diff options
Diffstat (limited to 'qemu_tracing/qemu_tracing.c')
-rw-r--r-- | qemu_tracing/qemu_tracing.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/qemu_tracing/qemu_tracing.c b/qemu_tracing/qemu_tracing.c new file mode 100644 index 00000000..aacd1aa0 --- /dev/null +++ b/qemu_tracing/qemu_tracing.c @@ -0,0 +1,71 @@ +#include <stdio.h> +#include <string.h> +#include <errno.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <fcntl.h> +#include <unistd.h> + +// This is the pathname to the sysfs file that enables and disables +// tracing on the qemu emulator. +#define SYS_QEMU_TRACE_STATE "/sys/qemu_trace/state" + + +// This is the pathname to the sysfs file that adds new (address, symbol) +// pairs to the trace. +#define SYS_QEMU_TRACE_SYMBOL "/sys/qemu_trace/symbol" + +// The maximum length of a symbol name +#define MAX_SYMBOL_NAME_LENGTH (4 * 1024) + +// Allow space in the buffer for the address plus whitespace. +#define MAX_BUF_SIZE (MAX_SYMBOL_NAME_LENGTH + 20) + +// return 0 on success, or an error if the qemu driver cannot be opened +int qemu_start_tracing() +{ + int fd = open(SYS_QEMU_TRACE_STATE, O_WRONLY); + if (fd < 0) + return fd; + write(fd, "1\n", 2); + close(fd); + return 0; +} + +int qemu_stop_tracing() +{ + int fd = open(SYS_QEMU_TRACE_STATE, O_WRONLY); + if (fd < 0) + return fd; + write(fd, "0\n", 2); + close(fd); + return 0; +} + +int qemu_add_mapping(unsigned int addr, const char *name) +{ + char buf[MAX_BUF_SIZE]; + + if (strlen(name) > MAX_SYMBOL_NAME_LENGTH) + return EINVAL; + int fd = open(SYS_QEMU_TRACE_SYMBOL, O_WRONLY); + if (fd < 0) + return fd; + sprintf(buf, "%x %s\n", addr, name); + write(fd, buf, strlen(buf)); + close(fd); + return 0; +} + +int qemu_remove_mapping(unsigned int addr) +{ + char buf[MAX_BUF_SIZE]; + + int fd = open(SYS_QEMU_TRACE_SYMBOL, O_WRONLY); + if (fd < 0) + return fd; + sprintf(buf, "%x\n", addr); + write(fd, buf, strlen(buf)); + close(fd); + return 0; +} |