linux/arch/arm64/kernel
Ard Biesheuvel f2b9ba871b arm64/kernel: kaslr: reduce module randomization range to 4 GB
We currently have to rely on the GCC large code model for KASLR for
two distinct but related reasons:
- if we enable full randomization, modules will be loaded very far away
  from the core kernel, where they are out of range for ADRP instructions,
- even without full randomization, the fact that the 128 MB module region
  is now no longer fully reserved for kernel modules means that there is
  a very low likelihood that the normal bottom-up allocation of other
  vmalloc regions may collide, and use up the range for other things.

Large model code is suboptimal, given that each symbol reference involves
a literal load that goes through the D-cache, reducing cache utilization.
But more importantly, literals are not instructions but part of .text
nonetheless, and hence mapped with executable permissions.

So let's get rid of our dependency on the large model for KASLR, by:
- reducing the full randomization range to 4 GB, thereby ensuring that
  ADRP references between modules and the kernel are always in range,
- reduce the spillover range to 4 GB as well, so that we fallback to a
  region that is still guaranteed to be in range
- move the randomization window of the core kernel to the middle of the
  VMALLOC space

Note that KASAN always uses the module region outside of the vmalloc space,
so keep the kernel close to that if KASAN is enabled.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-08 13:49:26 +00:00
..
probes License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
vdso arm64 updates for 4.15 2017-11-15 10:56:56 -08:00
.gitignore
acpi_numa.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
acpi_parking_protocol.c arm64: fix endianness annotation in acpi_parking_protocol.c 2017-06-29 11:33:15 +01:00
acpi.c More ACPI updates for v4.16-rc1 2018-02-09 09:44:25 -08:00
alternative.c arm64: alternatives: use tpidr_el2 on VHE hosts 2018-01-13 10:44:33 +00:00
arm64ksyms.c arm64: uaccess: Mask __user pointers for __arch_{clear, copy_*}_user 2018-02-06 22:53:40 +00:00
armv8_deprecated.c arm64: signal: Make force_signal_inject more robust 2018-03-06 18:52:22 +00:00
asm-offsets.c KVM: arm64: Handle RAS SErrors from EL2 on guest exit 2018-01-16 15:09:36 +00:00
bpi.S arm64: Kill PSCI_GET_VERSION as a variant-2 workaround 2018-02-06 22:54:18 +00:00
cacheinfo.c arm64: cacheinfo: Remove CCSIDR-based cache information probing 2017-03-20 16:16:54 +00:00
cpu_errata.c arm64: Add missing Falkor part number for branch predictor hardening 2018-02-12 11:28:45 +00:00
cpu_ops.c arm64: cpu_ops: Add missing 'const' qualifiers 2017-12-01 13:05:08 +00:00
cpu-reset.h arm64: Use __pa_symbol for kernel symbols 2017-01-12 15:05:39 +00:00
cpu-reset.S arm64: idmap: Use "awx" flags for .idmap.text .pushsection directives 2018-02-06 22:53:27 +00:00
cpufeature.c arm64: Revert L1_CACHE_SHIFT back to 6 (64-byte cache line size) 2018-03-06 18:52:32 +00:00
cpuidle.c ARM64 / cpuidle: Use new cpuidle macro for entering retention state 2018-01-02 13:50:34 +00:00
cpuinfo.c arm64: v8.4: Support for new floating point multiplication instructions 2018-01-05 11:29:48 +00:00
crash_dump.c arm64: kdump: provide /proc/vmcore file 2017-04-05 18:31:38 +01:00
debug-monitors.c arm64: Use arm64_force_sig_info instead of force_sig_info 2018-03-06 18:52:32 +00:00
efi-entry.S arm64: Add software workaround for Falkor erratum 1041 2018-02-06 22:53:13 +00:00
efi-header.S arm64: efi: split Image code and data into separate PE/COFF sections 2017-04-04 17:50:59 +01:00
efi.c arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables 2018-02-16 18:13:57 +00:00
entry32.S arm64: entry32: remove pointless register assignment 2015-07-10 16:47:13 +01:00
entry-fpsimd.S arm64/sve: Low-level SVE architectural state manipulation functions 2017-11-03 15:24:14 +00:00
entry-ftrace.S arm64: Fix static use of function graph 2017-11-03 12:05:23 +00:00
entry.S 2nd set of arm64 updates for 4.16: 2018-02-08 10:44:25 -08:00
fpsimd.c arm64: signal: Make force_signal_inject more robust 2018-03-06 18:52:22 +00:00
ftrace.c arm64: ftrace: emit ftrace-mod.o contents through code 2017-12-01 13:04:59 +00:00
