target/breakpoints.c: add breakpoint intersection detection

Modify the breakpoint insertion logic to include intersection detection
between breakpoints.

Change-Id: I294bea83b18335c2f304ddd99361872eadaaa684
Signed-off-by: Kulyatskaya Alexandra <a.kulyatskaya@syntacore.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/9146
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/helper/util.c

@@ -40,3 +40,26 @@ int util_init(struct command_context *cmd_ctx)
 {
 	return register_commands(cmd_ctx, NULL, util_command_handlers);
 }
+
+bool is_memory_regions_overlap(target_addr_t start1,
+	unsigned int size1,
+	target_addr_t start2,
+	unsigned int  size2)
+{
+	/* Two memory regions: [S1,E1] and [S2,E2] where:
+	 * E1 = S1 + size1 - 1, E2 = S2 + size2 - 1
+	 *
+	 * After normalization:
+	 *  Region 1: [0, size1 - 1]
+	 *  Region 2: [start2 - start1, (start2 - start1) + size2 - 1]
+	 *
+	 * Intersection cases:
+	 *  1. Normalized region 2 wraps around 0 (unsigned overflow)
+	 *  2. Start of normalized region 2 is within region 1
+	 */
+	start2 -= start1;
+	target_addr_t end1 = size1 - 1;
+	target_addr_t end2 = start2 + size2 - 1;
+
+	return start2 > end2 || start2 <= end1;
+}

src/helper/util.h

@@ -10,5 +10,7 @@
 struct command_context;
 
 int util_init(struct command_context *cmd_ctx);
+bool is_memory_regions_overlap(target_addr_t start1, unsigned int size1,
+		target_addr_t start2, unsigned int size2);
 
 #endif /* OPENOCD_HELPER_UTIL_H */

src/target/breakpoints.c

@@ -16,6 +16,7 @@
 #include <helper/log.h>
 #include "breakpoints.h"
 #include "smp.h"
+#include "helper/util.h"
 
 enum breakpoint_watchpoint {
 	BREAKPOINT,
@@ -56,6 +57,13 @@ static int breakpoint_add_internal(struct target *target,
 				address, breakpoint->unique_id);
 			return ERROR_TARGET_DUPLICATE_BREAKPOINT;
 		}
+		if (type == BKPT_SOFT &&
+				is_memory_regions_overlap(address, length, breakpoint->address, breakpoint->length)) {
+			LOG_TARGET_ERROR(target, "Breakpoint intersects with another one at " TARGET_ADDR_FMT
+				" of length %u (BP %" PRIu32 ")", breakpoint->address,
+				breakpoint->length, breakpoint->unique_id);
+			return ERROR_TARGET_INTERSECT_BREAKPOINT;
+		}
 		breakpoint_p = &breakpoint->next;
 		breakpoint = breakpoint->next;
 	}

src/target/target.h

@@ -796,6 +796,7 @@ int target_profiling_default(struct target *target, uint32_t *samples, uint32_t
 #define ERROR_TARGET_SIZE_NOT_SUPPORTED  (-314)
 #define ERROR_TARGET_PACKING_NOT_SUPPORTED  (-315)
 #define ERROR_TARGET_HALTED_DO_RESUME  (-316)	/* used to workaround incorrect debug halt */
+#define ERROR_TARGET_INTERSECT_BREAKPOINT (-317)
 
 extern bool get_target_reset_nag(void);