diff mbox series

[v5,6/9] target/arm: Factor out code for setting MTE TCF0 field

Message ID 20240627041349.356704-7-gustavo.romero@linaro.org
State Superseded
Headers show
Series Add MTE stubs for aarch64 user mode | expand

Commit Message

Gustavo Romero June 27, 2024, 4:13 a.m. UTC 
Factor out the code used for setting the MTE TCF0 field from the prctl
code into a convenient function. Other subsystems, like gdbstub, need to
set this field as well, so keep it as a separate function to avoid
duplication and ensure consistency in how this field is set across the
board.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
---
 linux-user/aarch64/meson.build       |  2 ++
 linux-user/aarch64/mte_user_helper.c | 34 ++++++++++++++++++++++++++++
 linux-user/aarch64/mte_user_helper.h | 25 ++++++++++++++++++++
 linux-user/aarch64/target_prctl.h    | 22 ++----------------
 4 files changed, 63 insertions(+), 20 deletions(-)
 create mode 100644 linux-user/aarch64/mte_user_helper.c
 create mode 100644 linux-user/aarch64/mte_user_helper.h

Comments

Philippe Mathieu-Daudé June 27, 2024, 6:05 a.m. UTC | #1 
On 27/6/24 06:13, Gustavo Romero wrote:
> Factor out the code used for setting the MTE TCF0 field from the prctl
> code into a convenient function. Other subsystems, like gdbstub, need to
> set this field as well, so keep it as a separate function to avoid
> duplication and ensure consistency in how this field is set across the
> board.
> 
> Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
> ---
>   linux-user/aarch64/meson.build       |  2 ++
>   linux-user/aarch64/mte_user_helper.c | 34 ++++++++++++++++++++++++++++
>   linux-user/aarch64/mte_user_helper.h | 25 ++++++++++++++++++++
>   linux-user/aarch64/target_prctl.h    | 22 ++----------------
>   4 files changed, 63 insertions(+), 20 deletions(-)
>   create mode 100644 linux-user/aarch64/mte_user_helper.c
>   create mode 100644 linux-user/aarch64/mte_user_helper.h


> diff --git a/linux-user/aarch64/mte_user_helper.h b/linux-user/aarch64/mte_user_helper.h
> new file mode 100644
> index 0000000000..ee3f6b190a
> --- /dev/null
> +++ b/linux-user/aarch64/mte_user_helper.h
> @@ -0,0 +1,25 @@
> +/*
> + * ARM MemTag convenience functions.
> + *
> + * This code is licensed under the GNU GPL v2 or later.
> + *
> + * SPDX-License-Identifier: LGPL-2.1-or-later
> + */
> +
> +#ifndef AARCH64_MTE_USER_HELPER_H
> +#define AARCH64_MTE USER_HELPER_H
> +
> +#include "qemu/osdep.h"

https://www.qemu.org/docs/master/devel/style.html#include-directives

   Do not include “qemu/osdep.h” from header files since the .c file
   will have already included it.

> +#include "qemu.h"

"qemu.h" shouldn't be required neither.

Conditional to removing both lines:

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Gustavo Romero June 28, 2024, 5:20 a.m. UTC | #2 
Hi Phil,

On 6/27/24 3:05 AM, Philippe Mathieu-Daudé wrote:
> On 27/6/24 06:13, Gustavo Romero wrote:
>> Factor out the code used for setting the MTE TCF0 field from the prctl
>> code into a convenient function. Other subsystems, like gdbstub, need to
>> set this field as well, so keep it as a separate function to avoid
>> duplication and ensure consistency in how this field is set across the
>> board.
>>
>> Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
>> ---
>>   linux-user/aarch64/meson.build       |  2 ++
>>   linux-user/aarch64/mte_user_helper.c | 34 ++++++++++++++++++++++++++++
>>   linux-user/aarch64/mte_user_helper.h | 25 ++++++++++++++++++++
>>   linux-user/aarch64/target_prctl.h    | 22 ++----------------
>>   4 files changed, 63 insertions(+), 20 deletions(-)
>>   create mode 100644 linux-user/aarch64/mte_user_helper.c
>>   create mode 100644 linux-user/aarch64/mte_user_helper.h
> 
> 
>> diff --git a/linux-user/aarch64/mte_user_helper.h b/linux-user/aarch64/mte_user_helper.h
>> new file mode 100644
>> index 0000000000..ee3f6b190a
>> --- /dev/null
>> +++ b/linux-user/aarch64/mte_user_helper.h
>> @@ -0,0 +1,25 @@
>> +/*
>> + * ARM MemTag convenience functions.
>> + *
>> + * This code is licensed under the GNU GPL v2 or later.
>> + *
>> + * SPDX-License-Identifier: LGPL-2.1-or-later
>> + */
>> +
>> +#ifndef AARCH64_MTE_USER_HELPER_H
>> +#define AARCH64_MTE USER_HELPER_H
>> +
>> +#include "qemu/osdep.h"
> 
> https://www.qemu.org/docs/master/devel/style.html#include-directives
> 
>    Do not include “qemu/osdep.h” from header files since the .c file
>    will have already included it.
> 
>> +#include "qemu.h"
> 
> "qemu.h" shouldn't be required neither.

