From: Richard Henderson <richard.henderson@linaro.org>
To: "Philippe Mathieu-Daudé" <f4bug@amsat.org>, qemu-devel@nongnu.org
Subject: Re: [PATCH v4 07/43] tcg: Add in_code_gen_buffer
Date: Tue, 15 Dec 2020 16:43:12 -0600 [thread overview]
Message-ID: <a79b5c1f-80c3-d0cf-770e-838cafa3373d@linaro.org> (raw)
In-Reply-To: <0ca448f1-bbd1-36b3-67c7-d430005db00d@amsat.org>
On 12/14/20 4:09 PM, Philippe Mathieu-Daudé wrote:
> On 12/14/20 3:02 PM, Richard Henderson wrote:
>> Create a function to determine if a pointer is within the buffer.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>> include/tcg/tcg.h | 6 ++++++
>> accel/tcg/translate-all.c | 26 ++++++++------------------
>> 2 files changed, 14 insertions(+), 18 deletions(-)
>>
>> diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h
>> index bb1e97b13b..e4d0ace44b 100644
>> --- a/include/tcg/tcg.h
>> +++ b/include/tcg/tcg.h
>> @@ -680,6 +680,12 @@ extern __thread TCGContext *tcg_ctx;
>> extern void *tcg_code_gen_epilogue;
>> extern TCGv_env cpu_env;
>>
>> +static inline bool in_code_gen_buffer(const void *p)
>> +{
>> + const TCGContext *s = &tcg_init_ctx;
>> + return (size_t)(p - s->code_gen_buffer) <= s->code_gen_buffer_size;
>
> If 'p == s->code_gen_buffer + s->code_gen_buffer_size',
> is it really "in" the buffer?
Well, sort of.
Compare the fact that in C, a pointer to the end of an array is valid as a
pointer even though it can't be dereferenced. This is a pointer to the end of
the buffer.
Extra commentary required?
r~
next prev parent reply other threads:[~2020-12-15 22:47 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-14 14:02 [PATCH v4 00/43] Mirror map JIT memory for TCG Richard Henderson
2020-12-14 14:02 ` [PATCH v4 01/43] tcg: Do not flush icache for interpreter Richard Henderson
2020-12-14 21:17 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 02/43] util: Extract flush_icache_range to cacheflush.c Richard Henderson
2020-12-14 21:59 ` Philippe Mathieu-Daudé
2020-12-15 1:41 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 03/43] util: Enhance flush_icache_range with separate data pointer Richard Henderson
2020-12-15 1:43 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 04/43] util: Specialize flush_idcache_range for aarch64 Richard Henderson
2020-12-15 1:46 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 05/43] tcg: Move tcg prologue pointer out of TCGContext Richard Henderson
2020-12-14 22:01 ` Philippe Mathieu-Daudé
2020-12-15 1:48 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 06/43] tcg: Move tcg epilogue " Richard Henderson
2020-12-15 1:54 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 07/43] tcg: Add in_code_gen_buffer Richard Henderson
2020-12-14 22:09 ` Philippe Mathieu-Daudé
2020-12-15 22:43 ` Richard Henderson [this message]
2020-12-15 23:15 ` Philippe Mathieu-Daudé
2020-12-14 14:02 ` [PATCH v4 08/43] tcg: Introduce tcg_splitwx_to_{rx,rw} Richard Henderson
2021-01-02 20:00 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 09/43] tcg: Adjust TCGLabel for const Richard Henderson
2021-01-02 20:01 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 10/43] tcg: Adjust tcg_out_call " Richard Henderson
2020-12-14 22:16 ` Philippe Mathieu-Daudé
2021-01-02 20:02 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 11/43] tcg: Adjust tcg_out_label " Richard Henderson
2020-12-14 22:18 ` Philippe Mathieu-Daudé
2021-01-02 20:03 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 12/43] tcg: Adjust tcg_register_jit " Richard Henderson
2021-01-02 20:03 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 13/43] tcg: Adjust tb_target_set_jmp_target for split-wx Richard Henderson
2021-01-02 20:05 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 14/43] tcg: Make DisasContextBase.tb const Richard Henderson
2020-12-14 22:14 ` Philippe Mathieu-Daudé
