diff options
| author | Mark Rutland <mark.rutland@arm.com> | 2023-05-30 12:03:25 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2023-06-06 17:39:05 +0100 |
| commit | 6e13b6b923b35a965d128a40ef0c5d9dd101e603 (patch) | |
| tree | a65f78e4f8822acf9f294fcc1a466cf70ec905a9 /arch/arm64/kernel/setup.c | |
| parent | 55123afffe931ab02066f60084c9c495b9b52fda (diff) | |
arm64: kaslr: split kaslr/module initialization
Currently kaslr_init() handles a mixture of detecting/announcing whether
KASLR is enabled, and randomizing the module region depending on whether
KASLR is enabled.
To make it easier to rework the module region initialization, split the
KASLR initialization into two steps:
* kaslr_init() determines whether KASLR should be enabled, and announces
this choice, recording this to a new global boolean variable. This is
called from setup_arch() just before the existing call to
kaslr_requires_kpti() so that this will always provide the expected
result.
* kaslr_module_init() randomizes the module region when required. This
is called as a subsys_initcall, where we previously called
kaslr_init().
As a bonus, moving the KASLR reporting earlier makes it easier to spot
and permits it to be logged via earlycon, making it easier to debug any
issues that could be triggered by KASLR.
Booting a v6.4-rc1 kernel with this patch applied, the log looks like:
| EFI stub: Booting Linux Kernel...
| EFI stub: Generating empty DTB
| EFI stub: Exiting boot services...
| [ 0.000000] Booting Linux on physical CPU 0x0000000000 [0x000f0510]
| [ 0.000000] Linux version 6.4.0-rc1-00006-g4763a8f8aeb3 (mark@lakrids) (aarch64-linux-gcc (GCC) 12.1.0, GNU ld (GNU Binutils) 2.38) #2 SMP PREEMPT Tue May 9 11:03:37 BST 2023
| [ 0.000000] KASLR enabled
| [ 0.000000] earlycon: pl11 at MMIO 0x0000000009000000 (options '')
| [ 0.000000] printk: bootconsole [pl11] enabled
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Will Deacon <will@kernel.org>
Tested-by: Shanker Donthineni <sdonthineni@nvidia.com>
Link: https://lore.kernel.org/r/20230530110328.2213762-4-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/setup.c')
| -rw-r--r-- | arch/arm64/kernel/setup.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index b8ec7b3ac9cb..417a8a86b2db 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -296,6 +296,8 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) *cmdline_p = boot_command_line; + kaslr_init(); + /* * If know now we are going to need KPTI then use non-global * mappings from the start, avoiding the cost of rewriting |