![David Woodhouse](/assets/img/avatar_default.png)
This cleanup patch speeds up the null syscall path on ppc64 by about 3%, and brings the ppc32 and ppc64 code slightly closer together. The ppc64 code was checking current_thread_info()->flags twice in the syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after disabling interrupts. Now we do the same as ppc32 -- check the flags only once in the fast path, and re-enable interrupts if necessary in the ptrace case. The patch abolishes the 'syscall_noerror' member of struct thread_info and replaces it with a TIF_NOERROR bit in the flags, which is handled in the slow path. This shortens the syscall entry code, which no longer needs to clear syscall_noerror. The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow path to save the non-volatile GPRs into a signal frame. This removes the need for the assembly wrappers around sys_sigsuspend(), sys_rt_sigsuspend(), et al which existed solely to save those registers in advance. It also means I don't have to add new wrappers for ppoll() and pselect(), which is what I was supposed to be doing when I got distracted into this... Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit directly into a signal handler (as required by sigsuspend et al) by introducing a TIF_RESTOREALL flag which causes _all_ the registers to be reloaded from the pt_regs by taking the ret_from_exception path, instead of the normal syscall exit path which stomps on the callee-saved GPRs. It appears to pass an LTP test run on ppc64, and passes basic testing on ppc32 too. Brief tests of ptrace functionality with strace and gdb also appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :) Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
249 lines
6.7 KiB
C
249 lines
6.7 KiB
C
#ifndef _ASM_POWERPC_PTRACE_H
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#define _ASM_POWERPC_PTRACE_H
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/*
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* Copyright (C) 2001 PPC64 Team, IBM Corp
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*
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* This struct defines the way the registers are stored on the
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* kernel stack during a system call or other kernel entry.
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*
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* this should only contain volatile regs
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* since we can keep non-volatile in the thread_struct
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* should set this up when only volatiles are saved
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* by intr code.
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*
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* Since this is going on the stack, *CARE MUST BE TAKEN* to insure
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* that the overall structure is a multiple of 16 bytes in length.
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*
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* Note that the offsets of the fields in this struct correspond with
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* the PT_* values below. This simplifies arch/powerpc/kernel/ptrace.c.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef __ASSEMBLY__
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struct pt_regs {
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unsigned long gpr[32];
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unsigned long nip;
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unsigned long msr;
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unsigned long orig_gpr3; /* Used for restarting system calls */
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unsigned long ctr;
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unsigned long link;
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unsigned long xer;
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unsigned long ccr;
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#ifdef __powerpc64__
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unsigned long softe; /* Soft enabled/disabled */
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#else
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unsigned long mq; /* 601 only (not used at present) */
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/* Used on APUS to hold IPL value. */
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#endif
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unsigned long trap; /* Reason for being here */
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/* N.B. for critical exceptions on 4xx, the dar and dsisr
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fields are overloaded to hold srr0 and srr1. */
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unsigned long dar; /* Fault registers */
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unsigned long dsisr; /* on 4xx/Book-E used for ESR */
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unsigned long result; /* Result of a system call */
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};
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#endif /* __ASSEMBLY__ */
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#ifdef __KERNEL__
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#ifdef __powerpc64__
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#define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */
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/* Size of dummy stack frame allocated when calling signal handler. */
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#define __SIGNAL_FRAMESIZE 128
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#define __SIGNAL_FRAMESIZE32 64
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#else /* __powerpc64__ */
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#define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */
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/* Size of stack frame allocated when calling signal handler. */
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#define __SIGNAL_FRAMESIZE 64
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#endif /* __powerpc64__ */
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#ifndef __ASSEMBLY__
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#define instruction_pointer(regs) ((regs)->nip)
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#ifdef CONFIG_SMP
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extern unsigned long profile_pc(struct pt_regs *regs);
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#else
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#define profile_pc(regs) instruction_pointer(regs)
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#endif
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#ifdef __powerpc64__
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#define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
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#else
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#define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
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#endif
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#define force_successful_syscall_return() \
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do { \
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set_thread_flag(TIF_NOERROR); \
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} while(0)
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/*
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* We use the least-significant bit of the trap field to indicate
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* whether we have saved the full set of registers, or only a
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* partial set. A 1 there means the partial set.
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* On 4xx we use the next bit to indicate whether the exception
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* is a critical exception (1 means it is).
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*/
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#define FULL_REGS(regs) (((regs)->trap & 1) == 0)
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#ifndef __powerpc64__
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#define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) == 0)
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#endif /* ! __powerpc64__ */
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#define TRAP(regs) ((regs)->trap & ~0xF)
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#ifdef __powerpc64__
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#define CHECK_FULL_REGS(regs) BUG_ON(regs->trap & 1)
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#else
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#define CHECK_FULL_REGS(regs) \
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do { \
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if ((regs)->trap & 1) \
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printk(KERN_CRIT "%s: partial register set\n", __FUNCTION__); \
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} while (0)
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#endif /* __powerpc64__ */
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#endif /* __ASSEMBLY__ */
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#endif /* __KERNEL__ */
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/*
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* Offsets used by 'ptrace' system call interface.
