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2025-04-14libio: Add test case for fflushFrédéric Bérat1-0/+2
Since one path uses _IO_SYNC and the other _IO_OVERFLOW, the newly added test cases verifies that `fflush (FILE)` and `fflush (NULL)` are semantically equivalent from the FILE perspective. Reviewed-by: Joseph Myers <josmyers@redhat.com>
2025-01-01Update copyright dates with scripts/update-copyrightsPaul Eggert1-1/+1
2024-12-27libio: asprintf should write NULL upon failureFlorian Weimer1-0/+1
This was suggested most recently by Solar Designer, noting that code replacing vsprintf with vasprintf in a security fix was subtly wrong: Re: GStreamer Security Advisory 2024-0003: Orc compiler stack-based buffer overflow <https://www.openwall.com/lists/oss-security/2024/07/26/2> Previous libc-alpha discussions: I: [PATCH] asprintf error handling fix <https://inbox.sourceware.org/libc-alpha/20011205185828.GA8376@ldv.office.alt-linux.org/> asprintf() issue <https://inbox.sourceware.org/libc-alpha/CANSoFxt-cdc-+C4u-rTENMtY4X9RpRSuv+axDswSPxbDgag8_Q@mail.gmail.com/> I don't think we need a compatibility symbol for this. As the GStreamer example shows, this change is much more likely to fix bugs than cause compatibility issues. Suggested-by: Dmitry V. Levin <ldv@altlinux.org> Suggested-by: Archie Cobbs <archie.cobbs@gmail.com> Suggested-by: Solar Designer <solar@openwall.com> Reviewed-by: Sam James <sam@gentoo.org>
2024-12-23Check if TEST_CC supports -Wno-restrict before using itAdhemerval Zanella1-2/+4
Check if TEST_CC supports -Wno-restrict before using it to avoid Clang error: error: unknown warning option '-Wno-restrict' [-Werror,-Wunknown-warning-option] Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Reviewed-by: Sam James <sam@gentoo.org>
2024-10-25libio: Fix crash in fputws [BZ #20632]Peter Ammon1-0/+2
This fixes a buffer overflow in wide character string output, reproducing when output fails, such as if the output fd is closed or is redirected to a full device. Wide character output data attempts to maintain the invariant that `_IO_buf_base <= _IO_write_base <= _IO_write_end <= _IO_buf_end` (that is, that the write region is a sub-region of `_IO_buf`). Prior to this commit, this invariant is violated by the `_IO_wfile_overflow` function as so: 1. `_IO_wsetg` is called, assigning `_IO_write_base` to `_IO_buf_base` 2. `_IO_doallocbuf` is called, which jumps to `_IO_wfile_doallocate` via the _IO_wfile_jumps vtable. This function then assigns the wide data `_IO_buf_base` and `_IO_buf_end` to a malloc'd buffer. Thus the invariant is violated. The fix is simply to reverse the order: malloc the `_IO_buf` first and then assign `_IO_write_base` to it. We also take this opportunity to defensively guard the initialization of the number of unwritten characters via pointer arithmetic. We now check that the buffer end is not before the buffer beginning; this matches a similar defensive check in the narrow analogue `fileops.c`. Add a test which fails without the fix. Signed-off-by: Peter Ammon <corydoras@ridiculousfish.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2024-10-25libio: Correctly link tst-popen-fork against libpthreadArjun Shankar1-0/+2
tst-popen-fork failed to build for Hurd due to not being linked with libpthread. This commit fixes that. Tested with build-many-glibcs.py for i686-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
2024-10-23libio: Fix a deadlock after fork in popenArjun Shankar1-0/+1
popen modifies its file handler book-keeping under a lock that wasn't being taken during fork. This meant that a concurrent popen and fork could end up copying the lock in a "locked" state into the fork child, where subsequently calling popen would lead to a deadlock due to the already (spuriously) held lock. This commit fixes the deadlock by appropriately taking the lock before fork, and releasing/resetting it in the parent/child after the fork. A new test for concurrent popen and fork is also added. It consistently hangs (and therefore fails via timeout) without the fix applied. Reviewed-by: Florian Weimer <fweimer@redhat.com>
2024-10-01libio: Set _vtable_offset before calling _IO_link_in [BZ #32148]H.J. Lu1-0/+7
Since _IO_vtable_offset is used to detect the old binaries, set it in _IO_old_file_init_internal before calling _IO_link_in which checks _IO_vtable_offset. Add a glibc 2.0 test with copy relocation on _IO_stderr_@GLIBC_2.0 to verify that fopen won't cause memory corruption. This fixes BZ #32148. Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2024-09-20Add another test for fclose on an unopened fileAaron Merey1-0/+12
