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086df229ee
On Linux/i386, there are 3 ways to make a system call: 1. call *%gs:SYSINFO_OFFSET. This requires TLS initialization. 2. call *_dl_sysinfo. This requires relocation of _dl_sysinfo. 3. int $0x80. This is slower than #2 and #3, but works everywhere. When an object file is compiled with PIC, #1 is prefered since it is faster than #3 and doesn't require relocation of _dl_sysinfo. For dynamic executables, ld.so initializes TLS. However, for static executables, before TLS is initialized by __libc_setup_tls, #3 should be used for system calls. This patch adds <startup.h> which defines _startup_fatal and defaults it to __libc_fatal. It replaces __libc_fatal with _startup_fatal in static executables where it is called before __libc_setup_tls is called. This header file is included in all files containing functions which are called before __libc_setup_tls is called. On Linux/i386, when PIE is enabled by default, _startup_fatal is turned into ABORT_INSTRUCTION and I386_USE_SYSENTER is defined to 0 so that "int $0x80" is used for system calls before __libc_setup_tls is called. Tested on i686 and x86-64. Without this patch, all statically-linked tests will fail on i686 when the compiler defaults to -fPIE. [BZ #21913] * csu/libc-tls.c: Include <startup.h> first. (__libc_setup_tls): Call _startup_fatal instead of __libc_fatal. * elf/dl-tunables.c: Include <startup.h> first. * include/libc-symbols.h (BUILD_PIE_DEFAULT): New. * sysdeps/generic/startup.h: New file. * sysdeps/unix/sysv/linux/i386/startup.h: Likewise. * sysdeps/unix/sysv/linux/i386/brk.c [BUILD_PIE_DEFAULT != 0] (I386_USE_SYSENTER): New. Defined to 0. |
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| .. | ||
| abi-note.S | ||
| check_fds.c | ||
| dso_handle.c | ||
| elf-init.c | ||
| errno-loc.c | ||
| errno.c | ||
| gmon-start.c | ||
| init-first.c | ||
| init.c | ||
| libc-start.c | ||
| libc-tls.c | ||
| Makefile | ||
| start.c | ||
| sysdep.c | ||
| version.c | ||
| Versions | ||