Hello there, I'm a little late to the party. But what is necessary to get this upstreamed, and how can I help?
PS: Sorry if I picked the wrong e-mail addresses, I wasn't subscribed to the ML at that point and used the addresses I could find for the people who answered to the original thread here: https://lists.gnu.org/archive/html/qemu-devel/2017-09/msg08073.html Thanks, Oliver From: Zhuowei Zhang <address@hidden> > Linux returns success for the special case of calling write with a > zero-length NULL buffer: compiling and running > > ``` > > int main() { > ssize_t ret = write(STDOUT_FILENO, NULL, 0); > fprintf(stderr, "write returned %ld\n", ret); > return 0; > } > ``` > gives "write returned 0" when run directly, but "write returned -1" in > QEMU. > > This commit checks for this situation and returns success if found. > > Signed-off-by: Zhuowei Zhang <address@hidden> > --- > linux-user/syscall.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index 9b6364a..ecadf49 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -7783,6 +7783,11 @@ abi_long do_syscall(void *cpu_env, int num, abi_long > arg1, > } > break; > case TARGET_NR_write: > + if (arg2 == 0 && arg3 == 0) { > + /* special case: write(fd, NULL, 0) returns success. */ > + ret = 0; > + break; > + } > if (!(p = lock_user(VERIFY_READ, arg2, arg3, 1))) > goto efault; > if (fd_trans_target_to_host_data(arg1)) { > -- > 1.9.1
