drivers/bcm2835gpio: Release resources on error and when quitting

The /dev/mem file descriptor can be closed without invalidating the
mappings so close as soon as possible.

munmap() all memory, either on error or from quit.

Signed-off-by: Steve Marple <stevemarple@googlemail.com>
Change-Id: I2b6a8365f554e332520fa77ccf076188083a932f
Reviewed-on: https://review.openocd.org/c/openocd/+/7122
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

diff --git a/src/jtag/drivers/bcm2835gpio.c b/src/jtag/drivers/bcm2835gpio.c
index 11d9a8020ce7e953a03b9662e98c7ab7a4b50ae7..0bbbc6fced2f5d75f80d0f9b12697a4f92d3e0b9 100644 (file)
--- a/src/jtag/drivers/bcm2835gpio.c
+++ b/src/jtag/drivers/bcm2835gpio.c
@@ -37,7 +37,8 @@ uint32_t bcm2835_peri_base = 0x20000000;
 #define GPIO_LEV (*(pio_base+13)) /* current level of the pin */
 
 static int dev_mem_fd;
-static volatile uint32_t *pio_base;
+static volatile uint32_t *pio_base = MAP_FAILED;
+static volatile uint32_t *pads_base = MAP_FAILED;
 
 static bb_value_t bcm2835gpio_read(void);
 static int bcm2835gpio_write(int tck, int tms, int tdi);
@@ -479,6 +480,19 @@ static bool bcm2835gpio_swd_mode_possible(void)
        return 1;
 }
 
+static void bcm2835gpio_munmap(void)
+{
+       if (pio_base != MAP_FAILED) {
+               munmap((void *)pio_base, sysconf(_SC_PAGE_SIZE));
+               pio_base = MAP_FAILED;
+       }
+
+       if (pads_base != MAP_FAILED) {
+               munmap((void *)pads_base, sysconf(_SC_PAGE_SIZE));
+               pads_base = MAP_FAILED;
+       }
+}
+
 static int bcm2835gpio_init(void)
 {
        bitbang_interface = &bcm2835gpio_bitbang;
@@ -514,16 +528,18 @@ static int bcm2835gpio_init(void)
                return ERROR_JTAG_INIT_FAILED;
        }
 
-       static volatile uint32_t *pads_base;
        pads_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
                                MAP_SHARED, dev_mem_fd, BCM2835_PADS_GPIO_0_27);
 
        if (pads_base == MAP_FAILED) {
                LOG_ERROR("mmap: %s", strerror(errno));
+               bcm2835gpio_munmap();
                close(dev_mem_fd);
                return ERROR_JTAG_INIT_FAILED;
        }
 
+       close(dev_mem_fd);
+
        /* set 4mA drive strength, slew rate limited, hysteresis on */
        pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1;
 
@@ -605,5 +621,7 @@ static int bcm2835gpio_quit(void)
        if (is_gpio_valid(swdio_dir_gpio))
                SET_MODE_GPIO(swdio_dir_gpio, swdio_dir_gpio_mode);
 
+       bcm2835gpio_munmap();
+
        return ERROR_OK;
 }