Add new file libio/tst-fclose-unopened2.c that tests whether fclose on an unopened file returns EOF. This test differs from tst-fclose-unopened.c by ensuring the file's buffer is allocated prior to double-fclose. A comment in tst-fclose-unopened.c now clarifies that it is testing a file with an unallocated buffer. Calling fclose on unopened files normally causes a use-after-free bug, however the standard streams are an exception since they are not deallocated by fclose. Tested for x86_64. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-09-05Test fclose on an unopened file.Aaron Merey1-0/+1
Add new file libio/tst-fclosed-unopened.c that tests whether fclose on an unopened file returns EOF. Calling fclose on unopened files normally causes a use-after-free bug, however the standard streams are an exception since they are not deallocated by fclose. fclose returning EOF for unopened files is not part of the external contract but there are dependancies on this behaviour. For example, gnulib's close_stdout in lib/closeout.c. Tested for x86_64. Signed-off-by: Aaron Merey <amerey@redhat.com>
2024-07-09libio: handle opening a file when all files are closed (bug 31963)Andreas Schwab1-0/+1
_IO_list_all becomes NULL when all files (including standard files) are closed.
2024-07-01Fix conditionals on mtrace-based tests (bug 31892)Carlos O'Donell1-11/+31
The conditionals for several mtrace-based tests in catgets, elf, libio, malloc, misc, nptl, posix, and stdio-common were incorrect leading to test failures when bootstrapping glibc without perl. The correct conditional for mtrace-based tests requires three checks: first checking for run-built-tests, then build-shared, and lastly that PERL is not equal to "no" (missing perl). Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2024-06-04libio: Test for fdopen memory leak without SEEK_END support (bug 31840)Florian Weimer1-2/+16
The bug report used /dev/mem, but /proc/self/mem works as well (if available).
2024-05-06Add crt1-2.0.o for glibc 2.0 compatibility testsH.J. Lu1-0/+6
Starting from glibc 2.1, crt1.o contains _IO_stdin_used which is checked by _IO_check_libio to provide binary compatibility for glibc 2.0. Add crt1-2.0.o for tests against glibc 2.0. Define tests-2.0 for glibc 2.0 compatibility tests. Add and update glibc 2.0 compatibility tests for stderr, matherr and pthread_kill. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-04-30libio: Sort test variables in MakefileH.J. Lu1-20/+84
Sort test variables in libio/Makefile using scripts/sort-makefile-lines.py. Reviewed-by: Sunil K Pandey <skpgkp2@gmail.com>
2024-01-01Update copyright dates with scripts/update-copyrightsPaul Eggert1-1/+1
2023-07-05Exclude routines from fortificationFrédéric Bérat1-2/+21
Since the _FORTIFY_SOURCE feature uses some routines of Glibc, they need to be excluded from the fortification. On top of that: - some tests explicitly verify that some level of fortification works appropriately, we therefore shouldn't modify the level set for them. - some objects need to be build with optimization disabled, which prevents _FORTIFY_SOURCE to be used for them. Assembler files that implement architecture specific versions of the fortified routines were not excluded from _FORTIFY_SOURCE as there is no C header included that would impact their behavior. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-03-27libio: Remove the usage of __libc_IO_vtablesAdhemerval Zanella Netto1-0/+2
Instead of using a special ELF section along with a linker script directive to put the IO vtables within the RELRO section, the libio vtables are all moved to an array marked as data.relro (so linker will place in the RELRO segment without the need of extra directives). To avoid static linking namespace issues and including all vtable referenced objects, all required function pointers are set to weak alias. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-01-06Update copyright dates with scripts/update-copyrightsJoseph Myers1-1/+1
2023-01-02getdelim: ensure error indicator is set on error (bug 29917)Andreas Schwab1-1/+1
POSIX requires that getdelim and getline set the error indicator on the stream when an error occured, in addition to setting errno.
