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| author | Florian Fainelli <f.fainelli@gmail.com> | 2019-06-18 01:29:59 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2019-06-24 20:10:39 +0300 |
| commit | 58557e486f89823763039502923647037ef7032f (patch) | |
| tree | fc5142f498471cc3de911fc6780663bbb6adcec3 /arch/arm64/Kconfig | |
| parent | 2af22f3ec3ca452f1e79b967f634708ff01ced8a (diff) | |
| download | linux-58557e486f89823763039502923647037ef7032f.tar.xz | |
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>
Diffstat (limited to 'arch/arm64/Kconfig')
| -rw-r--r-- | arch/arm64/Kconfig | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 57b02d4ceb71..22f8e6b3b0f9 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -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" |