glibc/sysdeps/unix
Florian Weimer 035c012e32 Reduce the statically linked startup code [BZ #23323]
It turns out the startup code in csu/elf-init.c has a perfect pair of
ROP gadgets (see Marco-Gisbert and Ripoll-Ripoll, "return-to-csu: A
New Method to Bypass 64-bit Linux ASLR").  These functions are not
needed in dynamically-linked binaries because DT_INIT/DT_INIT_ARRAY
are already processed by the dynamic linker.  However, the dynamic
linker skipped the main program for some reason.  For maximum
backwards compatibility, this is not changed, and instead, the main
map is consulted from __libc_start_main if the init function argument
is a NULL pointer.

For statically linked binaries, the old approach based on linker
symbols is still used because there is nothing else available.

A new symbol version __libc_start_main@@GLIBC_2.34 is introduced because
new binaries running on an old libc would not run their ELF
constructors, leading to difficult-to-debug issues.
2021-02-25 12:13:02 +01:00
..
alpha Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
arm Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
bsd Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
i386 Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
inet
mips Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
powerpc Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
sh Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
sysv/linux Reduce the statically linked startup code [BZ #23323] 2021-02-25 12:13:02 +01:00
x86_64 Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
confstr.h
get_child_max.c Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
getlogin_r.c Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
getlogin.c Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
getpagesize.c Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
grantpt.c Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
ifreq.c Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
Implies
make-syscalls.sh Add SYSCALL_ULONG_ARG_[12] to pass long to syscall [BZ #25810] 2020-04-29 05:35:34 -07:00
Makefile Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
pt-fcntl.c Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
s-proto-cancel.S
s-proto.S
setxid.h
sockatmark.c Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
syscall-template.S Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
syscall.S Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
syscalls.list Mark unsigned long arguments with U in more syscalls [BZ #25810] 2020-04-29 08:10:01 -07:00
sysdep.h Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00