa: Statically allocate xtensa_insnbufs in DisasContext

[Richard Henderson]

From: Max Filippov <jcmvbkbc@gmail.com>

Rather than dynamically allocate, and risk failing to free
when we longjmp out of the translator, allocate the maximum
buffer size from any of the supported cpus.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
[rth: Merged the fixup in Max's reply to his original]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/xtensa/cpu.h       |  3 +++
 target/xtensa/helper.c    |  1 +
 target/xtensa/translate.c | 18 ++----------------
 3 files changed, 6 insertions(+), 16 deletions(-)

diff --git a/target/xtensa/cpu.h b/target/xtensa/cpu.h
index c0d69fad96..7a46dccbe1 100644
--- a/target/xtensa/cpu.h
+++ b/target/xtensa/cpu.h
@@ -213,6 +213,9 @@ enum {
 #define MEMCTL_IL0EN 0x1
 
 #define MAX_INSN_LENGTH 64
+#define MAX_INSNBUF_LENGTH \
+    ((MAX_INSN_LENGTH + sizeof(xtensa_insnbuf_word) - 1) / \
+     sizeof(xtensa_insnbuf_word))
 #define MAX_INSN_SLOTS 32
 #define MAX_OPCODE_ARGS 16
 #define MAX_NAREG 64
diff --git a/target/xtensa/helper.c b/target/xtensa/helper.c
index 376a61f339..7073381f03 100644
--- a/target/xtensa/helper.c
+++ b/target/xtensa/helper.c
@@ -96,6 +96,7 @@ static void init_libisa(XtensaConfig *config)
 
     config->isa = xtensa_isa_init(config->isa_internal, NULL, NULL);
     assert(xtensa_isa_maxlength(config->isa) <= MAX_INSN_LENGTH);
+    assert(xtensa_insnbuf_size(config->isa) <= MAX_INSNBUF_LENGTH);
     opcodes = xtensa_isa_num_opcodes(config->isa);
     formats = xtensa_isa_num_formats(config->isa);
     regfiles = xtensa_isa_num_regfiles(config->isa);
diff --git a/target/xtensa/translate.c b/target/xtensa/translate.c
index 37f65b1f03..b898ee2261 100644
--- a/target/xtensa/translate.c
+++ b/target/xtensa/translate.c
@@ -72,8 +72,8 @@ struct DisasContext {
     unsigned cpenable;
 
     uint32_t op_flags;
-    xtensa_insnbuf insnbuf;
-    xtensa_insnbuf slotbuf;
+    xtensa_insnbuf_word insnbuf[MAX_INSNBUF_LENGTH];
+    xtensa_insnbuf_word slotbuf[MAX_INSNBUF_LENGTH];
 };
 
 static TCGv_i32 cpu_pc;
@@ -1173,16 +1173,6 @@ static void xtensa_tr_init_disas_context(DisasContextBase *dcbase,
     dc->cwoe = tb_flags & XTENSA_TBFLAG_CWOE;
     dc->callinc = ((tb_flags & XTENSA_TBFLAG_CALLINC_MASK) >>
                    XTENSA_TBFLAG_CALLINC_SHIFT);
-
-    /*
-     * FIXME: This will leak when a failed instruction load or similar
-     * event causes us to longjump out of the translation loop and
-     * hence not clean-up in xtensa_tr_tb_stop
-     */
-    if (dc->config->isa) {
-        dc->insnbuf = xtensa_insnbuf_alloc(dc->config->isa);
-        dc->slotbuf = xtensa_insnbuf_alloc(dc->config->isa);
-    }
     init_sar_tracker(dc);
 }
 
@@ -1272,10 +1262,6 @@ static void xtensa_tr_tb_stop(DisasContextBase *dcbase, CPUState *cpu)
     DisasContext *dc = container_of(dcbase, DisasContext, base);
 
     reset_sar_tracker(dc);
-    if (dc->config->isa) {
-        xtensa_insnbuf_free(dc->config->isa, dc->insnbuf);
-        xtensa_insnbuf_free(dc->config->isa, dc->slotbuf);
-    }
     if (dc->icount) {
         tcg_temp_free(dc->next_icount);
     }
-- 
2.20.1

Re: [PATCH for-5.0? v2] target/xtensa: Statically allocate xtensa_insnbufs in DisasContext

[Max Filippov]

On Tue, Apr 7, 2020 at 12:07 PM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> From: Max Filippov <jcmvbkbc@gmail.com>
>
> Rather than dynamically allocate, and risk failing to free
> when we longjmp out of the translator, allocate the maximum
> buffer size from any of the supported cpus.
>
> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
> [rth: Merged the fixup in Max's reply to his original]
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/xtensa/cpu.h       |  3 +++
>  target/xtensa/helper.c    |  1 +
>  target/xtensa/translate.c | 18 ++----------------
>  3 files changed, 6 insertions(+), 16 deletions(-)

I've re-posted it almost at the same time (:
Should I take it, or do you have another plan for it?

