On 07/05/2014 09:38 PM, Theodore Ts'o wrote: > Commit 2500ebfc89 (util: fix make dependencies for subst) broke cross > compilation because it unconditionally used config.h without setting a > includes path so that the config.h file could be found. > > The proposed fix of adding the include path (such as was proposed at > http://patchwork.ozlabs.org/patch/355662/ or in Debian Bug #753375) > aren't really the right fix, since the information in config.h is for > the target environment, and not the build environment. So using > config.h when building helper programs used as part of the build can > potentially cause more problems than it solves. > > In general, build helpers must be written to be as portable as > possible, and to not require any autoconf defined #ifdef's whenever > possible. The subst program broke this rule to (1) address a Coverity > security complaint by using futimes if is present, and (2) to preserve > the nanosecond portion of the file timestamp. > > Oh, well. We won't be able to do the latter when cross compiling, and > as to the former, if an attacker has write access to your build tree > while you are building programs that will be run as root, you've got > bigger problems. :-) > > Fix the problem that commit 2500ebfc89 was trying to address by > explicitly adding @DEFS@ to CFLAGS, so that -DHAVE_CONFIG_H is passed > to make depend. This fixes up the make depend without forcing the use > of config.h when cross-compiling. > > Addresses-Debian-Bug: #753375 > Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> > Cc: Helmut Grohne <helmut@xxxxxxxxxx> > Cc: Gustavo Zacarias <gustavo@xxxxxxxxxxxxxxx> > Cc: 753375@xxxxxxxxxxxxxxx Tested-by: Gustavo Zacarias <gustavo@xxxxxxxxxxxxxxx> Indeed cleaner than my solution, thanks. Regards. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
