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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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2366e04784
The gdbstub and kdb should get detached if the system is rebooting. Calling gdbstub_exit() will set the proper debug core state and send a message to any debugger that is connected to correctly detach. An attached debugger will receive the exit code from include/linux/reboot.h based on SYS_HALT, SYS_REBOOT, etc... Reported-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
1142 lines
25 KiB
C
1142 lines
25 KiB
C
/*
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* Kernel Debug Core
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*
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* Maintainer: Jason Wessel <jason.wessel@windriver.com>
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*
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* Copyright (C) 2000-2001 VERITAS Software Corporation.
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* Copyright (C) 2002-2004 Timesys Corporation
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* Copyright (C) 2003-2004 Amit S. Kale <amitkale@linsyssoft.com>
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* Copyright (C) 2004 Pavel Machek <pavel@ucw.cz>
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* Copyright (C) 2004-2006 Tom Rini <trini@kernel.crashing.org>
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* Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd.
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* Copyright (C) 2005-2009 Wind River Systems, Inc.
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* Copyright (C) 2007 MontaVista Software, Inc.
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* Copyright (C) 2008 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
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*
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* Contributors at various stages not listed above:
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* Jason Wessel ( jason.wessel@windriver.com )
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* George Anzinger <george@mvista.com>
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* Anurekh Saxena (anurekh.saxena@timesys.com)
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* Lake Stevens Instrument Division (Glenn Engel)
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* Jim Kingdon, Cygnus Support.
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*
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* Original KGDB stub: David Grothe <dave@gcom.com>,
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* Tigran Aivazian <tigran@sco.com>
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*
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* This file is licensed under the terms of the GNU General Public License
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* version 2. This program is licensed "as is" without any warranty of any
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* kind, whether express or implied.
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*/
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#include <linux/kernel.h>
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#include <linux/kgdb.h>
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#include <linux/kdb.h>
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#include <linux/reboot.h>
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#include <linux/uaccess.h>
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#include <asm/cacheflush.h>
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#include <asm/unaligned.h>
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#include "debug_core.h"
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#define KGDB_MAX_THREAD_QUERY 17
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/* Our I/O buffers. */
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static char remcom_in_buffer[BUFMAX];
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static char remcom_out_buffer[BUFMAX];
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static int gdbstub_use_prev_in_buf;
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static int gdbstub_prev_in_buf_pos;
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/* Storage for the registers, in GDB format. */
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static unsigned long gdb_regs[(NUMREGBYTES +
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sizeof(unsigned long) - 1) /
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sizeof(unsigned long)];
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/*
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* GDB remote protocol parser:
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*/
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#ifdef CONFIG_KGDB_KDB
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static int gdbstub_read_wait(void)
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{
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int ret = -1;
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int i;
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if (unlikely(gdbstub_use_prev_in_buf)) {
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if (gdbstub_prev_in_buf_pos < gdbstub_use_prev_in_buf)
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return remcom_in_buffer[gdbstub_prev_in_buf_pos++];
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else
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gdbstub_use_prev_in_buf = 0;
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}
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/* poll any additional I/O interfaces that are defined */
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while (ret < 0)
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for (i = 0; kdb_poll_funcs[i] != NULL; i++) {
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ret = kdb_poll_funcs[i]();
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if (ret > 0)
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break;
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}
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return ret;
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}
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#else
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static int gdbstub_read_wait(void)
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{
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int ret = dbg_io_ops->read_char();
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while (ret == NO_POLL_CHAR)
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ret = dbg_io_ops->read_char();
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return ret;
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}
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#endif
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/* scan for the sequence $<data>#<checksum> */
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static void get_packet(char *buffer)
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{
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unsigned char checksum;
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unsigned char xmitcsum;
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int count;
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char ch;
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do {
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/*
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* Spin and wait around for the start character, ignore all
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* other characters:
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*/
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while ((ch = (gdbstub_read_wait())) != '$')
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/* nothing */;
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kgdb_connected = 1;
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checksum = 0;
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xmitcsum = -1;
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count = 0;
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/*
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* now, read until a # or end of buffer is found:
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*/
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while (count < (BUFMAX - 1)) {
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ch = gdbstub_read_wait();
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if (ch == '#')
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break;
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checksum = checksum + ch;
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buffer[count] = ch;
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count = count + 1;
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}
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if (ch == '#') {
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xmitcsum = hex_to_bin(gdbstub_read_wait()) << 4;
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xmitcsum += hex_to_bin(gdbstub_read_wait());
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if (checksum != xmitcsum)
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/* failed checksum */
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dbg_io_ops->write_char('-');
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else
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/* successful transfer */
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dbg_io_ops->write_char('+');
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if (dbg_io_ops->flush)
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dbg_io_ops->flush();
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}
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buffer[count] = 0;
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} while (checksum != xmitcsum);
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}
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/*
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* Send the packet in buffer.
