From ffd6b78a2c47d1c15629dc72c71caea30ef8161a Mon Sep 17 00:00:00 2001 From: Matthias Welwarsky Date: Mon, 12 Mar 2018 16:56:05 +0100 Subject: [PATCH] aarch64: fix debug entry from EL0 If we enter debug state from EL0, some registers are not accessible. Temporarily move to EL1H and back to gain access. Also, fix armv8_dpm_modeswitch() to not immediately restore the previous state on elevating the privilege level. Change-Id: Ic2a92109230ff4eb6834c00ef544397a5b7ad56a Signed-off-by: Matthias Welwarsky Reviewed-on: http://openocd.zylin.com/4461 Tested-by: jenkins Reviewed-by: Matthias Welwarsky --- src/target/aarch64.c | 4 ++-- src/target/armv8.c | 9 +++++++++ src/target/armv8_cache.c | 9 +++++++++ src/target/armv8_dpm.c | 9 +++++---- src/target/armv8_dpm.h | 2 +- 5 files changed, 26 insertions(+), 7 deletions(-) diff --git a/src/target/aarch64.c b/src/target/aarch64.c index 0630ffb9b..b586e24eb 100644 --- a/src/target/aarch64.c +++ b/src/target/aarch64.c @@ -1861,7 +1861,7 @@ static int aarch64_write_cpu_memory(struct target *target, if (dscr & (DSCR_ERR | DSCR_SYS_ERROR_PEND)) { /* Abort occurred - clear it and exit */ LOG_ERROR("abort occurred - dscr = 0x%08" PRIx32, dscr); - armv8_dpm_handle_exception(dpm); + armv8_dpm_handle_exception(dpm, true); return ERROR_FAIL; } @@ -2080,7 +2080,7 @@ static int aarch64_read_cpu_memory(struct target *target, if (dscr & (DSCR_ERR | DSCR_SYS_ERROR_PEND)) { /* Abort occurred - clear it and exit */ LOG_ERROR("abort occurred - dscr = 0x%08" PRIx32, dscr); - armv8_dpm_handle_exception(dpm); + armv8_dpm_handle_exception(dpm, true); return ERROR_FAIL; } diff --git a/src/target/armv8.c b/src/target/armv8.c index 86bb8707e..e8c700af3 100644 --- a/src/target/armv8.c +++ b/src/target/armv8.c @@ -620,6 +620,7 @@ void armv8_select_reg_access(struct armv8_common *armv8, bool is_aarch64) int armv8_read_mpidr(struct armv8_common *armv8) { int retval = ERROR_FAIL; + struct arm *arm = &armv8->arm; struct arm_dpm *dpm = armv8->arm.dpm; uint32_t mpidr; @@ -627,6 +628,13 @@ int armv8_read_mpidr(struct armv8_common *armv8) if (retval != ERROR_OK) goto done; + /* check if we're in an unprivileged mode */ + if (armv8_curel_from_core_mode(arm->core_mode) < SYSTEM_CUREL_EL1) { + retval = armv8_dpm_modeswitch(dpm, ARMV8_64_EL1H); + if (retval != ERROR_OK) + return retval; + } + retval = dpm->instr_read_data_r0(dpm, armv8_opcode(armv8, READ_REG_MPIDR), &mpidr); if (retval != ERROR_OK) goto done; @@ -642,6 +650,7 @@ int armv8_read_mpidr(struct armv8_common *armv8) LOG_ERROR("mpidr not in multiprocessor format"); done: + armv8_dpm_modeswitch(dpm, ARM_MODE_ANY); dpm->finish(dpm); return retval; } diff --git a/src/target/armv8_cache.c b/src/target/armv8_cache.c index 7f610c953..40965ebd8 100644 --- a/src/target/armv8_cache.c +++ b/src/target/armv8_cache.c @@ -310,6 +310,7 @@ int armv8_identify_cache(struct armv8_common *armv8) { /* read