Re: [PATCH glibc v1 1/1] hurd: let the root user raise its priority

And applied the rest, thanks!

Samuel

[email protected], le mer. 20 mai 2026 23:49:27 +0100, a ecrit:
> From: Diego Nieto Cid <[email protected]>
> 
>     Check for task_max_priority RPC
> 
>       * config.h.in: add #undef for HAVE_MACH_TASK_MAX_PRIORITY.
>       * sysdeps/mach/configure.ac: use mach_RPC_CHECK to check for
>         task_max_priority RPC in mach_host.defs.
>       * sysdeps/mach/configure: regenerate file.
> 
>     Use task_max_priority when setpriority is called by root
> 
>       * sysdeps/mach/hurd/setpriority.c: clamp the prio argument
>         to the range [-NZERO, NZERO-1] and use task_max_priority
>         when called by root.
> ---
>  config.h.in                     |  3 +++
>  sysdeps/mach/configure          | 30 ++++++++++++++++++++++++
>  sysdeps/mach/configure.ac       |  2 ++
>  sysdeps/mach/hurd/setpriority.c | 41 +++++++++++++++++++++++++++++++--
>  4 files changed, 74 insertions(+), 2 deletions(-)
> 
> diff --git a/config.h.in b/config.h.in
> index b53731c393..87befaa9c6 100644
> --- a/config.h.in
> +++ b/config.h.in
> @@ -170,6 +170,9 @@
>  /* Mach specific: define if the `vm_set_size_limit' RPC is available.  */
>  #undef  HAVE_MACH_VM_SET_SIZE_LIMIT
>  
> +/* Mach specific: define if the `task_max_priority' RPC is available.  */
> +#undef  HAVE_MACH_TASK_MAX_PRIORITY
> +
>  /* Mach/i386 specific: define if the `i386_io_perm_*' RPCs are available.  */
>  #undef	HAVE_I386_IO_PERM_MODIFY
>  
> diff --git a/sysdeps/mach/configure b/sysdeps/mach/configure
> index 0161937ab4..a725cd1c7d 100755
> --- a/sysdeps/mach/configure
> +++ b/sysdeps/mach/configure
> @@ -641,6 +641,36 @@ if test $libc_cv_mach_rpc_vm_get_size_limit = yes; then
>  
>  fi
>  
> +{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for task_max_priority in mach_host.defs" >&5
> +printf %s "checking for task_max_priority in mach_host.defs... " >&6; }
> +if test ${libc_cv_mach_rpc_task_max_priority+y}
> +then :
> +  printf %s "(cached) " >&6
> +else case e in #(
> +  e) cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +/* end confdefs.h.  */
> +#include <mach/mach_host.defs>
> +
> +_ACEOF
> +if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
> +  $EGREP_TRADITIONAL "task_max_priority" >/dev/null 2>&1
> +then :
> +  libc_cv_mach_rpc_task_max_priority=yes
> +else case e in #(
> +  e) libc_cv_mach_rpc_task_max_priority=no ;;
> +esac
> +fi
> +rm -rf conftest*
> + ;;
> +esac
> +fi
> +{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_mach_rpc_task_max_priority" >&5
> +printf "%s\n" "$libc_cv_mach_rpc_task_max_priority" >&6; }
> +if test $libc_cv_mach_rpc_task_max_priority = yes; then
> +  printf "%s\n" "#define HAVE_MACH_TASK_MAX_PRIORITY 1" >>confdefs.h
> +
> +fi
> +
>  
>  ac_fn_c_check_header_preproc "$LINENO" "mach/machine/ndr_def.h" "ac_cv_header_mach_machine_ndr_def_h"
>  if test "x$ac_cv_header_mach_machine_ndr_def_h" = xyes
> diff --git a/sysdeps/mach/configure.ac b/sysdeps/mach/configure.ac
> index 237b8be937..b591e6fd9b 100644
> --- a/sysdeps/mach/configure.ac
