Re: [PATCH v2 1/2] src/plugins: add helper functions for drcov

[Alex Bennée]

NDNF <arkaisp2021@gmail.com> writes:

> This patch adds helper functions to the drcov plugin.
> Which provide information about:
> - start_code.
> - end_code.
> - entry.
> - path to the executable binary.
>
> Signed-off-by: Ivanov Arkady <arkadiy.ivanov@ispras.ru>
> ---
>  include/qemu/qemu-plugin.h   |    5 +++++
>  plugins/api.c                |   27 +++++++++++++++++++++++++++
>  plugins/qemu-plugins.symbols |    4 ++++
>  3 files changed, 36 insertions(+)
>
> diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h
> index 5775e82c4e..807d932e02 100644
> --- a/include/qemu/qemu-plugin.h
> +++ b/include/qemu/qemu-plugin.h
> @@ -405,4 +405,9 @@ int qemu_plugin_n_max_vcpus(void);
>   */
>  void qemu_plugin_outs(const char *string);
>  
> +QEMU_PLUGIN_EXPORT const char *qemu_plugin_path_to_binary(void);
> +QEMU_PLUGIN_EXPORT uint64_t qemu_plugin_start_code(void);
> +QEMU_PLUGIN_EXPORT uint64_t qemu_plugin_end_code(void);
> +QEMU_PLUGIN_EXPORT uint64_t qemu_plugin_entry_code(void);
> +

Could you please add some documentation to these functions to explain
what each one does. Using the jdoc style:

/**
 * foo() - does bar
 * @baz: the amount of bar
 ...

as this gets automatically translated into API documentation in the
developer docs.

>  #endif /* QEMU_PLUGIN_API_H */
> diff --git a/plugins/api.c b/plugins/api.c
> index bbdc5a4eb4..4e8a582d58 100644
> --- a/plugins/api.c
> +++ b/plugins/api.c
> @@ -340,3 +340,30 @@ void qemu_plugin_outs(const char *string)
>  {
>      qemu_log_mask(CPU_LOG_PLUGIN, "%s", string);
>  }
> +
> +#ifdef CONFIG_USER_ONLY
> +#include "qemu.h"
> +const char *qemu_plugin_path_to_binary(void)
> +{
> +    TaskState *ts = (TaskState *) current_cpu->opaque;
> +    return ts->bprm->filename;
> +}
> +
> +uint64_t qemu_plugin_start_code(void)
> +{
> +    TaskState *ts = (TaskState *) current_cpu->opaque;
> +    return ts->info->start_code;
> +}
> +
> +uint64_t qemu_plugin_end_code(void)
> +{
> +    TaskState *ts = (TaskState *) current_cpu->opaque;
> +    return ts->info->end_code;
> +}
> +
> +uint64_t qemu_plugin_entry_code(void)
> +{
> +    TaskState *ts = (TaskState *) current_cpu->opaque;
> +    return ts->info->entry;
> +}
> +#endif

You need some stub functions here for system emulation mode although you
might be able to return something useful for the binary path?

> diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols
> index 4bdb381f48..021851fb7d 100644
> --- a/plugins/qemu-plugins.symbols
> +++ b/plugins/qemu-plugins.symbols
> @@ -37,4 +37,8 @@
>    qemu_plugin_n_vcpus;
>    qemu_plugin_n_max_vcpus;
>    qemu_plugin_outs;
> +  qemu_plugin_path_to_binary;
> +  qemu_plugin_start_code;
> +  qemu_plugin_end_code;
> +  qemu_plugin_entry_code;

Please maintain the sorted list as it makes it easier to find missing
symbols ;-)

-- 
Alex Bennée