[PATCH]: ab9102d3ae target: aarch64: access reg ELR_EL3 only in EL3

[gerrit]

This is an automated email from Gerrit.

"Antonio Borneo <borneo.anto...@gmail.com>" just uploaded a new patch set to 
Gerrit, which you can find at https://review.openocd.org/c/openocd/+/8268

-- gerrit

commit ab9102d3ae3379846e23ab86012322f959a0d2b7
Author: Antonio Borneo <borneo.anto...@gmail.com>
Date:   Mon May 13 18:19:55 2024 +0200

    target: aarch64: access reg ELR_EL3 only in EL3
    
    The register ELR_EL3 is accessible and it's content is relevant
    only when the target is in EL3.
    
    Without this patch, an error:
            Error: Opcode 0xd53e4020, DSCR.ERR=1, DSCR.EL=1
    is triggered by GDB register window or through GDB command
            x/p $ELR_EL3
    or through OpenOCD command
            reg ELR_EL3
    
    Detect the EL and return error if the register cannot be accessed.
    
    Change-Id: I545abb196e5c34e462c7e5d5d3ec952e588642da
    Signed-off-by: Antonio Borneo <borneo.anto...@gmail.com>

diff --git a/src/target/armv8.c b/src/target/armv8.c
index 8d97902f55..e36e2f6f41 100644
--- a/src/target/armv8.c
+++ b/src/target/armv8.c
@@ -278,6 +278,7 @@ static int armv8_get_pauth_mask(struct armv8_common *armv8, 
uint64_t *mask)
 static int armv8_read_reg(struct armv8_common *armv8, int regnum, uint64_t 
*regval)
 {
        struct arm_dpm *dpm = &armv8->dpm;
+       unsigned int curel = armv8_curel_from_core_mode(dpm->arm->core_mode);
        int retval;
        uint32_t value;
        uint64_t value_64;
@@ -322,6 +323,11 @@ static int armv8_read_reg(struct armv8_common *armv8, int 
regnum, uint64_t *regv
                                ARMV8_MRS(SYSTEM_ELR_EL2, 0), &value_64);
                break;
        case ARMV8_ELR_EL3:
+               if (curel < SYSTEM_CUREL_EL3) {
+                       LOG_DEBUG("ELR_EL3 not accessible in EL%u", curel);
+                       retval = ERROR_FAIL;
+                       break;
+               }
                retval = dpm->instr_read_data_r0_64(dpm,
                                ARMV8_MRS(SYSTEM_ELR_EL3, 0), &value_64);
                break;
@@ -396,6 +402,7 @@ static int armv8_read_reg_simdfp_aarch64(struct 
armv8_common *armv8, int regnum,
 static int armv8_write_reg(struct armv8_common *armv8, int regnum, uint64_t 
value_64)
 {
        struct arm_dpm *dpm = &armv8->dpm;
+       unsigned int curel = armv8_curel_from_core_mode(dpm->arm->core_mode);
        int retval;
        uint32_t value;
 
@@ -443,6 +450,11 @@ static int armv8_write_reg(struct armv8_common *armv8, int 
regnum, uint64_t valu
                                ARMV8_MSR_GP(SYSTEM_ELR_EL2, 0), value_64);
                break;
        case ARMV8_ELR_EL3:
+               if (curel < SYSTEM_CUREL_EL3) {
+                       LOG_DEBUG("ELR_EL3 not accessible in EL%u", curel);
+                       retval = ERROR_FAIL;
+                       break;
+               }
                retval = dpm->instr_write_data_r0_64(dpm,
                                ARMV8_MSR_GP(SYSTEM_ELR_EL3, 0), value_64);
                break;

--