linux/arch/s390/include/asm/thread_info.h
Martin Schwidefsky 916cda1aa1 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>
2017-03-22 08:14:25 +01:00

83 lines
2.7 KiB
C

/*
* S390 version
* Copyright IBM Corp. 2002, 2006
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
*/
#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H
#include <linux/const.h>
/*
* Size of kernel stack for each process
*/
#define THREAD_SIZE_ORDER 2
#define ASYNC_ORDER 2
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
#define ASYNC_SIZE (PAGE_SIZE << ASYNC_ORDER)
#ifndef __ASSEMBLY__
#include <asm/lowcore.h>
#include <asm/page.h>
#include <asm/processor.h>
/*
* low level task data that entry.S needs immediate access to
* - this struct should fit entirely inside of one cache line
* - this struct shares the supervisor stack pages
* - if the contents of this structure are changed, the assembly constants must also be changed
*/
struct thread_info {
unsigned long flags; /* low level flags */
};
/*
* macros/functions for gaining access to the thread information structure
*/
#define INIT_THREAD_INFO(tsk) \
{ \
.flags = 0, \
}
#define init_stack (init_thread_union.stack)
void arch_release_task_struct(struct task_struct *tsk);
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
#endif
/*
* thread information flags bit numbers
*/
#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_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() */
#define TIF_SINGLE_STEP 19 /* This task is single stepped */
#define TIF_BLOCK_STEP 20 /* This task is block stepped */
#define TIF_UPROBE_SINGLESTEP 21 /* This task is uprobe single stepped */
#define _TIF_NOTIFY_RESUME _BITUL(TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING _BITUL(TIF_SIGPENDING)
#define _TIF_NEED_RESCHED _BITUL(TIF_NEED_RESCHED)
#define _TIF_SYSCALL_TRACE _BITUL(TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT _BITUL(TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP _BITUL(TIF_SECCOMP)
#define _TIF_SYSCALL_TRACEPOINT _BITUL(TIF_SYSCALL_TRACEPOINT)
#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 */