The gnulib version contains an important change (9ce573cde), which
fixes some problems with multithreading, entropy loss, and ASLR leak
nfo. It also fixes an issue where getrandom is not being used
on some new files generation (only for __GT_NOCREATE on first try).
The 044bf893ac removed __path_search, which is now moved to another
gnulib shared files (stdio-common/tmpdir.{c,h}). Tthis patch
also fixes direxists to use __stat64_time64 instead of __xstat64,
and move the include of pathmax.h for !_LIBC (since it is not used
by glibc). The license is also changed from GPL 3.0 to 2.1, with
permission from the authors (Bruno Haible and Paul Eggert).
The sync also removed the clock fallback, since clock_gettime
with CLOCK_REALTIME is expected to always succeed.
It syncs with gnulib commit 323834962817af7b115187e8c9a833437f8d20ec.
Checked on x86_64-linux-gnu.
Co-authored-by: Bruno Haible <bruno@clisp.org>
Co-authored-by: Paul Eggert <eggert@cs.ucla.edu>
Reviewed-by: Bruno Haible <bruno@clisp.org>
We would like to avoid statically defining any specific page size on
aarch64-gnu, and instead make sure that everything uses the dynamic
page size, available via vm_page_size and GLRO(dl_pagesize).
There are currently a few places in glibc that require EXEC_PAGESIZE
to be defined. Per Roland's suggestion [0], drop the static
GLRO(dl_pagesize) initializers (for now, only if EXEC_PAGESIZE is not
defined), and don't require EXEC_PAGESIZE definition for libio to
enable mmap usage.
[0]: https://mail.gnu.org/archive/html/bug-hurd/2011-10/msg00035.html
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240323173301.151066-4-bugaevc@gmail.com>
It improve fortify checks for sprintf, vsprintf, vsnsprintf, fprintf,
dprintf, asprintf, __asprintf, obstack_printf, gets, fgets,
fgets_unlocked, fread, and fread_unlocked. The runtime checks have
similar support coverage as with GCC.
For function with variadic argument (sprintf, snprintf, fprintf, printf,
dprintf, asprintf, __asprintf, obstack_printf) the fortify wrapper calls
the va_arg version since clang does not support __va_arg_pack.
Checked on aarch64, armhf, x86_64, and i686.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
WG14 decided to use the name C23 as the informal name of the next
revision of the C standard (notwithstanding the publication date in
2024). Update references to C2X in glibc to use the C23 name.
This is intended to update everything *except* where it involves
renaming files (the changes involving renaming tests are intended to
be done separately). In the case of the _ISOC2X_SOURCE feature test
macro - the only user-visible interface involved - support for that
macro is kept for backwards compatibility, while adding
_ISOC23_SOURCE.
Tested for x86_64.
The multibyte character needs to fit into the remaining buffer space,
not the already-written buffer space. Without the fix, we were never
moving the write pointer from the start of the buffer, always using
the single-character fallback buffer.
Fixes commit 04b76b5aa8 ("Don't error out writing
a multibyte character to an unbuffered stream (bug 17522)").
During the review of a GCC analyzer test case, we found most stdio
functions accepting a FILE * argument expect it to be nonnull and just
segfault when the argument is NULL. Add nonnull attribute for them.
fflush and fflush_unlocked are well defined when __stream is NULL so
they are not touched.
For fputs, fgets, fread, fwrite, fprintf, vfprintf, and their unlocked
version, if __stream is empty but there is nothing to read or write,
they did not segfault. But the standard disallow __stream to be empty
here, so nonnull attribute is also added for them. Note that this may
blow up some old code already subtly broken.
Also add __nonnull for _chk variants and __fortify_function versions for
them.
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Reviewed-by: Alejandro Colomar <alx@kernel.org>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
IO_VTABLES_LEN is the size of the struct array in bytes, not the number
of __IO_jump_t's in the array. Drops just under 384kb from .rodata on
LP64 machines.
Fixes: 3020f72618 ("libio: Remove the usage of __libc_IO_vtables")
Signed-off-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Tested-by: Florian Weimer <fweimer@redhat.com>
On GNU/Hurd, O_RDWR actually is O_WRONLY|O_RDONLY, so checking through
bitness really is wrong. O_ACCMODE is there for this.
