arm64: Allow user selection of ARM64_MODULE_PLTS

Make ARM64_MODULE_PLTS a selectable Kconfig symbol, since some people
might have very big modules spilling out of the dedicated module area
into vmalloc. Help text is copied from the ARM 32-bit counterpart and
modified to a mention of KASLR and specific ARM errata workaround(s).

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Florian Fainelli 2019-06-17 15:29:59 -07:00 committed by Catalin Marinas
parent 2af22f3ec3
commit 58557e486f

View File

@ -1418,8 +1418,23 @@ config ARM64_SVE
KVM in the same kernel image.
config ARM64_MODULE_PLTS
bool
bool "Use PLTs to allow module memory to spill over into vmalloc area"
select HAVE_MOD_ARCH_SPECIFIC
help
Allocate PLTs when loading modules so that jumps and calls whose
targets are too far away for their relative offsets to be encoded
in the instructions themselves can be bounced via veneers in the
module's PLT. This allows modules to be allocated in the generic
vmalloc area after the dedicated module memory area has been
exhausted.
When running with address space randomization (KASLR), the module
region itself may be too far away for ordinary relative jumps and
calls, and so in that case, module PLTs are required and cannot be
disabled.
Specific errata workaround(s) might also force module PLTs to be
enabled (ARM64_ERRATUM_843419).
config ARM64_PSEUDO_NMI
bool "Support for NMI-like interrupts"