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* These can't be changed without breaking binary compatibility
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* with MkLinux, etc.
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*/
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#define PT_R0 0
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#define PT_R1 1
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#define PT_R2 2
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#define PT_R3 3
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#define PT_R4 4
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#define PT_R5 5
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#define PT_R6 6
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#define PT_R7 7
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#define PT_R8 8
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#define PT_R9 9
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#define PT_R10 10
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#define PT_R11 11
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#define PT_R12 12
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#define PT_R13 13
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#define PT_R14 14
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#define PT_R15 15
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#define PT_R16 16
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#define PT_R17 17
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#define PT_R18 18
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#define PT_R19 19
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#define PT_R20 20
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#define PT_R21 21
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#define PT_R22 22
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#define PT_R23 23
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#define PT_R24 24
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#define PT_R25 25
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#define PT_R26 26
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#define PT_R27 27
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#define PT_R28 28
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#define PT_R29 29
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#define PT_R30 30
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#define PT_R31 31
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#define PT_NIP 32
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#define PT_MSR 33
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#ifdef __KERNEL__
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#define PT_ORIG_R3 34
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#endif
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#define PT_CTR 35
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#define PT_LNK 36
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#define PT_XER 37
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#define PT_CCR 38
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#ifndef __powerpc64__
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#define PT_MQ 39
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#else
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#define PT_SOFTE 39
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#define PT_TRAP 40
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#define PT_DAR 41
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#define PT_DSISR 42
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#define PT_RESULT 43
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#endif
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#define PT_FPR0 48 /* each FP reg occupies 2 slots in this space */
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#ifndef __powerpc64__
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#define PT_FPR31 (PT_FPR0 + 2*31)
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#define PT_FPSCR (PT_FPR0 + 2*32 + 1)
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#else /* __powerpc64__ */
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#define PT_FPSCR (PT_FPR0 + 32) /* each FP reg occupies 1 slot in 64-bit space */
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#ifdef __KERNEL__
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#define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */
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#endif
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#define PT_VR0 82 /* each Vector reg occupies 2 slots in 64-bit */
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#define PT_VSCR (PT_VR0 + 32*2 + 1)
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#define PT_VRSAVE (PT_VR0 + 33*2)
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#ifdef __KERNEL__
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#define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */
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#define PT_VSCR_32 (PT_VR0 + 32*4 + 3)
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#define PT_VRSAVE_32 (PT_VR0 + 33*4)
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#endif
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#endif /* __powerpc64__ */
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/*
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* Get/set all the altivec registers vr0..vr31, vscr, vrsave, in one go.
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* The transfer totals 34 quadword. Quadwords 0-31 contain the
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* corresponding vector registers. Quadword 32 contains the vscr as the
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* last word (offset 12) within that quadword. Quadword 33 contains the
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* vrsave as the first word (offset 0) within the quadword.
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*
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* This definition of the VMX state is compatible with the current PPC32
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* ptrace interface. This allows signal handling and ptrace to use the same
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* structures. This also simplifies the implementation of a bi-arch
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* (combined (32- and 64-bit) gdb.
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*/
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#define PTRACE_GETVRREGS 18
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#define PTRACE_SETVRREGS 19
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#ifndef __powerpc64__
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/* Get/set all the upper 32-bits of the SPE registers, accumulator, and
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* spefscr, in one go */
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#define PTRACE_GETEVRREGS 20
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#define PTRACE_SETEVRREGS 21
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#endif /* __powerpc64__ */
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/*
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* Get or set a debug register. The first 16 are DABR registers and the
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* second 16 are IABR registers.
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*/
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#define PTRACE_GET_DEBUGREG 25
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#define PTRACE_SET_DEBUGREG 26
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#ifdef __powerpc64__
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/* Additional PTRACE requests implemented on PowerPC. */
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#define PPC_PTRACE_GETREGS 0x99 /* Get GPRs 0 - 31 */
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#define PPC_PTRACE_SETREGS 0x98 /* Set GPRs 0 - 31 */
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#define PPC_PTRACE_GETFPREGS 0x97 /* Get FPRs 0 - 31 */
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#define PPC_PTRACE_SETFPREGS 0x96 /* Set FPRs 0 - 31 */
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/* Calls to trace a 64bit program from a 32bit program */
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#define PPC_PTRACE_PEEKTEXT_3264 0x95
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#define PPC_PTRACE_PEEKDATA_3264 0x94
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#define PPC_PTRACE_POKETEXT_3264 0x93
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#define PPC_PTRACE_POKEDATA_3264 0x92
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#define PPC_PTRACE_PEEKUSR_3264 0x91
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#define PPC_PTRACE_POKEUSR_3264 0x90
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#endif /* __powerpc64__ */
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#endif /* _ASM_POWERPC_PTRACE_H */
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