2022-11-01configure: Use -Wno-ignored-attributes if compiler warns about multiple aliasesAdhemerval Zanella1-3/+11
clang emits an warning when a double alias redirection is used, to warn the the original symbol will be used even when weak definition is overridden. However, this is a common pattern for weak_alias, where multiple alias are set to same symbol. Reviewed-by: Fangrui Song <maskray@google.com>
2022-07-14Apply asm redirections in stdio.h before first use [BZ #27087]Tulio Magno Quites Machado Filho1-1/+1
Compilers may not be able to apply asm redirections to functions after these functions are used for the first time, e.g. clang 13. Fix [BZ #27087] by applying all long double-related asm redirections before using functions in bits/stdio.h. However, as these asm redirections depend on the declarations provided by libio/bits/stdio2.h, this header was split in 2: - libio/bits/stdio2-decl.h contains all function declarations; - libio/bits/stdio2.h remains with the remaining contents, including redirections. This also adds the access attribute to __vsnprintf_chk that was missing. Tested with build-many-glibcs.py. Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
2022-03-08libio: Ensure output buffer for wchars (bug #28828)José Bollo1-1/+1
The _IO_wfile_overflow does not check if the write pointer for wide data is valid before access, different than _IO_file_overflow. This leads to crash on some cases, as described by bug 28828. The minimal sequence to produce the crash was: #include <stdio.h> #include <wchar.h> int main (int ac, char **av) { setvbuf (stdout, NULL, _IOLBF, 0); fgetwc (stdin); fputwc (10, stdout); /*CRASH HERE!*/ return 0; } The "fgetwc(stdin);" is necessary since it triggers the bug by setting the flag _IO_CURRENTLY_PUTTING on stdout indirectly (file wfileops.c, function _IO_wfile_underflow, line 213). Signed-off-by: Jose Bollo <jobol@nonadev.net>
2022-01-01Update copyright dates with scripts/update-copyrightsPaul Eggert1-1/+1
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 7061 files FOO. I then removed trailing white space from math/tgmath.h, support/tst-support-open-dev-null-range.c, and sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following obscure pre-commit check failure diagnostics from Savannah. I don't know why I run into these diagnostics whereas others evidently do not. remote: *** 912-#endif remote: *** 913: remote: *** 914- remote: *** error: lines with trailing whitespace found ... remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2021-07-22Move malloc hooks into a compat DSOSiddhesh Poyarekar1-4/+8
Remove all malloc hook uses from core malloc functions and move it into a new library libc_malloc_debug.so. With this, the hooks now no longer have any effect on the core library. libc_malloc_debug.so is a malloc interposer that needs to be preloaded to get hooks functionality back so that the debugging features that depend on the hooks, i.e. malloc-check, mcheck and mtrace work again. Without the preloaded DSO these debugging features will be nops. These features will be ported away from hooks in subsequent patches. Similarly, legacy applications that need hooks functionality need to preload libc_malloc_debug.so. The symbols exported by libc_malloc_debug.so are maintained at exactly the same version as libc.so. Finally, static binaries will no longer be able to use malloc debugging features since they cannot preload the debugging DSO. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-05-16Enable support for GCC 11 -Wmismatched-dealloc.Martin Sebor1-1/+1
To help detect common kinds of memory (and other resource) management bugs, GCC 11 adds support for the detection of mismatched calls to allocation and deallocation functions. At each call site to a known deallocation function GCC checks the set of allocation functions the former can be paired with and, if the two don't match, issues a -Wmismatched-dealloc warning (something similar happens in C++ for mismatched calls to new and delete). GCC also uses the same mechanism to detect attempts to deallocate objects not allocated by any allocation function (or pointers past the first byte into allocated objects) by -Wfree-nonheap-object. This support is enabled for built-in functions like malloc and free. To extend it beyond those, GCC extends attribute malloc to designate a deallocation function to which pointers returned from the allocation function may be passed to deallocate the allocated objects. Another, optional argument designates the positional argument to which the pointer must be passed. This change is the first step in enabling this extended support for Glibc.
