[PATCH v2 1/9] hw/usb/redirect.c: Stop using qemu_oom_check()

[Peter Maydell]

qemu_oom_check() is a function which essentially says "if you pass me
a NULL pointer then print a message then abort()".  On POSIX systems
the message includes strerror(errno); on Windows it includes the
GetLastError() error value printed as an integer.

Other than in the implementation of qemu_memalign(), we use this
function only in hw/usb/redirect.c, for three checks:

 * on a call to usbredirparser_create()
 * on a call to usberedirparser_serialize()
 * on a call to malloc()

The usbredir library API functions make no guarantees that they will
set errno on errors, let alone that they might set the
Windows-specific GetLastError string.  malloc() is documented as
setting errno, not GetLastError -- and in any case the only thing it
might set errno to is ENOMEM.  So qemu_oom_check() isn't the right
thing for any of these.  Replace them with straightforward
error-checking code.  This will allow us to get rid of
qemu_oom_check().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20220226180723.1706285-2-peter.maydell@linaro.org
---
 hw/usb/redirect.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c
index 5f0ef9cb3b0..8692ea25610 100644
--- a/hw/usb/redirect.c
+++ b/hw/usb/redirect.c
@@ -1239,7 +1239,11 @@ static void usbredir_create_parser(USBRedirDevice *dev)
 
     DPRINTF("creating usbredirparser\n");
 
-    dev->parser = qemu_oom_check(usbredirparser_create());
+    dev->parser = usbredirparser_create();
+    if (!dev->parser) {
+        error_report("usbredirparser_create() failed");
+        exit(1);
+    }
     dev->parser->priv = dev;
     dev->parser->log_func = usbredir_log;
     dev->parser->read_func = usbredir_read;
@@ -2239,7 +2243,10 @@ static int usbredir_put_parser(QEMUFile *f, void *priv, 
size_t unused,
     }
 
     usbredirparser_serialize(dev->parser, &data, &len);
-    qemu_oom_check(data);
+    if (!data) {
+        error_report("usbredirparser_serialize failed");
+        exit(1);
+    }
 
     qemu_put_be32(f, len);
     qemu_put_buffer(f, data, len);
@@ -2330,7 +2337,11 @@ static int usbredir_get_bufpq(QEMUFile *f, void *priv, 
size_t unused,
         bufp->len = qemu_get_be32(f);
         bufp->status = qemu_get_be32(f);
         bufp->offset = 0;
-        bufp->data = qemu_oom_check(malloc(bufp->len)); /* regular malloc! */
+        bufp->data = malloc(bufp->len); /* regular malloc! */
+        if (!bufp->data) {
+            error_report("usbredir_get_bufpq: out of memory");
+            exit(1);
+        }
         bufp->free_on_destroy = bufp->data;
         qemu_get_buffer(f, bufp->data, bufp->len);
         QTAILQ_INSERT_TAIL(&endp->bufpq, bufp, next);
-- 
2.25.1