linux/kernel
Linus Torvalds 050e9baa9d Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables
The changes to automatically test for working stack protector compiler
support in the Kconfig files removed the special STACKPROTECTOR_AUTO
option that picked the strongest stack protector that the compiler
supported.

That was all a nice cleanup - it makes no sense to have the AUTO case
now that the Kconfig phase can just determine the compiler support
directly.

HOWEVER.

It also meant that doing "make oldconfig" would now _disable_ the strong
stackprotector if you had AUTO enabled, because in a legacy config file,
the sane stack protector configuration would look like

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  # CONFIG_CC_STACKPROTECTOR_NONE is not set
  # CONFIG_CC_STACKPROTECTOR_REGULAR is not set
  # CONFIG_CC_STACKPROTECTOR_STRONG is not set
  CONFIG_CC_STACKPROTECTOR_AUTO=y

and when you ran this through "make oldconfig" with the Kbuild changes,
it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had
been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just
CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version
used to be disabled (because it was really enabled by AUTO), and would
disable it in the new config, resulting in:

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
  CONFIG_CC_STACKPROTECTOR=y
  # CONFIG_CC_STACKPROTECTOR_STRONG is not set
  CONFIG_CC_HAS_SANE_STACKPROTECTOR=y

That's dangerously subtle - people could suddenly find themselves with
the weaker stack protector setup without even realizing.

The solution here is to just rename not just the old RECULAR stack
protector option, but also the strong one.  This does that by just
removing the CC_ prefix entirely for the user choices, because it really
is not about the compiler support (the compiler support now instead
automatially impacts _visibility_ of the options to users).

This results in "make oldconfig" actually asking the user for their
choice, so that we don't have any silent subtle security model changes.
The end result would generally look like this:

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
  CONFIG_STACKPROTECTOR=y
  CONFIG_STACKPROTECTOR_STRONG=y
  CONFIG_CC_HAS_SANE_STACKPROTECTOR=y

where the "CC_" versions really are about internal compiler
infrastructure, not the user selections.

Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-14 12:21:18 +09:00
..
bpf treewide: Use array_size() in vzalloc() 2018-06-12 16:19:22 -07:00
cgroup treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
configs Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables 2018-06-14 12:21:18 +09:00
debug treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
events treewide: kzalloc_node() -> kcalloc_node() 2018-06-12 16:19:22 -07:00
gcov gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT 2018-06-08 18:56:02 +09:00
irq Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-10 09:44:53 -07:00
livepatch
locking treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
power treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
printk Printk changes for 4.18 2018-06-06 16:04:55 -07:00
rcu treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
sched treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
time Power management updates for 4.18-rc1 2018-06-05 09:38:39 -07:00
trace treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
.gitignore
acct.c
async.c
audit.c audit: use inline function to get audit context 2018-05-14 17:24:18 -04:00
audit.h
audit_fsnotify.c
audit_tree.c
audit_watch.c audit: use inline function to get audit context 2018-05-14 17:24:18 -04:00
auditfilter.c audit: use existing session info function 2018-05-18 15:47:54 -04:00
auditsc.c audit: Fix wrong task in comparison of session ID 2018-05-21 14:27:43 -04:00
backtracetest.c
bounds.c
capability.c
compat.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 20:27:54 -07:00
configs.c
context_tracking.c
cpu.c
cpu_pm.c
crash_core.c mm: split page_type out from _mapcount 2018-06-07 17:34:37 -07:00
crash_dump.c
cred.c
delayacct.c delayacct: Use raw_spinlocks 2018-04-27 14:34:51 +02:00
dma.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
elfcore.c
exec_domain.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
exit.c
extable.c
fail_function.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
fork.c Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables 2018-06-14 12:21:18 +09:00
freezer.c
futex.c
futex_compat.c
groups.c
hung_task.c kernel/hung_task.c: show all hung tasks before panic 2018-06-07 17:34:39 -07:00
iomem.c memremap: split devm_memremap_pages() and memremap() infrastructure 2018-05-15 23:08:33 -07:00
irq_work.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kexec.c
kexec_core.c
kexec_file.c treewide: Use array_size() in vzalloc() 2018-06-12 16:19:22 -07:00
kexec_internal.h
kmod.c
kprobes.c kprobes: Fix random address output of blacklist file 2018-04-25 10:27:56 -04:00
ksysfs.c
kthread.c kthread: Allow kthread_park() on a parked kthread 2018-05-25 08:03:51 +02:00
latencytop.c
Makefile Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-10 10:17:09 -07:00
memremap.c mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS 2018-05-22 06:59:39 -07:00
module-internal.h
module.c - Introduce arithmetic overflow test helper functions (Rasmus) 2018-06-06 17:27:14 -07:00
module_signing.c
notifier.c
nsproxy.c
padata.c
panic.c Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables 2018-06-14 12:21:18 +09:00
params.c
pid.c
pid_namespace.c
profile.c
ptrace.c
range.c
reboot.c
relay.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
resource.c libnvdimm for 4.18 2018-06-08 17:21:52 -07:00
rseq.c rseq: Introduce restartable sequences system call 2018-06-06 11:58:31 +02:00
seccomp.c audit/stable-4.18 PR 20180605 2018-06-06 16:34:00 -07:00
signal.c signal: Remove no longer required irqsave/restore 2018-06-10 06:14:01 +02:00
smp.c
smpboot.c
smpboot.h
softirq.c Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 19:59:22 -07:00
stacktrace.c
stop_machine.c Linux 4.17-rc5 2018-05-15 08:10:50 +02:00
sys.c mm: introduce arg_lock to protect arg_start|end and env_start|end in mm_struct 2018-06-07 17:34:34 -07:00
sys_ni.c Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-10 10:17:09 -07:00
sysctl.c treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
sysctl_binary.c
task_work.c
taskstats.c
test_kprobes.c
torture.c rcu: Rename cond_resched_rcu_qs() to cond_resched_tasks_rcu_qs() 2018-05-15 10:27:29 -07:00
tracepoint.c tracepoints: Fix the descriptions of tracepoint_probe_register{_prio} 2018-05-28 12:49:51 -04:00
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c umh: fix race condition 2018-06-07 16:56:28 -04:00
up.c
user-return-notifier.c
user.c
user_namespace.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
utsname.c
utsname_sysctl.c
watchdog.c
watchdog_hld.c
workqueue.c treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
workqueue_internal.h workqueue: Set worker->desc to workqueue name by default 2018-05-18 08:47:13 -07:00