On Tue, 09 May 2023 04:14:26 PDT (-0700), heiko@xxxxxxxxx wrote:
Hi,
need to poke this more, but one issue popped up at first compile.
Am Dienstag, 9. Mai 2023, 12:30:29 CEST schrieb Andy Chiu:
This patch add two riscv-specific prctls, to allow usespace control the
use of vector unit:
* PR_RISCV_V_SET_CONTROL: control the permission to use Vector at next,
or all following execve for a thread. Turning off a thread's Vector
live is not possible since libraries may have registered ifunc that
may execute Vector instructions.
* PR_RISCV_V_GET_CONTROL: get the same permission setting for the
current thread, and the setting for following execve(s).
Signed-off-by: Andy Chiu <andy.chiu@xxxxxxxxxx>
Reviewed-by: Greentime Hu <greentime.hu@xxxxxxxxxx>
Reviewed-by: Vincent Chen <vincent.chen@xxxxxxxxxx>
diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c
index 960a343799c6..16ccb35625a9 100644
--- a/arch/riscv/kernel/vector.c
+++ b/arch/riscv/kernel/vector.c
@@ -9,6 +9,7 @@
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
+#include <linux/prctl.h>
#include <asm/thread_info.h>
#include <asm/processor.h>
@@ -19,6 +20,8 @@
#include <asm/ptrace.h>
#include <asm/bug.h>
+static bool riscv_v_implicit_uacc = !IS_ENABLED(CONFIG_RISCV_V_DISABLE);
+
unsigned long riscv_v_vsize __read_mostly;
EXPORT_SYMBOL_GPL(riscv_v_vsize);
@@ -91,11 +94,51 @@ static int riscv_v_thread_zalloc(void)
return 0;
}
+#define VSTATE_CTRL_GET_CUR(x) ((x) & PR_RISCV_V_VSTATE_CTRL_CUR_MASK)
+#define VSTATE_CTRL_GET_NEXT(x) (((x) & PR_RISCV_V_VSTATE_CTRL_NEXT_MASK) >> 2)
+#define VSTATE_CTRL_MAKE_NEXT(x) (((x) << 2) & PR_RISCV_V_VSTATE_CTRL_NEXT_MASK)
+#define VSTATE_CTRL_GET_INHERIT(x) (!!((x) & PR_RISCV_V_VSTATE_CTRL_INHERIT))
+static inline int riscv_v_get_cur_ctrl(struct task_struct *tsk)
+{
+ return VSTATE_CTRL_GET_CUR(tsk->thread.vstate_ctrl);
+}
+
+static inline int riscv_v_get_next_ctrl(struct task_struct *tsk)
+{
+ return VSTATE_CTRL_GET_NEXT(tsk->thread.vstate_ctrl);
+}
+
+static inline bool riscv_v_test_ctrl_inherit(struct task_struct *tsk)
+{
+ return VSTATE_CTRL_GET_INHERIT(tsk->thread.vstate_ctrl);
+}
+
+static inline void riscv_v_set_ctrl(struct task_struct *tsk, int cur, int nxt,
+ bool inherit)
+{
+ unsigned long ctrl;
+
+ ctrl = cur & PR_RISCV_V_VSTATE_CTRL_CUR_MASK;
+ ctrl |= VSTATE_CTRL_MAKE_NEXT(nxt);
+ if (inherit)
+ ctrl |= PR_RISCV_V_VSTATE_CTRL_INHERIT;
+ tsk->thread.vstate_ctrl = ctrl;
+}
+
+bool riscv_v_user_allowed(void)
+{
+ return riscv_v_get_cur_ctrl(current) == PR_RISCV_V_VSTATE_CTRL_ON;
+}
EXPORT_SYMBOL(riscv_v_user_allowed);
kvm is allowed to be built as module, so you could end up with:
ERROR: modpost: "riscv_v_user_allowed" [arch/riscv/kvm/kvm.ko] undefined!
make[2]: *** [../scripts/Makefile.modpost:136: Module.symvers] Fehler 1
make[1]: *** [/home/devel/hstuebner/00_git-repos/linux-riscv/Makefile:1978: modpost] Fehler 2
make[1]: Verzeichnis „/home/devel/hstuebner/00_git-repos/linux-riscv/_build-riscv64“ wird verlassen
make: *** [Makefile:226: __sub-make] Fehler 2
and presumably that means that "make allmodconfig" hasn't been run,
which might shake out some more issues.
Heiko
