[Bug gdb/27989] New: gdb.base/args.exp fails with native-extended-gdbserver board

[Bug gdb/27989] New: gdb.base/args.exp fails with native-extended-gdbserver board

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=27989

            Bug ID: 27989
           Summary: gdb.base/args.exp fails with native-extended-gdbserver
                    board
           Product: gdb
           Version: HEAD
            Status: NEW
          Severity: normal
          Priority: P2
         Component: gdb
          Assignee: unassigned at sourceware dot org
          Reporter: simark at simark dot ca
  Target Milestone: ---

It boils down to this.  With native:

$ ./gdb -nx -q --data-directory=data-directory \
    -ex r \
    --args
/home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/args/args salut
"''" toi

produces:

salut
''
toi


With extended-remote (with a gdbserver --multi listening on 1234):

$ ./gdb -nx -q --data-directory=data-directory \
    -ex "tar ext :1234" \
    -ex "set remote exec-file
/home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/args/args" \
    -ex "set sysroot" \
    -ex r \
    --args
/home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/args/args salut
"''" toi

produces:

salut
\'\'
toi


I have not dug more than that, but I think that shows a bug in the
extended-remote version.  Here, I want to literally pass
<single-quote><single-quote> as the argument to my program, such that

  strcmp ("''", argv[2]) == 0

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[Bug gdb/27989] gdb.base/args.exp fails with native-extended-gdbserver board

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=27989

--- Comment #1 from Simon Marchi <simark at simark dot ca> ---
Same goes for a newline.  The argument passed on the shell is literally just a
newline character, 0x0a.  I added some HTML-like annotations to see where the
args start and end, for clarity.  With native:

$ ./gdb -nx -q --data-directory=data-directory \
    -ex r \              
    --args
/home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/args/args salut
"              
" toi

produces

<arg1>salut</arg1>
<arg2>
</arg2>
<arg3>toi</arg3>


With extended-remote:

./gdb -nx -q --data-directory=data-directory \
    -ex "tar ext :1234" \
    -ex "set remote exec-file
/home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/args/args" \
    -ex "set sysroot" \
    -ex r \
    --args
/home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/args/args salut
"
" toi

produces

<arg1>salut</arg1>
<arg2>'
'</arg2>
<arg3>toi</arg3>


In the second case, single quotes appeared out of nowhere.

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[Bug gdb/27989] gdb.base/args.exp fails with native-extended-gdbserver board

[cvs-commit at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=27989

--- Comment #2 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Simon Marchi <simark@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=18263be7565782a9c07045a7a72d80c507a5be09

commit 18263be7565782a9c07045a7a72d80c507a5be09
Author: Simon Marchi <simon.marchi@efficios.com>
Date:   Thu Jun 17 09:41:59 2021 -0400

    gdb/testsuite: gdb.base/args.exp: add KFAIL for native-extended-gdbserver

    This test tests passing arguments made of exactly two single-quotes
    ('') or a single newline character through the --args argument of GDB.
    For some reason, GDB adds some extra single quotes when transmitting the
    arguments to GDBserver.  This produces some FAILs when testing with the
    native-extended-gdbserver board:

        FAIL: gdb.base/args.exp: argv[2] for one empty (with single quotes)
        FAIL: gdb.base/args.exp: argv[2] for two empty (with single quotes)
        FAIL: gdb.base/args.exp: argv[3] for two empty (with single quotes)
        FAIL: gdb.base/args.exp: argv[2] for one newline
        FAIL: gdb.base/args.exp: argv[2] for two newlines
        FAIL: gdb.base/args.exp: argv[3] for two newlines

    This is documented as PR 27989.  Add some appropriate KFAILs.

    gdb/testsuite/ChangeLog:

            * gdb.base/args.exp: Check target, KFAIL if remote.
            (args_test): Add parameter and use it.

    Change-Id: I49225d1c7df7ebaba480ebdd596df80f8fbf62f0

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[Bug gdb/27989] gdb.base/args.exp fails with native-extended-gdbserver board

[m.weghorn at posteo dot de]

https://sourceware.org/bugzilla/show_bug.cgi?id=27989

Michael Weghorn <m.weghorn at posteo dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |m.weghorn at posteo dot de

--- Comment #3 from Michael Weghorn <m.weghorn at posteo dot de> ---
That's also related to commit bea571ebd78ee29cb94adf648fbcda1e109e1be6
("Use construct_inferior_arguments which handles special chars"). I'm looking
at this in the context of PR 28392.

