helper/binarybuffer: fix clang static analyzer warnings

Writing bits to an uninitialized buffer generated false warnings.
Zero buffers before setting them by buf_set_u32|64()
(do it only if bit-by-bit copy loop is used,
zeroed buffer is not necessary if a fast path write is used)

Change-Id: I2f7f8ddb45b0cbd08d3e249534fc51f4b5cc6694
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/5383
Tested-by: jenkins
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>

16 files changed, 40 insertions, 37 deletions

diff --git a/src/flash/nor/jtagspi.c b/src/flash/nor/jtagspi.c
index a9f2dd4a..f6e311ab 100644
--- a/src/flash/nor/jtagspi.c
+++ b/src/flash/nor/jtagspi.c
@@ -59,7 +59,7 @@ static void jtagspi_set_ir(struct flash_bank *bank)
 {
 	struct jtagspi_flash_bank *info = bank->driver_priv;
 	struct scan_field field;
-	uint8_t buf[4];
+	uint8_t buf[4] = { 0 };
 
 	LOG_DEBUG("loading jtagspi ir");
 	buf_set_u32(buf, 0, info->tap->ir_length, info->ir);
diff --git a/src/helper/binarybuffer.h b/src/helper/binarybuffer.h
index 7ac221e4..3f2481d9 100644
--- a/src/helper/binarybuffer.h
+++ b/src/helper/binarybuffer.h
@@ -33,6 +33,7 @@
  * using the bits in @c value.  This routine fast-paths writes
  * of little-endian, byte-aligned, 32-bit words.
  * @param _buffer The buffer whose bits will be set.
+ *	Do not use uninitialized buffer or clang static analyzer emits a warning.
  * @param first The bit offset in @c _buffer to start writing (0-31).
  * @param num The number of bits from @c value to copy (1-32).
  * @param value Up to 32 bits that will be copied to _buffer.
@@ -62,6 +63,7 @@ static inline void buf_set_u32(uint8_t *_buffer,
  * using the bits in @c value.  This routine fast-paths writes
  * of little-endian, byte-aligned, 64-bit words.
  * @param _buffer The buffer whose bits will be set.
+ *	Do not use uninitialized buffer or clang static analyzer emits a warning.
  * @param first The bit offset in @c _buffer to start writing (0-63).
  * @param num The number of bits from @c value to copy (1-64).
  * @param value Up to 64 bits that will be copied to _buffer.
diff --git a/src/jtag/core.c b/src/jtag/core.c
index 1d59712d..c5011e52 100644
--- a/src/jtag/core.c
+++ b/src/jtag/core.c
@@ -1233,7 +1233,7 @@ static int jtag_examine_chain(void)
 	/* Add room for end-of-chain marker. */
 	max_taps++;
 
-	uint8_t *idcode_buffer = malloc(max_taps * 4);
+	uint8_t *idcode_buffer = calloc(4, max_taps);
 	if (idcode_buffer == NULL)
 		return ERROR_JTAG_INIT_FAILED;
 
diff --git a/src/jtag/tcl.c b/src/jtag/tcl.c
index ba0cb1d1..734b9c1c 100644
--- a/src/jtag/tcl.c
+++ b/src/jtag/tcl.c
@@ -1131,7 +1131,7 @@ COMMAND_HANDLER(handle_irscan_command)
 		}
 		int field_size = tap->ir_length;
 		fields[i].num_bits = field_size;
-		uint8_t *v = malloc(DIV_ROUND_UP(field_size, 8));
+		uint8_t *v = calloc(1, DIV_ROUND_UP(field_size, 8));
 
 		uint64_t value;
 		retval = parse_u64(CMD_ARGV[i * 2 + 1], &value);
diff --git a/src/target/arm_jtag.c b/src/target/arm_jtag.c
index 9b73d4ea..49aca348 100644
--- a/src/target/arm_jtag.c
+++ b/src/target/arm_jtag.c
@@ -33,7 +33,7 @@ int arm_jtag_set_instr_inner(struct jtag_tap *tap,
 		uint32_t new_instr, void *no_verify_capture, tap_state_t end_state)
 {
 	struct scan_field field;
-	uint8_t t[4];
+	uint8_t t[4] = { 0 };
 
 	field.num_bits = tap->ir_length;
 	field.out_value = t;
@@ -56,7 +56,7 @@ int arm_jtag_scann_inner(struct arm_jtag *jtag_info, uint32_t new_scan_chain, ta
 {
 	int retval = ERROR_OK;
 
