linux/arch/s390/include/asm/ptrace.h
Heiko Carstens 87d5986345 s390/mm: remove set_fs / rework address space handling
Remove set_fs support from s390. With doing this rework address space
handling and simplify it. As a result address spaces are now setup
like this:

CPU running in              | %cr1 ASCE | %cr7 ASCE | %cr13 ASCE
----------------------------|-----------|-----------|-----------
user space                  |  user     |  user     |  kernel
kernel, normal execution    |  kernel   |  user     |  kernel
kernel, kvm guest execution |  gmap     |  user     |  kernel

To achieve this the getcpu vdso syscall is removed in order to avoid
secondary address mode and a separate vdso address space in for user
space. The getcpu vdso syscall will be implemented differently with a
subsequent patch.

The kernel accesses user space always via secondary address space.
This happens in different ways:
- with mvcos in home space mode and directly read/write to secondary
  address space
- with mvcs/mvcp in primary space mode and copy from primary space to
  secondary space or vice versa
- with e.g. cs in secondary space mode and access secondary space

Switching translation modes happens with sacf before and after
instructions which access user space, like before.

Lazy handling of control register reloading is removed in the hope to
make everything simpler, but at the cost of making kernel entry and
exit a bit slower. That is: on kernel entry the primary asce is always
changed to contain the kernel asce, and on kernel exit the primary
asce is changed again so it contains the user asce.

In kernel mode there is only one exception to the primary asce: when
kvm guests are executed the primary asce contains the gmap asce (which
describes the guest address space). The primary asce is reset to
kernel asce whenever kvm guest execution is interrupted, so that this
doesn't has to be taken into account for any user space accesses.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23 12:01:12 +01:00

