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![Michael Ellerman](/assets/img/avatar_default.png)
KASAN causes increased stack usage, which can lead to stack overflows.
The logic in Kconfig to suggest a larger default doesn't work if a user
has CONFIG_EXPERT enabled and has an existing .config with a smaller
value.
Follow the lead of x86 and arm64, and force the thread size to be
increased when KASAN is enabled.
That also has the effect of enlarging the stack for 64-bit KASAN builds,
which is also desirable.
Fixes: edbadaf067
("powerpc/kasan: Fix stack overflow by increasing THREAD_SHIFT")
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Use MIN_THREAD_SHIFT as suggested by Christophe]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220601143114.133524-1-mpe@ellerman.id.au
193 lines
6.1 KiB
C
193 lines
6.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* thread_info.h: PowerPC low-level thread information
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* adapted from the i386 version by Paul Mackerras
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*
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* Copyright (C) 2002 David Howells (dhowells@redhat.com)
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* - Incorporating suggestions made by Linus Torvalds and Dave Miller
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*/
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#ifndef _ASM_POWERPC_THREAD_INFO_H
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#define _ASM_POWERPC_THREAD_INFO_H
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#include <asm/asm-const.h>
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#include <asm/page.h>
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#ifdef __KERNEL__
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#ifdef CONFIG_KASAN
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#define MIN_THREAD_SHIFT (CONFIG_THREAD_SHIFT + 1)
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#else
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#define MIN_THREAD_SHIFT CONFIG_THREAD_SHIFT
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#endif
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#if defined(CONFIG_VMAP_STACK) && MIN_THREAD_SHIFT < PAGE_SHIFT
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#define THREAD_SHIFT PAGE_SHIFT
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#else
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#define THREAD_SHIFT MIN_THREAD_SHIFT
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#endif
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#define THREAD_SIZE (1 << THREAD_SHIFT)
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/*
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* By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
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* checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
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* assembly.
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*/
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#ifdef CONFIG_VMAP_STACK
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#define THREAD_ALIGN_SHIFT (THREAD_SHIFT + 1)
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#else
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#define THREAD_ALIGN_SHIFT THREAD_SHIFT
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#endif
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#define THREAD_ALIGN (1 << THREAD_ALIGN_SHIFT)
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#ifndef __ASSEMBLY__
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#include <linux/cache.h>
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#include <asm/processor.h>
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#include <asm/accounting.h>
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#define SLB_PRELOAD_NR 16U
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/*
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* low level task data.
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*/
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struct thread_info {
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int preempt_count; /* 0 => preemptable,
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<0 => BUG */
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#ifdef CONFIG_SMP
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unsigned int cpu;
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#endif
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unsigned long local_flags; /* private flags for thread */
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#ifdef CONFIG_LIVEPATCH_64
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unsigned long *livepatch_sp;
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#endif
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#if defined(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) && defined(CONFIG_PPC32)
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struct cpu_accounting_data accounting;
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#endif
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unsigned char slb_preload_nr;
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unsigned char slb_preload_tail;
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u32 slb_preload_esid[SLB_PRELOAD_NR];
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/* low level flags - has atomic operations done on it */
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unsigned long flags ____cacheline_aligned_in_smp;
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};
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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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#define INIT_THREAD_INFO(tsk) \
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{ \
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.preempt_count = INIT_PREEMPT_COUNT, \
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.flags = 0, \
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}
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#define THREAD_SIZE_ORDER (THREAD_SHIFT - PAGE_SHIFT)
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/* how to get the thread information struct from C */
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extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
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void arch_setup_new_exec(void);
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#define arch_setup_new_exec arch_setup_new_exec
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#endif /* __ASSEMBLY__ */
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/*
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* thread information flag bit numbers
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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_NOTIFY_SIGNAL 3 /* signal notifications exist */
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#define TIF_SYSCALL_EMU 4 /* syscall emulation active */
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#define TIF_RESTORE_TM 5 /* need to restore TM FP/VEC/VSX */
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#define TIF_PATCH_PENDING 6 /* pending live patching update */