2021-04-16Set the retain attribute on _elf_set_element if CC supports [BZ #27492]Fangrui Song1-0/+28
So that text_set_element/data_set_element/bss_set_element defined variables will be retained by the linker. Note: 'used' and 'retain' are orthogonal: 'used' makes sure the variable will not be optimized out; 'retain' prevents section garbage collection if the linker support SHF_GNU_RETAIN. GNU ld 2.37 and LLD 13 will support -z start-stop-gc which allow C identifier name sections to be GCed even if there are live __start_/__stop_ references. Without the change, there are some static linking problems, e.g. _IO_cleanup (libio/genops.c) may be discarded by ld --gc-sections, so stdout is not flushed on exit. Note: GCC may warning 'retain' attribute ignored while __has_attribute(retain) is 1 (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99587). Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-01-02Update copyright dates with scripts/update-copyrightsPaul Eggert1-1/+1
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master
2020-10-08Revert "Fix missing redirects in testsuite targets"Andreas Schwab1-1/+1
This reverts commit d5afb38503. The log files are actually created by the various shell scripts that drive the tests.
2020-07-21libio: Remove __libc_readline_unlockedFlorian Weimer1-2/+2
__nss_readline supersedes it. This reverts part of commit 3f5e3f5d066dcffb80af48ae2cf35a01a85a8f10 ("libio: Implement internal function __libc_readline_unlocked"). The internal aliases __fseeko64 and __ftello64 are preserved because they are needed by __nss_readline as well. Tested-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-07signal: Move sys_errlist to a compat symbolAdhemerval Zanella1-1/+1
The symbol is deprecated by strerror since its usage imposes some issues such as copy relocations. Its internal name is also changed to _sys_errlist_internal to avoid static linking usage. The compat code is also refactored by removing the over enginered errlist-compat.c generation from manual entried and extra comment token in linker script file. It disantangle the code generation from manual and simplify both Linux and Hurd compat code. The definitions from errlist.c are moved to errlist.h and a new test is added to avoid a new errno entry without an associated one in manual. Checked on x86_64-linux-gnu and i686-linux-gnu. I also run a check-abi on all affected platforms. Tested-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-01-01Update copyright dates with scripts/update-copyrights.Joseph Myers1-1/+1
2019-09-07Prefer https to http for gnu.org and fsf.org URLsPaul Eggert1-1/+1
Also, change sources.redhat.com to sourceware.org. This patch was automatically generated by running the following shell script, which uses GNU sed, and which avoids modifying files imported from upstream: sed -ri ' s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g ' \ $(find $(git ls-files) -prune -type f \ ! -name '*.po' \ ! -name 'ChangeLog*' \ ! -path COPYING ! -path COPYING.LIB \ ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \ ! -path manual/texinfo.tex ! -path scripts/config.guess \ ! -path scripts/config.sub ! -path scripts/install-sh \ ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \ ! -path INSTALL ! -path locale/programs/charmap-kw.h \ ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \ ! '(' -name configure \ -execdir test -f configure.ac -o -f configure.in ';' ')' \ ! '(' -name preconfigure \ -execdir test -f preconfigure.ac ';' ')' \ -print) and then by running 'make dist-prepare' to regenerate files built from the altered files, and then executing the following to cleanup: chmod a+x