diff options
| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2016-10-17 16:18:39 +0100 |
|---|---|---|
| committer | Runmin Wang <runminw@codeaurora.org> | 2017-01-13 14:05:32 -0800 |
| commit | 0d5578df07cbcedd13637465384a868eae9109b6 (patch) | |
| tree | 7da864075f636c87e477c33425f1e9f97c94c727 | |
| parent | 2116b44bd37e0245ac3442be3dd094397ce017c9 (diff) | |
arm64: kaslr: keep modules close to the kernel when DYNAMIC_FTRACE=y
The RANDOMIZE_MODULE_REGION_FULL Kconfig option allows KASLR to be
configured in such a way that kernel modules and the core kernel are
allocated completely independently, which implies that modules are likely
to require branches via PLT entries to reach the core kernel. The dynamic
ftrace code does not expect that, and assumes that it can patch module
code to perform a relative branch to anywhere in the core kernel. This
may result in errors such as
branch_imm_common: offset out of range
------------[ cut here ]------------
WARNING: CPU: 3 PID: 196 at kernel/trace/ftrace.c:1995 ftrace_bug+0x220/0x2e8
Modules linked in:
CPU: 3 PID: 196 Comm: systemd-udevd Not tainted 4.8.0-22-generic #24
Hardware name: AMD Seattle/Seattle, BIOS 10:34:40 Oct 6 2016
task: ffff8d1bef7dde80 task.stack: ffff8d1bef6b0000
PC is at ftrace_bug+0x220/0x2e8
LR is at ftrace_process_locs+0x330/0x430
So make RANDOMIZE_MODULE_REGION_FULL mutually exclusive with DYNAMIC_FTRACE
at the Kconfig level.
Change-Id: I60868f2cb0194b61000946e1d524fa27342dec6b
Git-commit: 8fe88a4145cdeee486af60e61f5d5a14f804fa45
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Runmin Wang <runminw@codeaurora.org>
| -rw-r--r-- | arch/arm64/Kconfig | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 8eeb297d7b6f..0efb7c66e818 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -910,7 +910,7 @@ config RANDOMIZE_BASE config RANDOMIZE_MODULE_REGION_FULL bool "Randomize the module region independently from the core kernel" - depends on RANDOMIZE_BASE + depends on RANDOMIZE_BASE && !DYNAMIC_FTRACE default y help Randomizes the location of the module region without considering the |