It is a lot easier to understand the meaning of the tty interface if
it is explained from the beginning as conceptually emulating an RS232
serial port. This greatly simplifies the discussions of specific
items like the meaning of line speed.
Distinguish between "modem disconnect request" (deasserting DTR) and
"modem disconnect" (DCD deasserted). Conflating the two terms is
confusing, especially for non-RS232 devices. In particular, on most
systems, a pseudo-terminal will *not* respond to a modem disconnect
request by triggering a modem disconnect event for the purpose of the
HUPCL flag.
It is not necessarily true that the line speed has no effect on
non-serial port devices: e.g. an SPI port may interpret it as the
clock frequency to use; however, SPI does not use asynchronous framing
bits, instead synchronization is handled by the SS# wire. Similarly,
it is common but not by any means universal for interfaces that employ
various forms of fixed data to symbol rate encodings to encode the
data link layer bit rate rather than the physical symbol rate, which
may be higher (e.g. 8B10B) or lower (e.g. QAM/Trellis), without the
encoding or framing overhead.
Finally, a handful of devices use the line rate for entirely
nonstandard purposes. One example is Arduino USB interfaces, which
often interprets changing the baud rate to 1200 baud as a command to
reset the device.
[ v2: removed a bogus stray chunk from editing ]
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The function cfsetospeed() is defined twice in the manual. Remove the
one that seems out of place.
Signed-off-by: "H. Peter Anvin" (Intel) <hpa@zytor.com>
Reviewed-by: Collin Funk <collin.funk1@gmail.com>
Fix a typo in the manual: tcsetattr misspelled as tcsettattr.
Signed-off-by: "H. Peter Anvin" (Intel) <hpa@zytor.com>
Reviewed-by: Collin Funk <collin.funk1@gmail.com>
Call support_create_temp_directory to create a temporary directory for
symlink test, instead of a fixed file in the glibc source tree, to avoid
the race condition when there are more than one glibc tests running at the
same time with the same glibc source tree. This fixes BZ #33178.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Andreas K. Huettel <dilfridge@gentoo.org>
The _dl_read_only_area function in the uninitialized ld.so after
static dlopen is not able to find anything. Instead, we need to
redirect to the code from the statically linked main program.
Fixes commit d60fffe28a46b2a41fc308c1804ff02375d27408 ("debug:
Improve '%n' fortify detection (BZ 30932)").
Reviewed-by: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
The test intends to load tst-sprintf-fortify-rdonly-dlopen.so via
dlopen, and directly linking against it prevents that.
Reviewed-by: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
There are 3 variants of modf and modff: SSE2, SSE4.1 and AVX. s_modf.c
and s_modff.c include the generic implementation compiled with the minimum
x86 ISA level. The IFUNC selector is used only if the minimum ISA level
is less than AVX. SSE4.1 variant is included only if the ISA level is
less than SSE4.1. AVX variant is included only the ISA level is less than
AVX.
AVX variant should be compiled with -mavx, not -msse2avx -DSSE2AVX which
are used to encode SSE assembly sources with EVEX encoding.
The routines that are shared between libc and libm should use different
rules to avoid using the same MODULE_NAME, to avoid potential issues
like BZ #33165 where __stack_chk_fail not being routed to the internal
symbol.
Tested with -march=x86-64, -march=x86-64-v2, -march=x86-64-v3 and
-march=x86-64-v4.
This fixes BZ #33165 and BZ #33173.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Since modf and modff are compiled into both libc and libm, when glibc is
configured with --enable-stack-protector=all, ISA versions of modf and
modff should be compiled with -fno-stack-protector to avoid calling
__stack_chk_fail via PLT in libc.so.
This fixes BZ #33165.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Andreas K. Huettel <dilfridge@gentoo.org>
The mistake is that open must use 0666 to pick up the umask,
and not 0777 (which is required by mkdir).
Fixes commit 8ef3cff9d1
("iconv: Support in-place conversions (bug 10460, bug 32033)").
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
When SFrame is enabled, we need to tests DW backtracer as well. Do
this by executing the same backtrace tests with .sframe section
stripped.
