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"We don't need it any more" The INTR_MSG_TRAP macro in intr-msg.h used to play little trick with the stack pointer: it would temporarily save the "real" stack pointer into ecx, while setting esp to point to just before the message buffer, and then invoke the mach_msg trap. This way, INTR_MSG_TRAP reused the on-stack arguments laid out for the containing call of _hurd_intr_rpc_mach_msg (), passing them to the mach_msg trap directly. This, however, required special support in hurdsig.c and trampoline.c, since they now had to recognize when a thread is inside the piece of code where esp doesn't point to the real tip of the stack, and handle this situation specially. Commit 1d20f33ff4fb634310f27493b7b87d0b20f4a0b0 has removed the actual temporary change of esp by actually re-pushing mach_msg arguments onto the stack, and popping them back at end. It did not, however, deal with the rest of "the ecx kludge" code in other files, resulting in potential crashes if a signal arrives in the middle of pushing arguments onto the stack. Fix that by removing "the ecx kludge". Instead, when we want a thread to skip the RPC, but cannot make just make it jump to after the trap since it's not done adjusting the stack yet, set the SYSRETURN register to MACH_SEND_INTERRUPTED (as we do anyway), and rely on the thread itself for detecting this case and skipping the RPC. This simplifies things somewhat and paves the way for a future x86_64 port of this code. Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> Message-Id: <20230301162355.426887-1-bugaevc@gmail.com>
This directory contains the sources of the GNU C Library. See the file "version.h" for what release version you have. The GNU C Library is the standard system C library for all GNU systems, and is an important part of what makes up a GNU system. It provides the system API for all programs written in C and C-compatible languages such as C++ and Objective C; the runtime facilities of other programming languages use the C library to access the underlying operating system. In GNU/Linux systems, the C library works with the Linux kernel to implement the operating system behavior seen by user applications. In GNU/Hurd systems, it works with a microkernel and Hurd servers. The GNU C Library implements much of the POSIX.1 functionality in the GNU/Hurd system, using configurations i[4567]86-*-gnu. When working with Linux kernels, this version of the GNU C Library requires Linux kernel version 3.2 or later. Also note that the shared version of the libgcc_s library must be installed for the pthread library to work correctly. The GNU C Library supports these configurations for using Linux kernels: aarch64*-*-linux-gnu alpha*-*-linux-gnu arc*-*-linux-gnu arm-*-linux-gnueabi csky-*-linux-gnuabiv2 hppa-*-linux-gnu i[4567]86-*-linux-gnu x86_64-*-linux-gnu Can build either x86_64 or x32 ia64-*-linux-gnu loongarch64-*-linux-gnu Hardware floating point, LE only. m68k-*-linux-gnu microblaze*-*-linux-gnu mips-*-linux-gnu mips64-*-linux-gnu or1k-*-linux-gnu powerpc-*-linux-gnu Hardware or software floating point, BE only. powerpc64*-*-linux-gnu Big-endian and little-endian. s390-*-linux-gnu s390x-*-linux-gnu riscv32-*-linux-gnu riscv64-*-linux-gnu sh[34]-*-linux-gnu sparc*-*-linux-gnu sparc64*-*-linux-gnu If you are interested in doing a port, please contact the glibc maintainers; see https://www.gnu.org/software/libc/ for more information. See the file INSTALL to find out how to configure, build, and install the GNU C Library. You might also consider reading the WWW pages for the C library at https://www.gnu.org/software/libc/. The GNU C Library is (almost) completely documented by the Texinfo manual found in the `manual/' subdirectory. The manual is still being updated and contains some known errors and omissions; we regret that we do not have the resources to work on the manual as much as we would like. For corrections to the manual, please file a bug in the `manual' component, following the bug-reporting instructions below. Please be sure to check the manual in the current development sources to see if your problem has already been corrected. Please see https://www.gnu.org/software/libc/bugs.html for bug reporting information. We are now using the Bugzilla system to track all bug reports. This web page gives detailed information on how to report bugs properly. The GNU C Library is free software. See the file COPYING.LIB for copying conditions, and LICENSES for notices about a few contributions that require these additional notices to be distributed. License copyright years may be listed using range notation, e.g., 1996-2015, indicating that every year in the range, inclusive, is a copyrightable year that would otherwise be listed individually.