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arm-trusted-firmware/lib/el3_runtime/aarch64/context.S
Alexei Fedorov ed108b5605 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>
2019-09-13 14:11:59 +01:00

531 lines
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/*
* Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch.h>
#include <asm_macros.S>
#include <context.h>
.global el1_sysregs_context_save
.global el1_sysregs_context_restore
#if CTX_INCLUDE_FPREGS
.global fpregs_context_save
.global fpregs_context_restore
#endif
.global save_gp_pmcr_pauth_regs
.global restore_gp_pmcr_pauth_regs
.global el3_exit
/* ------------------------------------------------------------------
* The following function strictly follows the AArch64 PCS to use
* x9-x17 (temporary caller-saved registers) to save EL1 system
* register context. It assumes that 'x0' is pointing to a
* 'el1_sys_regs' structure where the register context will be saved.
* ------------------------------------------------------------------
*/
func el1_sysregs_context_save
mrs x9, spsr_el1
mrs x10, elr_el1
stp x9, x10, [x0, #CTX_SPSR_EL1]
mrs x15, sctlr_el1
mrs x16, actlr_el1
stp x15, x16, [x0, #CTX_SCTLR_EL1]
mrs x17, cpacr_el1
mrs x9, csselr_el1
stp x17, x9, [x0, #CTX_CPACR_EL1]
mrs x10, sp_el1
mrs x11, esr_el1
stp x10, x11, [x0, #CTX_SP_EL1]
mrs x12, ttbr0_el1
mrs x13, ttbr1_el1
stp x12, x13, [x0, #CTX_TTBR0_EL1]
mrs x14, mair_el1
mrs x15, amair_el1
stp x14, x15, [x0, #CTX_MAIR_EL1]
mrs x16, tcr_el1
mrs x17, tpidr_el1
stp x16, x17, [x0, #CTX_TCR_EL1]
mrs x9, tpidr_el0
mrs x10, tpidrro_el0
stp x9, x10, [x0, #CTX_TPIDR_EL0]
mrs x13, par_el1
mrs x14, far_el1
stp x13, x14, [x0, #CTX_PAR_EL1]
mrs x15, afsr0_el1
mrs x16, afsr1_el1
stp x15, x16, [x0, #CTX_AFSR0_EL1]
mrs x17, contextidr_el1
mrs x9, vbar_el1
stp x17, x9, [x0, #CTX_CONTEXTIDR_EL1]
/* Save AArch32 system registers if the build has instructed so */
#if CTX_INCLUDE_AARCH32_REGS
mrs x11, spsr_abt
mrs x12, spsr_und
stp x11, x12, [x0, #CTX_SPSR_ABT]
mrs x13, spsr_irq
mrs x14, spsr_fiq
stp x13, x14, [x0, #CTX_SPSR_IRQ]
mrs x15, dacr32_el2
mrs x16, ifsr32_el2
stp x15, x16, [x0, #CTX_DACR32_EL2]
#endif
/* Save NS timer registers if the build has instructed so */
#if NS_TIMER_SWITCH
mrs x10, cntp_ctl_el0
mrs x11, cntp_cval_el0
stp x10, x11, [x0, #CTX_CNTP_CTL_EL0]
mrs x12, cntv_ctl_el0
mrs x13, cntv_cval_el0
stp x12, x13, [x0, #CTX_CNTV_CTL_EL0]
mrs x14, cntkctl_el1
str x14, [x0, #CTX_CNTKCTL_EL1]
#endif
/* Save MTE system registers if the build has instructed so */
#if CTX_INCLUDE_MTE_REGS
mrs x15, TFSRE0_EL1
mrs x16, TFSR_EL1
stp x15, x16, [x0, #CTX_TFSRE0_EL1]
mrs x9, RGSR_EL1
mrs x10, GCR_EL1
stp x9, x10, [x0, #CTX_RGSR_EL1]
#endif
ret
endfunc el1_sysregs_context_save
