diff options
| author | WANG Rui <wangrui@loongson.cn> | 2026-05-21 20:58:36 +0800 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2026-05-21 20:58:36 +0800 |
| commit | 08ade00fbb088b8f5a1af706ee970c26cf842bf0 (patch) | |
| tree | 690e40769e067177fc9e99ac31580b6a75e4ddde | |
| parent | 03d8273542146f228c0019f08b57545fdee79704 (diff) | |
LoongArch: Skip relocation-time KASLR if already applied
When the kernel is relocated during early boot (efistub or kexec_file),
a randomized load address may has already been selected and applied. In
this case, performing KASLR again in relocate.c is unnecessary.
Note: strictly-defined KASLR means the kernel's final runtime address
has a random offset from the kernel's load address, which is implemented
in relocate.c; broadly-defined KALSR means the kernel's final runtime
address has a random offset from the kernel's link address (a.k.a.
VMLINUX_LOAD_ADDRESS), which also include the efistlub implementation,
kexec_file implementation and QEMU direct kernel boot. kaslr_disabled()
return true only means strictly-defined KASLR is disabled.
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| -rw-r--r-- | arch/loongarch/kernel/relocate.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/relocate.c b/arch/loongarch/kernel/relocate.c index 16f6a9b39659..0a045964fad5 100644 --- a/arch/loongarch/kernel/relocate.c +++ b/arch/loongarch/kernel/relocate.c @@ -134,11 +134,23 @@ early_param("nokaslr", nokaslr); #define KASLR_DISABLED_MESSAGE "KASLR is disabled by %s in %s cmdline.\n" +/* + * Note: strictly-defined KASLR means the kernel's final runtime address + * has a random offset from the kernel's load address, which is implemented + * in relocate.c; broadly-defined KALSR means the kernel's final runtime + * address has a random offset from the kernel's link address (a.k.a. + * VMLINUX_LOAD_ADDRESS), which also include the efistlub implementation, + * kexec_file implementation and QEMU direct kernel boot. kaslr_disabled() + * return true only means strictly-defined KASLR is disabled. + */ static inline __init bool kaslr_disabled(void) { char *str; const char *builtin_cmdline = CONFIG_CMDLINE; + if (kaslr_offset()) + return true; /* KASLR is performed during early boot. */ + str = strstr(builtin_cmdline, "nokaslr"); if (str == builtin_cmdline || (str > builtin_cmdline && *(str - 1) == ' ')) { pr_info(KASLR_DISABLED_MESSAGE, "\'nokaslr\'", "built-in"); |