Fixes: 5324d25842 ("fileops: Don't process ,ccs= as individual mode flags (BZ#18906)")
In processing the first 7 individual characters of the mode for fopen
if ,ccs= is used those characters will be processed as well. Stop
processing individual mode flags once a comma is encountered. This has
the effect of requiring ,ccs= to be the last mode flag in the mode
string. Add a testcase to check that the ,ccs= mode flag is not
processed as individual mode flags.
Reviewed-by: DJ Delorie <dj@redhat.com>
The change is meant to avoid unwanted PLT entry for the fgets_unlocked
routine when _FORTIFY_SOURCE is set.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Move declarations from libio/bits/stdio.h to existing
libio/bits/stdio2-decl.h. This will enable future use of
__REDIRECT_FORTIFY in place of some __REDIRECT.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
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>
Now that abort no longer calls fflush there is no reason to avoid locking
the stdio streams anywhere. This fixes a conformance issue and potential
heap corruption during exit.
With fortification enabled, system calls return result needs to be checked,
has it gets the __wur macro enabled.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
With fortification enabled, fread calls return result needs to be checked,
has it gets the __wur macro enabled.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Calling fclose or freopen with a null FILE * is undefined behavior, and
doing so in practice will cause a SIGSEGV. So it seems suitable for
__nonnull.
This will help the compiler to warn for some buggy code, like
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109570.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
GCC docs explicitly list perror () as a good candidate for using
__attribute__ ((cold)). So apply __COLD to perror () and similar
functions.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230429131223.2507236-3-bugaevc@gmail.com>
FreeBSD makes these functions available by default, so we should
not treat them as GNU-specific and restrict them to _GNU_SOURCE.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Prevent sh from interpreting a user string as shell options if it
starts with '-' or '+'. Since the version of /bin/sh used for testing
system() is different from the full-fledged system /bin/sh add support
to it for handling "--" after "-c". Add a testcase to ensure the
expected behavior.
Signed-off-by: Joe Simmons-Talbott <josimmon@redhat.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
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>
Instead define the required fields in system dependend files. The only
system dependent definition is FILENAME_MAX, which should match POSIX
PATH_MAX, and it is obtained from either kernel UAPI or mach headers.
Currently set pre-defined value from current kernels.
It avoids a circular dependendy when including stdio.h in
gen-as-const-headers files.
Checked on x86_64-linux-gnu and i686-linux-gnu
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
They are both used by __libc_freeres to free all library malloc
allocated resources to help tooling like mtrace or valgrind with
memory leak tracking.
The current scheme uses assembly markers and linker script entries
to consolidate the free routine function pointers in the RELRO segment
and to be freed buffers in BSS.
This patch changes it to use specific free functions for
libc_freeres_ptrs buffers and call the function pointer array directly
with call_function_static_weak.
It allows the removal of both the internal macros and the linker
script sections.
Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
C2x adds binary integer constants starting with 0b or 0B, and supports
those constants for the %i scanf format (in addition to the %b format,
which isn't yet implemented for scanf in glibc). Implement that scanf
support for glibc.
As with the strtol support, this is incompatible with previous C
standard versions, in that such an input string starting with 0b or 0B
was previously required to be parsed as 0 (with the rest of the input
potentially matching subsequent parts of the scanf format string).
Thus this patch adds 12 new __isoc23_* functions per long double
format (12, 24 or 36 depending on how many long double formats the
glibc configuration supports), with appropriate header redirection
support (generally very closely following that for the __isoc99_*
scanf functions - note that __GLIBC_USE (DEPRECATED_SCANF) takes
precedence over __GLIBC_USE (C2X_STRTOL), so the case of GNU
extensions to C89 continues to get old-style GNU %a and does not get
this new feature). The function names would remain as __isoc23_* even
if C2x ends up published in 2024 rather than 2023.
When scanf %b support is added, I think it will be appropriate for all
versions of scanf to follow C2x rules for inputs to the %b format
(given that there are no compatibility concerns for a new format).
Tested for x86_64 (full glibc testsuite). The first version was also
tested for powerpc (32-bit) and powerpc64le (stdio-common/ and wcsmbs/
tests), and with build-many-glibcs.py.
Almost all uses of rawmemchr find the end of a string. Since most targets use
a generic implementation, replacing it with strchr is better since that is
optimized by compilers into strlen (s) + s. Also fix the generic rawmemchr
implementation to use a cast to unsigned char in the if statement.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
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 8ece45e4f5
("libio: Convert __vdprintf_internal to buffers").