Signed-off-by: Claudiu Zissulescu <claudiu.zissulescu-ianculescu@oracle.com>
Reviewed-by: DJ Delorie <dj@redhat.com>
Enable SFrame stack track information. The --enable-sframe option
allows the glibc build to compile with SFrame stack track
information. Thus, enabling glibc's backtrace to work within glibc.
Signed-off-by: Claudiu Zissulescu <claudiu.zissulescu-ianculescu@oracle.com>
Reviewed-by: DJ Delorie <dj@redhat.com>
Reviewed-by: Sam James <sam@gentoo.org>
This patch adds the necessary bits to enable stack tracing using
SFrame. In the case the new SFrame stack tracing procedure doesn't
find SFrame related info, the stack tracing falls back on default
Dwarf implementation.
The new SFrame stack tracing procedure is added to debug/backtrace.c
file, the support functions are added in sysdeps folder, namely
sframe.h, read-sframe.c and read-sfame.h.
Signed-off-by: Claudiu Zissulescu <claudiu.zissulescu-ianculescu@oracle.com>
Reviewed-by: DJ Delorie <dj@redhat.com>
The SFrame is supported for AArch64 architecture.
Enable SFrame stack tracer for AArch64 too.
Signed-off-by: Claudiu Zissulescu <claudiu.zissulescu-ianculescu@oracle.com>
Reviewed-by: DJ Delorie <dj@redhat.com>
The SFrame is well supported by x86 architecture since binutils 2.41.
Enable it to be used as default frame tracer.
Signed-off-by: Claudiu Zissulescu <claudiu.zissulescu-ianculescu@oracle.com>
Reviewed-by: DJ Delorie <dj@redhat.com>
The SFrame provides information to be able to do stack trace is now
well defined and implemented in Binutils 2.41. The format simply
contains enough information to be able to do stack trace given a
program counter (PC) value, the stack pointer, and the frame pointer.
The SFrame information is stored in a .sframe ELF section, which is
loaded into its own PT_GNU_SFRAME segment. We consider for this support
SFrame version 2.
This patch adds the bits to _dl_find_object to recognize and store in
struct dl_find_object the necessary info about SFrame section.
Signed-off-by: Claudiu Zissulescu <claudiu.zissulescu-ianculescu@oracle.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Undefine TCGETS, TCGETS2, and related ioctl constants in the installed
headers. Extract the correct constants (using the kernel type
definitions) automatically from the UAPI headers. The kernel
constants are available under KERNEL_* names during the glibc build,
computed using assembler constant extraction mechanism.
Alpha may have to use TCGETS instead of TCGETS2 because TCTGETS2
became available in Linux 4.20 only. Introduce ARCH_TCGETS to make
this choice explict.
To support emulation on powerpc, glibc versions of the termios
constants are added to the emulation code in internal-ioctl.h.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The use of the termios2 ioctl interface is an implementation detail which
should not bleed into public headers. Remove the PowerPC version of
<bits/ioctls.h> and define the termios2 ioctl numbers in <termios_arch.h>
instead. Also remove the include check from there which is unneeded in an
internal header.
This is required so the generated ld.so.conf files take effect.
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This way, a nonstandard directory within the testroot containing
libgcc_s.so can actually be picked up and used during the test runs.
Also provide a subdirectory ld.so.conf.d for drop-in configuration
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* This needs to be done twice, for test runs with and without
--enable-hardcoded-path-in-tests
* Also, we need to query the used $(CC) for the library location.
* The container tests run ldd and dump the list of needed libraries, then
copy these into the container.
* Without this patch, ldd may not find libgcc_s.so, resulting in"not found"
output and no copying of the library.
* With this patch, the library is picked up independent of its location (as
long as the proper directory is provided) and copied into the testroot.
* This does not mean yet that ld.so in the testroot actually finds it.
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
As discussed here:
https://sourceware.org/pipermail/libc-alpha/2025-July/168492.html
The support for TX lock elision of pthread mutexes is deprecated on
all architectures and will be removed in the next release.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Since mcount_internal is called from mcount/__fentry__ which preserve
only RAX, RCX, RDX, RSI, RDI, R8 and R9, compile mcount.c with
-fno-tree-loop-distribute-patterns -mgeneral-regs-only -mno-apxf
to void vector/r16-r31 registers and memcpy/memset in mcount_internal.
