need this.
Consider the following code:
case 'O':
output_filename = malloc(strlen(arg)+4);
strcpy(output_filename, arg);
strcat(output_filename, ".tmp");
real_output_filename = arg;
return;
The idea here is to malloc() a buffer big enough to hold the name of
a supplied file name, plus ".tmp". So we malloc() 'size of filename'
bytes plus 4, right? Wrong! ".tmp" is _FIVE_ bytes long! There's a
traling '\0' which strcat() gleefully tacks on _outside_ the bounds
of the buffer. Result: program corrupts own memory. Program SEGVs at
seemingly random times. Bill not like random SEGVs. Bill smash.
Know how I found this? I've been trying to bootstrap -current on my
2.1.0-RELEASE machine at work and I couldn't seem to get libc.a built
because the linker would intermittently blow chunks while executing
things like 'ld -O foo.o -X -r foo.o'. Since this is an initial
bootstrap version of ld, it was linked against the 2.1.0 libc, who's
malloc() behaves differently than that in -current.
Presumeably ld -O doesn't blow up in -current, otherwise someone would
have spotted this already. I don't know if this is a bug or a feature.
Anyway. I'm changing the strlen(arg)+4 to strlen(arg)+5. Bah.
-O filename
Specifies the name of the output file. The file is created as
filename.tmp and when output is complete renamed to filename.
This allows us to:
ld -O ${.TARGET} -x -r ${.TARGET}
"-X" must survive, because of references from relocations, don't
qualify the symbol name with the name of the input file. This
saves some string space. It makes libc_pic.a about 2.4% smaller.
Adapted from a suggestion by Bruce Evans.
first place and we were too long in finding out. Now we know, and the
damage is hard to fix. This is part one: ld will not link gcc dynamic,
if specified as "-lgcc".
Suggested by: dyson & davidg
NetBSD ld code except for local changes for dlopen() and friends and
the hashing on the minor value of the shlibs. We should be binary
compatible now with all their libraries.
Obtained from: NetBSD
warning handling and allows for link-time warnings with a modified
version of gas.
Note: Not all of the newer bits were updated such as some of the non-x86
machine-dependant code is relevant to FreeBSD right now.
Obtained from: NetBSD
handling of errors through the standard err() and warn()
more fixes for Geoff Rehmet's NULL pointer bug.
fixes NULL pointer bugs when linking mono and nested X servers.
supports a `-nostdlib' option.
accept object files without a symbol table
don't attempt dynamic linking when `-A' is given
a few variable names have chaged (desc -> fd), and the formatting has
changed which should make it much easier to track his sources.
I tested 'make world' for /usr/src and X twice with these changes.
late stage due to the fact that link.h was copyright Sun Microsystems.
This version of ld sync's us up with NetBSD's ld and supports compatablily
with NetBSD's -[zZ] flags (which we had reversed). Compiling with this
new ld will give you RRS warnings for libraries which do not contain .type
infomation - these wsarnings are harmless and will go away as soon as you
recompile your libraries (cd /usr/src; make libraries).
On any other system -z means "standard" ZMAGIC format and is the
default. Therefore I've made -z be standard ZMAGIC and -Z be ZMAGIC
stored in the new a_midmag format.
The "standard" ZMAGIC format is now the default as well.
lib.c:
Pull in archives containing definitions needed by shared objects.
warnings.c:
Less spurious "undefined symbol" msgs for shared library defined
symbols.
ld.c:
Do a better job of recognising data in text segments, eg. `const char []'.
shlib.c,ld/rtld/{Makefile rtld.c}
Use strsep() in stead of strtok() and restore colons in eg. env. vars.
to output the same QMAGIC format as BSDI does. This is triggered by
a new '-q' flag ('-Xlinker -q' in gcc). The default can be changed from
ZMAGIC to QMAGIC by defining DEFAULT_MAGIC=QMAGIC when building ld.
ld won't generate output if there are two .o files with the same
name. It thinks they are multiply defined external references. This
patch explictly allows multiple /file names/ with the same value.
This can happen if you do a two stage link or if you link in file
names that are identical to files in libc.
Otherwise ld.c exits with a status=1 and non error message. Rich
