Some applications set environ to a heap-allocated pointer, call
setenv (expecting it to call realloc), free environ, and then
restore the original environ pointer. This breaks after
commit 7a61e7f557 ("stdlib: Make
getenv thread-safe in more cases") because after the setenv call,
the environ pointer does not point to the start of a heap allocation.
Instead, setenv creates a separate allocation and changes environ
to point into that. This means that the free call in the application
results in heap corruption.
The interim approach was more compatible with other libcs because
it does not assume that the incoming environ pointer is allocated
as if by malloc (if it was written by the application). However,
it seems to be more important to stay compatible with previous
glibc version: assume the incoming pointer is heap allocated,
and preserve this property after setenv calls.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* posix/Makefile (aux): Add environ.
* posix/environ.c: New file.
* sysdeps/unix/sparc/start.c: Remove __environ definition.
* sysdeps/unix/start.c: Likewise.
* sysdeps/unix/sysv/irix4/start.c: Likewise.
* sysdeps/mach/hurd/start.c: Likewise.
* sysdeps/mach/start.c: Likewise.
* sysdeps/stub/start.c: Likewise.
* sysdeps/unix/make_errlist.c: In produced program, test
HAVE_WEAK_SYMBOLS instead of HAVE_GNU_LD.
* sysdeps/unix/sysv/sysv4/dup2.c: Fix #include of renamed file.
Remove extra weak alias.
* sysdeps/unix/sysv/sysv4/sigaltstack.S: Fix unsquashed file name
in #include.
* libc-symbols.h: Put comment around ^L to pacify Solaris as.
* sysdeps/posix/Makefile (cded-objdir-includes): New variable
replaced cded-objdir-CPPFLAGS; transform $(+includes) instead of
$(CPPFLAGS).
(mk-stdiolim): Use it instead.
* mach/mach_init.c (__vm_page_size): Make it initialized. It does
not work to make a weak alias to a bss symbol.
* stdio/Makefile (distribute): Remove mpn-copy.mk; add gen-mpn-copy.
(tests): Add test-fwrite.
* stdio/test-fwrite.c: New file.
* stdlib/stdlib.h [__USE_GNU]: Declare strtof, strtold, __strtof,
__strtold.
* Makefile (autoconf-it): New canned sequence. Do cvs commit if
there is a CVS directory.
(configure, %/configure): Use $(autoconf-it) for cmds.
* Make-dist: Likewise.
* Makerules ($(gpl2lgpl)): Likewise.
inlines cause trouble for files defining global register variables.
* stdio/vfprintf.c: Set PREC to zero for %. without following digit.
