From: Florian Weimer <fweimer@redhat.com>
To: "Dmitry V. Levin" <ldv@altlinux.org>
Cc: libc-alpha@sourceware.org
Subject: Re: [PATCH v3] libio: do not unbuffer legacy standard files in compatibility mode [BZ #24228]
Date: Wed, 19 Jun 2019 15:10:14 +0200 [thread overview]
Message-ID: <87lfxx4t6x.fsf@oldenburg2.str.redhat.com> (raw)
In-Reply-To: <20190219012913.GB29070@altlinux.org> (Dmitry V. Levin's message of "Tue, 19 Feb 2019 04:29:13 +0300")
* Dmitry V. Levin:
> diff --git a/libio/genops.c b/libio/genops.c
> index 2a0d9b81df..aa92d61b6b 100644
> --- a/libio/genops.c
> +++ b/libio/genops.c
> @@ -789,6 +789,10 @@ _IO_unbuffer_all (void)
>
> for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain)
> {
> +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
> + if (__glibc_unlikely (&_IO_stdin_used == NULL) && _IO_legacy_file (fp))
> + continue;
> +#endif
> if (! (fp->_flags & _IO_UNBUFFERED)
> /* Iff stream is un-orientated, it wasn't used. */
> && fp->_mode != 0)
I believe a better fix would be this, in case an old-style file showed
up for a different reason:
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
bool potentially_wide_stream = _IO_vtable_offset (fp) != 0;
#else
bool potentially_wide_stream = true;
#endif
if (potentially_wide_stream && fp->_mode > 0)
_IO_wsetb (fp, NULL, NULL, 0);
This is _IO_new_fclose handles this situation.
I fear the test is unreliable because it depends on what fp->_mode
evaluates to (which is not actually present in the struct with old
files). But the test is definitely better than nothing.
Thanks,
Florian
next prev parent reply other threads:[~2019-06-19 13:10 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-18 12:44 [PATCH] libio: do not cleanup wide buffers of legacy standard files [BZ #24228] Dmitry V. Levin
2019-02-18 12:56 ` Florian Weimer
2019-02-18 19:10 ` Dmitry V. Levin
2019-02-18 21:38 ` [PATCH v2] " Dmitry V. Levin
2019-02-19 0:57 ` [PATCH] " Dmitry V. Levin
2019-02-19 1:29 ` [PATCH v3] libio: do not unbuffer legacy standard files in compatibility mode " Dmitry V. Levin
2019-03-13 15:08 ` Florian Weimer
2019-03-13 15:46 ` Dmitry V. Levin
2019-03-13 15:49 ` Florian Weimer
2019-03-13 15:59 ` Dmitry V. Levin
2019-06-19 13:10 ` Florian Weimer [this message]
2019-06-19 16:03 ` Dmitry V. Levin
2019-06-19 16:15 ` Florian Weimer
2019-06-19 17:46 ` Dmitry V. Levin
2019-06-19 19:04 ` Florian Weimer
2019-06-19 19:51 ` [PATCH v4] libio: do not attempt to free wide buffers of legacy streams " Dmitry V. Levin
2019-06-19 21:15 ` Florian Weimer
2019-06-19 22:08 ` [PATCH v5] " Dmitry V. Levin
2019-06-20 8:59 ` Florian Weimer
2019-06-20 17:42 ` Dmitry V. Levin
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