target,flash: allow target_free_working_area on NULL area pointer

Standard C library free() allows NULL pointer as a parameter.

Change target_free_working_area() to conform this convention.

Remove NULL pointer tests before target_free_working_area() calls.

While on it add missing setting pointer to NULL after target_free_working_area().

Change-Id: I7c692ab04a9933398ba5bc614723ad0bdecb87b3
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/6712
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/flash/nor/cc26xx.c

@@ -140,8 +140,9 @@ static int cc26xx_init(struct flash_bank *bank)
 		return retval;
 
 	/* Check for working area to use for flash helper algorithm */
-	if (cc26xx_bank->working_area)
+	target_free_working_area(target, cc26xx_bank->working_area);
-		target_free_working_area(target, cc26xx_bank->working_area);
+	cc26xx_bank->working_area = NULL;
+
 	retval = target_alloc_working_area(target, cc26xx_bank->algo_working_size,
 				&cc26xx_bank->working_area);
 	if (retval != ERROR_OK)
@@ -158,6 +159,7 @@ static int cc26xx_init(struct flash_bank *bank)
 		LOG_ERROR("%s: Failed to load flash helper algorithm",
 			cc26xx_bank->family_name);
 		target_free_working_area(target, cc26xx_bank->working_area);
+		cc26xx_bank->working_area = NULL;
 		return retval;
 	}
 
@@ -172,6 +174,7 @@ static int cc26xx_init(struct flash_bank *bank)
 		LOG_ERROR("%s: Failed to start flash helper algorithm",
 			cc26xx_bank->family_name);
 		target_free_working_area(target, cc26xx_bank->working_area);
+		cc26xx_bank->working_area = NULL;
 		return retval;
 	}
 

src/flash/nor/cfi.c

@@ -1359,9 +1359,7 @@ static int cfi_intel_write_block(struct flash_bank *bank, const uint8_t *buffer,
 
 	/* free up resources */
 cleanup:
-	if (source)
+	target_free_working_area(target, source);
-		target_free_working_area(target, source);
-
 	target_free_working_area(target, write_algorithm);
 
 	destroy_reg_param(&reg_params[0]);

src/flash/nor/fespi.c

@@ -661,10 +661,8 @@ static int fespi_write(struct flash_bank *bank, const uint8_t *buffer,
 	return ERROR_OK;
 
 err:
-	if (algorithm_wa) {
+	target_free_working_area(target, data_wa);
-		target_free_working_area(target, data_wa);
+	target_free_working_area(target, algorithm_wa);
-		target_free_working_area(target, algorithm_wa);
-	}
 
 	/* Switch to HW mode before return to prompt */
 	if (fespi_enable_hw_mode(bank) != ERROR_OK)

src/flash/nor/msp432.c

@@ -335,8 +335,9 @@ static int msp432_init(struct flash_bank *bank)
 	}
 
 	/* Check for working area to use for flash helper algorithm */
-	if (msp432_bank->working_area)
+	target_free_working_area(target, msp432_bank->working_area);
-		target_free_working_area(target, msp432_bank->working_area);
+	msp432_bank->working_area = NULL;
+
 	retval = target_alloc_working_area(target, ALGO_WORKING_SIZE,
 				&msp432_bank->working_area);
 	if (retval != ERROR_OK)

src/flash/nor/npcx.c

@@ -80,10 +80,8 @@ static int npcx_init(struct flash_bank *bank)
 	struct npcx_flash_bank *npcx_bank = bank->driver_priv;
 
 	/* Check for working area to use for flash helper algorithm */
-	if (npcx_bank->working_area) {
+	target_free_working_area(target, npcx_bank->working_area);
-		target_free_working_area(target, npcx_bank->working_area);
+	npcx_bank->working_area = NULL;
-		npcx_bank->working_area = NULL;
-	}
 
 	int retval = target_alloc_working_area(target, npcx_bank->algo_working_size,
 				&npcx_bank->working_area);

src/flash/nor/psoc6.c

@@ -182,10 +182,8 @@ destroy_rp_free_wa:
 	/* Something went wrong, do some cleanup */
 	destroy_reg_param(&reg_params);
 
-	if (g_stack_area) {
+	target_free_working_area(target, g_stack_area);
-		target_free_working_area(target, g_stack_area);
+	g_stack_area = NULL;
-		g_stack_area = NULL;
-	}
 
 	return hr;
 }

src/flash/nor/sh_qspi.c

@@ -703,11 +703,14 @@ static int sh_qspi_upload_helper(struct flash_bank *bank)
 	};
 	int ret;
 
-	if (info->source)
+	target_free_working_area(target, info->source);
-		target_free_working_area(target, info->source);
+	target_free_working_area(target, info->io_algorithm);
-	if (info->io_algorithm)
-		target_free_working_area(target, info->io_algorithm);
 
+	/* FIXME: Working areas are allocated during flash probe
+	 * and eventual target_free_all_working_areas() called in case
+	 * of target reset or run is not handled at all.
+	 * Not a big problem if area backp is off.
+	 */
 	/* flash write code */
 	if (target_alloc_working_area(target, sizeof(sh_qspi_io_code),
 			&info->io_algorithm) != ERROR_OK) {

src/target/riscv/riscv-013.c

@@ -1199,10 +1199,7 @@ static int scratch_reserve(struct target *target,
 static int scratch_release(struct target *target,
 		scratch_mem_t *scratch)
 {
-	if (scratch->area)
+	return target_free_working_area(target, scratch->area);
-		return target_free_working_area(target, scratch->area);
-
-	return ERROR_OK;
 }
 
 static int scratch_read64(struct target *target, scratch_mem_t *scratch,

src/target/target.c

@@ -2148,11 +2148,10 @@ static int target_restore_working_area(struct target *target, struct working_are
 /* Restore the area's backup memory, if any, and return the area to the allocation pool */
 static int target_free_working_area_restore(struct target *target, struct working_area *area, int restore)
 {
+	if (!area || area->free)
+		return ERROR_OK;
+
 	int retval = ERROR_OK;
-
-	if (area->free)
-		return retval;
-
 	if (restore) {
 		retval = target_restore_working_area(target, area);
 		/* REVISIT: Perhaps the area should be freed even if restoring fails. */
@@ -6401,8 +6400,7 @@ next:
 out:
 	free(test_pattern);
 
-	if (wa)
+	target_free_working_area(target, wa);
-		target_free_working_area(target, wa);
 
 	/* Test writes */
 	num_bytes = test_size + 4 + 4 + 4;
@@ -6486,8 +6484,7 @@ nextw:
 
 	free(test_pattern);
 
-	if (wa)
+	target_free_working_area(target, wa);
-		target_free_working_area(target, wa);
 	return retval;
 }
 

src/target/target.h

@@ -726,6 +726,13 @@ int target_alloc_working_area(struct target *target,
  */
 int target_alloc_working_area_try(struct target *target,
 		uint32_t size, struct working_area **area);
+/**
+ * Free a working area.
+ * Restore target data if area backup is configured.
+ * @param target
+ * @param area Pointer to the area to be freed or NULL
+ * @returns ERROR_OK if successful; error code if restore failed
+ */
 int target_free_working_area(struct target *target, struct working_area *area);
 void target_free_all_working_areas(struct target *target);
 uint32_t target_get_working_area_avail(struct target *target);