-	uint8_t out_value[4];
+	uint8_t out_value[4] = { 0 };
 	buf_set_u32(out_value, 0, jtag_info->scann_size, new_scan_chain);
 	struct scan_field field = { .num_bits = jtag_info->scann_size, .out_value = out_value, };
 
diff --git a/src/target/avr32_jtag.c b/src/target/avr32_jtag.c
index c17fbe7f..6a4d4b3e 100644
--- a/src/target/avr32_jtag.c
+++ b/src/target/avr32_jtag.c
@@ -35,7 +35,7 @@ static int avr32_jtag_set_instr(struct avr32_jtag *jtag_info, int new_instr)
 	if (buf_get_u32(tap->cur_instr, 0, tap->ir_length) != (uint32_t)new_instr) {
 		do {
 			struct scan_field field;
-			uint8_t t[4];
+			uint8_t t[4] = { 0 };
 			uint8_t ret[4];
 
 			field.num_bits = tap->ir_length;
diff --git a/src/target/esirisc_jtag.c b/src/target/esirisc_jtag.c
index 333a6222..700ae3a6 100644
--- a/src/target/esirisc_jtag.c
+++ b/src/target/esirisc_jtag.c
@@ -36,7 +36,7 @@ static void esirisc_jtag_set_instr(struct esirisc_jtag *jtag_info, uint32_t new_
 
 	if (buf_get_u32(tap->cur_instr, 0, tap->ir_length) != new_instr) {
 		struct scan_field field;
-		uint8_t t[4];
+		uint8_t t[4] = { 0 };
 
 		field.num_bits = tap->ir_length;
 		field.out_value = t;
diff --git a/src/target/etb.c b/src/target/etb.c
index 392c6ad7..0c03c4db 100644
--- a/src/target/etb.c
+++ b/src/target/etb.c
@@ -176,13 +176,13 @@ static int etb_read_ram(struct etb *etb, uint32_t *data, int num_frames)
 	fields[0].in_value = NULL;
 
 	fields[1].num_bits = 7;
-	uint8_t temp1;
+	uint8_t temp1 = 0;
 	fields[1].out_value = &temp1;
 	buf_set_u32(&temp1, 0, 7, 4);
 	fields[1].in_value = NULL;
 
 	fields[2].num_bits = 1;
-	uint8_t temp2;
+	uint8_t temp2 = 0;
 	fields[2].out_value = &temp2;
 	buf_set_u32(&temp2, 0, 1, 0);
 	fields[2].in_value = NULL;
@@ -229,7 +229,7 @@ static int etb_read_reg_w_check(struct reg *reg,
 	fields[0].check_mask = NULL;
 
 	fields[1].num_bits = 7;
-	uint8_t temp1;
+	uint8_t temp1 = 0;
 	fields[1].out_value = &temp1;
 	buf_set_u32(&temp1, 0, 7, reg_addr);
 	fields[1].in_value = NULL;
@@ -237,7 +237,7 @@ static int etb_read_reg_w_check(struct reg *reg,
 	fields[1].check_mask = NULL;
 
 	fields[2].num_bits = 1;
-	uint8_t temp2;
+	uint8_t temp2 = 0;
 	fields[2].out_value = &temp2;
 	buf_set_u32(&temp2, 0, 1, 0);
 	fields[2].in_value = NULL;
@@ -310,13 +310,13 @@ static int etb_write_reg(struct reg *reg, uint32_t value)
 	fields[0].in_value = NULL;
 