cache descriptor */ int retval = ERROR_FAIL; + struct arm *arm = &armv8->arm; struct arm_dpm *dpm = armv8->arm.dpm; uint32_t csselr, clidr, ctr; uint32_t cache_reg; @@ -320,6 +321,13 @@ int armv8_identify_cache(struct armv8_common *armv8) if (retval != ERROR_OK) goto done; + /* check if we're in an unprivileged mode */ + if (armv8_curel_from_core_mode(arm->core_mode) < SYSTEM_CUREL_EL1) { + retval = armv8_dpm_modeswitch(dpm, ARMV8_64_EL1H); + if (retval != ERROR_OK) + return retval; + } + /* retrieve CTR */ retval = dpm->instr_read_data_r0(dpm, armv8_opcode(armv8, READ_REG_CTR), &ctr); @@ -417,6 +425,7 @@ int armv8_identify_cache(struct armv8_common *armv8) } done: + armv8_dpm_modeswitch(dpm, ARM_MODE_ANY); dpm->finish(dpm); return retval; diff --git a/src/target/armv8_dpm.c b/src/target/armv8_dpm.c index 91b2f5171..3c941fa2d 100644 --- a/src/target/armv8_dpm.c +++ b/src/target/armv8_dpm.c @@ -258,7 +258,7 @@ static int dpmv8_exec_opcode(struct arm_dpm *dpm, if (dscr & DSCR_ERR) { LOG_ERROR("Opcode 0x%08"PRIx32", DSCR.ERR=1, DSCR.EL=%i", opcode, dpm->last_el); - armv8_dpm_handle_exception(dpm); + armv8_dpm_handle_exception(dpm, true); retval = ERROR_FAIL; } @@ -600,7 +600,7 @@ int armv8_dpm_modeswitch(struct arm_dpm *dpm, enum arm_mode mode) armv8_opcode(armv8, ARMV8_OPC_DCPS) | target_el); /* DCPS clobbers registers just like an exception taken */ - armv8_dpm_handle_exception(dpm); + armv8_dpm_handle_exception(dpm, false); } else { core_state = armv8_dpm_get_core_state(dpm); if (core_state != ARM_STATE_AARCH64) { @@ -1298,7 +1298,7 @@ void armv8_dpm_report_wfar(struct arm_dpm *dpm, uint64_t addr) * This function must not perform any actions that trigger another exception * or a recursion will happen. */ -void armv8_dpm_handle_exception(struct arm_dpm *dpm) +void armv8_dpm_handle_exception(struct arm_dpm *dpm, bool do_restore) { struct armv8_common *armv8 = dpm->arm->arch_info; struct reg_cache *cache = dpm->arm->core_cache; @@ -1344,7 +1344,8 @@ void armv8_dpm_handle_exception(struct arm_dpm *dpm) armv8_select_opcodes(armv8, core_state == ARM_STATE_AARCH64); armv8_select_reg_access(armv8, core_state == ARM_STATE_AARCH64); - armv8_dpm_modeswitch(dpm, ARM_MODE_ANY); + if (do_restore) + armv8_dpm_modeswitch(dpm, ARM_MODE_ANY); } /*----------------------------------------------------------------------*/ diff --git a/src/target/armv8_dpm.h b/src/target/armv8_dpm.h index c03935928..f40440370 100644 --- a/src/target/armv8_dpm.h +++ b/src/target/armv8_dpm.h @@ -116,7 +116,7 @@ void armv8_dpm_report_wfar(struct arm_dpm *, uint64_t wfar); #define PRCR_COREPURQ (1 << 3) void armv8_dpm_report_dscr(struct arm_dpm *dpm, uint32_t dcsr); -void armv8_dpm_handle_exception(struct arm_dpm *dpm); +void armv8_dpm_handle_exception(struct arm_dpm *dpm, bool do_restore); enum arm_state armv8_dpm_get_core_state(struct arm_dpm *dpm); #endif /* OPENOCD_TARGET_ARM_DPM_H */