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[Bug gdb/27989] gdb.base/args.exp fails with native-extended-gdbserver board

[cvs-commit at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=27989

--- Comment #4 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Andrew Burgess <aburgess@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=f1f0a06d5b34231edd75fbd71a3be79097437f62

commit f1f0a06d5b34231edd75fbd71a3be79097437f62
Author: Andrew Burgess <aburgess@redhat.com>
Date:   Tue Sep 26 17:32:24 2023 +0100

    gdbserver: fix handling of single quote arguments

    I noticed that passing arguments containing single quotes to gdbserver
    didn't work correctly:

      gdb -ex 'set sysroot' --args /tmp/show-args
      Reading symbols from /tmp/show-args...
      (gdb) target extended-remote | gdbserver --once --multi - /tmp/show-args
      Remote debugging using | gdbserver --once --multi - /tmp/show-args
      stdin/stdout redirected
      Process /tmp/show-args created; pid = 176054
      Remote debugging using stdio
      Reading symbols from /lib64/ld-linux-x86-64.so.2...
      (No debugging symbols found in /lib64/ld-linux-x86-64.so.2)
      0x00007ffff7fd3110 in _start () from /lib64/ld-linux-x86-64.so.2
      (gdb) set args \'
      (gdb) r
      The program being debugged has been started already.
      Start it from the beginning? (y or n) y
      Starting program: /tmp/show-args \'
      stdin/stdout redirected
      Process /tmp/show-args created; pid = 176088
      2 args are:
        /tmp/show-args
        \'
      Done.
      [Inferior 1 (process 176088) exited normally]
      (gdb) target native
      Done.  Use the "run" command to start a process.
      (gdb) run
      Starting program: /tmp/show-args \'
      2 args are:
        /tmp/show-args
        '
      Done.
      [Inferior 1 (process 176095) exited normally]
      (gdb) q

    The 'shows-args' program used here just prints the arguments passed to
    the inferior.

    Notice that when starting the inferior using the extended-remote
    target the second argument is "\'", while when running using native
    target the argument is "'".  The second of these is correct, the \'
    used with the "set args" command is just to show GDB that the single
    quote is not opening an argument string.

    It turns out that the extra backslash is injected on the gdbserver
    side when gdbserver processes the arguments that GDB passes it, the
    code that does this was added as part of this much larger commit:

      commit 2090129c36c7e582943b7d300968d19b46160d84
      Date:   Thu Dec 22 21:11:11 2016 -0500

          Share fork_inferior et al with gdbserver

    In this commit I propose removing the specific code that adds what I
    believe is a stray backslash.  I've extended an existing test to cover
    this case, and I now see identical behaviour when using an
    extended-remote target as with the native target.

    This partially fixes PR gdb/27989, though there are still some issues
    with newline handling which I'll address in a later commit.

    During review I was pointed to this older series:

     
https://inbox.sourceware.org/gdb-patches/20211022071933.3478427-1-m.weghorn@posteo.de/

    which also includes this fix as part of a larger set of changes.  I'm
    giving a Co-Authored-By credit to the author of that original series.
    I believe this smaller fix brings some benefits on its own, though the
    original series does offer additional improvements.  Once this is
    merged I'll take a look at rebasing and resubmitting the original series.

    Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=27989

    Co-Authored-By: Michael Weghorn <m.weghorn@posteo.de>
    Approved-By: Tom Tromey <tom@tromey.com>

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[Bug gdb/27989] gdb.base/args.exp fails with native-extended-gdbserver board

[cvs-commit at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=27989

--- Comment #5 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Andrew Burgess <aburgess@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=67e6945b7e3a5c1577d19b9d83ee9be86c0a8424

commit 67e6945b7e3a5c1577d19b9d83ee9be86c0a8424
Author: Andrew Burgess <aburgess@redhat.com>
Date:   Wed Sep 27 17:54:15 2023 +0100

    gdbserver: handle newlines in inferior arguments

    Similarly to how single quotes were mishandled, which was fixed two
    commits ago, this commit fixes handling of newlines in arguments
    passed to gdbserver.

    We already had a test that covered this, gdb.base/args.exp, which,
    when run with the native-extended-gdbserver board contained several
    KFAIL covering this situation.

    In this commit I remove the unnecessary, attempt to quote incoming
    newlines within arguments, and do some minimal cleanup of the related
    code.  There is additional cleanup that can be done, but I'm leaving
    that for the next commit.

    Then I've removed the KFAIL from the test case, and performed some
    minimal cleanup there too.

    After this commit the gdb.base/args.exp is 100% passing with the
    native-extended-gdbserver board file.

    During review I was pointed to this older series:

     
https://inbox.sourceware.org/gdb-patches/20211022071933.3478427-1-m.weghorn@posteo.de/

    which also includes this fix as part of a larger set of changes.  I'm
    giving a Co-Authored-By credit to the author of that original series.
    I believe this smaller fix brings some benefits on its own, though the
    original series does offer additional improvements.  Once this is
    merged I'll take a look at rebasing and resubmitting the original series.

    Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=27989

    Co-Authored-By: Michael Weghorn <m.weghorn@posteo.de>
    Approved-By: Tom Tromey <tom@tromey.com>

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[Bug gdb/27989] gdb.base/args.exp fails with native-extended-gdbserver board

[aburgess at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=27989

Andrew Burgess <aburgess at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |aburgess at redhat dot com
         Resolution|---                         |FIXED

--- Comment #6 from Andrew Burgess <aburgess at redhat dot com> ---
Should now be fixed.  As is mentioned in comment 3, this issue is a sub-set of
the issue reported as bug PR 28392.  The bigger issue is still not fixed, but
this small part has now been resolved.

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