Re: [PATCH v3 29/37] nptl: Move the internal thread priority protection symbols into libc

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

On 16/03/2021 14:31, Florian Weimer via Libc-alpha wrote:
> This is a prerequisite for moving the mutex implementation.

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  nptl/Makefile   |  2 +-
>  nptl/Versions   |  5 +++++
>  nptl/pthreadP.h | 16 ++++++++++------
>  nptl/tpp.c      |  6 +++++-
>  4 files changed, 21 insertions(+), 8 deletions(-)
> 
> diff --git a/nptl/Makefile b/nptl/Makefile
> index 1eca75ef35..353cbf8911 100644
> --- a/nptl/Makefile
> +++ b/nptl/Makefile
> @@ -93,6 +93,7 @@ routines = \
>    pthread_setschedparam \
>    pthread_setspecific \
>    pthread_sigmask \
> +  tpp \
>    unwind \
>  
>  shared-only-routines = forward
> @@ -232,7 +233,6 @@ libpthread-routines = \
>    sem_unlink \
>    sem_wait \
>    sigaction \
> -  tpp \
>    vars \
>    version \
>  

Ok.

> diff --git a/nptl/Versions b/nptl/Versions
> index b3feadd045..4dee682ed9 100644
> --- a/nptl/Versions
> +++ b/nptl/Versions
> @@ -121,6 +121,7 @@ libc {
>    GLIBC_PRIVATE {
>      __futex_abstimed_wait64;
>      __futex_abstimed_wait_cancelable64;
> +    __init_sched_fifo_prio;
>      __libc_alloca_cutoff;
>      __libc_allocate_rtsig_private;
>      __libc_cleanup_pop_restore;
> @@ -147,13 +148,17 @@ libc {
>      __pthread_cleanup_upto;
>      __pthread_cond_destroy; # Used by the C11 threads.
>      __pthread_cond_init; # Used by the C11 threads.
> +    __pthread_current_priority;
>      __pthread_exit;
>      __pthread_force_elision;
>      __pthread_getattr_default_np;
>      __pthread_key_delete;
>      __pthread_keys;
>      __pthread_setcancelstate;
> +    __pthread_tpp_change_priority;
>      __pthread_unwind;
> +    __sched_fifo_max_prio;
> +    __sched_fifo_min_prio;
>    }
>  }
>  

Ok. I presume we might remove them once mutex code is moved to libc, right?

> diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h
> index 527e4acd4f..7fd290e004 100644
> --- a/nptl/pthreadP.h
> +++ b/nptl/pthreadP.h
> @@ -231,12 +231,16 @@ rtld_hidden_proto (__nptl_set_robust_list_avail)
>  #endif
>  
>  /* Thread Priority Protection.  */
> -extern int __sched_fifo_min_prio attribute_hidden;
> -extern int __sched_fifo_max_prio attribute_hidden;
> -extern void __init_sched_fifo_prio (void) attribute_hidden;
> -extern int __pthread_tpp_change_priority (int prev_prio, int new_prio)
> -     attribute_hidden;
> -extern int __pthread_current_priority (void) attribute_hidden;
> +extern int __sched_fifo_min_prio;
> +libc_hidden_proto (__sched_fifo_min_prio)
> +extern int __sched_fifo_max_prio;
> +libc_hidden_proto (__sched_fifo_max_prio)
> +extern void __init_sched_fifo_prio (void);
> +libc_hidden_proto (__init_sched_fifo_prio)
> +extern int __pthread_tpp_change_priority (int prev_prio, int new_prio);
> +libc_hidden_proto (__pthread_tpp_change_priority)
> +extern int __pthread_current_priority (void);
> +libc_hidden_proto (__pthread_current_priority)
>  
>  /* The library can run in debugging mode where it performs a lot more
>     tests.  */

Ok.

> diff --git a/nptl/tpp.c b/nptl/tpp.c
> index 8b7d9a2d23..7f58a75731 100644
> --- a/nptl/tpp.c
> +++ b/nptl/tpp.c
> @@ -25,9 +25,10 @@
>  #include <stdlib.h>
>  #include <atomic.h>
>  
> -
>  int __sched_fifo_min_prio = -1;
> +libc_hidden_data_def (__sched_fifo_min_prio)
>  int __sched_fifo_max_prio = -1;
> +libc_hidden_data_def (__sched_fifo_max_prio)
>  
>  /* We only want to initialize __sched_fifo_min_prio and __sched_fifo_max_prio
>     once.  The standard solution would be similar to pthread_once, but then
> @@ -47,6 +48,7 @@ __init_sched_fifo_prio (void)
>    atomic_store_relaxed (&__sched_fifo_min_prio,
>  			__sched_get_priority_min (SCHED_FIFO));
>  }
> +libc_hidden_def (__init_sched_fifo_prio)
>  
>  int
>  __pthread_tpp_change_priority (int previous_prio, int new_prio)
> @@ -155,6 +157,7 @@ __pthread_tpp_change_priority (int previous_prio, int new_prio)
>  
>    return result;
>  }
> +libc_hidden_def (__pthread_tpp_change_priority)
>  
>  int
>  __pthread_current_priority (void)
> @@ -193,3 +196,4 @@ __pthread_current_priority (void)
>  
>    return result;
>  }
> +libc_hidden_def (__pthread_current_priority)
> 

Ok.