head.S arm64: idmap: Use "awx" flags for .idmap.text .pushsection directives 2018-02-06 22:53:27 +00:00
hibernate-asm.S arm64: assembler: Change order of macro arguments in phys_to_ttbr 2018-02-06 22:53:21 +00:00
hibernate.c arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables 2018-02-16 18:13:57 +00:00
hw_breakpoint.c arm64: hw_breakpoint: Use linux/uaccess.h instead of asm/uaccess.h 2017-12-12 11:53:26 +00:00
hyp-stub.S arm64: hyp-stub: Zero x0 on successful stub handling 2017-04-09 07:49:35 -07:00
image.h arm64 updates for 4.7: 2016-05-16 17:17:24 -07:00
insn.c arm64 updates for 4.13: 2017-07-05 17:09:27 -07:00
io.c arm64: Avoid aligning normal memory pointers in __memcpy_{to,from}io 2017-10-24 16:23:07 +01:00
irq.c arm64: Add vmap_stack header file 2018-01-13 10:45:03 +00:00
jump_label.c jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP} 2015-08-03 11:34:12 +02:00
kaslr.c arm64/kernel: kaslr: reduce module randomization range to 4 GB 2018-03-08 13:49:26 +00:00
kgdb.c arm64/debug: Fix registers on sleeping tasks 2018-03-06 18:52:34 +00:00
kuser32.S
machine_kexec.c arm64: explicitly mask all exceptions 2017-11-02 15:55:40 +00:00
Makefile arm64: kernel: Add arch-specific SDEI entry code and CPU masking 2018-01-13 10:45:17 +00:00
module-plts.c arm64: module: don't BUG when exceeding preallocated PLT count 2018-03-08 13:49:26 +00:00
module.c arm64/kernel: kaslr: reduce module randomization range to 4 GB 2018-03-08 13:49:26 +00:00
module.lds arm64: ftrace: emit ftrace-mod.o contents through code 2017-12-01 13:04:59 +00:00
paravirt.c arm64: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_ops 2015-12-21 14:40:54 +00:00
pci.c PCI: Add a generic weak pcibios_align_resource() 2017-08-02 14:53:16 -05:00
perf_callchain.c arm64: unwind: remove sp from struct stackframe 2017-08-09 14:10:29 +01:00
perf_event.c arm64: perf: correct PMUVer probing 2018-02-20 11:34:54 +00:00
perf_regs.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
process.c arm64: __show_regs: Only resolve kernel symbols when running at EL1 2018-02-19 17:07:12 +00:00
psci.c arm64: Use __pa_symbol for kernel symbols 2017-01-12 15:05:39 +00:00
ptrace.c arm64: Use arm64_force_sig_info instead of force_sig_info 2018-03-06 18:52:32 +00:00
reloc_test_core.c arm64: relocation testing module 2017-04-04 17:03:32 +01:00
reloc_test_syms.S arm64: relocation testing module 2017-04-04 17:03:32 +01:00
relocate_kernel.S arm64: Add software workaround for Falkor erratum 1041 2018-02-06 22:53:13 +00:00
return_address.c arm64: unwind: remove sp from struct stackframe 2017-08-09 14:10:29 +01:00
sdei.c arm64: sdei: Add trampoline code for remapping the kernel 2018-01-14 18:49:50 +00:00
setup.c arm64: Move the async/fiq helpers to explicitly set process context flags 2017-11-02 15:55:41 +00:00
signal32.c arm64: signal: Call arm64_notify_segfault when failing to deliver signal 2018-03-06 18:52:25 +00:00
signal.c arm64: signal: Call arm64_notify_segfault when failing to deliver signal 2018-03-06 18:52:25 +00:00
sleep.S arm64: idmap: Use "awx" flags for .idmap.text .pushsection directives 2018-02-06 22:53:27 +00:00
smccc-call.S firmware: qcom: scm: Fix interrupted SCM calls 2017-02-03 18:46:33 +00:00
smp_spin_table.c arm64: Use __pa_symbol for kernel symbols 2017-01-12 15:05:39 +00:00
smp.c arm64: kernel: Add arch-specific SDEI entry code and CPU masking 2018-01-13 10:45:17 +00:00
stacktrace.c arm64: fix unwind_frame() for filtered out fn for function graph tracing 2018-02-23 13:46:38 +00:00
suspend.c arm64: uaccess: Add PAN helper 2018-01-13 10:45:10 +00:00
sys32.c
sys_compat.c arm64: Mirror arm for unimplemented compat syscalls 2018-03-05 12:06:43 +00:00
sys.c arm64: compat: Check for AArch32 state 2016-04-20 12:22:42 +01:00
time.c arm64: fix unwind_frame() for filtered out fn for function graph tracing 2018-02-23 13:46:38 +00:00
topology.c arm64: Use of_cpu_node_to_id helper for CPU topology parsing 2018-01-02 16:43:12 +00:00
trace-events-emulation.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
traps.c arm64: Use arm64_force_sig_info instead of force_sig_info 2018-03-06 18:52:32 +00:00
vdso.c arm64/vdso: Support mremap() for vDSO 2017-08-09 12:16:28 +01:00
vmlinux.lds.S arm64: Extend early page table code to allow for larger kernels 2018-01-14 18:49:52 +00:00