[Bug libc/15846] New: getauxval api is broken

[Bug libc/15846] New: getauxval api is broken

[bugdal at aerifal dot cx]

http://sourceware.org/bugzilla/show_bug.cgi?id=15846

            Bug ID: 15846
           Summary: getauxval api is broken
           Product: glibc
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: libc
          Assignee: unassigned at sourceware dot org
          Reporter: bugdal at aerifal dot cx
                CC: drepper.fsp at gmail dot com

getauxval is documented to (and does) return 0 if the requested item is not
found. Unfortunately, 0 is also a valid value for many items, e.g.
getauxval(AT_UID), or perhaps worse, getauxval(AT_EXECFD).

Ideally, the error return should be changed to something not otherwise
used/usable, e.g. -1UL. Short of that, perhaps getauxval could at least set
errno to ENOENT when the item is not found and guarantee that errno will be
undisturbed on success.

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[Bug libc/15846] getauxval api is broken

[ppluzhnikov at google dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=15846

Paul Pluzhnikov <ppluzhnikov at google dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ppluzhnikov at google dot com

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[Bug libc/15846] getauxval api is broken

[brooks at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=15846

Brooks Moses <brooks at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |brooks at gcc dot gnu.org

--- Comment #1 from Brooks Moses <brooks at gcc dot gnu.org> ---
Patch proposed to set errno to ENOENT:

https://sourceware.org/ml/libc-alpha/2013-12/msg00353.html

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[Bug libc/15846] getauxval api is broken

[cvs-commit at gcc dot gnu.org]

http://sourceware.org/bugzilla/show_bug.cgi?id=15846

--- Comment #2 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "GNU C Library master sources".

The branch, master has been updated
       via  b9ab448f980e296eac21ac65f53783967cc6037b (commit)
      from  f889953b44da50bf8a7824c97d09dbe03fd11b83 (commit)

Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
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- Log -----------------------------------------------------------------
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=b9ab448f980e296eac21ac65f53783967cc6037b

commit b9ab448f980e296eac21ac65f53783967cc6037b
Author: Brooks Moses <bmoses@google.com>
Date:   Wed Dec 11 16:58:12 2013 -0800

    Add error reporting (via errno) to getauxval().

    [BZ 15846] As discussed in the recent thread on my $EXEC_ORIGIN patch
    and in BZ 15846, getauxval() presently has no unambiguous way of
    reporting an error condition.  It currently returns zero on error, but
    this may also be a valid result for some auxv entries.  As there is no
    clear invalid result for all current and future auxv entries, this patch
    sets errno (following a suggestion in the BZ entry).

    This version of the patch also adds documentation and tests for the
    value-not-found conditions in getauxval().

-----------------------------------------------------------------------

Summary of changes:
 ChangeLog           |   11 +++++++++++
 elf/tst-auxv.c      |   28 ++++++++++++++++++++++++++--
 manual/startup.texi |    3 ++-
 misc/getauxval.c    |    3 +++
 misc/sys/auxv.h     |    4 ++--
 5 files changed, 44 insertions(+), 5 deletions(-)

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[Bug libc/15846] getauxval api is broken

[brooks at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=15846

Brooks Moses <brooks at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|---                         |2.19

--- Comment #3 from Brooks Moses <brooks at gcc dot gnu.org> ---
Resolved by setting errno to ENOENT on error, as per the above patch.

Rich, if you think this is insufficient, please feel free to reopen.

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[Bug libc/15846] getauxval api is broken

[cvs-commit at gcc dot gnu.org]

http://sourceware.org/bugzilla/show_bug.cgi?id=15846

--- Comment #4 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "GNU C Library master sources".

The branch, master has been updated
       via  a588438951a271ca10623fb8c7e25693c7ebea67 (commit)
      from  b9ab448f980e296eac21ac65f53783967cc6037b (commit)

Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.

- Log -----------------------------------------------------------------
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=a588438951a271ca10623fb8c7e25693c7ebea67

commit a588438951a271ca10623fb8c7e25693c7ebea67
Author: Brooks Moses <bmoses@google.com>
Date:   Wed Dec 18 11:06:37 2013 -0800

    Updated NEWS to mention resolution of bug 15846.

-----------------------------------------------------------------------

Summary of changes:
 NEWS |   14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)

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[Bug libc/15846] getauxval api is broken

[bugdal at aerifal dot cx]

https://sourceware.org/bugzilla/show_bug.cgi?id=15846

--- Comment #5 from Rich Felker <bugdal at aerifal dot cx> ---
Brooks, this fix is completely acceptable to me; in fact it seems to be the
only fix that was possible without leaving ambiguity or adding a new API. So I
agree with closing the bug as fixed.

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[Bug libc/15846] getauxval api is broken

[brooks at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=15846

Brooks Moses <brooks at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at sourceware dot org   |brooks at gcc dot gnu.org

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[Bug libc/15846] getauxval api is broken

[fweimer at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=15846

Florian Weimer <fweimer at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
              Flags|                            |security-

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