forked from Minki/linux
a0fc1436f1
The result of the s32ex opcode is recorded in the ATOMCTL special
register and must be retrieved with the getex opcode. Context switch
between s32ex and getex may trash the ATOMCTL register and result in
duplicate update or missing update of the atomic variable.
Add atomctl8 field to the struct thread_info and use getex to swap
ATOMCTL bit 8 as a part of context switch.
Clear exclusive access monitor on kernel entry.
Cc: stable@vger.kernel.org
Fixes: f7c34874f0 ("xtensa: add exclusive atomics support")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
137 lines
3.7 KiB
C
137 lines
3.7 KiB
C
/*
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* include/asm-xtensa/thread_info.h
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2001 - 2005 Tensilica Inc.
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*/
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#ifndef _XTENSA_THREAD_INFO_H
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#define _XTENSA_THREAD_INFO_H
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#include <linux/stringify.h>
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#include <asm/kmem_layout.h>
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#define CURRENT_SHIFT KERNEL_STACK_SHIFT
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#ifndef __ASSEMBLY__
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# include <asm/processor.h>
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#endif
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/*
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* low level task data that entry.S needs immediate access to
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* - this struct should fit entirely inside of one cache line
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* - this struct shares the supervisor stack pages
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* - if the contents of this structure are changed, the assembly constants
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* must also be changed
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*/
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#ifndef __ASSEMBLY__
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#if XTENSA_HAVE_COPROCESSORS
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typedef struct xtregs_coprocessor {
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xtregs_cp0_t cp0;
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xtregs_cp1_t cp1;
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xtregs_cp2_t cp2;
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xtregs_cp3_t cp3;
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xtregs_cp4_t cp4;
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xtregs_cp5_t cp5;
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xtregs_cp6_t cp6;
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xtregs_cp7_t cp7;
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} xtregs_coprocessor_t;
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#endif
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struct thread_info {
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struct task_struct *task; /* main task structure */
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unsigned long flags; /* low level flags */
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unsigned long status; /* thread-synchronous flags */
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__u32 cpu; /* current CPU */
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__s32 preempt_count; /* 0 => preemptable,< 0 => BUG*/
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mm_segment_t addr_limit; /* thread address space */
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unsigned long cpenable;
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#if XCHAL_HAVE_EXCLUSIVE
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/* result of the most recent exclusive store */
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unsigned long atomctl8;
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#endif
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/* Allocate storage for extra user states and coprocessor states. */
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#if XTENSA_HAVE_COPROCESSORS
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xtregs_coprocessor_t xtregs_cp;
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#endif
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xtregs_user_t xtregs_user;
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};
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#endif
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/*
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* macros/functions for gaining access to the thread information structure
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*/
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#ifndef __ASSEMBLY__
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#define INIT_THREAD_INFO(tsk) \
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{ \
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.task = &tsk, \
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.flags = 0, \
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.cpu = 0, \
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.preempt_count = INIT_PREEMPT_COUNT, \
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.addr_limit = KERNEL_DS, \
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}
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/* how to get the thread information struct from C */
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static inline struct thread_info *current_thread_info(void)
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{
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struct thread_info *ti;
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__asm__("extui %0, a1, 0, "__stringify(CURRENT_SHIFT)"\n\t"
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"xor %0, a1, %0" : "=&r" (ti) : );
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return ti;
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}
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#else /* !__ASSEMBLY__ */
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/* how to get the thread information struct from ASM */
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#define GET_THREAD_INFO(reg,sp) \
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extui reg, sp, 0, CURRENT_SHIFT; \
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xor reg, sp, reg
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#endif
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/*
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* thread information flags
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* - these are process state flags that various assembly files may need to access
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*/
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#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
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#define TIF_SIGPENDING 1 /* signal pending */
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#define TIF_NEED_RESCHED 2 /* rescheduling necessary */
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#define TIF_SINGLESTEP 3 /* restore singlestep on return to user mode */
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#define TIF_SYSCALL_TRACEPOINT 4 /* syscall tracepoint instrumentation */
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#define TIF_MEMDIE 5 /* is terminating due to OOM killer */
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#define TIF_RESTORE_SIGMASK 6 /* restore signal mask in do_signal() */
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#define TIF_NOTIFY_RESUME 7 /* callback before returning to user */
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#define TIF_DB_DISABLED 8 /* debug trap disabled for syscall */
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#define TIF_SYSCALL_AUDIT 9 /* syscall auditing active */
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#define TIF_SECCOMP 10 /* secure computing */
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#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
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#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
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#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
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#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
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#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
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#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
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#define _TIF_SECCOMP (1<<TIF_SECCOMP)
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#define _TIF_WORK_MASK (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP | \
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_TIF_SYSCALL_TRACEPOINT | \
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_TIF_SYSCALL_AUDIT | _TIF_SECCOMP)
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#define THREAD_SIZE KERNEL_STACK_SIZE
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#define THREAD_SIZE_ORDER (KERNEL_STACK_SHIFT - PAGE_SHIFT)
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#endif /* _XTENSA_THREAD_INFO */
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