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linux-next/arch/powerpc/include/asm/ptrace.h
Mike Wolf a71f5d5d27 powerpc/ptrace: Remove BUG_ON when full register set not available
In some cases during a threaded core dump not all the threads will have
a full register set. This happens when the signal causing the core dump
races with a thread exiting.  The race happens when the exiting thread
has entered the kernel for the last time before the signal arrives, but
doesn't get far enough through the exit code to avoid being included
in the core dump.

So we get a thread included in the core dump which is never going to go
out to userspace again and only has a partial register set recorded

Normally we would catch each thread as it is about to go into userspace
and capture the full register set then.

However, this exiting thread is never going to go out to userspace
again, so we have no way to capture its full register set.  It doesn't
really matter, though, as this is a thread which is effectively
already dead.

So instead of hitting a BUG() in this case (a really bad choice of
action in the first place), we use a poison value for the register
values.

[BenH]: Some cosmetic/stylistic changes and fix build on ppc32

Signed-off-by: Mike Wolf <mjw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-03-21 11:18:14 +11:00

430 lines
13 KiB
C

#ifndef _ASM_POWERPC_PTRACE_H
#define _ASM_POWERPC_PTRACE_H
/*
* Copyright (C) 2001 PPC64 Team, IBM Corp
*
* This struct defines the way the registers are stored on the
* kernel stack during a system call or other kernel entry.
*
* this should only contain volatile regs
* since we can keep non-volatile in the thread_struct
* should set this up when only volatiles are saved
* by intr code.
*
* Since this is going on the stack, *CARE MUST BE TAKEN* to insure
* that the overall structure is a multiple of 16 bytes in length.
*
* Note that the offsets of the fields in this struct correspond with
* the PT_* values below. This simplifies arch/powerpc/kernel/ptrace.c.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/types.h>
#ifndef __ASSEMBLY__
struct pt_regs {
unsigned long gpr[32];
unsigned long nip;
unsigned long msr;
unsigned long orig_gpr3; /* Used for restarting system calls */
unsigned long ctr;
unsigned long link;
unsigned long xer;
unsigned long ccr;
#ifdef __powerpc64__
unsigned long softe; /* Soft enabled/disabled */
#else
unsigned long mq; /* 601 only (not used at present) */
/* Used on APUS to hold IPL value. */
#endif
unsigned long trap; /* Reason for being here */
/* N.B. for critical exceptions on 4xx, the dar and dsisr
fields are overloaded to hold srr0 and srr1. */
unsigned long dar; /* Fault registers */
unsigned long dsisr; /* on 4xx/Book-E used for ESR */
unsigned long result; /* Result of a system call */
};
#endif /* __ASSEMBLY__ */
#ifdef __KERNEL__
#ifdef __powerpc64__
#define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */
#define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */
#define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265)
#define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \
STACK_FRAME_OVERHEAD + 288)
#define STACK_FRAME_MARKER 12
/* Size of dummy stack frame allocated when calling signal handler. */
#define __SIGNAL_FRAMESIZE 128
#define __SIGNAL_FRAMESIZE32 64
#else /* __powerpc64__ */
#define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */