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#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
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#define TIF_SINGLESTEP 8 /* singlestepping active */
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#define TIF_SECCOMP 10 /* secure computing */
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#define TIF_RESTOREALL 11 /* Restore all regs (implies NOERROR) */
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#define TIF_NOERROR 12 /* Force successful syscall return */
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#define TIF_NOTIFY_RESUME 13 /* callback before returning to user */
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#define TIF_UPROBE 14 /* breakpointed or single-stepping */
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#define TIF_SYSCALL_TRACEPOINT 15 /* syscall tracepoint instrumentation */
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#define TIF_EMULATE_STACK_STORE 16 /* Is an instruction emulation
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for stack store? */
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#define TIF_MEMDIE 17 /* is terminating due to OOM killer */
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#if defined(CONFIG_PPC64)
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#define TIF_ELF2ABI 18 /* function descriptors must die! */
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#endif
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#define TIF_POLLING_NRFLAG 19 /* true if poll_idle() is polling TIF_NEED_RESCHED */
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#define TIF_32BIT 20 /* 32 bit binary */
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/* as above, but as bit values */
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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_NOTIFY_SIGNAL (1<<TIF_NOTIFY_SIGNAL)
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#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
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#define _TIF_32BIT (1<<TIF_32BIT)
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#define _TIF_RESTORE_TM (1<<TIF_RESTORE_TM)
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#define _TIF_PATCH_PENDING (1<<TIF_PATCH_PENDING)
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#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
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#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
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#define _TIF_SECCOMP (1<<TIF_SECCOMP)
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#define _TIF_RESTOREALL (1<<TIF_RESTOREALL)
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#define _TIF_NOERROR (1<<TIF_NOERROR)
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#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
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#define _TIF_UPROBE (1<<TIF_UPROBE)
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#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
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#define _TIF_EMULATE_STACK_STORE (1<<TIF_EMULATE_STACK_STORE)
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#define _TIF_SYSCALL_EMU (1<<TIF_SYSCALL_EMU)
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#define _TIF_SYSCALL_DOTRACE (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
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_TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
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_TIF_SYSCALL_EMU)
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#define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
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_TIF_NOTIFY_RESUME | _TIF_UPROBE | \
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_TIF_RESTORE_TM | _TIF_PATCH_PENDING | \
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_TIF_NOTIFY_SIGNAL)
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#define _TIF_PERSYSCALL_MASK (_TIF_RESTOREALL|_TIF_NOERROR)
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/* Bits in local_flags */
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/* Don't move TLF_NAPPING without adjusting the code in entry_32.S */
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#define TLF_NAPPING 0 /* idle thread enabled NAP mode */
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#define TLF_SLEEPING 1 /* suspend code enabled SLEEP mode */
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#define TLF_LAZY_MMU 3 /* tlb_batch is active */
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#define TLF_RUNLATCH 4 /* Is the runlatch enabled? */
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#define _TLF_NAPPING (1 << TLF_NAPPING)
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#define _TLF_SLEEPING (1 << TLF_SLEEPING)
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#define _TLF_LAZY_MMU (1 << TLF_LAZY_MMU)
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#define _TLF_RUNLATCH (1 << TLF_RUNLATCH)
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#ifndef __ASSEMBLY__
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static inline void clear_thread_local_flags(unsigned int flags)
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{
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struct thread_info *ti = current_thread_info();
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ti->local_flags &= ~flags;
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}
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static inline bool test_thread_local_flags(unsigned int flags)
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{
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struct thread_info *ti = current_thread_info();
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return (ti->local_flags & flags) != 0;
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}
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#ifdef CONFIG_COMPAT
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#define is_32bit_task() (test_thread_flag(TIF_32BIT))
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#define is_tsk_32bit_task(tsk) (test_tsk_thread_flag(tsk, TIF_32BIT))
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#else
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#define is_32bit_task() (IS_ENABLED(CONFIG_PPC32))
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#define is_tsk_32bit_task(tsk) (IS_ENABLED(CONFIG_PPC32))
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#endif
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#if defined(CONFIG_PPC64)
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#define is_elf2_task() (test_thread_flag(TIF_ELF2ABI))
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#else
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#define is_elf2_task() (0)
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#endif
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#endif /* !__ASSEMBLY__ */
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#endif /* __KERNEL__ */
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#endif /* _ASM_POWERPC_THREAD_INFO_H */
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