/* ------------------------------------------------------------------
* The following function strictly follows the AArch64 PCS to use
* x9-x17 (temporary caller-saved registers) to restore EL1 system
* register context. It assumes that 'x0' is pointing to a
* 'el1_sys_regs' structure from where the register context will be
* restored
* ------------------------------------------------------------------
*/
func el1_sysregs_context_restore
ldp x9, x10, [x0, #CTX_SPSR_EL1]
msr spsr_el1, x9
msr elr_el1, x10
ldp x15, x16, [x0, #CTX_SCTLR_EL1]
msr sctlr_el1, x15
msr actlr_el1, x16
ldp x17, x9, [x0, #CTX_CPACR_EL1]
msr cpacr_el1, x17
msr csselr_el1, x9
ldp x10, x11, [x0, #CTX_SP_EL1]
msr sp_el1, x10
msr esr_el1, x11
ldp x12, x13, [x0, #CTX_TTBR0_EL1]
msr ttbr0_el1, x12
msr ttbr1_el1, x13
ldp x14, x15, [x0, #CTX_MAIR_EL1]
msr mair_el1, x14
msr amair_el1, x15
ldp x16, x17, [x0, #CTX_TCR_EL1]
msr tcr_el1, x16
msr tpidr_el1, x17
ldp x9, x10, [x0, #CTX_TPIDR_EL0]
msr tpidr_el0, x9
msr tpidrro_el0, x10
ldp x13, x14, [x0, #CTX_PAR_EL1]
msr par_el1, x13
msr far_el1, x14
ldp x15, x16, [x0, #CTX_AFSR0_EL1]
msr afsr0_el1, x15
msr afsr1_el1, x16
ldp x17, x9, [x0, #CTX_CONTEXTIDR_EL1]
msr contextidr_el1, x17
msr vbar_el1, x9
/* Restore AArch32 system registers if the build has instructed so */
#if CTX_INCLUDE_AARCH32_REGS
ldp x11, x12, [x0, #CTX_SPSR_ABT]
msr spsr_abt, x11
msr spsr_und, x12
ldp x13, x14, [x0, #CTX_SPSR_IRQ]
msr spsr_irq, x13
msr spsr_fiq, x14
ldp x15, x16, [x0, #CTX_DACR32_EL2]
msr dacr32_el2, x15
msr ifsr32_el2, x16
#endif
/* Restore NS timer registers if the build has instructed so */
#if NS_TIMER_SWITCH
ldp x10, x11, [x0, #CTX_CNTP_CTL_EL0]
msr cntp_ctl_el0, x10
msr cntp_cval_el0, x11
ldp x12, x13, [x0, #CTX_CNTV_CTL_EL0]
msr cntv_ctl_el0, x12
msr cntv_cval_el0, x13
ldr x14, [x0, #CTX_CNTKCTL_EL1]
msr cntkctl_el1, x14
#endif
/* Restore MTE system registers if the build has instructed so */
#if CTX_INCLUDE_MTE_REGS
ldp x11, x12, [x0, #CTX_TFSRE0_EL1]
msr TFSRE0_EL1, x11
msr TFSR_EL1, x12
ldp x13, x14, [x0, #CTX_RGSR_EL1]
msr RGSR_EL1, x13
msr GCR_EL1, x14
#endif
/* No explict ISB required here as ERET covers it */
ret
endfunc el1_sysregs_context_restore
/* ------------------------------------------------------------------
* The following function follows the aapcs_64 strictly to use
* x9-x17 (temporary caller-saved registers according to AArch64 PCS)
* to save floating point register context. It assumes that 'x0' is
* pointing to a 'fp_regs' structure where the register context will
* be saved.
*
* Access to VFP registers will trap if CPTR_EL3.TFP is set.
* However currently we don't use VFP registers nor set traps in
* Trusted Firmware, and assume it's cleared.