-- 
Thanks.
-- Max

Re: [PATCH for-5.0? v2] target/xtensa: Statically allocate xtensa_insnbufs in DisasContext

[Richard Henderson]

On 4/7/20 12:17 PM, Max Filippov wrote:
> On Tue, Apr 7, 2020 at 12:07 PM Richard Henderson
> <richard.henderson@linaro.org> wrote:
>>
>> From: Max Filippov <jcmvbkbc@gmail.com>
>>
>> Rather than dynamically allocate, and risk failing to free
>> when we longjmp out of the translator, allocate the maximum
>> buffer size from any of the supported cpus.
>>
>> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
>> [rth: Merged the fixup in Max's reply to his original]
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>>  target/xtensa/cpu.h       |  3 +++
>>  target/xtensa/helper.c    |  1 +
>>  target/xtensa/translate.c | 18 ++----------------
>>  3 files changed, 6 insertions(+), 16 deletions(-)
> 
> I've re-posted it almost at the same time (:
> Should I take it, or do you have another plan for it?

I'm happy for you to take it.


r~

[PATCH for-5.0? v2] target/xtensa: Statically allocate xtensa_insnbufs in DisasContext

[Richard Henderson]

From: Max Filippov <jcmvbkbc@gmail.com>

Rather than dynamically allocate, and risk failing to free
when we longjmp out of the translator, allocate the maximum
buffer size from any of the supported cpus.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
[rth: Merged the fixup in Max's reply to his original]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/xtensa/cpu.h       |  3 +++
 target/xtensa/helper.c    |  1 +
 target/xtensa/translate.c | 18 ++----------------
 3 files changed, 6 insertions(+), 16 deletions(-)

diff --git a/target/xtensa/cpu.h b/target/xtensa/cpu.h
index c0d69fad96..7a46dccbe1 100644
--- a/target/xtensa/cpu.h
+++ b/target/xtensa/cpu.h
@@ -213,6 +213,9 @@ enum {
 #define MEMCTL_IL0EN 0x1
 
 #define MAX_INSN_LENGTH 64
+#define MAX_INSNBUF_LENGTH \
+    ((MAX_INSN_LENGTH + sizeof(xtensa_insnbuf_word) - 1) / \
+     sizeof(xtensa_insnbuf_word))
 #define MAX_INSN_SLOTS 32
 #define MAX_OPCODE_ARGS 16
 #define MAX_NAREG 64
diff --git a/target/xtensa/helper.c b/target/xtensa/helper.c
index 376a61f339..7073381f03 100644
--- a/target/xtensa/helper.c
+++ b/target/xtensa/helper.c
@@ -96,6 +96,7 @@ static void init_libisa(XtensaConfig *config)
 
     config->isa = xtensa_isa_init(config->isa_internal, NULL, NULL);
     assert(xtensa_isa_maxlength(config->isa) <= MAX_INSN_LENGTH);
+    assert(xtensa_insnbuf_size(config->isa) <= MAX_INSNBUF_LENGTH);
     opcodes = xtensa_isa_num_opcodes(config->isa);
     formats = xtensa_isa_num_formats(config->isa);
     regfiles = xtensa_isa_num_regfiles(config->isa);
diff --git a/target/xtensa/translate.c b/target/xtensa/translate.c
index 37f65b1f03..b898ee2261 100644
--- a/target/xtensa/translate.c
+++ b/target/xtensa/translate.c
@@ -72,8 +72,8 @@ struct DisasContext {
     unsigned cpenable;
 
     uint32_t op_flags;
-    xtensa_insnbuf insnbuf;
-    xtensa_insnbuf slotbuf;
+    xtensa_insnbuf_word insnbuf[MAX_INSNBUF_LENGTH];
+    xtensa_insnbuf_word slotbuf[MAX_INSNBUF_LENGTH];
 };
 
 static TCGv_i32 cpu_pc;
@@ -1173,16 +1173,6 @@ static void xtensa_tr_init_disas_context(DisasContextBase *dcbase,
     dc->cwoe = tb_flags & XTENSA_TBFLAG_CWOE;
     dc->callinc = ((tb_flags & XTENSA_TBFLAG_CALLINC_MASK) >>
                    XTENSA_TBFLAG_CALLINC_SHIFT);
-
-    /*
-     * FIXME: This will leak when a failed instruction load or similar
-     * event causes us to longjump out of the translation loop and
-     * hence not clean-up in xtensa_tr_tb_stop
-     */
-    if (dc->config->isa) {
-        dc->insnbuf = xtensa_insnbuf_alloc(dc->config->isa);
-        dc->slotbuf = xtensa_insnbuf_alloc(dc->config->isa);
-    }
     init_sar_tracker(dc);
 }
 
@@ -1272,10 +1262,6 @@ static void xtensa_tr_tb_stop(DisasContextBase *dcbase, CPUState *cpu)
     DisasContext *dc = container_of(dcbase, DisasContext, base);
 
     reset_sar_tracker(dc);
-    if (dc->config->isa) {
-        xtensa_insnbuf_free(dc->config->isa, dc->insnbuf);
-        xtensa_insnbuf_free(dc->config->isa, dc->slotbuf);
-    }
     if (dc->icount) {
         tcg_temp_free(dc->next_icount);
     }
-- 
2.20.1

Re: [PATCH for-5.0? v2] target/xtensa: Statically allocate xtensa_insnbufs in DisasContext

[Richard Henderson]

On 4/8/20 8:30 AM, Richard Henderson wrote:
> From: Max Filippov <jcmvbkbc@gmail.com>
> 
> Rather than dynamically allocate, and risk failing to free
> when we longjmp out of the translator, allocate the maximum
> buffer size from any of the supported cpus.
> 
> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
> [rth: Merged the fixup in Max's reply to his original]
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---

Oops.  Leftover file in my to-mail directory.
Not part of the rx pull, obviously.


r~