NetBSD Problem Report #53553

From eric@cirr.com  Sat Aug 25 22:17:56 2018
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Message-Id: <20180825221752.856FF1BC05@snoopy.cirr.com>
Date: Sat, 25 Aug 2018 17:17:52 -0500 (CDT)
From: eric@cirr.com
Reply-To: eric@cirr.com
To: gnats-bugs@NetBSD.org
Subject: gpt biosboot forcibly prepends /usr/mdec to any other paht
X-Send-Pr-Version: 3.95

>Number:         53553
>Category:       bin
>Synopsis:       gpt biosboot forcibly prepends /usr/mdec to any other paht
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    jnemeth
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Aug 25 22:20:00 +0000 2018
>Closed-Date:    
>Last-Modified:  Wed Jun 09 03:37:56 +0000 2021
>Originator:     eric@cirr.com
>Release:        NetBSD 8.0_STABLE
>Organization:
Eric Schnoebelen		eric@cirr.com		http://www.cirr.com
    IBM is really really good at documentation. They may implement
    something so amazingly stupid it makes you slap your forehead,
    but darn if they don't document what they did. -- Kevin P. Neal
>Environment:
System: NetBSD snoopy 8.0_STABLE NetBSD 8.0_STABLE (GENERIC) #3: Thu Aug 16 22:38:01 CDT 2018 eric@bob-the-builder:/work/eric/NetBSD-8/obj/amd64/sys/arch/amd64/compile/GENERIC amd64
Architecture: x86_64
Machine: amd64
>Description:
	Attempting to use a gpt(8) biosboot subcommand with a file
	in any location other than /usr/mdec gets /usr/mdec forcibly
	prepended to the path.
>How-To-Repeat:
	I was attempting to install the -HEAD version of gptmbr.bin
	on a disk, on a system running NetBSD 8.  The file was in
	a subdirectory of my home directory.

	Below is a copy of the sessions:

snoopy-> sudo gpt -v biosboot -A -c usr/mdec/gptmbr.bin -i 1 sd0
/dev/rsd0d: mediasize=3000592982016; sectorsize=512; blocks=5860533168
gpt: /dev/rsd0d: Can't open `/usr/mdec/usr/mdec/gptmbr.bin' (No such
file or directory)
gpt: /dev/rsd0d: Error reading bootcode

snoopy-> sudo gpt -v biosboot -A -c ./usr/mdec/gptmbr.bin -i 1 sd0
/dev/rsd0d: mediasize=3000592982016; sectorsize=512; blocks=5860533168
gpt: /dev/rsd0d: Can't open `/usr/mdec/./usr/mdec/gptmbr.bin' (No such
file or directory)
gpt: /dev/rsd0d: Error reading bootcode

snoopy-> sudo install usr/mdec/gptmbr.bin /usr/mdec/gptmbr-8.99.22.bin

snoopy-> sudo gpt -v biosboot -A -c !$ -i 1 sd0
sudo gpt -v biosboot -A -c /usr/mdec/gptmbr-8.99.22.bin -i 1 sd0
/dev/rsd0d: mediasize=3000592982016; sectorsize=512; blocks=5860533168
/dev/rsd0d: Partition 1 marked as bootable
snoopy-> 

	For giggles and grins, I decided to change to the directory
	where the gptmbr.bin file is located, and it works.

snoopy-> pushd usr/mdec/
~/usr/mdec ~ 

snoopy-> sudo gpt -v biosboot -A -c gptmbr.bin -i 1 sd0
/dev/rsd0d: mediasize=3000592982016; sectorsize=512; blocks=5860533168
/dev/rsd0d: Partition 1 marked as bootable

snoopy-> sudo gpt -v biosboot -A -c ./gptmbr.bin -i 1 sd0
/dev/rsd0d: mediasize=3000592982016; sectorsize=512; blocks=5860533168
/dev/rsd0d: Partition 1 marked as bootable
snoopy-> 

	It seems that gpt is forcibly prepending '/usr/mdec' on
	any path that has a directory seperator in it?  Or any file
	that is not in the current working directory? (I haven't
	examined the code, but I did quickly check to see if the
	code was unchanged between netbsd-8 and HEAD.

>Fix:
	Work-around: move to the same directory as the biosboot image file.

