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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2016-01-26 14:10:34 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2017-03-22 08:14:25 +0100
commit916cda1aa1b412d7cf2991c3af7479544942d121 (patch)
tree51e373acacf962c1635899f1567484be0baed745 /arch/s390/include/asm/thread_info.h
parentmm, swap: Remove WARN_ON_ONCE() in free_swap_slot() (diff)
downloadlinux-916cda1aa1b412d7cf2991c3af7479544942d121.tar.xz
linux-916cda1aa1b412d7cf2991c3af7479544942d121.zip
s390: add a system call for guarded storage
This adds a new system call to enable the use of guarded storage for user space processes. The system call takes two arguments, a command and pointer to a guarded storage control block: s390_guarded_storage(int command, struct gs_cb *gs_cb); The second argument is relevant only for the GS_SET_BC_CB command. The commands in detail: 0 - GS_ENABLE Enable the guarded storage facility for the current task. The initial content of the guarded storage control block will be all zeros. After the enablement the user space code can use load-guarded-storage-controls instruction (LGSC) to load an arbitrary control block. While a task is enabled the kernel will save and restore the current content of the guarded storage registers on context switch. 1 - GS_DISABLE Disables the use of the guarded storage facility for the current task. The kernel will cease to save and restore the content of the guarded storage registers, the task specific content of these registers is lost. 2 - GS_SET_BC_CB Set a broadcast guarded storage control block. This is called per thread and stores a specific guarded storage control block in the task struct of the current task. This control block will be used for the broadcast event GS_BROADCAST. 3 - GS_CLEAR_BC_CB Clears the broadcast guarded storage control block. The guarded- storage control block is removed from the task struct that was established by GS_SET_BC_CB. 4 - GS_BROADCAST Sends a broadcast to all thread siblings of the current task. Every sibling that has established a broadcast guarded storage control block will load this control block and will be enabled for guarded storage. The broadcast guarded storage control block is used up, a second broadcast without a refresh of the stored control block with GS_SET_BC_CB will not have any effect. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/thread_info.h')
-rw-r--r--arch/s390/include/asm/thread_info.h12
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index a5b54a445eb8..f36e6e2b73f0 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -54,11 +54,12 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
#define TIF_NOTIFY_RESUME 0 /* callback before returning to user */
#define TIF_SIGPENDING 1 /* signal pending */
#define TIF_NEED_RESCHED 2 /* rescheduling necessary */
-#define TIF_SYSCALL_TRACE 3 /* syscall trace active */
-#define TIF_SYSCALL_AUDIT 4 /* syscall auditing active */
-#define TIF_SECCOMP 5 /* secure computing */
-#define TIF_SYSCALL_TRACEPOINT 6 /* syscall tracepoint instrumentation */
-#define TIF_UPROBE 7 /* breakpointed or single-stepping */
+#define TIF_UPROBE 3 /* breakpointed or single-stepping */
+#define TIF_GUARDED_STORAGE 4 /* load guarded storage control block */
+#define TIF_SYSCALL_TRACE 8 /* syscall trace active */
+#define TIF_SYSCALL_AUDIT 9 /* syscall auditing active */
+#define TIF_SECCOMP 10 /* secure computing */
+#define TIF_SYSCALL_TRACEPOINT 11 /* syscall tracepoint instrumentation */
#define TIF_31BIT 16 /* 32bit process */
#define TIF_MEMDIE 17 /* is terminating due to OOM killer */
#define TIF_RESTORE_SIGMASK 18 /* restore signal mask in do_signal() */
@@ -76,5 +77,6 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
#define _TIF_UPROBE _BITUL(TIF_UPROBE)
#define _TIF_31BIT _BITUL(TIF_31BIT)
#define _TIF_SINGLE_STEP _BITUL(TIF_SINGLE_STEP)
+#define _TIF_GUARDED_STORAGE _BITUL(TIF_GUARDED_STORAGE)
#endif /* _ASM_THREAD_INFO_H */