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/bl2/aarch64/bl2_el3_entrypoint.S b/bl2/aarch64/bl2_el3_entrypoint.S
index 261d295..6fe2dd9 100644
--- a/bl2/aarch64/bl2_el3_entrypoint.S
+++ b/bl2/aarch64/bl2_el3_entrypoint.S
@@ -43,22 +43,12 @@
*/
bl bl2_el3_setup
- /* ---------------------------------------------
- * Enable pointer authentication
- * ---------------------------------------------
- */
#if ENABLE_PAUTH
- mrs x0, sctlr_el3
- orr x0, x0, #SCTLR_EnIA_BIT
-#if ENABLE_BTI
/* ---------------------------------------------
- * Enable PAC branch type compatibility
+ * Program APIAKey_EL1 and enable pointer authentication.
* ---------------------------------------------
*/
- bic x0, x0, #SCTLR_BT_BIT
-#endif /* ENABLE_BTI */
- msr sctlr_el3, x0
- isb
+ bl pauth_init_enable_el3
#endif /* ENABLE_PAUTH */
/* ---------------------------------------------
@@ -87,16 +77,13 @@
tlbi alle3
bl bl2_el3_plat_prepare_exit
+#if ENABLE_PAUTH
/* ---------------------------------------------
- * Disable pointer authentication before jumping to BL31 or that will
- * cause an authentication failure during the early platform init.
+ * Disable pointer authentication before jumping
+ * to next boot image.
* ---------------------------------------------
*/
-#if ENABLE_PAUTH
- mrs x0, sctlr_el3
- bic x0, x0, #SCTLR_EnIA_BIT
- msr sctlr_el3, x0
- isb
+ bl pauth_disable_el3
#endif /* ENABLE_PAUTH */
ldp x0, x1, [x20, #ENTRY_POINT_INFO_PC_OFFSET]