2021-01-02 20:05 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 15/43] tcg: Make tb arg to synchronize_from_tb const Richard Henderson
2020-12-14 22:15 ` Philippe Mathieu-Daudé
2021-01-02 20:06 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 16/43] tcg: Use Error with alloc_code_gen_buffer Richard Henderson
2021-01-02 20:09 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 17/43] tcg: Add --accel tcg,split-wx property Richard Henderson
2020-12-15 2:05 ` Joelle van Dyne
2020-12-15 22:50 ` Richard Henderson
2020-12-14 14:02 ` [PATCH v4 18/43] accel/tcg: Support split-wx for linux with memfd Richard Henderson
2021-01-02 20:11 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 19/43] accel/tcg: Support split-wx for darwin/iOS with vm_remap Richard Henderson
2021-01-05 6:02 ` Joelle van Dyne
2021-01-05 16:57 ` Richard Henderson
2020-12-14 14:02 ` [PATCH v4 20/43] tcg: Return the TB pointer from the rx region from exit_tb Richard Henderson
2021-01-02 20:14 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 21/43] tcg/i386: Support split-wx code generation Richard Henderson
2021-01-02 20:15 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 22/43] tcg/aarch64: Use B not BL for tcg_out_goto_long Richard Henderson
2021-01-02 20:15 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 23/43] tcg/aarch64: Support split-wx code generation Richard Henderson
2021-01-02 20:16 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 24/43] disas: Push const down through host disasassembly Richard Henderson
2020-12-14 22:13 ` Philippe Mathieu-Daudé
2021-01-02 20:18 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 25/43] tcg/tci: Push const down through bytecode reading Richard Henderson
2021-01-02 20:19 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 26/43] tcg: Introduce tcg_tbrel_diff Richard Henderson
2021-01-02 20:19 ` Joelle van Dyne
2020-12-14 14:02 ` [PATCH v4 27/43] tcg/ppc: Use tcg_tbrel_diff Richard Henderson
2020-12-14 14:02 ` [PATCH v4 28/43] tcg/ppc: Use tcg_out_mem_long to reset TCG_REG_TB Richard Henderson
2020-12-14 14:03 ` [PATCH v4 29/43] tcg/ppc: Support split-wx code generation Richard Henderson
2020-12-14 14:03 ` [PATCH v4 30/43] tcg/sparc: Use tcg_tbrel_diff Richard Henderson
2020-12-14 14:03 ` [PATCH v4 31/43] tcg/sparc: Support split-wx code generation Richard Henderson
2020-12-14 14:03 ` [PATCH v4 32/43] tcg/s390: Use tcg_tbrel_diff Richard Henderson
2020-12-14 14:03 ` [PATCH v4 33/43] tcg/s390: Support split-wx code generation Richard Henderson
2020-12-14 14:03 ` [PATCH v4 34/43] tcg/riscv: Fix branch range checks Richard Henderson
2020-12-15 17:29 ` Alistair Francis
2020-12-14 14:03 ` [PATCH v4 35/43] tcg/riscv: Remove branch-over-branch fallback Richard Henderson
2020-12-15 17:30 ` Alistair Francis
2020-12-14 14:03 ` [PATCH v4 36/43] tcg/riscv: Support split-wx code generation Richard Henderson
2020-12-15 17:31 ` Alistair Francis
2020-12-14 14:03 ` [PATCH v4 37/43] accel/tcg: Add mips support to alloc_code_gen_buffer_splitwx_memfd Richard Henderson
2020-12-14 14:03 ` [PATCH v4 38/43] tcg/mips: Do not assert on relocation overflow Richard Henderson
2020-12-14 14:03 ` [PATCH v4 39/43] tcg/mips: Support split-wx code generation Richard Henderson
2020-12-14 14:03 ` [PATCH v4 40/43] tcg/arm: " Richard Henderson
2020-12-14 14:03 ` [PATCH v4 41/43] tcg: Remove TCG_TARGET_SUPPORT_MIRROR Richard Henderson
2021-01-02 20:22 ` Joelle van Dyne
2020-12-14 14:03 ` [PATCH v4 42/43] tcg: Constify tcg_code_gen_epilogue Richard Henderson
2021-01-02 20:23 ` Joelle van Dyne
2020-12-14 14:03 ` [PATCH v4 43/43] tcg: Constify TCGLabelQemuLdst.raddr Richard Henderson
2021-01-02 20:24 ` Joelle van Dyne
2020-12-14 21:01 ` [PATCH v4 00/43] Mirror map JIT memory for TCG no-reply
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