Some of the places in Redmine (e.g. Associated revisions) print
revisions using only 8 characters. Even when I copied a revision from
there, I want to prepend commit: in the message.
This changes the automatic detection of -fstack-protector,
-D_FORTIFY_SOURCE, and -mbranch-protection to write to $hardenflags
instead of $XCFLAGS. The definition of $cflags is changed to
"$hardenflags $orig_cflags $optflags $debugflags $warnflags" to match.
Furthermore, these flags are _prepended_ to $hardenflags, rather than
appended.
The implications of doing this are as follows:
* If a CRuby builder specifies cflags="-mbranch-protection=foobar" at
the ./configure script, and the configure script detects that
-mbranch-protection=pac-ret is accepted, then GCC will be invoked as
"gcc -mbranch-protection=pac-ret -mbranch-protection=foobar". Since
the last flags take precedence, that means that user-supplied values
of these flags in $cflags will take priority.
* Likewise, if a CRuby builder explicitly specifies
"hardenflags=-mbranch-protection=foobar", because we _prepend_ to
$hardenflags in our autoconf script, we will still invoke GCC as
"gcc -mbranch-protection=pac-ret -mbranch-protection=foobar".
* If a CRuby builder specifies CFLAGS="..." at the configure line,
automatic detection of hardening flags is ignored as before.
* C extensions will _also_ be built with hardening flags now as well
(this was not the case by default before because the detected flags
went into $XCFLAGS).
Additionally, as part of this work, I changed how the detection of
PAC/BTI in Context.S works. Rather than appending the autodetected
option to ASFLAGS, we simply compile a set of test programs with the
actual CFLAGS in use to determine what PAC/BTI settings were actually
chosen by the builder. Context.S is made aware of these choices through
some custom macros.
The result of this work is that:
* Ruby will continue to choose some sensible defaults for hardening
options for the C compiler
* Distributors are able to specify CFLAGS that are consistent with their
distribution and override these defaults
* Context.S will react to whatever -mbranch-protection is actually in
use, not what was autodetected
* Extensions get built with hardening flags too.
[Bug #20154]
[Bug #20520]
retguard symbols are added on OpenBSD as part of stack protection.
They should be ignored by the leaked symbols checker, just as we
ignore asan symbols.
Takashi Kokubun
KJ Tsanaktsidis
Jeremy Evans
Hiroshi SHIBATA
Nobuyoshi Nakada
Sorah Fukumori
Kevin Newton
yui-knk
Eugene Kenny
NARUSE, Yui