Refactor ARMv8.3 Pointer Authentication support code
This patch provides the following features and makes modifications
listed below:
- Individual APIAKey key generation for each CPU.
- New key generation on every BL31 warm boot and TSP CPU On event.
- Per-CPU storage of APIAKey added in percpu_data[]
of cpu_data structure.
- `plat_init_apiakey()` function replaced with `plat_init_apkey()`
which returns 128-bit value and uses Generic timer physical counter
value to increase the randomness of the generated key.
The new function can be used for generation of all ARMv8.3-PAuth keys
- ARMv8.3-PAuth specific code placed in `lib\extensions\pauth`.
- New `pauth_init_enable_el1()` and `pauth_init_enable_el3()` functions
generate, program and enable APIAKey_EL1 for EL1 and EL3 respectively;
pauth_disable_el1()` and `pauth_disable_el3()` functions disable
PAuth for EL1 and EL3 respectively;
`pauth_load_bl31_apiakey()` loads saved per-CPU APIAKey_EL1 from
cpu-data structure.
- Combined `save_gp_pauth_registers()` function replaces calls to
`save_gp_registers()` and `pauth_context_save()`;
`restore_gp_pauth_registers()` replaces `pauth_context_restore()`
and `restore_gp_registers()` calls.
- `restore_gp_registers_eret()` function removed with corresponding
code placed in `el3_exit()`.
- Fixed the issue when `pauth_t pauth_ctx` structure allocated space
for 12 uint64_t PAuth registers instead of 10 by removal of macro
CTX_PACGAKEY_END from `include/lib/el3_runtime/aarch64/context.h`
and assigning its value to CTX_PAUTH_REGS_END.
- Use of MODE_SP_ELX and MODE_SP_EL0 macro definitions
in `msr spsel` instruction instead of hard-coded values.
- Changes in documentation related to ARMv8.3-PAuth and ARMv8.5-BTI.
Change-Id: Id18b81cc46f52a783a7e6a09b9f149b6ce803211
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
diff --git a/bl31/aarch64/ea_delegate.S b/bl31/aarch64/ea_delegate.S
index 8dca10c..6e71a06 100644
--- a/bl31/aarch64/ea_delegate.S
+++ b/bl31/aarch64/ea_delegate.S
@@ -65,22 +65,16 @@
mrs x30, esr_el3
tbz x30, #ESR_ISS_EABORT_EA_BIT, 2f
- /* Save GP registers */
- bl save_gp_registers
-
/*
- * If Secure Cycle Counter is not disabled in MDCR_EL3
- * when ARMv8.5-PMU is implemented, save PMCR_EL0 and
- * disable all event counters and cycle counter.
+ * Save general purpose and ARMv8.3-PAuth registers (if enabled).
+ * If Secure Cycle Counter is not disabled in MDCR_EL3 when
+ * ARMv8.5-PMU is implemented, save PMCR_EL0 and disable Cycle Counter.
*/
- bl save_pmcr_disable_pmu
+ bl save_gp_pmcr_pauth_regs
- /* Save ARMv8.3-PAuth registers and load firmware key */
-#if CTX_INCLUDE_PAUTH_REGS
- bl pauth_context_save
-#endif
#if ENABLE_PAUTH
- bl pauth_load_bl_apiakey
+ /* Load and program APIAKey firmware key */
+ bl pauth_load_bl31_apiakey
#endif
/* Setup exception class and syndrome arguments for platform handler */
@@ -110,22 +104,16 @@
*/
str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
- /* Save GP registers */
- bl save_gp_registers
-
/*
- * If Secure Cycle Counter is not disabled in MDCR_EL3
- * when ARMv8.5-PMU is implemented, save PMCR_EL0 and
- * disable all event counters and cycle counter.
+ * Save general purpose and ARMv8.3-PAuth registers (if enabled).
+ * If Secure Cycle Counter is not disabled in MDCR_EL3 when
+ * ARMv8.5-PMU is implemented, save PMCR_EL0 and disable Cycle Counter.
*/
- bl save_pmcr_disable_pmu
+ bl save_gp_pmcr_pauth_regs
- /* Save ARMv8.3-PAuth registers and load firmware key */
-#if CTX_INCLUDE_PAUTH_REGS
- bl pauth_context_save
-#endif
#if ENABLE_PAUTH
- bl pauth_load_bl_apiakey
+ /* Load and program APIAKey firmware key */
+ bl pauth_load_bl31_apiakey
#endif
/* Setup exception class and syndrome arguments for platform handler */
@@ -247,7 +235,7 @@
/* Switch to runtime stack */
ldr x5, [sp, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP]
- msr spsel, #0
+ msr spsel, #MODE_SP_EL0
mov sp, x5
mov x29, x30
@@ -269,7 +257,7 @@
#endif
/* Make SP point to context */
- msr spsel, #1
+ msr spsel, #MODE_SP_ELX
/* Restore EL3 state and ESR */
ldp x1, x2, [sp, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3]