195 lines
5.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* S390 version
* Copyright IBM Corp. 1999, 2000
* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
*/
#ifndef _S390_PTRACE_H
#define _S390_PTRACE_H
#include <linux/bits.h>
#include <uapi/asm/ptrace.h>
#define PIF_SYSCALL 0 /* inside a system call */
#define PIF_PER_TRAP 1 /* deliver sigtrap on return to user */
#define PIF_SYSCALL_RESTART 2 /* restart the current system call */
#define PIF_GUEST_FAULT 3 /* indicates program check in sie64a */
#define _PIF_SYSCALL BIT(PIF_SYSCALL)
#define _PIF_PER_TRAP BIT(PIF_PER_TRAP)
#define _PIF_SYSCALL_RESTART BIT(PIF_SYSCALL_RESTART)
#define _PIF_GUEST_FAULT BIT(PIF_GUEST_FAULT)
#ifndef __ASSEMBLY__
#define PSW_KERNEL_BITS (PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_ASC_HOME | \
PSW_MASK_EA | PSW_MASK_BA)
#define PSW_USER_BITS (PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | \
PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_MCHECK | \
PSW_MASK_PSTATE | PSW_ASC_PRIMARY)
struct psw_bits {
unsigned long : 1;
unsigned long per : 1; /* PER-Mask */
unsigned long : 3;
unsigned long dat : 1; /* DAT Mode */
unsigned long io : 1; /* Input/Output Mask */
unsigned long ext : 1; /* External Mask */
unsigned long key : 4; /* PSW Key */
unsigned long : 1;
unsigned long mcheck : 1; /* Machine-Check Mask */
unsigned long wait : 1; /* Wait State */
unsigned long pstate : 1; /* Problem State */
unsigned long as : 2; /* Address Space Control */
unsigned long cc : 2; /* Condition Code */
unsigned long pm : 4; /* Program Mask */
unsigned long ri : 1; /* Runtime Instrumentation */
unsigned long : 6;
unsigned long eaba : 2; /* Addressing Mode */
unsigned long : 31;
unsigned long ia : 64; /* Instruction Address */
};
enum {
PSW_BITS_AMODE_24BIT = 0,
PSW_BITS_AMODE_31BIT = 1,
PSW_BITS_AMODE_64BIT = 3
};
enum {
PSW_BITS_AS_PRIMARY = 0,
PSW_BITS_AS_ACCREG = 1,
PSW_BITS_AS_SECONDARY = 2,
PSW_BITS_AS_HOME = 3
};
#define psw_bits(__psw) (*({ \
typecheck(psw_t, __psw); \
&(*(struct psw_bits *)(&(__psw))); \
}))
/*
* The pt_regs struct defines the way the registers are stored on
* the stack during a system call.
*/
struct pt_regs
{
union {
user_pt_regs user_regs;
struct {
unsigned long args[1];
psw_t psw;
unsigned long gprs[NUM_GPRS];
};
};
unsigned long orig_gpr2;
unsigned int int_code;
unsigned int int_parm;
unsigned long int_parm_long;
unsigned long flags;
unsigned long cr1;
};
/*
* Program event recording (PER) register set.
*/
struct per_regs {
unsigned long control; /* PER control bits */
unsigned long start; /* PER starting address */
unsigned long end; /* PER ending address */
};
/*
* PER event contains information about the cause of the last PER exception.
*/
struct per_event {
unsigned short cause; /* PER code, ATMID and AI */
unsigned long address; /* PER address */
unsigned char paid; /* PER access identification */
};
/*
* Simplified per_info structure used to decode the ptrace user space ABI.
*/
struct per_struct_kernel {
unsigned long cr9; /* PER control bits */
unsigned long cr10; /* PER starting address */
unsigned long cr11; /* PER ending address */
unsigned long bits; /* Obsolete software bits */
unsigned long starting_addr; /* User specified start address */
unsigned long ending_addr; /* User specified end address */
unsigned short perc_atmid; /* PER trap ATMID */
unsigned long address; /* PER trap instruction address */
unsigned char access_id; /* PER trap access identification */
};
#define PER_EVENT_MASK 0xEB000000UL
#define PER_EVENT_BRANCH 0x80000000UL
#define PER_EVENT_IFETCH 0x40000000UL
#define PER_EVENT_STORE 0x20000000UL
#define PER_EVENT_STORE_REAL 0x08000000UL
#define PER_EVENT_TRANSACTION_END 0x02000000UL
#define PER_EVENT_NULLIFICATION 0x01000000UL
#define PER_CONTROL_MASK 0x00e00000UL
#define PER_CONTROL_BRANCH_ADDRESS 0x00800000UL
#define PER_CONTROL_SUSPENSION 0x00400000UL
#define PER_CONTROL_ALTERATION 0x00200000UL
static inline void set_pt_regs_flag(struct pt_regs *regs, int flag)
{
regs->flags |= (1UL << flag);
}
static inline void clear_pt_regs_flag(struct pt_regs *regs, int flag)
{
regs->flags &= ~(1UL << flag);
}
static inline int test_pt_regs_flag(struct pt_regs *regs, int flag)
{
return !!(regs->flags & (1UL << flag));
}
/*
* These are defined as per linux/ptrace.h, which see.
*/
#define arch_has_single_step() (1)
#define arch_has_block_step() (1)
#define user_mode(regs) (((regs)->psw.mask & PSW_MASK_PSTATE) != 0)
#define instruction_pointer(regs) ((regs)->psw.addr)
#define user_stack_pointer(regs)((regs)->gprs[15])
#define profile_pc(regs) instruction_pointer(regs)
static inline long regs_return_value(struct pt_regs *regs)
{
return regs->gprs[2];
}
static inline void instruction_pointer_set(struct pt_regs *regs,
unsigned long val)
{
regs->psw.addr = val;
}
int regs_query_register_offset(const char *name);
const char *regs_query_register_name(unsigned int offset);
unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset);
unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n);
static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
{
return regs->gprs[15];
}
static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
{
regs->gprs[2] = rc;
}
#endif /* __ASSEMBLY__ */
#endif /* _S390_PTRACE_H */