freebsd-nq/sys/amd64/include/pcb.h
John Baldwin 645743ea99 Export various helper variables describing the layout and size of
certain kernel structures for use by debuggers. This mostly aids
in examining cores from a kernel without debug symbols as a debugger
can infer these values if debug symbols are available.

One set of variables describes the layout of 'struct linker_file' to
walk the list of loaded kernel modules.

A second set of variables describes the layout of 'struct proc' and
'struct thread' to walk the list of processes in the kernel and the
threads in each process.

The 'pcb_size' variable is used to index into the stoppcbs[] array.

The 'vm_maxuser_address' is used to distinguish kernel virtual addresses
from user addresses. This doesn't have to be perfect, and
'vm_maxuser_address' is a cheap and simple way to differentiate kernel
pointers from simple values like TIDs and PIDs.

While here, annotate the fields in struct pcb used by kgdb on amd64
and i386 to note that their ABI should be preserved.  Annotations for
other platforms will be added in the future.

Reviewed by:	kib
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D3773
2015-11-12 22:00:59 +00:00

158 lines
4.8 KiB
C

/*-
* Copyright (c) 2003 Peter Wemm.
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)pcb.h 5.10 (Berkeley) 5/12/91
* $FreeBSD$
*/
#ifndef _AMD64_PCB_H_
#define _AMD64_PCB_H_
/*
* AMD64 process control block
*/
#include <machine/fpu.h>
#include <machine/segments.h>
#ifdef __amd64__
/*
* NB: The fields marked with (*) are used by kernel debuggers. Their
* ABI should be preserved.
*/
struct pcb {
register_t pcb_r15; /* (*) */
register_t pcb_r14; /* (*) */
register_t pcb_r13; /* (*) */
register_t pcb_r12; /* (*) */
register_t pcb_rbp; /* (*) */
register_t pcb_rsp; /* (*) */
register_t pcb_rbx; /* (*) */
register_t pcb_rip; /* (*) */
register_t pcb_fsbase;
register_t pcb_gsbase;
register_t pcb_kgsbase;
register_t pcb_cr0;
register_t pcb_cr2;
register_t pcb_cr3;
register_t pcb_cr4;
register_t pcb_dr0;
register_t pcb_dr1;
register_t pcb_dr2;
register_t pcb_dr3;
register_t pcb_dr6;
register_t pcb_dr7;
struct region_descriptor pcb_gdt;
struct region_descriptor pcb_idt;
struct region_descriptor pcb_ldt;
uint16_t pcb_tr;
u_int pcb_flags;
#define PCB_FULL_IRET 0x01 /* full iret is required */
#define PCB_DBREGS 0x02 /* process using debug registers */
#define PCB_KERNFPU 0x04 /* kernel uses fpu */
#define PCB_FPUINITDONE 0x08 /* fpu state is initialized */
#define PCB_USERFPUINITDONE 0x10 /* fpu user state is initialized */
#define PCB_32BIT 0x40 /* process has 32 bit context (segs etc) */
uint16_t pcb_initial_fpucw;
/* copyin/out fault recovery */
caddr_t pcb_onfault;
uint64_t pcb_pad0;
/* local tss, with i/o bitmap; NULL for common */
struct amd64tss *pcb_tssp;
/* model specific registers */
register_t pcb_efer;
register_t pcb_star;
register_t pcb_lstar;
register_t pcb_cstar;
register_t pcb_sfmask;
struct savefpu *pcb_save;
uint64_t pcb_pad[5];
};
/* Per-CPU state saved during suspend and resume. */
struct susppcb {
struct pcb sp_pcb;
/* fpu context for suspend/resume */
void *sp_fpususpend;
};
#endif
#ifdef _KERNEL
struct trapframe;
/*
* The pcb_flags is only modified by current thread, or by other threads
* when current thread is stopped. However, current thread may change it
* from the interrupt context in cpu_switch(), or in the trap handler.
* When we read-modify-write pcb_flags from C sources, compiler may generate
* code that is not atomic regarding the interrupt handler. If a trap or
* interrupt happens and any flag is modified from the handler, it can be
* clobbered with the cached value later. Therefore, we implement setting
* and clearing flags with single-instruction functions, which do not race
* with possible modification of the flags from the trap or interrupt context,
* because traps and interrupts are executed only on instruction boundary.
*/
static __inline void
set_pcb_flags(struct pcb *pcb, const u_int flags)
{
__asm __volatile("orl %1,%0"
: "=m" (pcb->pcb_flags) : "ir" (flags), "m" (pcb->pcb_flags)
: "cc");
}
static __inline void
clear_pcb_flags(struct pcb *pcb, const u_int flags)
{
__asm __volatile("andl %1,%0"
: "=m" (pcb->pcb_flags) : "ir" (~flags), "m" (pcb->pcb_flags)
: "cc");
}
void makectx(struct trapframe *, struct pcb *);
int savectx(struct pcb *) __returns_twice;
void resumectx(struct pcb *);
#endif
#endif /* _AMD64_PCB_H_ */