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* Check for gdb connection if asked for.
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*/
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static void put_packet(char *buffer)
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{
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unsigned char checksum;
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int count;
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char ch;
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/*
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* $<packet info>#<checksum>.
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*/
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while (1) {
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dbg_io_ops->write_char('$');
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checksum = 0;
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count = 0;
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while ((ch = buffer[count])) {
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dbg_io_ops->write_char(ch);
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checksum += ch;
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count++;
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}
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dbg_io_ops->write_char('#');
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dbg_io_ops->write_char(hex_asc_hi(checksum));
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dbg_io_ops->write_char(hex_asc_lo(checksum));
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if (dbg_io_ops->flush)
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dbg_io_ops->flush();
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/* Now see what we get in reply. */
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ch = gdbstub_read_wait();
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if (ch == 3)
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ch = gdbstub_read_wait();
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/* If we get an ACK, we are done. */
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if (ch == '+')
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return;
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/*
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* If we get the start of another packet, this means
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* that GDB is attempting to reconnect. We will NAK
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* the packet being sent, and stop trying to send this
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* packet.
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*/
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if (ch == '$') {
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dbg_io_ops->write_char('-');
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if (dbg_io_ops->flush)
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dbg_io_ops->flush();
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return;
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}
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}
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}
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static char gdbmsgbuf[BUFMAX + 1];
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void gdbstub_msg_write(const char *s, int len)
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{
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char *bufptr;
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int wcount;
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int i;
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if (len == 0)
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len = strlen(s);
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/* 'O'utput */
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gdbmsgbuf[0] = 'O';
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/* Fill and send buffers... */
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while (len > 0) {
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bufptr = gdbmsgbuf + 1;
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/* Calculate how many this time */
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if ((len << 1) > (BUFMAX - 2))
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wcount = (BUFMAX - 2) >> 1;
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else
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wcount = len;
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/* Pack in hex chars */
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for (i = 0; i < wcount; i++)
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bufptr = hex_byte_pack(bufptr, s[i]);
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*bufptr = '\0';
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/* Move up */
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s += wcount;
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len -= wcount;
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/* Write packet */
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put_packet(gdbmsgbuf);
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}
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}
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/*
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* Convert the memory pointed to by mem into hex, placing result in
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* buf. Return a pointer to the last char put in buf (null). May
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* return an error.
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*/
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char *kgdb_mem2hex(char *mem, char *buf, int count)
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{
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char *tmp;
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int err;
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/*
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* We use the upper half of buf as an intermediate buffer for the
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* raw memory copy. Hex conversion will work against this one.
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*/
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tmp = buf + count;
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err = probe_kernel_read(tmp, mem, count);
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if (err)
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return NULL;
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while (count > 0) {
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buf = hex_byte_pack(buf, *tmp);
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tmp++;
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count--;
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}
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*buf = 0;
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return buf;
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}
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/*
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* Convert the hex array pointed to by buf into binary to be placed in
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* mem. Return a pointer to the character AFTER the last byte
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* written. May return an error.
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*/
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int kgdb_hex2mem(char *buf, char *mem, int count)
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{
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char *tmp_raw;
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char *tmp_hex;
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/*
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* We use the upper half of buf as an intermediate buffer for the
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* raw memory that is converted from hex.
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*/
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tmp_raw = buf + count * 2;
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tmp_hex = tmp_raw - 1;
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while (tmp_hex >= buf) {
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tmp_raw--;
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*tmp_raw = hex_to_bin(*tmp_hex--);
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*tmp_raw |= hex_to_bin(*tmp_hex--) << 4;
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}
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return probe_kernel_write(mem, tmp_raw, count);
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}
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/*
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* While we find nice hex chars, build a long_val.
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* Return number of chars processed.
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*/
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int kgdb_hex2long(char **ptr, unsigned long *long_val)
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{
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int hex_val;
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int num = 0;
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int negate = 0;
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*long_val = 0;
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if (**ptr == '-') {
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negate = 1;
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(*ptr)++;
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}
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while (**ptr) {
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hex_val = hex_to_bin(**ptr);
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if (hex_val < 0)
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break;
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*long_val = (*long_val << 4) | hex_val;
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num++;
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(*ptr)++;
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}
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if (negate)
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*long_val = -*long_val;
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return num;
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}
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/*
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* Copy the binary array pointed to by buf into mem. Fix $, #, and
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* 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success.