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
This shows up as an assertion failure when sprintf is called with
a specifier like "%.8g" and libquadmath is linked in:
Fatal glibc error: printf_buffer_as_file.c:31
(__printf_buffer_as_file_commit): assertion failed:
file->stream._IO_write_ptr <= file->next->write_end
Fix this by detecting pointer wraparound in __vsprintf_internal
and saturate the addition to the end of the address space instead.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
Always null-terminate the buffer and set E2BIG if the buffer is too
small. This fixes bug 27857.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The internal buffer size is set to 2048 bytes. This is less than
the original BUFSIZ value used by buffered_vfprintf before
the conversion, but it hopefully covers all cases where write
boundaries matter.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The buffer resizing algorithm is slightly different. The initial
buffer is on the stack, and small buffers are directly allocated
on the heap using the exact required size. The overhead of the
additional copy is compensated by the lowered setup cost for buffers
compared to libio streams.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
vfprintf is entangled with vfwprintf (of course), __printf_fp,
__printf_fphex, __vstrfmon_l_internal, and the strfrom family of
functions. The latter use the internal snprintf functionality,
so vsnprintf is converted as well.
The simples conversion is __printf_fphex, followed by
__vstrfmon_l_internal and __printf_fp, and finally
__vfprintf_internal and __vfwprintf_internal. __vsnprintf_internal
and strfrom* are mostly consuming the new interfaces, so they
are comparatively simple.
__printf_fp is a public symbol, so the FILE *-based interface
had to preserved.
The __printf_fp rewrite does not change the actual binary-to-decimal
conversion algorithm, and digits are still not emitted directly to
the target buffer. However, the staging buffer now uses bytes
instead of wide characters, and one buffer copy is eliminated.
The changes are at least performance-neutral in my testing.
Floating point printing and snprintf improved measurably, so that
this Lua script
for i=1,5000000 do
print(i, i * math.pi)
end
runs about 5% faster for me. To preserve fprintf performance for
a simple "%d" format, this commit has some logic changes under
LABEL (unsigned_number) to avoid additional function calls. There
are certainly some very easy performance improvements here: binary,
octal and hexadecimal formatting can easily avoid the temporary work
buffer (the number of digits can be computed ahead-of-time using one
of the __builtin_clz* built-ins). Decimal formatting can use a
specialized version of _itoa_word for base 10.
The existing (inconsistent) width handling between strfmon and printf
is preserved here. __print_fp_buffer_1 would have to use
__translated_number_width to achieve ISO conformance for printf.
Test expectations in libio/tst-vtables-common.c are adjusted because
the internal staging buffer merges all virtual function calls into
one.
In general, stack buffer usage is greatly reduced, particularly for
unbuffered input streams. __printf_fp can still use a large buffer
in binary128 mode for %g, though.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
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>
In the future, this will result in a compilation failure if the
macros are unexpectedly undefined (due to header inclusion ordering
or header inclusion missing altogether).
Assembler sources are more difficult to convert. In many cases,
they are hand-optimized for the mangling and no-mangling variants,
which is why they are not converted.
sysdeps/s390/s390-32/__longjmp.c and sysdeps/s390/s390-64/__longjmp.c
are special: These are C sources, but most of the implementation is
in assembler, so the PTR_DEMANGLE macro has to be undefined in some
cases, to match the assembler style.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This allows us to define a generic no-op version of PTR_MANGLE and
PTR_DEMANGLE. In the future, we can use PTR_MANGLE and PTR_DEMANGLE
unconditionally in C sources, avoiding an unintended loss of hardening
due to missing include files or unlucky header inclusion ordering.
In i386 and x86_64, we can avoid a <tls.h> dependency in the C
code by using the computed constant from <tcb-offsets.h>. <sysdep.h>
no longer includes these definitions, so there is no cyclic dependency
anymore when computing the <tcb-offsets.h> constants.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The Z modifier is a nonstandard synonymn for z (that predates z
itself) and compiler might issue an warning for in invalid
conversion specifier.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
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>
In general, _IO_str_overflow returns the character passed as an argument
on success. However, if flush-only operation is requested by passing
EOF, returning EOF looks like an error, and the caller cannot tell
whether the operation was successful or not.
_IO_wstr_overflow had the same bug regarding WEOF.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
