[bug #58438] setpci write mask value is wrongly ignored

[Larry Carver]

URL:
  <https://savannah.gnu.org/bugs/?58438>

                 Summary: setpci write mask value is wrongly ignored
                 Project: GNU GRUB
            Submitted by: lcarver
            Submitted on: Sun 24 May 2020 11:30:17 AM UTC
                Category: None
                Severity: Major
                Priority: 5 - Normal
              Item Group: Software Error
                  Status: None
                 Privacy: Public
             Assigned to: None
         Originator Name: Larry Carver
        Originator Email: address@hidden
             Open/Closed: Open
                 Release: 
                 Release: Git master
         Discussion Lock: Any
         Reproducibility: Every Time
         Planned Release: None

    _______________________________________________________

Details:

Problem -- Write mask value given to setpci is ignored.
Example --

grub> setpci -s b6:0.0 70.L
Register 70 of b6:00.0 is 27

grub> setpci -s b6:0.0 70.L=0:1

grub> setpci -s b6:0.0 70.L
Register 70 of b6:00.0 is 0

Reason -- I think the following assignment is wrong, and should be removed.
Please see the following line 315, following
  the assignment to write_mask and the error check.
The code is re-assigning the value to be 0xffffffff.
At
  https://github.com/coreos/grub/blob/master/grub-core/commands/setpci.c#L315

  write_mask = 0;
  if (*ptr == '=')
    {
      ptr++;
      regwrite = grub_strtoul (ptr, (char **) &ptr, 16);
      if (grub_errno)
       return grub_errno;
      write_mask = 0xffffffff;
      if (*ptr == ':')
       {
         ptr++;
         write_mask = grub_strtoul (ptr, (char **) &ptr, 16);
         if (grub_errno)
           return grub_errno;
         write_mask = 0xffffffff;    /*  <-- Why is this here ??  */
       }
      regwrite &= write_mask;
    }





    _______________________________________________________

Reply to this item at:

  <https://savannah.gnu.org/bugs/?58438>

_______________________________________________
  Message sent via Savannah
  https://savannah.gnu.org/