#define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */
#define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773)
#define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
#define STACK_FRAME_MARKER 2
/* Size of stack frame allocated when calling signal handler. */
#define __SIGNAL_FRAMESIZE 64
#endif /* __powerpc64__ */
#ifndef __ASSEMBLY__
#define instruction_pointer(regs) ((regs)->nip)
#define user_stack_pointer(regs) ((regs)->gpr[1])
#define kernel_stack_pointer(regs) ((regs)->gpr[1])
#define regs_return_value(regs) ((regs)->gpr[3])
#ifdef CONFIG_SMP
extern unsigned long profile_pc(struct pt_regs *regs);
#else
#define profile_pc(regs) instruction_pointer(regs)
#endif
#ifdef __powerpc64__
#define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
#else
#define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
#endif
#define force_successful_syscall_return() \
do { \
set_thread_flag(TIF_NOERROR); \
} while(0)
struct task_struct;
extern unsigned long ptrace_get_reg(struct task_struct *task, int regno);
extern int ptrace_put_reg(struct task_struct *task, int regno,
unsigned long data);
/*
* We use the least-significant bit of the trap field to indicate
* whether we have saved the full set of registers, or only a
* partial set. A 1 there means the partial set.
* On 4xx we use the next bit to indicate whether the exception
* is a critical exception (1 means it is).
*/
#define FULL_REGS(regs) (((regs)->trap & 1) == 0)
#ifndef __powerpc64__
#define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0)
#define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0)
#define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0)
#endif /* ! __powerpc64__ */
#define TRAP(regs) ((regs)->trap & ~0xF)
#ifdef __powerpc64__
#define NV_REG_POISON 0xdeadbeefdeadbeefUL
#define CHECK_FULL_REGS(regs) BUG_ON(regs->trap & 1)
#else
#define NV_REG_POISON 0xdeadbeef
#define CHECK_FULL_REGS(regs) \
do { \
if ((regs)->trap & 1) \
printk(KERN_CRIT "%s: partial register set\n", __func__); \
} while (0)
#endif /* __powerpc64__ */
#define arch_has_single_step() (1)
#define arch_has_block_step() (!cpu_has_feature(CPU_FTR_601))
#define ARCH_HAS_USER_SINGLE_STEP_INFO
/*
* kprobe-based event tracer support
*/
#include <linux/stddef.h>
#include <linux/thread_info.h>
extern int regs_query_register_offset(const char *name);
extern const char *regs_query_register_name(unsigned int offset);
#define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr))
/**
* regs_get_register() - get register value from its offset
* @regs: pt_regs from which register value is gotten
* @offset: offset number of the register.
*
* regs_get_register returns the value of a register whose offset from @regs.
* The @offset is the offset of the register in struct pt_regs.
* If @offset is bigger than MAX_REG_OFFSET, this returns 0.
*/
static inline unsigned long regs_get_register(struct pt_regs *regs,
unsigned int offset)
{
if (unlikely(offset > MAX_REG_OFFSET))
return 0;
return *(unsigned long *)((unsigned long)regs + offset);
}
/**
* regs_within_kernel_stack() - check the address in the stack
* @regs: pt_regs which contains kernel stack pointer.
* @addr: address which is checked.
*
* regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
* If @addr is within the kernel stack, it returns true. If not, returns false.
*/
static inline bool regs_within_kernel_stack(struct pt_regs *regs,
unsigned long addr)
