a87e810f61
In commita3e5b356b3"powerpc: Don't use local named register variable in current_thread_info" Anton changed the way we did current_thread_info() to accommodate LLVM, and it was not meant to have any effect elsewhere. Unfortunately it has exposed a gcc bug, where r1 gets copied into another register and then gcc uses that register to restore the toc after a function call, even when that register is volatile and has been clobbered by the function call. We could revert Anton's patch, but it's not clear the original code is safe either, we may just have been lucky. The cleanest solution is to just use the existing CURRENT_THREAD_INFO() asm macro, and call it using inline asm. Segher points out we don't need volatile on the asm, if the result of the shift is unused it's fine for the compiler to elide it. Fixes:a3e5b356b3("powerpc: Don't use local named register variable in current_thread_info") Reported-by: Alexander Graf <agraf@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
199 lines
6.1 KiB
C
199 lines
6.1 KiB
C
/* 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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#ifdef __KERNEL__
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/* We have 8k stacks on ppc32 and 16k on ppc64 */
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#if defined(CONFIG_PPC64)
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#define THREAD_SHIFT 14
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#elif defined(CONFIG_PPC_256K_PAGES)
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#define THREAD_SHIFT 15
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#else
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#define THREAD_SHIFT 13
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#endif
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#define THREAD_SIZE (1 << THREAD_SHIFT)
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#ifdef CONFIG_PPC64
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#define CURRENT_THREAD_INFO(dest, sp) stringify_in_c(clrrdi dest, sp, THREAD_SHIFT)
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#else
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#define CURRENT_THREAD_INFO(dest, sp) stringify_in_c(rlwinm dest, sp, 0, 0, 31-THREAD_SHIFT)
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#endif
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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/page.h>
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#include <linux/stringify.h>
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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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struct task_struct *task; /* main task structure */
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struct exec_domain *exec_domain; /* execution domain */
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int cpu; /* cpu we're on */
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int preempt_count; /* 0 => preemptable,
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<0 => BUG */
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struct restart_block restart_block;
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unsigned long local_flags; /* private flags for thread */
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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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.task = &tsk, \
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.exec_domain = &default_exec_domain, \
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.cpu = 0, \
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.preempt_count = INIT_PREEMPT_COUNT, \
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.restart_block = { \
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.fn = do_no_restart_syscall, \
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}, \
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.flags = 0, \
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}
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#define init_thread_info (init_thread_union.thread_info)
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#define init_stack (init_thread_union.stack)
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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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static inline struct thread_info *current_thread_info(void)
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{
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unsigned long val;
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asm (CURRENT_THREAD_INFO(%0,1) : "=r" (val));
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return (struct thread_info *)val;
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}
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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_POLLING_NRFLAG 3 /* true if poll_idle() is polling
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TIF_NEED_RESCHED */
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#define TIF_32BIT 4 /* 32 bit binary */
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#define TIF_RESTORE_TM 5 /* need to restore TM FP/VEC/VSX */
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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_NOHZ 9 /* in adaptive nohz mode */
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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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/* 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_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_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_NOHZ (1<<TIF_NOHZ)
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#define _TIF_SYSCALL_T_OR_A (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
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_TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
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_TIF_NOHZ)
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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)
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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_RESTORE_SIGMASK 2 /* Restore signal mask in do_signal */
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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_RESTORE_SIGMASK (1 << TLF_RESTORE_SIGMASK)
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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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#define HAVE_SET_RESTORE_SIGMASK 1
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static inline void set_restore_sigmask(void)
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{
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struct thread_info *ti = current_thread_info();
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ti->local_flags |= _TLF_RESTORE_SIGMASK;
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WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags));
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}
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static inline void clear_restore_sigmask(void)
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{
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current_thread_info()->local_flags &= ~_TLF_RESTORE_SIGMASK;
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}
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static inline bool test_restore_sigmask(void)
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{
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return current_thread_info()->local_flags & _TLF_RESTORE_SIGMASK;
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}
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static inline bool test_and_clear_restore_sigmask(void)
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{
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struct thread_info *ti = current_thread_info();
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if (!(ti->local_flags & _TLF_RESTORE_SIGMASK))
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return false;
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ti->local_flags &= ~_TLF_RESTORE_SIGMASK;
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return true;
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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_PPC64
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#define is_32bit_task() (test_thread_flag(TIF_32BIT))
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#else
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#define is_32bit_task() (1)
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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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