*
* TODO: Revisit when VFP is used in secure world
* ------------------------------------------------------------------
*/
#if CTX_INCLUDE_FPREGS
func fpregs_context_save
stp q0, q1, [x0, #CTX_FP_Q0]
stp q2, q3, [x0, #CTX_FP_Q2]
stp q4, q5, [x0, #CTX_FP_Q4]
stp q6, q7, [x0, #CTX_FP_Q6]
stp q8, q9, [x0, #CTX_FP_Q8]
stp q10, q11, [x0, #CTX_FP_Q10]
stp q12, q13, [x0, #CTX_FP_Q12]
stp q14, q15, [x0, #CTX_FP_Q14]
stp q16, q17, [x0, #CTX_FP_Q16]
stp q18, q19, [x0, #CTX_FP_Q18]
stp q20, q21, [x0, #CTX_FP_Q20]
stp q22, q23, [x0, #CTX_FP_Q22]
stp q24, q25, [x0, #CTX_FP_Q24]
stp q26, q27, [x0, #CTX_FP_Q26]
stp q28, q29, [x0, #CTX_FP_Q28]
stp q30, q31, [x0, #CTX_FP_Q30]
mrs x9, fpsr
str x9, [x0, #CTX_FP_FPSR]
mrs x10, fpcr
str x10, [x0, #CTX_FP_FPCR]
#if CTX_INCLUDE_AARCH32_REGS
mrs x11, fpexc32_el2
str x11, [x0, #CTX_FP_FPEXC32_EL2]
#endif
ret
endfunc fpregs_context_save
/* ------------------------------------------------------------------
* The following function follows the aapcs_64 strictly to use x9-x17
* (temporary caller-saved registers according to AArch64 PCS) to
* restore floating point register context. It assumes that 'x0' is
* pointing to a 'fp_regs' structure from where the register context
* will be restored.
*
* Access to VFP registers will trap if CPTR_EL3.TFP is set.
* However currently we don't use VFP registers nor set traps in
* Trusted Firmware, and assume it's cleared.
*
* TODO: Revisit when VFP is used in secure world
* ------------------------------------------------------------------
*/
func fpregs_context_restore
ldp q0, q1, [x0, #CTX_FP_Q0]
ldp q2, q3, [x0, #CTX_FP_Q2]
ldp q4, q5, [x0, #CTX_FP_Q4]
ldp q6, q7, [x0, #CTX_FP_Q6]
ldp q8, q9, [x0, #CTX_FP_Q8]
ldp q10, q11, [x0, #CTX_FP_Q10]
ldp q12, q13, [x0, #CTX_FP_Q12]
ldp q14, q15, [x0, #CTX_FP_Q14]
ldp q16, q17, [x0, #CTX_FP_Q16]
ldp q18, q19, [x0, #CTX_FP_Q18]
ldp q20, q21, [x0, #CTX_FP_Q20]
ldp q22, q23, [x0, #CTX_FP_Q22]
ldp q24, q25, [x0, #CTX_FP_Q24]
ldp q26, q27, [x0, #CTX_FP_Q26]
ldp q28, q29, [x0, #CTX_FP_Q28]
ldp q30, q31, [x0, #CTX_FP_Q30]
ldr x9, [x0, #CTX_FP_FPSR]
msr fpsr, x9
ldr x10, [x0, #CTX_FP_FPCR]
msr fpcr, x10
#if CTX_INCLUDE_AARCH32_REGS
ldr x11, [x0, #CTX_FP_FPEXC32_EL2]
msr fpexc32_el2, x11
#endif
/*
* No explict ISB required here as ERET to
* switch to secure EL1 or non-secure world
* covers it
*/
ret
endfunc fpregs_context_restore
#endif /* CTX_INCLUDE_FPREGS */
/* ------------------------------------------------------------------
* The following function is used to save and restore all the general
* purpose and ARMv8.3-PAuth (if enabled) registers.
* It also checks if Secure Cycle Counter is not disabled in MDCR_EL3
* when ARMv8.5-PMU is implemented, and if called from Non-secure
* state saves PMCR_EL0 and disables Cycle Counter.
*
* Ideally we would only save and restore the callee saved registers
* when a world switch occurs but that type of implementation is more
* complex. So currently we will always save and restore these
* registers on entry and exit of EL3.