sysdeps/unix/sysv/linux/riscv/configure # Omit irrelevant whitespace and comment-only changes, # perhaps from a slightly-different Autoconf version. git checkout -f \ sysdeps/csky/configure \ sysdeps/hppa/configure \ sysdeps/riscv/configure \ sysdeps/unix/sysv/linux/csky/configure # Omit changes that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines git checkout -f \ sysdeps/powerpc/powerpc64/ppc-mcount.S \ sysdeps/unix/sysv/linux/s390/s390-64/syscall.S # Omit change that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-07-31iconv: Revert steps array reference counting changesFlorian Weimer1-14/+2
The changes introduce a memory leak for gconv steps arrays whose first element is an internal conversion, which has a fixed reference count which is not decremented. As a result, after the change in commit 50ce3eae5ba304650459d4441d7d246a7cefc26f, the steps array is never freed, resulting in an unbounded memory leak. This reverts commit 50ce3eae5ba304650459d4441d7d246a7cefc26f ("gconv: Check reference count in __gconv_release_cache [BZ #24677]") and commit 7e740ab2e7be7d83b75513aa406e0b10875f7f9c ("libio: Fix gconv-related memory leak [BZ #24583]"). It reintroduces bug 24583. (Bug 24677 was just a regression caused by the second commit.)
2019-06-20libio: do not attempt to free wide buffers of legacy streams [BZ #24228]Dmitry V. Levin1-1/+13
Commit a601b74d31ca086de38441d316a3dee24c866305 aka glibc-2.23~693 ("In preparation for fixing BZ#16734, fix failure in misc/tst-error1-mem when _G_HAVE_MMAP is turned off.") introduced a regression: _IO_unbuffer_all now invokes _IO_wsetb to free wide buffers of all files, including legacy standard files which are small statically allocated objects that do not have wide buffers and the _mode member, causing memory corruption. Another memory corruption in _IO_unbuffer_all happens when -1 is assigned to the _mode member of legacy standard files that do not have it. [BZ #24228] * libio/genops.c (_IO_unbuffer_all) [SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)]: Do not attempt to free wide buffers and access _IO_FILE_complete members of legacy libio streams. * libio/tst-bz24228.c: New file. * libio/tst-bz24228.map: Likewise. * libio/Makefile [build-shared] (tests): Add tst-bz24228. [build-shared] (generated): Add tst-bz24228.mtrace and tst-bz24228.check. [run-built-tests && build-shared] (tests-special): Add $(objpfx)tst-bz24228-mem.out. (LDFLAGS-tst-bz24228, tst-bz24228-ENV): New variables. ($(objpfx)tst-bz24228-mem.out): New rule.
2019-05-21libio: Fix gconv-related memory leak [BZ #24583]Florian Weimer1-2/+14
struct gconv_fcts for the C locale is statically allocated, and __gconv_close_transform deallocates the steps object. Therefore this commit introduces __wcsmbs_close_conv to avoid freeing the statically allocated steps objects.
2019-05-15Fix crash in _IO_wfile_sync (bug 20568)Andreas Schwab1-1/+3
When computing the length of the converted part of the stdio buffer, use the number of consumed wide characters, not the (negative) distance to the end of the wide buffer.
2019-02-03libio: Use stdin consistently for input functions [BZ #24153]Florian Weimer1-1/+1
The internal _IO_stdin_ variable is not updated when the application assigns to stdin, which is a GNU extension.
2019-01-31libio: use stdout in puts and putchar, etc [BZ #24051].Paul Pluzhnikov1-1/+1
GLIBC explicitly allows one to assign a new FILE pointer to stdout and other standard streams. printf and wprintf were honouring assignment to stdout and using the new value, but puts, putchar, and wide char variants did not. The stdout part is fixed here. The stdin part will be fixed in a followup.
