The documentation says the write should return the number of bytes not written on an error (0 means everything was written). Read provides a buffer length and the return value should be the buffer length - bytes actually read. Remove the incorrect FIXME's and return the correct values.
Signed-off-by: Alex Bennée <alex.ben...@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com> diff --git a/target/arm/arm-semi.c b/target/arm/arm-semi.c index 86e6ec48c2f..53e807ab721 100644 --- a/target/arm/arm-semi.c +++ b/target/arm/arm-semi.c @@ -331,13 +331,15 @@ target_ulong do_arm_semihosting(CPUARMState *env) } else { s = lock_user(VERIFY_READ, arg1, len, 1); if (!s) { - /* FIXME - should this error code be -TARGET_EFAULT ? */ - return (uint32_t)-1; + /* Return bytes not written on error */ + return len; } ret = set_swi_errno(ts, write(arg0, s, len)); unlock_user(s, arg1, 0); - if (ret == (uint32_t)-1) - return -1; + if (ret == (uint32_t)-1) { + ret = 0; + } + /* Return bytes not written */ return len - ret; } case TARGET_SYS_READ: @@ -352,15 +354,17 @@ target_ulong do_arm_semihosting(CPUARMState *env) } else { s = lock_user(VERIFY_WRITE, arg1, len, 0); if (!s) { - /* FIXME - should this error code be -TARGET_EFAULT ? */ - return (uint32_t)-1; + /* return bytes not read */ + return len; } do { ret = set_swi_errno(ts, read(arg0, s, len)); } while (ret == -1 && errno == EINTR); unlock_user(s, arg1, len); - if (ret == (uint32_t)-1) - return -1; + if (ret == (uint32_t)-1) { + ret = 0; + } + /* Return bytes not read */ return len - ret; } case TARGET_SYS_READC: -- 2.20.1