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arm64: kaslr: Check command line before looking for a seed 

Now that we print diagnostics at boot the reason why we do not initialise
KASLR matters. Currently we check for a seed before we check if the user
has explicitly disabled KASLR on the command line which will result in
misleading diagnostics so reverse the order of those checks. We still
parse the seed from the DT early so that if the user has both provided a
seed and disabled KASLR on the command line we still mask the seed on
the command line.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Mark Brown 2019-11-08 17:12:44 +00:00 committed by Catalin Marinas
parent 294a9ddde6
commit 2203e1adb9
1 changed files with 6 additions and 5 deletions
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11
arch/arm64/kernel/kaslr.c
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@ -26,7 +26,7 @@ enum kaslr_status {
KASLR_DISABLED_FDT_REMAP, KASLR_DISABLED_FDT_REMAP,
}; };
enum kaslr_status __ro_after_init kaslr_status; static enum kaslr_status __initdata kaslr_status;
u64 __ro_after_init module_alloc_base; u64 __ro_after_init module_alloc_base;
u16 __initdata memstart_offset_seed; u16 __initdata memstart_offset_seed;
@ -108,10 +108,6 @@ u64 __init kaslr_early_init(u64 dt_phys)
* Retrieve (and wipe) the seed from the FDT * Retrieve (and wipe) the seed from the FDT
*/ */
seed = get_kaslr_seed(fdt); seed = get_kaslr_seed(fdt);
if (!seed) {
kaslr_status = KASLR_DISABLED_NO_SEED;
return 0;
}
/* /*
* Check if 'nokaslr' appears on the command line, and * Check if 'nokaslr' appears on the command line, and
@ -124,6 +120,11 @@ u64 __init kaslr_early_init(u64 dt_phys)
return 0; return 0;
} }
if (!seed) {
kaslr_status = KASLR_DISABLED_NO_SEED;
return 0;
}
/* /*
* OK, so we are proceeding with KASLR enabled. Calculate a suitable * OK, so we are proceeding with KASLR enabled. Calculate a suitable
* kernel image offset from the seed. Let's place the kernel in the * kernel image offset from the seed. Let's place the kernel in the