target/arm/arm-semi: Don't let the guest close stdin/stdout/stderr
The guest can use the semihosting API to open a handle
corresponding to QEMU's own stdin, stdout, or stderr.
When the guest closes this handle, we should not
close the underlying host stdin/stdout/stderr
the way we would do if the handle corresponded to
a host fd we'd opened on behalf of the guest in SYS_OPEN.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200124172954.28481-1-peter.maydell@linaro.org
diff --git a/target/arm/arm-semi.c b/target/arm/arm-semi.c
index 788fe61..8718fd0 100644
--- a/target/arm/arm-semi.c
+++ b/target/arm/arm-semi.c
@@ -403,6 +403,15 @@
{
CPUARMState *env = &cpu->env;
+ /*
+ * Only close the underlying host fd if it's one we opened on behalf
+ * of the guest in SYS_OPEN.
+ */
+ if (gf->hostfd == STDIN_FILENO ||
+ gf->hostfd == STDOUT_FILENO ||
+ gf->hostfd == STDERR_FILENO) {
+ return 0;
+ }
return set_swi_errno(env, close(gf->hostfd));
}