 	fields[1].num_bits = 7;
-	uint8_t temp1;
+	uint8_t temp1 = 0;
 	fields[1].out_value = &temp1;
 	buf_set_u32(&temp1, 0, 7, reg_addr);
 	fields[1].in_value = NULL;
 
 	fields[2].num_bits = 1;
-	uint8_t temp2;
+	uint8_t temp2 = 0;
 	fields[2].out_value = &temp2;
 	buf_set_u32(&temp2, 0, 1, 1);
 	fields[2].in_value = NULL;
diff --git a/src/target/etm.c b/src/target/etm.c
index d1cfe61f..5218a9e4 100644
--- a/src/target/etm.c
+++ b/src/target/etm.c
@@ -533,7 +533,7 @@ static int etm_read_reg_w_check(struct reg *reg,
 	fields[0].check_mask = NULL;
 
 	fields[1].num_bits = 7;
-	uint8_t temp1;
+	uint8_t temp1 = 0;
 	fields[1].out_value = &temp1;
 	buf_set_u32(&temp1, 0, 7, reg_addr);
 	fields[1].in_value = NULL;
@@ -541,7 +541,7 @@ static int etm_read_reg_w_check(struct reg *reg,
 	fields[1].check_mask = NULL;
 
 	fields[2].num_bits = 1;
-	uint8_t temp2;
+	uint8_t temp2 = 0;
 	fields[2].out_value = &temp2;
 	buf_set_u32(&temp2, 0, 1, 0);
 	fields[2].in_value = NULL;
@@ -620,13 +620,13 @@ static int etm_write_reg(struct reg *reg, uint32_t value)
 	fields[0].in_value = NULL;
 
 	fields[1].num_bits = 7;
-	uint8_t tmp2;
+	uint8_t tmp2 = 0;
 	fields[1].out_value = &tmp2;
 	buf_set_u32(&tmp2, 0, 7, reg_addr);
 	fields[1].in_value = NULL;
 
 	fields[2].num_bits = 1;
-	uint8_t tmp3;
+	uint8_t tmp3 = 0;
 	fields[2].out_value = &tmp3;
 	buf_set_u32(&tmp3, 0, 1, 1);
 	fields[2].in_value = NULL;
diff --git a/src/target/ls1_sap.c b/src/target/ls1_sap.c
index bc46ed4d..330042f0 100644
--- a/src/target/ls1_sap.c
+++ b/src/target/ls1_sap.c
@@ -113,7 +113,7 @@ static void ls1_sap_set_instr(struct jtag_tap *tap, uint32_t new_instr)
 static void ls1_sap_set_addr_high(struct jtag_tap *tap, uint16_t addr_high)
 {
 	struct scan_field field;
-	uint8_t buf[2];
+	uint8_t buf[2] = { 0 };
 
 	ls1_sap_set_instr(tap, 0x21);
 
@@ -130,7 +130,7 @@ static void ls1_sap_memory_cmd(struct jtag_tap *tap, uint32_t address,
 			       int32_t size, bool rnw)
 {
 	struct scan_field field;
-	uint8_t cmd[8];
+	uint8_t cmd[8] = { 0 };
 
 	ls1_sap_set_instr(tap, 0x24);
 
diff --git a/src/target/mips_ejtag.c b/src/target/mips_ejtag.c
index 6d35e211..00bafd03 100644
--- a/src/target/mips_ejtag.c
+++ b/src/target/mips_ejtag.c
@@ -43,7 +43,7 @@ void mips_ejtag_set_instr(struct mips_ejtag *ejtag_info, uint32_t new_instr)
 		struct scan_field field;
 		field.num_bits = tap->ir_length;
 
-		uint8_t t[4];
+		uint8_t t[4] = { 0 };
 		field.out_value = t;
 		buf_set_u32(t, 0, field.num_bits, new_instr);
 