	Fix: Unknown, I haven't examined the code beyond a 'cvs diff'
	between netbsd-8 and -HEAD

>Release-Note:

>Audit-Trail:
From: Robert Elz <kre@munnari.OZ.AU>
To: gnats-bugs@NetBSD.org
Cc: 
Subject: Re: bin/53553: gpt biosboot forcibly prepends /usr/mdec to any other paht
Date: Sun, 26 Aug 2018 07:05:56 +0700

     Date:        Sat, 25 Aug 2018 22:20:00 +0000 (UTC)
     From:        eric@cirr.com
     Message-ID:  <20180825222000.986E47A111@mollari.NetBSD.org>

   | 	It seems that gpt is forcibly prepending '/usr/mdec' on
   | 	any path that has a directory seperator in it?  Or any file
   | 	that is not in the current working directory?

 It uses /usr/mdec for any name that isn't a full path name.   I'm guessing
 that when you did the later tests you still have gptmbr.bin installed in
 /usr/mdec - it would have been using that one.

   | 	Work-around: move to the same directory as the biosboot image file.

 Use a full path name if you want to get the file from elsewhere.

 Whether it could allow more flexibility (not prepend /usr/mdec if the name
 starts ./ or ../ as well as /) is someone else's decision, but at the very 
 least the man page needs improvement.

 kre


From: eric@cirr.com (Eric Schnoebelen)
To: gnats-bugs@NetBSD.org
Cc: gnats-admin@netbsd.org, netbsd-bugs@netbsd.org
Subject: Re: bin/53553: gpt biosboot forcibly prepends /usr/mdec to any other paht
Date: Sat, 25 Aug 2018 19:43:55 -0500

 Robert Elz writes:
 - The following reply was made to PR bin/53553; it has been noted by GNATS.
 -
 - From: Robert Elz <kre@munnari.OZ.AU>
 - To: gnats-bugs@NetBSD.org
 - Cc: 
 - Subject: Re: bin/53553: gpt biosboot forcibly prepends /usr/mdec to any oth
 - er paht
 - Date: Sun, 26 Aug 2018 07:05:56 +0700
 -
 -      Date:        Sat, 25 Aug 2018 22:20:00 +0000 (UTC)
 -      From:        eric@cirr.com
 -      Message-ID:  <20180825222000.986E47A111@mollari.NetBSD.org>
 -  
 -    | 	It seems that gpt is forcibly prepending '/usr/mdec' on
 -    | 	any path that has a directory seperator in it?  Or any file
 -    | 	that is not in the current working directory?
 -  
 -  It uses /usr/mdec for any name that isn't a full path name.   I'm guessing
 -  that when you did the later tests you still have gptmbr.bin installed in
 -  /usr/mdec - it would have been using that one.

 It may well have been taking it from the wrwong place when I was
 attempting from the current directory.  I'll acknowledge I
 didn't verify that well enough.

 -    | 	Work-around: move to the same directory as the biosboot image file.
 -  
 -  Use a full path name if you want to get the file from elsewhere.

 I would have sworn I tried that and got an error.  But I didn't.

 -  Whether it could allow more flexibility (not prepend /usr/mdec if the name
 -  starts ./ or ../ as well as /) is someone else's decision, but at the very
 -  least the man page needs improvement.

 Yes, please.  If I get bored after getting this problem machine
 to boot, I'll look into that.

 Thanks,	
 	Eric

 --
 Eric Schnoebelen		eric@cirr.com 		http://www.cirr.com
       Whenever people agree with me I always feel I must be wrong.
 			   -- Oscar Wilde

Responsible-Changed-From-To: bin-bug-people->jnemeth
Responsible-Changed-By: jnemeth@NetBSD.org
Responsible-Changed-When: Sun, 26 Aug 2018 00:46:30 +0000
Responsible-Changed-Why:
I'll hande it.


State-Changed-From-To: open->feedback
State-Changed-By: jnemeth@NetBSD.org
State-Changed-When: Sun, 26 Aug 2018 00:46:30 +0000
State-Changed-Why:
I asked a question.


From: John Nemeth <jnemeth@cue.bc.ca>
To: gnats-bugs@NetBSD.org, gnats-admin@netbsd.org, netbsd-bugs@netbsd.org
Cc: 
Subject: Re: bin/53553: gpt biosboot forcibly prepends /usr/mdec to any other paht
Date: Sat, 25 Aug 2018 17:41:18 -0700

 On Aug 25, 10:20pm, eric@cirr.com wrote:
 }
 } >Number:         53553
 } >Category:       bin
 } >Synopsis:       gpt biosboot forcibly prepends /usr/mdec to any other paht
 } >Description:
 } 	Attempting to use a gpt(8) biosboot subcommand with a file
 } 	in any location other than /usr/mdec gets /usr/mdec forcibly
 } 	prepended to the path.

