hw/i2c/bitbang_i2c: Use in-place rather than malloc'd bitbang_i2c_interface struct

Currently the bitbang_i2c_init() function allocates a
bitbang_i2c_interface struct which it returns.  This is unfortunate
because it means that if the function is used from a DeviceState
init method then the memory will be leaked by an "init then delete"
cycle, as used by the qmp/hmp commands that list device properties.

Since three out of four of the uses of this function are in
device init methods, switch the function to do an in-place
initialization of a struct that can be embedded in the
device state struct of the caller.

This fixes LeakSanitizer leak warnings that have appeared in the
patchew configuration (which only tries to run the sanitizers
for the x86_64-softmmu target) now that we use the bitbang-i2c
code in an x86-64 config.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: BALATON Zoltan <balaton@eik.bme.hu>
Tested-by: BALATON Zoltan <balaton@eik.bme.hu>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190702163844.20458-1-peter.maydell@linaro.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 4 insertions, 43 deletions

diff --git a/hw/i2c/bitbang_i2c.c b/hw/i2c/bitbang_i2c.c
index 3cb0509b02..60c7a9be0b 100644
--- a/hw/i2c/bitbang_i2c.c
+++ b/hw/i2c/bitbang_i2c.c
@@ -25,39 +25,6 @@ do { printf("bitbang_i2c: " fmt , ## __VA_ARGS__); } while (0)
 #define DPRINTF(fmt, ...) do {} while(0)
 #endif
 
-typedef enum bitbang_i2c_state {
-    STOPPED = 0,
-    SENDING_BIT7,
-    SENDING_BIT6,
-    SENDING_BIT5,
-    SENDING_BIT4,
-    SENDING_BIT3,
-    SENDING_BIT2,
-    SENDING_BIT1,
-    SENDING_BIT0,
-    WAITING_FOR_ACK,
-    RECEIVING_BIT7,
-    RECEIVING_BIT6,
-    RECEIVING_BIT5,
-    RECEIVING_BIT4,
-    RECEIVING_BIT3,
-    RECEIVING_BIT2,
-    RECEIVING_BIT1,
-    RECEIVING_BIT0,
-    SENDING_ACK,
-    SENT_NACK
-} bitbang_i2c_state;
-
-struct bitbang_i2c_interface {
-    I2CBus *bus;
-    bitbang_i2c_state state;
-    int last_data;
-    int last_clock;
-    int device_out;
-    uint8_t buffer;
-    int current_addr;
-};
-
 static void bitbang_i2c_enter_stop(bitbang_i2c_interface *i2c)
 {
     DPRINTF("STOP\n");
@@ -184,18 +151,12 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level)
     abort();
 }
 
-bitbang_i2c_interface *bitbang_i2c_init(I2CBus *bus)
+void bitbang_i2c_init(bitbang_i2c_interface *s, I2CBus *bus)
 {
-    bitbang_i2c_interface *s;
-
-    s = g_malloc0(sizeof(bitbang_i2c_interface));
-
     s->bus = bus;
     s->last_data = 1;
     s->last_clock = 1;
     s->device_out = 1;
-
-    return s;
 }
 
 /* GPIO interface.  */
@@ -207,7 +168,7 @@ typedef struct GPIOI2CState {
     SysBusDevice parent_obj;
 
     MemoryRegion dummy_iomem;
-    bitbang_i2c_interface *bitbang;
+    bitbang_i2c_interface bitbang;
     int last_level;
     qemu_irq out;
 } GPIOI2CState;
@@ -216,7 +177,7 @@ static void bitbang_i2c_gpio_set(void *opaque, int irq, int level)
 {
     GPIOI2CState *s = opaque;
 
-    level = bitbang_i2c_set(s->bitbang, irq, level);
+    level = bitbang_i2c_set(&s->bitbang, irq, level);
     if (level != s->last_level) {
         s->last_level = level;
         qemu_set_irq(s->out, level);
@@ -234,7 +195,7 @@ static void gpio_i2c_init(Object *obj)
     sysbus_init_mmio(sbd, &s->dummy_iomem);
 
     bus = i2c_init_bus(dev, "i2c");
-    s->bitbang = bitbang_i2c_init(bus);
+    bitbang_i2c_init(&s->bitbang, bus);
 
     qdev_init_gpio_in(dev, bitbang_i2c_gpio_set, 2);
     qdev_init_gpio_out(dev, &s->out, 1);