@@ -100,7 +100,7 @@ int mips_ejtag_drscan_64(struct mips_ejtag *ejtag_info, uint64_t *data)
 	if (tap == NULL)
 		return ERROR_FAIL;
 	struct scan_field field;
-	uint8_t t[8], r[8];
+	uint8_t t[8] = { 0 }, r[8];
 	int retval;
 
 	field.num_bits = 64;
@@ -130,7 +130,7 @@ void mips_ejtag_drscan_32_queued(struct mips_ejtag *ejtag_info, uint32_t data_ou
 	struct scan_field field;
 	field.num_bits = 32;
 
-	uint8_t scan_out[4];
+	uint8_t scan_out[4] = { 0 };
 	field.out_value = scan_out;
 	buf_set_u32(scan_out, 0, field.num_bits, data_out);
 
diff --git a/src/target/openrisc/or1k_tap_vjtag.c b/src/target/openrisc/or1k_tap_vjtag.c
index 607451a7..db10f103 100644
--- a/src/target/openrisc/or1k_tap_vjtag.c
+++ b/src/target/openrisc/or1k_tap_vjtag.c
@@ -149,7 +149,7 @@ static int or1k_tap_vjtag_init(struct or1k_jtag *jtag_info)
 	 * into the USER1 DR is sufficient to cover the most conservative case for m and n.
 	 */
 
-	uint8_t t[4];
+	uint8_t t[4] = { 0 };
 	struct scan_field field;
 	struct jtag_tap *tap = jtag_info->tap;
 
diff --git a/src/target/riscv/riscv-011.c b/src/target/riscv/riscv-011.c
index eded8624..cb7b744d 100644
--- a/src/target/riscv/riscv-011.c
+++ b/src/target/riscv/riscv-011.c
@@ -280,7 +280,7 @@ static uint32_t dtmcontrol_scan(struct target *target, uint32_t out)
 {
 	struct scan_field field;
 	uint8_t in_value[4];
-	uint8_t out_value[4];
+	uint8_t out_value[4] = { 0 };
 
 	buf_set_u32(out_value, 0, 32, out);
 
@@ -422,7 +422,7 @@ static dbus_status_t dbus_scan(struct target *target, uint16_t *address_in,
 {
 	riscv011_info_t *info = get_info(target);
 	uint8_t in[8] = {0};
-	uint8_t out[8];
+	uint8_t out[8] = {0};
 	struct scan_field field = {
 		.num_bits = info->addrbits + DBUS_OP_SIZE + DBUS_DATA_SIZE,
 		.out_value = out,
diff --git a/src/target/riscv/riscv-013.c b/src/target/riscv/riscv-013.c
index 1e5c0276..66218b76 100644
--- a/src/target/riscv/riscv-013.c
+++ b/src/target/riscv/riscv-013.c
@@ -402,7 +402,7 @@ static uint32_t dtmcontrol_scan(struct target *target, uint32_t out)
 {
 	struct scan_field field;
 	uint8_t in_value[4];
-	uint8_t out_value[4];
+	uint8_t out_value[4] = { 0 };
 
 	buf_set_u32(out_value, 0, 32, out);
 
@@ -468,6 +468,7 @@ static dmi_status_t dmi_scan(struct target *target, uint32_t *address_in,
 	}
 
 	memset(in, 0, num_bytes);
+	memset(out, 0, num_bytes);
 
 	assert(info->abits != 0);
 
diff --git a/src/target/riscv/riscv.c b/src/target/riscv/riscv.c
index 8b5a361b..1d6f6669 100644
--- a/src/target/riscv/riscv.c
+++ b/src/target/riscv/riscv.c
@@ -203,7 +203,7 @@ static uint32_t dtmcontrol_scan(struct target *target, uint32_t out)
 {
 	struct scan_field field;
 	uint8_t in_value[4];
-	uint8_t out_value[4];
+	uint8_t out_value[4] = { 0 };
 
 	buf_set_u32(out_value, 0, 32, out);
 