This fixes BZ #33134.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Andreas K. Huettel <dilfridge@gentoo.org>
The fstatat behaviour when the target is a dangling symlink is different
if flags contains AT_SYMLINK_NOFOLLOW or not.
Add a test for this and document it.
Document the fstatat behaviour leading to a ENOENT errno, and extend
tests to test the case where filename does not exist.
Signed-off-by: Matteo Croce <teknoraver@meta.com>
The changes in commit a93d9e03a3
("Extend struct r_debug to support multiple namespaces [BZ #15971]")
break the dyninst dynamic instrumentation tool. It brings its
own definition of _r_debug (rather than a declaration).
Furthermore, it turns out it is rather hard to use the proposed
handshake for accessing _r_debug via DT_DEBUG. If applications want
to access _r_debug, they can do so directly if the relevant code has
been built as PIC. To protect against harm from accidental copy
relocations due to linker relaxations, this commit restores copy
relocation support by adjusting both copies if interposition or
copy relocations are in play. Therefore, it is possible to
use a hidden reference in ld.so to access _r_debug.
Only perform the copy relocation initialization if libc has been
loaded. Otherwise, the ld.so search scope can be empty, and the
lookup of the _r_debug symbol mail fail.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
It combines updating r_state with the debugger notification.
The second change to _dl_open introduces an additional debugger
notification for dlmopen, but debuggers are expected to ignore it.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
It replaces the ns_debug member of the namespaces. Previously,
the base namespace had an unused ns_debug member.
This change also fixes a concurrency issue: Now _dl_debug_initialize
only updates r_next of the previous namespace's r_debug after the new
r_debug is initialized, so that only the initialized version is
observed. (Client code accessing _r_debug will benefit from load
dependency tracking in CPUs even without explicit barriers.)
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Texinfo 7.2 began warning about the '.info' suffix in the manual names
passed to @ref and similar commands. They eventually plan to stop
stripping the '.info' suffix internally which will lead to broken links
in the manuals without this change.
Signed-off-by: Collin Funk <collin.funk1@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>
Add DL_ADDRESS_WITHOUT_RELOC to force an address into a general purpose
register to prevent loading it into a vector register directly before
run-time relocation. This is an updated fix for BZ #33088.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
The iovec size should account for all substrings between each conversion
specification. For the format:
"abc %s efg"
The list of substrings are:
["abc ", arg, " efg]
which is 2 times the number of maximum arguments *plus* one.
This issue triggered 'out of bounds' errors by stdlib/tst-bz20544 when
glibc is built with experimental UBSAN support [1].
Besides adjusting the iovec size, a new runtime and check is added to
avoid wrong __libc_message_impl usage.
Checked on x86_64-linux-gnu.
[1] https://sourceware.org/git/?p=glibc.git;a=shortlog;h=refs/heads/azanella/ubsan-undef
Co-authored-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
During early startup memcpy or memset must not be called since many targets
use ifuncs for them which won't be initialized yet. Security hardening may
use -ftrivial-auto-var-init=zero which inserts calls to memset. Redirect
memset to memset_generic by including dl-symbol-redir-ifunc.h in cpu-features.c.
This fixes BZ #33112.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Replaced all instances of __builtin_expect to __glibc_unlikely
within malloc.c and malloc-debug.c. This improves the portability
of glibc by avoiding calls to GNU C built-in functions. Since all
the expected results from calls to __builtin_expect were 0,
__glibc_likely was never used as a replacement. Multiple
calls to __builtin_expect within a single if statement have
been replaced with one call to __glibc_unlikely, which wraps
every condition.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Renamed aligned_OK to misaligned_mem as to be similar
to misaligned_chunk, and reversed any assertions using
the macro. Made misaligned_chunk call misaligned_mem after
chunk2mem rather than bitmasking with the malloc alignment
itself, since misaligned_chunk is meant to test the data
chunk itself rather than the header, and the compiler
will optimise the addition so the ternary operator is not
needed.
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
H. Peter Anvin
Andreas K. Hüttel
H.J. Lu
Florian Weimer
Cupertino Miranda
Claudiu Zissulescu
Adhemerval Zanella
Andreas Schwab
Yury Khrustalev
Stefan Liebler
Wilco Dijkstra
Matteo Croce
Samuel Thibault
Collin Funk
Arjun Shankar
William Hunt
Jitka Obselkova