{
return ((addr & ~(THREAD_SIZE - 1)) ==
(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
}
/**
* regs_get_kernel_stack_nth() - get Nth entry of the stack
* @regs: pt_regs which contains kernel stack pointer.
* @n: stack entry number.
*
* regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
* is specified by @regs. If the @n th entry is NOT in the kernel stack,
* this returns 0.
*/
static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
unsigned int n)
{
unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
addr += n;
if (regs_within_kernel_stack(regs, (unsigned long)addr))
return *addr;
else
return 0;
}
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
/*
* Offsets used by 'ptrace' system call interface.
* These can't be changed without breaking binary compatibility
* with MkLinux, etc.
*/
#define PT_R0 0
#define PT_R1 1
#define PT_R2 2
#define PT_R3 3
#define PT_R4 4
#define PT_R5 5
#define PT_R6 6
#define PT_R7 7
#define PT_R8 8
#define PT_R9 9
#define PT_R10 10
#define PT_R11 11
#define PT_R12 12
#define PT_R13 13
#define PT_R14 14
#define PT_R15 15
#define PT_R16 16
#define PT_R17 17
#define PT_R18 18
#define PT_R19 19
#define PT_R20 20
#define PT_R21 21
#define PT_R22 22
#define PT_R23 23
#define PT_R24 24
#define PT_R25 25
#define PT_R26 26
#define PT_R27 27
#define PT_R28 28
#define PT_R29 29
#define PT_R30 30
#define PT_R31 31
#define PT_NIP 32
#define PT_MSR 33
#define PT_ORIG_R3 34
#define PT_CTR 35
#define PT_LNK 36
#define PT_XER 37
#define PT_CCR 38
#ifndef __powerpc64__
#define PT_MQ 39
#else
#define PT_SOFTE 39
#endif
#define PT_TRAP 40
#define PT_DAR 41
#define PT_DSISR 42
#define PT_RESULT 43
#define PT_REGS_COUNT 44
#define PT_FPR0 48 /* each FP reg occupies 2 slots in this space */
#ifndef __powerpc64__
#define PT_FPR31 (PT_FPR0 + 2*31)
#define PT_FPSCR (PT_FPR0 + 2*32 + 1)
#else /* __powerpc64__ */
#define PT_FPSCR (PT_FPR0 + 32) /* each FP reg occupies 1 slot in 64-bit space */
#ifdef __KERNEL__
#define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */
#endif
#define PT_VR0 82 /* each Vector reg occupies 2 slots in 64-bit */
#define PT_VSCR (PT_VR0 + 32*2 + 1)
#define PT_VRSAVE (PT_VR0 + 33*2)
#ifdef __KERNEL__
#define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */
#define PT_VSCR_32 (PT_VR0 + 32*4 + 3)
#define PT_VRSAVE_32 (PT_VR0 + 33*4)
#endif
/*
* Only store first 32 VSRs here. The second 32 VSRs in VR0-31
*/
#define PT_VSR0 150 /* each VSR reg occupies 2 slots in 64-bit */
#define PT_VSR31 (PT_VSR0 + 2*31)
#ifdef __KERNEL__
#define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */
#endif
#endif /* __powerpc64__ */
/*
* Get/set all the altivec registers vr0..vr31, vscr, vrsave, in one go.
* The transfer totals 34 quadword. Quadwords 0-31 contain the
* corresponding vector registers. Quadword 32 contains the vscr as the
* last word (offset 12) within that quadword. Quadword 33 contains the
* vrsave as the first word (offset 0) within the quadword.
*
* This definition of the VMX state is compatible with the current PPC32
* ptrace interface. This allows signal handling and ptrace to use the same
* structures. This also simplifies the implementation of a bi-arch
* (combined (32- and 64-bit) gdb.
*/
#define PTRACE_GETVRREGS 18
#define PTRACE_SETVRREGS 19
/* Get/set all the upper 32-bits of the SPE registers, accumulator, and
* spefscr, in one go */
#define PTRACE_GETEVRREGS 20
#define PTRACE_SETEVRREGS 21