@@ -540,7 +540,7 @@ int riscv_add_breakpoint(struct target *target, struct breakpoint *breakpoint)
 			return ERROR_FAIL;
 		}
 
-		uint8_t buff[4];
+		uint8_t buff[4] = { 0 };
 		buf_set_u32(buff, 0, breakpoint->length * CHAR_BIT, breakpoint->length == 4 ? ebreak() : ebreak_c());
 		int const retval = target_write_memory(target, breakpoint->address, 2, breakpoint->length / 2, buff);
 
@@ -1047,7 +1047,7 @@ static int riscv_run_algorithm(struct target *target, int num_mem_params,
 
 	/* Disable Interrupts before attempting to run the algorithm. */
 	uint64_t current_mstatus;
-	uint8_t mstatus_bytes[8];
+	uint8_t mstatus_bytes[8] = { 0 };
 
 	LOG_DEBUG("Disabling Interrupts");
 	struct reg *reg_mstatus = register_get_by_name(target->reg_cache,
@@ -1103,7 +1103,7 @@ static int riscv_run_algorithm(struct target *target, int num_mem_params,
 	reg_mstatus->type->set(reg_mstatus, mstatus_bytes);
 
 	/* Restore registers */
-	uint8_t buf[8];
+	uint8_t buf[8] = { 0 };
 	buf_set_u64(buf, 0, info->xlen[0], saved_pc);
 	if (reg_pc->type->set(reg_pc, buf) != ERROR_OK)
 		return ERROR_FAIL;
diff --git a/src/target/xscale.c b/src/target/xscale.c
index 3ef8922b..e5799658 100644
--- a/src/target/xscale.c
+++ b/src/target/xscale.c
@@ -129,7 +129,7 @@ static const struct xscale_reg xscale_reg_arch_info[] = {
 /* convenience wrapper to access XScale specific registers */
 static int xscale_set_reg_u32(struct reg *reg, uint32_t value)
 {
-	uint8_t buf[4];
+	uint8_t buf[4] = { 0 };
 
 	buf_set_u32(buf, 0, 32, value);
 
@@ -154,7 +154,7 @@ static int xscale_jtag_set_instr(struct jtag_tap *tap, uint32_t new_instr, tap_s
 
 	if (buf_get_u32(tap->cur_instr, 0, tap->ir_length) != new_instr) {
 		struct scan_field field;
-		uint8_t scratch[4];
+		uint8_t scratch[4] = { 0 };
 
 		memset(&field, 0, sizeof field);
 		field.num_bits = tap->ir_length;
@@ -514,7 +514,7 @@ static int xscale_send(struct target *target, const uint8_t *buffer, int count,
 		TAP_IDLE);
 
 	static const uint8_t t0;
-	uint8_t t1[4];
+	uint8_t t1[4] = { 0 };
 	static const uint8_t t2 = 1;
 	struct scan_field fields[3] = {
 			{ .num_bits = 3, .out_value = &t0 },
@@ -645,8 +645,8 @@ static unsigned int parity(unsigned int v)
 static int xscale_load_ic(struct target *target, uint32_t va, uint32_t buffer[8])
 {
 	struct xscale_common *xscale = target_to_xscale(target);
-	uint8_t packet[4];
-	uint8_t cmd;
+	uint8_t packet[4] = { 0 };
+	uint8_t cmd = 0;
 	int word;
 	struct scan_field fields[2];
 
@@ -699,8 +699,8 @@ static int xscale_load_ic(struct target *target, uint32_t va, uint32_t buffer[8]
 static int xscale_invalidate_ic_line(struct target *target, uint32_t va)
 {
 	struct xscale_common *xscale = target_to_xscale(target);
-	uint8_t packet[4];
-	uint8_t cmd;
+	uint8_t packet[4] = { 0 };
+	uint8_t cmd = 0;
 	struct scan_field fields[2];
 
 	xscale_jtag_set_instr(target->tap,