freebsd-nq/sys/amd64/amd64/db_interface.c
Konstantin Belousov 2337dc6430 Provide KPI for handling of rw/ro kernel text.
This is a pure syntax patch to create an interface to enable and later
restore write access to the kernel text and other read-only mapped
regions.  It is in line with e.g. vm_fault_disable_pagefaults() by
allowing the nesting.

Discussed with:	Peter Lei <peter.lei@ieee.org>
Reviewed by:	jtl
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D14768
2018-03-20 17:43:50 +00:00

108 lines
2.6 KiB
C

/*-
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Interface to new debugger.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kdb.h>
#include <sys/pcpu.h>
#include <machine/cpufunc.h>
#include <machine/md_var.h>
#include <machine/specialreg.h>
#include <ddb/ddb.h>
/*
* Read bytes from kernel address space for debugger.
*/
int
db_read_bytes(vm_offset_t addr, size_t size, char *data)
{
jmp_buf jb;
void *prev_jb;
char *src;
int ret;
prev_jb = kdb_jmpbuf(jb);
ret = setjmp(jb);
if (ret == 0) {
src = (char *)addr;
while (size-- > 0)
*data++ = *src++;
}
(void)kdb_jmpbuf(prev_jb);
return (ret);
}
/*
* Write bytes to kernel address space for debugger.
* We need to disable write protection temporarily so we can write
* things (such as break points) that might be in write-protected
* memory.
*/
int
db_write_bytes(vm_offset_t addr, size_t size, char *data)
{
jmp_buf jb;
void *prev_jb;
char *dst;
bool old_wp;
int ret;
old_wp = false;
prev_jb = kdb_jmpbuf(jb);
ret = setjmp(jb);
if (ret == 0) {
old_wp = disable_wp();
dst = (char *)addr;
while (size-- > 0)
*dst++ = *data++;
}
restore_wp(old_wp);
(void)kdb_jmpbuf(prev_jb);
return (ret);
}
void
db_show_mdpcpu(struct pcpu *pc)
{
db_printf("curpmap = %p\n", pc->pc_curpmap);
db_printf("tssp = %p\n", pc->pc_tssp);
db_printf("commontssp = %p\n", pc->pc_commontssp);
db_printf("rsp0 = 0x%lx\n", pc->pc_rsp0);
db_printf("gs32p = %p\n", pc->pc_gs32p);
db_printf("ldt = %p\n", pc->pc_ldt);
db_printf("tss = %p\n", pc->pc_tss);
}