If I remove qemu/osdep.h CPUArchState can't resolved. If I remove qemu.h
then abi_long can't be resolved. I'm in a tight corner here.


Cheers,
Gustavo

> Conditional to removing both lines:
> 
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>
Philippe Mathieu-Daudé June 28, 2024, 9:22 a.m. UTC | #3 
On 28/6/24 07:20, Gustavo Romero wrote:
> Hi Phil,
> 
> On 6/27/24 3:05 AM, Philippe Mathieu-Daudé wrote:
>> On 27/6/24 06:13, Gustavo Romero wrote:
>>> Factor out the code used for setting the MTE TCF0 field from the prctl
>>> code into a convenient function. Other subsystems, like gdbstub, need to
>>> set this field as well, so keep it as a separate function to avoid
>>> duplication and ensure consistency in how this field is set across the
>>> board.
>>>
>>> Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
>>> ---
>>>   linux-user/aarch64/meson.build       |  2 ++
>>>   linux-user/aarch64/mte_user_helper.c | 34 ++++++++++++++++++++++++++++
>>>   linux-user/aarch64/mte_user_helper.h | 25 ++++++++++++++++++++
>>>   linux-user/aarch64/target_prctl.h    | 22 ++----------------
>>>   4 files changed, 63 insertions(+), 20 deletions(-)
>>>   create mode 100644 linux-user/aarch64/mte_user_helper.c
>>>   create mode 100644 linux-user/aarch64/mte_user_helper.h
>>
>>
>>> diff --git a/linux-user/aarch64/mte_user_helper.h 
>>> b/linux-user/aarch64/mte_user_helper.h
>>> new file mode 100644
>>> index 0000000000..ee3f6b190a
>>> --- /dev/null
>>> +++ b/linux-user/aarch64/mte_user_helper.h
>>> @@ -0,0 +1,25 @@
>>> +/*
>>> + * ARM MemTag convenience functions.
>>> + *
>>> + * This code is licensed under the GNU GPL v2 or later.
>>> + *
>>> + * SPDX-License-Identifier: LGPL-2.1-or-later
>>> + */
>>> +
>>> +#ifndef AARCH64_MTE_USER_HELPER_H
>>> +#define AARCH64_MTE USER_HELPER_H
>>> +
>>> +#include "qemu/osdep.h"
>>
>> https://www.qemu.org/docs/master/devel/style.html#include-directives
>>
>>    Do not include “qemu/osdep.h” from header files since the .c file
>>    will have already included it.
>>
>>> +#include "qemu.h"
>>
>> "qemu.h" shouldn't be required neither.
> 
> If I remove qemu/osdep.h CPUArchState can't resolved. If I remove qemu.h
> then abi_long can't be resolved. I'm in a tight corner here.

Does it work with "exec/cpu-all.h"?
diff mbox series

Patch

diff --git a/linux-user/aarch64/meson.build b/linux-user/aarch64/meson.build
index 248c578d15..f75bb3cd75 100644
--- a/linux-user/aarch64/meson.build
+++ b/linux-user/aarch64/meson.build
@@ -9,3 +9,5 @@  vdso_le_inc = gen_vdso.process('vdso-le.so',
                                extra_args: ['-r', '__kernel_rt_sigreturn'])
 