2019-01-02Set behavior of sprintf-like functions with overlapping source and destinationGabriel F. T. Gomes1-1/+6
According to ISO C99, passing the same buffer as source and destination to sprintf, snprintf, vsprintf, or vsnprintf has undefined behavior. Until the commit commit 4e2f43f842ef5e253cc23383645adbaa03cedb86 Author: Zack Weinberg <zackw@panix.com> Date: Wed Mar 7 14:32:03 2018 -0500 Use PRINTF_FORTIFY instead of _IO_FLAGS2_FORTIFY (bug 11319) a call to sprintf or vsprintf with overlapping buffers, for instance vsprintf (buf, "%sTEXT", buf), would append `TEXT' into buf, while a call to snprintf or vsnprintf would override the contents of buf. After the aforementioned commit, the behavior of sprintf and vsprintf changed (so that they also override the contents of buf). This patch reverts this behavioral change, because it will likely break applications that rely on the previous behavior, even though it is undefined by ISO C. As noted by Szabolcs Nagy, this is used in SPEC2017 507.cactuBSSN_r/src/PUGH/PughUtils.c: sprintf(mess," Size:"); for (i=0;i<dim+1;i++) { sprintf(mess,"%s %d",mess,pughGH->GFExtras[dim]->nsize[i]); } More important to notice is the fact that the overwriting of the destination buffer is not the only behavior affected by the refactoring. Before the refactoring, sprintf and vsprintf would use _IO_str_jumps, whereas __sprintf_chk and __vsprintf_chk would use _IO_str_chk_jumps. After the refactoring, all use _IO_str_chk_jumps, which would make sprintf and vsprintf report buffer overflows and terminate the program. This patch also reverts this behavior, by installing the appropriate jump table for each *sprintf functions. Apart from reverting the changes, this patch adds a test case that has the old behavior hardcoded, so that regressions are noticed if something else unintentionally changes the behavior. Tested for powerpc64le.
2019-01-01Update copyright dates with scripts/update-copyrights.Joseph Myers1-1/+1
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
2018-10-02libio: Flush stream at freopen (BZ#21037)Adhemerval Zanella1-2/+2
As POSIX states [1] a freopen call should first flush the stream as if by a call fflush. C99 (n1256) and C11 (n1570) only states the function should first close any file associated with the specific stream. Although current implementation only follow C specification, current BSD and other libc implementation (musl) are in sync with POSIX and fflush the stream. This patch change freopen{64} to fflush the stream before actually reopening it (or returning if the stream does not support reopen). It also changes the Linux implementation to avoid a dynamic allocation on 'fd_to_filename'. Checked on x86_64-linux-gnu. [BZ #21037] * libio/Makefile (tests): Add tst-memstream4 and tst-wmemstream4. * libio/freopen.c (freopen): Sync stream before reopen and adjust to new fd_to_filename interface. * libio/freopen64.c (freopen64): Likewise. * libio/tst-memstream.h: New file. * libio/tst-memstream4.c: Likewise. * libio/tst-wmemstream4.c: Likewise. * sysdeps/generic/fd_to_filename.h (fd_to_filename): Change signature. * sysdeps/unix/sysv/linux/fd_to_filename.h (fd_to_filename): Likewise and remove internal dynamic allocation. [1] http://pubs.opengroup.org/onlinepubs/9699919799/
2018-07-06libio: Implement internal function __libc_readline_unlockedFlorian Weimer1-2/+2
This is a variant of fgets which fails with ERANGE if the buffer is too small, and the buffer length is given as an argument of type size_t. This function will be useful for implementing NSS file reading operations. Compared to a direct implementation using the public API, it avoids an lseek system call in case the line terminator can be found in the internal read buffer.
2018-06-26libio: Add