xen: Replace zero-length array with flexible-array member

2020-03-05T15:41:58Z

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20200226212612.GA4663@embeddedor Reviewed-by: Juergen Gross Signed-off-by: Boris Ostrovsky

drivers/tpm: add xen tpmfront interface

2013-08-09T14:57:06Z

This is a complete rewrite of the Xen TPM frontend driver, taking advantage of a simplified frontend/backend interface and adding support for cancellation and timeouts. The backend for this driver is provided by a vTPM stub domain using the interface in Xen 4.3. Signed-off-by: Daniel De Graaf Acked-by: Matthew Fioravante Reviewed-by: Konrad Rzeszutek Wilk Acked-by: Peter Huewe Reviewed-by: Peter Huewe Signed-off-by: Konrad Rzeszutek Wilk

kernel/include/xen/interface/io/tpmif.h, branch linux-5.11.y

xen: Replace zero-length array with flexible-array member

drivers/tpm: add xen tpmfront interface