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| author | Kristina Martsenko <kristina.martsenko@arm.com> | 2020-03-13 14:34:56 +0530 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-03-18 09:50:20 +0000 |
| commit | 33e45234987ea3ed4b05fc512f4441696478f12d (patch) | |
| tree | e7dbf5120c409f20c20d7b095dca1244ec3f3b85 /arch/arm64/kernel/entry.S | |
| parent | 6982934e19f8ebb4152ba77308facdb1a38533f9 (diff) | |
| download | lwn-33e45234987ea3ed4b05fc512f4441696478f12d.tar.gz lwn-33e45234987ea3ed4b05fc512f4441696478f12d.zip | |
arm64: initialize and switch ptrauth kernel keys
Set up keys to use pointer authentication within the kernel. The kernel
will be compiled with APIAKey instructions, the other keys are currently
unused. Each task is given its own APIAKey, which is initialized during
fork. The key is changed during context switch and on kernel entry from
EL0.
The keys for idle threads need to be set before calling any C functions,
because it is not possible to enter and exit a function with different
keys.
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[Amit: Modified secondary cores key structure, comments]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/entry.S')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 684e475bfda0..3dad2d000e3c 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -178,6 +178,7 @@ alternative_cb_end apply_ssbd 1, x22, x23 + ptrauth_keys_install_kernel tsk, x20, x22, x23 .else add x21, sp, #S_FRAME_SIZE get_current_task tsk @@ -342,6 +343,7 @@ alternative_else_nop_endif msr cntkctl_el1, x1 4: #endif + /* No kernel C function calls after this as user keys are set. */ ptrauth_keys_install_user tsk, x0, x1, x2 apply_ssbd 0, x0, x1 @@ -898,6 +900,7 @@ ENTRY(cpu_switch_to) ldr lr, [x8] mov sp, x9 msr sp_el0, x1 + ptrauth_keys_install_kernel x1, x8, x9, x10 ret ENDPROC(cpu_switch_to) NOKPROBE(cpu_switch_to) |