* These are not macros to ensure their invocation fits within the 32
* instructions per exception vector.
* clobbers: x18
* ------------------------------------------------------------------
*/
func save_gp_pmcr_pauth_regs
stp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0]
stp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
stp x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
stp x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6]
stp x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8]
stp x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10]
stp x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12]
stp x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14]
stp x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
stp x18, x19, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18]
stp x20, x21, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X20]
stp x22, x23, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X22]
stp x24, x25, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X24]
stp x26, x27, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X26]
stp x28, x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X28]
mrs x18, sp_el0
str x18, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_SP_EL0]
/* ----------------------------------------------------------
* Check if earlier initialization MDCR_EL3.SCCD to 1 failed,
* meaning that ARMv8-PMU is not implemented and PMCR_EL0
* should be saved in non-secure context.
* ----------------------------------------------------------
*/
mrs x9, mdcr_el3
tst x9, #MDCR_SCCD_BIT
bne 1f
/* Secure Cycle Counter is not disabled */
mrs x9, pmcr_el0
/* Check caller's security state */
mrs x10, scr_el3
tst x10, #SCR_NS_BIT
beq 2f
/* Save PMCR_EL0 if called from Non-secure state */
str x9, [sp, #CTX_EL3STATE_OFFSET + CTX_PMCR_EL0]
/* Disable cycle counter when event counting is prohibited */
2: orr x9, x9, #PMCR_EL0_DP_BIT
msr pmcr_el0, x9
isb
1:
#if CTX_INCLUDE_PAUTH_REGS
/* ----------------------------------------------------------
* Save the ARMv8.3-PAuth keys as they are not banked
* by exception level
* ----------------------------------------------------------
*/
add x19, sp, #CTX_PAUTH_REGS_OFFSET
mrs x20, APIAKeyLo_EL1 /* x21:x20 = APIAKey */
mrs x21, APIAKeyHi_EL1
mrs x22, APIBKeyLo_EL1 /* x23:x22 = APIBKey */
mrs x23, APIBKeyHi_EL1
mrs x24, APDAKeyLo_EL1 /* x25:x24 = APDAKey */
mrs x25, APDAKeyHi_EL1
mrs x26, APDBKeyLo_EL1 /* x27:x26 = APDBKey */
mrs x27, APDBKeyHi_EL1
mrs x28, APGAKeyLo_EL1 /* x29:x28 = APGAKey */
mrs x29, APGAKeyHi_EL1
stp x20, x21, [x19, #CTX_PACIAKEY_LO]
stp x22, x23, [x19, #CTX_PACIBKEY_LO]
stp x24, x25, [x19, #CTX_PACDAKEY_LO]
stp x26, x27, [x19, #CTX_PACDBKEY_LO]
stp x28, x29, [x19, #CTX_PACGAKEY_LO]
#endif /* CTX_INCLUDE_PAUTH_REGS */
ret
endfunc save_gp_pmcr_pauth_regs
/* ------------------------------------------------------------------
* This function restores ARMv8.3-PAuth (if enabled) and all general
* purpose registers except x30 from the CPU context.
* x30 register must be explicitly restored by the caller.
* ------------------------------------------------------------------
*/
func restore_gp_pmcr_pauth_regs
#if CTX_INCLUDE_PAUTH_REGS
/* Restore the ARMv8.3 PAuth keys */
add x10, sp, #CTX_PAUTH_REGS_OFFSET
ldp x0, x1, [x10, #CTX_PACIAKEY_LO] /* x1:x0 = APIAKey */
ldp x2, x3, [x10, #CTX_PACIBKEY_LO] /* x3:x2 = APIBKey */
ldp x4, x5, [x10, #CTX_PACDAKEY_LO] /* x5:x4 = APDAKey */
ldp x6, x7, [x10, #CTX_PACDBKEY_LO] /* x7:x6 = APDBKey */
ldp x8, x9, [x10, #CTX_PACGAKEY_LO] /* x9:x8 = APGAKey */
msr APIAKeyLo_EL1, x0
msr APIAKeyHi_EL1, x1
msr APIBKeyLo_EL1, x2
msr APIBKeyHi_EL1, x3
msr APDAKeyLo_EL1, x4
msr APDAKeyHi_EL1, x5
msr APDBKeyLo_EL1, x6
msr APDBKeyHi_EL1, x7
msr APGAKeyLo_EL1, x8
msr APGAKeyHi_EL1, x9
#endif /* CTX_INCLUDE_PAUTH_REGS */
/* ----------------------------------------------------------
* Restore PMCR_EL0 when returning to Non-secure state if
* Secure Cycle Counter is not disabled in MDCR_EL3 when
* ARMv8.5-PMU is implemented.
