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Adhemerval Zanella
99e9c5d1ca
The BZ#33326 testcase triggers an assertion during process startup, which results in a segmentation fault instead of an error message and process termination with a SIGABRT. The assert issues __libc_message_impl, which in turn might call string functions depending on the ABI (strchrnul, strlen, memcpy/mempcpy), system calls (writev and mmap), and finally the abort call. The dl-symbol-redir-ifunc.h is also expanded to cover strchrnul on x86_64, s390, powerpc64 (both endianness) and loongarch, mempcpy on powerpc64be, and memcpy on aarch64. On s390 the redirection is only issued if the ifunc variant is built, since strchrnul-c.c only renames the C implementation to STRCHRNUL_DEFAULT when HAVE_STRCHRNUL_IFUNC is set. The buffer that backs up the assert message is now allocated through _dl_mmap, which issues the syscall directly instead of calling __mmap (setting errno on failure requires the thread pointer). The abort call now issues __raise_direct instead of raise (the Hurd port aliases __raise_direct to raise). On i386, syscalls should not use the vDSO during program startup because the thread pointer is not yet initialized. This requires __raise_direct, _dl_writev, and _dl_mmap to be built with I386_USE_SYSENTER set to 0. Creating a test case is challenging. For static-pie, the assert is only called for ill-formed ELF files on elf_get_dynamic_info and by some targets on ELF_DYNAMIC_RELOCATE (although not all targets use assert in their dl-machine.h). Some targets also issue __libc_fatal on ARCH_SETUP_IREL, but also only for ill-formatted ELF files. The test employs a different strategy and overrides the __tunables_init symbol, which is invoked immediately before self-relocation and TLS setup. The test is built with -Wl,-z,muldefs to avoid linker issues. I checked on aarch64, x86_64, i686, s390x (qemu), sparc (qemu), mips64el (qemu), armhf, riscv, and powerpc. Reviewed-by: Florian Weimer <fweimer@redhat.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 and x86_64-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 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. 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://sourceware.org/glibc/wiki/Bugzilla%20Procedures 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.