/* Get the first 32 128bit VSX registers */
#define PTRACE_GETVSRREGS 27
#define PTRACE_SETVSRREGS 28
/*
* Get or set a debug register. The first 16 are DABR registers and the
* second 16 are IABR registers.
*/
#define PTRACE_GET_DEBUGREG 25
#define PTRACE_SET_DEBUGREG 26
/* (new) PTRACE requests using the same numbers as x86 and the same
* argument ordering. Additionally, they support more registers too
*/
#define PTRACE_GETREGS 12
#define PTRACE_SETREGS 13
#define PTRACE_GETFPREGS 14
#define PTRACE_SETFPREGS 15
#define PTRACE_GETREGS64 22
#define PTRACE_SETREGS64 23
/* (old) PTRACE requests with inverted arguments */
#define PPC_PTRACE_GETREGS 0x99 /* Get GPRs 0 - 31 */
#define PPC_PTRACE_SETREGS 0x98 /* Set GPRs 0 - 31 */
#define PPC_PTRACE_GETFPREGS 0x97 /* Get FPRs 0 - 31 */
#define PPC_PTRACE_SETFPREGS 0x96 /* Set FPRs 0 - 31 */
/* Calls to trace a 64bit program from a 32bit program */
#define PPC_PTRACE_PEEKTEXT_3264 0x95
#define PPC_PTRACE_PEEKDATA_3264 0x94
#define PPC_PTRACE_POKETEXT_3264 0x93
#define PPC_PTRACE_POKEDATA_3264 0x92
#define PPC_PTRACE_PEEKUSR_3264 0x91
#define PPC_PTRACE_POKEUSR_3264 0x90
#define PTRACE_SINGLEBLOCK 0x100 /* resume execution until next branch */
#define PPC_PTRACE_GETHWDBGINFO 0x89
#define PPC_PTRACE_SETHWDEBUG 0x88
#define PPC_PTRACE_DELHWDEBUG 0x87
#ifndef __ASSEMBLY__
struct ppc_debug_info {
__u32 version; /* Only version 1 exists to date */
__u32 num_instruction_bps;
__u32 num_data_bps;
__u32 num_condition_regs;
__u32 data_bp_alignment;
__u32 sizeof_condition; /* size of the DVC register */
__u64 features;
};
#endif /* __ASSEMBLY__ */
/*
* features will have bits indication whether there is support for:
*/
#define PPC_DEBUG_FEATURE_INSN_BP_RANGE 0x0000000000000001
#define PPC_DEBUG_FEATURE_INSN_BP_MASK 0x0000000000000002
#define PPC_DEBUG_FEATURE_DATA_BP_RANGE 0x0000000000000004
#define PPC_DEBUG_FEATURE_DATA_BP_MASK 0x0000000000000008
#ifndef __ASSEMBLY__
struct ppc_hw_breakpoint {
__u32 version; /* currently, version must be 1 */
__u32 trigger_type; /* only some combinations allowed */
__u32 addr_mode; /* address match mode */
__u32 condition_mode; /* break/watchpoint condition flags */
__u64 addr; /* break/watchpoint address */
__u64 addr2; /* range end or mask */
__u64 condition_value; /* contents of the DVC register */
};
#endif /* __ASSEMBLY__ */
/*
* Trigger Type
*/
#define PPC_BREAKPOINT_TRIGGER_EXECUTE 0x00000001
#define PPC_BREAKPOINT_TRIGGER_READ 0x00000002
#define PPC_BREAKPOINT_TRIGGER_WRITE 0x00000004
#define PPC_BREAKPOINT_TRIGGER_RW \
(PPC_BREAKPOINT_TRIGGER_READ | PPC_BREAKPOINT_TRIGGER_WRITE)
/*
* Address Mode
*/
#define PPC_BREAKPOINT_MODE_EXACT 0x00000000
#define PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE 0x00000001
#define PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE 0x00000002
#define PPC_BREAKPOINT_MODE_MASK 0x00000003
/*
* Condition Mode
*/
#define PPC_BREAKPOINT_CONDITION_MODE 0x00000003
#define PPC_BREAKPOINT_CONDITION_NONE 0x00000000
#define PPC_BREAKPOINT_CONDITION_AND 0x00000001
#define PPC_BREAKPOINT_CONDITION_EXACT PPC_BREAKPOINT_CONDITION_AND
#define PPC_BREAKPOINT_CONDITION_OR 0x00000002
#define PPC_BREAKPOINT_CONDITION_AND_OR 0x00000003
#define PPC_BREAKPOINT_CONDITION_BE_ALL 0x00ff0000
#define PPC_BREAKPOINT_CONDITION_BE_SHIFT 16
#define PPC_BREAKPOINT_CONDITION_BE(n) \
(1<<((n)+PPC_BREAKPOINT_CONDITION_BE_SHIFT))
#endif /* _ASM_POWERPC_PTRACE_H */