* ----------------------------------------------------------
*/
mrs x0, scr_el3
tst x0, #SCR_NS_BIT
beq 2f
/* ----------------------------------------------------------
* Back to Non-secure state.
* Check if earlier initialization MDCR_EL3.SCCD to 1 failed,
* meaning that ARMv8-PMU is not implemented and PMCR_EL0
* should be restored from non-secure context.
* ----------------------------------------------------------
*/
mrs x0, mdcr_el3
tst x0, #MDCR_SCCD_BIT
bne 2f
ldr x0, [sp, #CTX_EL3STATE_OFFSET + CTX_PMCR_EL0]
msr pmcr_el0, x0
2:
ldp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0]
ldp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
ldp x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
ldp x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6]
ldp x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8]
ldp x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10]
ldp x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12]
ldp x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14]
ldp x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
ldp x18, x19, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18]
ldp x20, x21, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X20]
ldp x22, x23, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X22]
ldp x24, x25, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X24]
ldp x26, x27, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X26]
ldr x28, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_SP_EL0]
msr sp_el0, x28
ldp x28, x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X28]
ret
endfunc restore_gp_pmcr_pauth_regs
/* ------------------------------------------------------------------
* This routine assumes that the SP_EL3 is pointing to a valid
* context structure from where the gp regs and other special
* registers can be retrieved.
* ------------------------------------------------------------------
*/
func el3_exit
/* ----------------------------------------------------------
* Save the current SP_EL0 i.e. the EL3 runtime stack which
* will be used for handling the next SMC.
* Then switch to SP_EL3.
* ----------------------------------------------------------
*/
mov x17, sp
msr spsel, #MODE_SP_ELX
str x17, [sp, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP]
/* ----------------------------------------------------------
* Restore SPSR_EL3, ELR_EL3 and SCR_EL3 prior to ERET
* ----------------------------------------------------------
*/
ldr x18, [sp, #CTX_EL3STATE_OFFSET + CTX_SCR_EL3]
ldp x16, x17, [sp, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3]
msr scr_el3, x18
msr spsr_el3, x16
msr elr_el3, x17
#if IMAGE_BL31 && DYNAMIC_WORKAROUND_CVE_2018_3639
/* ----------------------------------------------------------
* Restore mitigation state as it was on entry to EL3
* ----------------------------------------------------------
*/
ldr x17, [sp, #CTX_CVE_2018_3639_OFFSET + CTX_CVE_2018_3639_DISABLE]
cbz x17, 1f
blr x17
1:
#endif
/* ----------------------------------------------------------
* Restore general purpose (including x30), PMCR_EL0 and
* ARMv8.3-PAuth registers.
* Exit EL3 via ERET to a lower exception level.
* ----------------------------------------------------------
*/
bl restore_gp_pmcr_pauth_regs
ldr x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
#if IMAGE_BL31 && RAS_EXTENSION
/* ----------------------------------------------------------
* Issue Error Synchronization Barrier to synchronize SErrors
* before exiting EL3. We're running with EAs unmasked, so
* any synchronized errors would be taken immediately;
* therefore no need to inspect DISR_EL1 register.
* ----------------------------------------------------------
*/
esb
#endif
eret
endfunc el3_exit
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