      The code is:

         if (bootpath == NULL)
                 bp = strdup(DEFAULT_BOOTDIR "/" DEFAULT_BOOTCODE);
         else if (*bootpath == '/')
                 bp = strdup(bootpath);
         else {
                 if (asprintf(&bp, "%s/%s", DEFAULT_BOOTDIR, bootpath) < 0)
                         bp = NULL;
         }

 It would be easy enough to change the second part to see if the
 path starts with "." which is a common way of stopping the prepending
 of a default path.  I'm undecided if it should check for "/" anywhere
 in the path.  However, if that's what people think is best, I'm
 willing to make either change.  I checked the installboot source
 to see what it does, and it just uses the path as given.  I think
 adding a default path makes it somewhat more convenient to use.

 }-- End of excerpt from eric@cirr.com

From: matthew green <mrg@eterna.com.au>
To: John Nemeth <jnemeth@cue.bc.ca>
Cc: gnats-bugs@NetBSD.org, gnats-admin@netbsd.org,
    netbsd-bugs@netbsd.org
Subject: re: bin/53553: gpt biosboot forcibly prepends /usr/mdec to any other paht
Date: Sun, 26 Aug 2018 11:21:18 +1000

 > path starts with "." which is a common way of stopping the prepending
 > of a default path.  I'm undecided if it should check for "/" anywhere
 > in the path.  However, if that's what people think is best, I'm
 > willing to make either change.  I checked the installboot source
 > to see what it does, and it just uses the path as given.  I think
 > adding a default path makes it somewhat more convenient to use.

 i think any path with a / should probably be used as-is.  only
 final names should look in /usr/mdec..

 alternatively, try the named path _as is_ first, and if that
 does not work, try it under /usr/mdec.


 .mrg.

From: eric@cirr.com (Eric Schnoebelen)
To: gnats-bugs@NetBSD.org
Cc: gnats-admin@netbsd.org, netbsd-bugs@netbsd.org
Subject: Re: bin/53553: gpt biosboot forcibly prepends /usr/mdec to any other paht
Date: Fri, 31 Aug 2018 11:28:52 -0500

 John Nemeth writes:
 -  On Aug 25, 10:20pm, eric@cirr.com wrote:
 -  } >Number:         53553
 -  } >Category:       bin
 -  } >Synopsis:       gpt biosboot forcibly prepends /usr/mdec to any othe=
 r paht
 -  } >Description:
 -  } 	Attempting to use a gpt(8) biosboot subcommand with a file
 -  } 	in any location other than /usr/mdec gets /usr/mdec forcibly
 -  } 	prepended to the path.
 -  =

 -       The code is:
 -  =

 -          if (bootpath =3D=3D NULL)
 -                  bp =3D strdup(DEFAULT_BOOTDIR "/" DEFAULT_BOOTCODE);
 -          else if (*bootpath =3D=3D '/')
 -                  bp =3D strdup(bootpath);
 -          else {
 -                  if (asprintf(&bp, "%s/%s", DEFAULT_BOOTDIR, bootpath) <=
  0)
 -                          bp =3D NULL;
 -          }
 -  =

 -  It would be easy enough to change the second part to see if the
 -  path starts with "." which is a common way of stopping the prepending
 -  of a default path.  I'm undecided if it should check for "/" anywhere
 -  in the path.  However, if that's what people think is best, I'm
 -  willing to make either change.  I checked the installboot source
 -  to see what it does, and it just uses the path as given.  I think
 -  adding a default path makes it somewhat more convenient to use.

 After a few days reflection, I would be happy if the current
 mechanisms were documented on the gpt(8) manual page.

 Given the lack of documentation there, and the first error when
 trying an unanchored path, I followed the common practice of
 prepending './' to try and anchor do the current directory.

 =46rom my perspective, either choice would be sufficent to remove
 the frustration I experienced.  However, the second might bring it into
 line with a large number of other tools. =


 Thanks,
 	Eric

State-Changed-From-To: feedback->open
State-Changed-By: dholland@NetBSD.org
State-Changed-When: Wed, 09 Jun 2021 03:37:56 +0000
State-Changed-Why:
Feedback was received, in 2018.


>Unformatted:

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