 linux_user_ss.add(when: 'TARGET_AARCH64', if_true: [vdso_be_inc, vdso_le_inc])
+
+linux_user_ss.add(when: 'TARGET_AARCH64', if_true: [files('mte_user_helper.c')])
diff --git a/linux-user/aarch64/mte_user_helper.c b/linux-user/aarch64/mte_user_helper.c
new file mode 100644
index 0000000000..8be6deaf03
--- /dev/null
+++ b/linux-user/aarch64/mte_user_helper.c
@@ -0,0 +1,34 @@ 
+/*
+ * ARM MemTag convenience functions.
+ *
+ * This code is licensed under the GNU GPL v2 or later.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include <sys/prctl.h>
+#include "mte_user_helper.h"
+
+void arm_set_mte_tcf0(CPUArchState *env, abi_long value)
+{
+    /*
+     * Write PR_MTE_TCF to SCTLR_EL1[TCF0].
+     *
+     * The kernel has a per-cpu configuration for the sysadmin,
+     * /sys/devices/system/cpu/cpu<N>/mte_tcf_preferred,
+     * which qemu does not implement.
+     *
+     * Because there is no performance difference between the modes, and
+     * because SYNC is most useful for debugging MTE errors, choose SYNC
+     * as the preferred mode.  With this preference, and the way the API
+     * uses only two bits, there is no way for the program to select
+     * ASYMM mode.
+     */
+    unsigned tcf = 0;
+    if (value & PR_MTE_TCF_SYNC) {
+        tcf = 1;
+    } else if (value & PR_MTE_TCF_ASYNC) {
+        tcf = 2;
+    }
+    env->cp15.sctlr_el[1] = deposit64(env->cp15.sctlr_el[1], 38, 2, tcf);
+}
diff --git a/linux-user/aarch64/mte_user_helper.h b/linux-user/aarch64/mte_user_helper.h
new file mode 100644
index 0000000000..ee3f6b190a
--- /dev/null
+++ b/linux-user/aarch64/mte_user_helper.h
@@ -0,0 +1,25 @@ 
+/*
+ * ARM MemTag convenience functions.
+ *
+ * This code is licensed under the GNU GPL v2 or later.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#ifndef AARCH64_MTE_USER_HELPER_H
+#define AARCH64_MTE USER_HELPER_H
+
+#include "qemu/osdep.h"
+#include "qemu.h"
+
+/**
+ * arm_set_mte_tcf0 - Set TCF0 field in SCTLR_EL1 register
+ * @env: The CPU environment
+ * @value: The value to be set for the Tag Check Fault in EL0 field.
+ *
+ * Only SYNC and ASYNC modes can be selected. If ASYMM mode is given, the SYNC
+ * mode is selected instead. So, there is no way to set the ASYMM mode.
+ */
+void arm_set_mte_tcf0(CPUArchState *env, abi_long value);
+
+#endif /* AARCH64_MTE_USER_HELPER_H */
diff --git a/linux-user/aarch64/target_prctl.h b/linux-user/aarch64/target_prctl.h
index aa8e203c15..ed75b9e4b5 100644
--- a/linux-user/aarch64/target_prctl.h
+++ b/linux-user/aarch64/target_prctl.h
@@ -7,6 +7,7 @@ 
 #define AARCH64_TARGET_PRCTL_H
 
 #include "target/arm/cpu-features.h"
+#include "mte_user_helper.h"
 
 static abi_long do_prctl_sve_get_vl(CPUArchState *env)
 {
@@ -173,26 +174,7 @@  static abi_long do_prctl_set_tagged_addr_ctrl(CPUArchState *env, abi_long arg2)
     env->tagged_addr_enable = arg2 & PR_TAGGED_ADDR_ENABLE;
 
     if (cpu_isar_feature(aa64_mte, cpu)) {
-        /*
-         * Write PR_MTE_TCF to SCTLR_EL1[TCF0].
-         *
-         * The kernel has a per-cpu configuration for the sysadmin,
-         * /sys/devices/system/cpu/cpu<N>/mte_tcf_preferred,
-         * which qemu does not implement.
-         *
-         * Because there is no performance difference between the modes, and
-         * because SYNC is most useful for debugging MTE errors, choose SYNC
-         * as the preferred mode.  With this preference, and the way the API
-         * uses only two bits, there is no way for the program to select
-         * ASYMM mode.
-         */
-        unsigned tcf = 0;
-        if (arg2 & PR_MTE_TCF_SYNC) {
-            tcf = 1;
-        } else if (arg2 & PR_MTE_TCF_ASYNC) {
-            tcf = 2;
-        }
-        env->cp15.sctlr_el[1] = deposit64(env->cp15.sctlr_el[1], 38, 2, tcf);
+        arm_set_mte_tcf0(env, arg2);
 
         /*
          * Write PR_MTE_TAG to GCR_EL1[Exclude].