> +++ b/sysdeps/mach/configure.ac
> @@ -104,6 +104,8 @@ mach_RPC_CHECK(gnumach.defs, vm_set_size_limit,
>                 HAVE_MACH_VM_SET_SIZE_LIMIT)
>  mach_RPC_CHECK(gnumach.defs, vm_get_size_limit,
>                 HAVE_MACH_VM_GET_SIZE_LIMIT)
> +mach_RPC_CHECK(mach_host.defs, task_max_priority,
> +	       HAVE_MACH_TASK_MAX_PRIORITY)
>  
>  AC_CHECK_HEADER(mach/machine/ndr_def.h, [dnl
>    DEFINES="$DEFINES -DNDR_DEF_HEADER='<mach/machine/ndr_def.h>'"], [dnl
> diff --git a/sysdeps/mach/hurd/setpriority.c b/sysdeps/mach/hurd/setpriority.c
> index 23d678bf40..bda13b0d7f 100644
> --- a/sysdeps/mach/hurd/setpriority.c
> +++ b/sysdeps/mach/hurd/setpriority.c
> @@ -28,7 +28,30 @@ __setpriority (enum __priority_which which, id_t who, int prio)
>    error_t pidloser, priloser;
>    unsigned int npids, ntasks, nwin, nperm, nacces;
>  
> -  prio = MAX (0, MIN (2 * NZERO - 1, prio));
> +  /*   * man getpriority(2) (i.e. man7.org)
> +   *
> +   *     << The prio argument is a value in the range -20 to 19. >>
> +   *
> +   *   * man nice(2)  (i.e. man7.org)
> +   *
> +   *     << Attempts to set a nice value outside the range are
> +   *       clamped to the range. >>
> +   *
> +   *   * The Open Group Base Specifications Issue 8
> +   *     getpriority ( https://pubs.opengroup.org/onlinepubs/9799919799/ )
> +   *
> +   *     << The nice value is in the range [0,2*{NZERO} -1], while the
> +   *        return value for getpriority() and the third parameter for
> +   *        setpriority() are in the range [-{NZERO},{NZERO} -1]. >>
> +   *
> +   *  So given that NZERO is defined to 20, we can use it to clamp to
> +   *  the range specified by POSIX, in concordance with the Linux man pages.
> +   *
> +   *  That range is then mapped to something similar to [0, 2*{NZERO}-1], as
> +   *  specified by POSIX, through the usage of the macro NICE_TO_MACH_PRIORITY
> +   *  and MACK_PRIORITY_TO_NICE. (i.e. [5, 45] )
> +   */
> +  prio = MAX ((-NZERO), MIN ((NZERO - 1), prio));
>  
>    error_t setonepriority (pid_t pid, struct procinfo *pi)
>      {
> @@ -57,11 +80,25 @@ __setpriority (enum __priority_which which, id_t who, int prio)
>  				    0, 1);
>  	  }
>  #else
> -	  prierr = __task_priority (task, NICE_TO_MACH_PRIORITY (prio), 1);
> +	  do {
> +#ifdef HAVE_MACH_TASK_MAX_PRIORITY
> +	    mach_port_t host = MACH_PORT_NULL;
> +	    error_t priverr = __get_privileged_ports (&host, NULL);
> +	    if (!priverr)
> +	      {
> +		prierr = __task_max_priority (host, task, NICE_TO_MACH_PRIORITY (prio), 1, 1);
> +		__mach_port_deallocate (__mach_task_self (), host);
> +		if (prierr != MIG_BAD_ID)
> +		  break;
> +	      }
> +#endif
> +	    prierr = __task_priority (task, NICE_TO_MACH_PRIORITY (prio), 1);
> +	  } while (0);
>  #endif
>  	  __mach_port_deallocate (__mach_task_self (), task);
>  	  switch (prierr)
>  	    {
> +	    case KERN_NO_ACCESS:
>  	    case KERN_FAILURE:
>  	      ++nacces;
>  	      break;
> -- 
> 2.53.0
> 
> 

-- 
Samuel
<y> le y est un animal discret se logeant facilement dans un terminal
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