On Tue, Mar 09, 2021 at 10:22:36PM +0900, Masahiro Yamada wrote: > On Tue, Mar 9, 2021 at 9:35 PM Michal Suchanek <msucha...@suse.de> wrote: > > > > When using dummy-tools STACKPROTECTOR_PER_TASK is unconditionally > > selected. This defeats the purpose of the all-enabled tool. > > > > Description copied from arm > > > > Cc: Masahiro Yamada <masahi...@kernel.org> > > Signed-off-by: Michal Suchanek <msucha...@suse.de> > > > Could you explain what problem > this patch is trying to solve?
The option cannot be disabled when compiler has the required capability. Thanks Michal > > > > --- > > arch/arm64/Kconfig | 13 ++++++++++++- > > 1 file changed, 12 insertions(+), 1 deletion(-) > > > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > > index a8ff7cd5f096..f59d391e31a4 100644 > > --- a/arch/arm64/Kconfig > > +++ b/arch/arm64/Kconfig > > @@ -1549,9 +1549,20 @@ config RANDOMIZE_MODULE_REGION_FULL > > config CC_HAVE_STACKPROTECTOR_SYSREG > > def_bool $(cc-option,-mstack-protector-guard=sysreg > > -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) > > > > + > > config STACKPROTECTOR_PER_TASK > > - def_bool y > > + bool "Use a unique stack canary value for each task" > > depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG > > + default y > > + help > > + Due to the fact that GCC uses an ordinary symbol reference from > > + which to load the value of the stack canary, this value can only > > + change at reboot time on SMP systems, and all tasks running in the > > + kernel's address space are forced to use the same canary value for > > + the entire duration that the system is up. > > + > > + Enable this option to switch to a different method that uses a > > + different canary value for each task. > > > > endmenu > > > > -- > > 2.26.2 > > > > > -- > Best Regards > Masahiro Yamada