From f5c65fa920d78cffe56fe4065f16241637808353 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Tue, 31 Jan 2023 22:22:02 +0100 Subject: libio: Update number of written bytes in dprintf implementation 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"). Reviewed-by: Carlos O'Donell Tested-by: Carlos O'Donell --- stdio-common/Makefile | 1 + stdio-common/tst-dprintf-length.c | 45 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+) create mode 100644 stdio-common/tst-dprintf-length.c (limited to 'stdio-common') 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 + . */ + +#include +#include +#include +#include +#include + +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 -- cgit 1.4.1