From: Florian Weimer <fweimer@redhat.com>
To: libc-alpha@sourceware.org
Cc: Carlos O'Donell <carlos@redhat.com>
Subject: [PATCH] libio: Update number of written bytes in dprintf implementation
Date: Tue, 31 Jan 2023 10:38:21 +0100 [thread overview]
Message-ID: <87k013vyb6.fsf@oldenburg.str.redhat.com> (raw)
The __printf_buffer_flush_dprintf function needs to record that
the buffer has been written before reusing it. Without this
accounting, dprintf always returns zero.
Fixes commit 8ece45e4f586abd212d1c02d74d38ef681a45600
("libio: Convert __vdprintf_internal to buffers.
Tested on i686-linux-gnu and x86_64-linux-gnu.
---
libio/iovdprintf.c | 1 +
stdio-common/Makefile | 1 +
stdio-common/tst-dprintf-length.c | 45 +++++++++++++++++++++++++++++++++++++++
3 files changed, 47 insertions(+)
diff --git a/libio/iovdprintf.c b/libio/iovdprintf.c
index fb359d263d..d9fa886fdf 100644
--- a/libio/iovdprintf.c
+++ b/libio/iovdprintf.c
@@ -54,6 +54,7 @@ __printf_buffer_flush_dprintf (struct __printf_buffer_dprintf *buf)
}
p += ret;
}
+ buf->base.written += buf->base.write_ptr - buf->base.write_base;
buf->base.write_ptr = buf->buf;
}
diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index da3034d847..34fdd6d1f8 100644
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -180,6 +180,7 @@ tests := \
tst-bz11319 \
tst-bz11319-fortify2 \
tst-cookie \
+ tst-dprintf-length \
tst-fdopen \
tst-ferror \
tst-fgets \
diff --git a/stdio-common/tst-dprintf-length.c b/stdio-common/tst-dprintf-length.c
new file mode 100644
index 0000000000..abe2caf45a
--- /dev/null
+++ b/stdio-common/tst-dprintf-length.c
@@ -0,0 +1,45 @@
+/* Test that dprintf returns the expected length.
+ Copyright (C) 2023 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+#include <string.h>
+#include <support/check.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+static int
+do_test (void)
+{
+ /* Use a datagram socket to check that everything arrives in one packet.
+ The dprintf function should perform a single write call. */
+ int fds[2];
+ TEST_VERIFY_EXIT (socketpair (AF_LOCAL, SOCK_DGRAM, 0, fds) == 0);
+
+ TEST_COMPARE (dprintf (fds[0], "(%d)%s[%d]", 123, "---", 4567), 14);
+
+ char buf[32];
+ ssize_t ret = read (fds[1], buf, sizeof (buf));
+ TEST_VERIFY_EXIT (ret > 0);
+ TEST_COMPARE_BLOB (buf, ret, "(123)---[4567]", strlen ("(123)---[4567]"));
+
+ close (fds[1]);
+ close (fds[0]);
+ return 0;
+}
+
+#include <support/test-driver.c>
base-commit: 2f39e44a8417b4186a7f15bfeac5d0b557e63e03
next reply other threads:[~2023-01-31 9:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-31 9:38 Florian Weimer [this message]
2023-01-31 9:52 ` Andreas Schwab
2023-01-31 10:35 ` Florian Weimer
2023-01-31 21:07 ` Carlos O'Donell
2023-01-31 21:22 ` Florian Weimer
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