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Deal with halt race. (#664) 

* Deal with halt race.

What could happen:
1. hart 1 halts due to a breakpoint
2. OpenOCD polls and notices hart 1 has halted.
3. hart 0 halts because it is in a halt group with halt 1
4. OpenOCD decides to halt hart 0 also.
5. OpenOCD discovers hart 0 is already halted, and doesn't update the
debug reason.

In that case OpenOCD would tell gdb that hart 0 halted, while the
interesting event is that hart 1 halted.

Fix this by updating the debug reason when we discover a hart is already
halted when we try to halt it.

This race was exposed in the Sv* address translation tests, but the bug
has nothing to do with address translation.

Change-Id: I59d871e8545bd644bf42581266f15234b93e9900
Signed-off-by: Tim Newsome <tim@sifive.com>

* Comment set_debug_reason

Co-authored-by: Jan Matyas <50193733+JanMatCodasip@users.noreply.github.com>

Co-authored-by: Jan Matyas <50193733+JanMatCodasip@users.noreply.github.com>
This commit is contained in:
Tim Newsome 2021-11-24 10:20:15 -08:00 committed by GitHub
parent f4f8b59f62
commit 0b965363a6
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 35 additions and 27 deletions
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62
src/target/riscv/riscv.c
View File

@ -1189,6 +1189,34 @@ int riscv_flush_registers(struct target *target)
return ERROR_OK; return ERROR_OK;
} }
/* Convert: RISC-V hart's halt reason --> OpenOCD's generic debug reason */
int set_debug_reason(struct target *target, enum riscv_halt_reason halt_reason)
{
switch (halt_reason) {
case RISCV_HALT_BREAKPOINT:
target->debug_reason = DBG_REASON_BREAKPOINT;
break;
case RISCV_HALT_TRIGGER:
target->debug_reason = DBG_REASON_WATCHPOINT;
break;
case RISCV_HALT_INTERRUPT:
case RISCV_HALT_GROUP:
target->debug_reason = DBG_REASON_DBGRQ;
break;
case RISCV_HALT_SINGLESTEP:
target->debug_reason = DBG_REASON_SINGLESTEP;
break;
case RISCV_HALT_UNKNOWN:
target->debug_reason = DBG_REASON_UNDEFINED;
break;
case RISCV_HALT_ERROR:
return ERROR_FAIL;
}
LOG_DEBUG("[%s] debug_reason=%d", target_name(target), target->debug_reason);
return ERROR_OK;
}
int halt_prep(struct target *target) int halt_prep(struct target *target)
{ {
RISCV_INFO(r); RISCV_INFO(r);
@ -1198,8 +1226,14 @@ int halt_prep(struct target *target)
if (riscv_select_current_hart(target) != ERROR_OK) if (riscv_select_current_hart(target) != ERROR_OK)
return ERROR_FAIL; return ERROR_FAIL;
if (riscv_is_halted(target)) { if (riscv_is_halted(target)) {
LOG_DEBUG("[%s] Hart is already halted (reason=%d).", LOG_DEBUG("[%s] Hart is already halted (debug_reason=%d).",
target_name(target), target->debug_reason); target_name(target), target->debug_reason);
if (target->debug_reason == DBG_REASON_NOTHALTED) {
enum riscv_halt_reason halt_reason =
riscv_halt_reason(target, r->current_hartid);
if (set_debug_reason(target, halt_reason) != ERROR_OK)
return ERROR_FAIL;
}
} else { } else {
if (r->halt_prep(target) != ERROR_OK) if (r->halt_prep(target) != ERROR_OK)
return ERROR_FAIL; return ERROR_FAIL;
@ -2153,32 +2187,6 @@ static enum riscv_poll_hart riscv_poll_hart(struct target *target, int hartid)
return RPH_NO_CHANGE; return RPH_NO_CHANGE;
} }
int set_debug_reason(struct target *target, enum riscv_halt_reason halt_reason)
{
switch (halt_reason) {
case RISCV_HALT_BREAKPOINT:
target->debug_reason = DBG_REASON_BREAKPOINT;
break;
case RISCV_HALT_TRIGGER:
target->debug_reason = DBG_REASON_WATCHPOINT;
break;
case RISCV_HALT_INTERRUPT:
case RISCV_HALT_GROUP:
target->debug_reason = DBG_REASON_DBGRQ;
break;
case RISCV_HALT_SINGLESTEP:
target->debug_reason = DBG_REASON_SINGLESTEP;
break;
case RISCV_HALT_UNKNOWN:
target->debug_reason = DBG_REASON_UNDEFINED;
break;
case RISCV_HALT_ERROR:
return ERROR_FAIL;
}
LOG_DEBUG("[%s] debug_reason=%d", target_name(target), target->debug_reason);
return ERROR_OK;
}
int sample_memory(struct target *target) int sample_memory(struct target *target)
{ {
RISCV_INFO(r); RISCV_INFO(r);