linux/include/asm-ia64/thread_info.h
Petr Tesarik 3b2ce0b178 [IA64] Synchronize kernel RSE to user-space and back
This is base kernel patch for ptrace RSE bug. It's basically a backport
from the utrace RSE patch I sent out several weeks ago. please review.

when a thread is stopped (ptraced), debugger might change thread's user
stack (change memory directly), and we must avoid the RSE stored in
kernel to override user stack (user space's RSE is newer than kernel's
in the case). To workaround the issue, we copy kernel RSE to user RSE
before the task is stopped, so user RSE has updated data.  we then copy
user RSE to kernel after the task is resummed from traced stop and
kernel will use the newer RSE to return to user.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
CC: Roland McGrath <roland@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-02-08 12:01:18 -08:00

125 lines
4.8 KiB
C

/*
* Copyright (C) 2002-2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*/
#ifndef _ASM_IA64_THREAD_INFO_H
#define _ASM_IA64_THREAD_INFO_H
#ifndef ASM_OFFSETS_C
#include <asm/asm-offsets.h>
#endif
#include <asm/processor.h>
#include <asm/ptrace.h>
#define PREEMPT_ACTIVE_BIT 30
#define PREEMPT_ACTIVE (1 << PREEMPT_ACTIVE_BIT)
#ifndef __ASSEMBLY__
/*
* On IA-64, we want to keep the task structure and kernel stack together, so they can be
* mapped by a single TLB entry and so they can be addressed by the "current" pointer
* without having to do pointer masking.
*/
struct thread_info {
struct task_struct *task; /* XXX not really needed, except for dup_task_struct() */
struct exec_domain *exec_domain;/* execution domain */
__u32 flags; /* thread_info flags (see TIF_*) */
__u32 cpu; /* current CPU */
__u32 last_cpu; /* Last CPU thread ran on */
__u32 status; /* Thread synchronous flags */
mm_segment_t addr_limit; /* user-level address space limit */
int preempt_count; /* 0=premptable, <0=BUG; will also serve as bh-counter */
struct restart_block restart_block;
};
#define THREAD_SIZE KERNEL_STACK_SIZE
#define INIT_THREAD_INFO(tsk) \
{ \
.task = &tsk, \
.exec_domain = &default_exec_domain, \
.flags = 0, \
.cpu = 0, \
.addr_limit = KERNEL_DS, \
.preempt_count = 0, \
.restart_block = { \
.fn = do_no_restart_syscall, \
}, \
}
#ifndef ASM_OFFSETS_C
/* how to get the thread information struct from C */
#define current_thread_info() ((struct thread_info *) ((char *) current + IA64_TASK_SIZE))
#define alloc_thread_info(tsk) ((struct thread_info *) ((char *) (tsk) + IA64_TASK_SIZE))
#define task_thread_info(tsk) ((struct thread_info *) ((char *) (tsk) + IA64_TASK_SIZE))
#else
#define current_thread_info() ((struct thread_info *) 0)
#define alloc_thread_info(tsk) ((struct thread_info *) 0)
#define task_thread_info(tsk) ((struct thread_info *) 0)
#endif
#define free_thread_info(ti) /* nothing */
#define task_stack_page(tsk) ((void *)(tsk))
#define __HAVE_THREAD_FUNCTIONS
#define setup_thread_stack(p, org) \
*task_thread_info(p) = *task_thread_info(org); \
task_thread_info(p)->task = (p);
#define end_of_stack(p) (unsigned long *)((void *)(p) + IA64_RBS_OFFSET)
#define __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
#define alloc_task_struct() ((struct task_struct *)__get_free_pages(GFP_KERNEL | __GFP_COMP, KERNEL_STACK_SIZE_ORDER))
#define free_task_struct(tsk) free_pages((unsigned long) (tsk), KERNEL_STACK_SIZE_ORDER)
#define tsk_set_notify_resume(tsk) \
set_ti_thread_flag(task_thread_info(tsk), TIF_NOTIFY_RESUME)
extern void tsk_clear_notify_resume(struct task_struct *tsk);
#endif /* !__ASSEMBLY */
/*
* thread information flags
* - these are process state flags that various assembly files may need to access
* - pending work-to-be-done flags are in least-significant 16 bits, other flags
* in top 16 bits
*/
#define TIF_SIGPENDING 0 /* signal pending */
#define TIF_NEED_RESCHED 1 /* rescheduling necessary */
#define TIF_SYSCALL_TRACE 2 /* syscall trace active */
#define TIF_SYSCALL_AUDIT 3 /* syscall auditing active */
#define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */
#define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */
#define TIF_NOTIFY_RESUME 6 /* resumption notification requested */
#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 17
#define TIF_MCA_INIT 18 /* this task is processing MCA or INIT */
#define TIF_DB_DISABLED 19 /* debug trap disabled for fsyscall */
#define TIF_FREEZE 20 /* is freezing for suspend */
#define TIF_RESTORE_RSE 21 /* user RBS is newer than kernel RBS */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
#define _TIF_SYSCALL_TRACEAUDIT (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP)
#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_MCA_INIT (1 << TIF_MCA_INIT)
#define _TIF_DB_DISABLED (1 << TIF_DB_DISABLED)
#define _TIF_FREEZE (1 << TIF_FREEZE)
#define _TIF_RESTORE_RSE (1 << TIF_RESTORE_RSE)
/* "work to do on user-return" bits */
#define TIF_ALLWORK_MASK (_TIF_SIGPENDING|_TIF_NOTIFY_RESUME|_TIF_SYSCALL_AUDIT|\
_TIF_NEED_RESCHED| _TIF_SYSCALL_TRACE|\
_TIF_RESTORE_SIGMASK)
/* like TIF_ALLWORK_BITS but sans TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT */
#define TIF_WORK_MASK (TIF_ALLWORK_MASK&~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT))
#define TS_POLLING 1 /* true if in idle loop and not sleeping */
#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
#endif /* _ASM_IA64_THREAD_INFO_H */