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* The input buf is overwitten with the result to write to mem.
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*/
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static int kgdb_ebin2mem(char *buf, char *mem, int count)
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{
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int size = 0;
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char *c = buf;
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while (count-- > 0) {
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c[size] = *buf++;
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if (c[size] == 0x7d)
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c[size] = *buf++ ^ 0x20;
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size++;
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}
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return probe_kernel_write(mem, c, size);
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}
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#if DBG_MAX_REG_NUM > 0
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void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
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{
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int i;
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int idx = 0;
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char *ptr = (char *)gdb_regs;
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for (i = 0; i < DBG_MAX_REG_NUM; i++) {
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dbg_get_reg(i, ptr + idx, regs);
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idx += dbg_reg_def[i].size;
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}
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}
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void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
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{
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int i;
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int idx = 0;
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char *ptr = (char *)gdb_regs;
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for (i = 0; i < DBG_MAX_REG_NUM; i++) {
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dbg_set_reg(i, ptr + idx, regs);
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idx += dbg_reg_def[i].size;
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}
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}
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#endif /* DBG_MAX_REG_NUM > 0 */
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/* Write memory due to an 'M' or 'X' packet. */
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static int write_mem_msg(int binary)
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{
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char *ptr = &remcom_in_buffer[1];
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unsigned long addr;
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unsigned long length;
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int err;
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if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' &&
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kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') {
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if (binary)
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err = kgdb_ebin2mem(ptr, (char *)addr, length);
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else
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err = kgdb_hex2mem(ptr, (char *)addr, length);
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if (err)
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return err;
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if (CACHE_FLUSH_IS_SAFE)
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flush_icache_range(addr, addr + length);
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return 0;
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}
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return -EINVAL;
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}
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static void error_packet(char *pkt, int error)
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{
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error = -error;
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pkt[0] = 'E';
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pkt[1] = hex_asc[(error / 10)];
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pkt[2] = hex_asc[(error % 10)];
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pkt[3] = '\0';
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}
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/*
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* Thread ID accessors. We represent a flat TID space to GDB, where
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* the per CPU idle threads (which under Linux all have PID 0) are
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* remapped to negative TIDs.
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*/
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#define BUF_THREAD_ID_SIZE 8
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static char *pack_threadid(char *pkt, unsigned char *id)
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{
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unsigned char *limit;
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int lzero = 1;
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limit = id + (BUF_THREAD_ID_SIZE / 2);
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while (id < limit) {
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if (!lzero || *id != 0) {
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pkt = hex_byte_pack(pkt, *id);
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lzero = 0;
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}
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id++;
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}
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if (lzero)
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pkt = hex_byte_pack(pkt, 0);
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return pkt;
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}
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static void int_to_threadref(unsigned char *id, int value)
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{
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put_unaligned_be32(value, id);
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}
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static struct task_struct *getthread(struct pt_regs *regs, int tid)
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{
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/*
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* Non-positive TIDs are remapped to the cpu shadow information
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*/
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if (tid == 0 || tid == -1)
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tid = -atomic_read(&kgdb_active) - 2;
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if (tid < -1 && tid > -NR_CPUS - 2) {
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if (kgdb_info[-tid - 2].task)
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return kgdb_info[-tid - 2].task;
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else
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return idle_task(-tid - 2);
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}
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if (tid <= 0) {
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printk(KERN_ERR "KGDB: Internal thread select error\n");
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dump_stack();
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return NULL;
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}
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/*
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* find_task_by_pid_ns() does not take the tasklist lock anymore
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* but is nicely RCU locked - hence is a pretty resilient
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* thing to use:
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*/
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return find_task_by_pid_ns(tid, &init_pid_ns);
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}
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|
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/*
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* Remap normal tasks to their real PID,
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* CPU shadow threads are mapped to -CPU - 2
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*/
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static inline int shadow_pid(int realpid)
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{
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if (realpid)
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return realpid;
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return -raw_smp_processor_id() - 2;
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}
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|
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/*
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* All the functions that start with gdb_cmd are the various
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* operations to implement the handlers for the gdbserial protocol
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* where KGDB is communicating with an external debugger
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*/
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/* Handle the '?' status packets */
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static void gdb_cmd_status(struct kgdb_state *ks)
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{
|
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/*
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* We know that this packet is only sent
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* during initial connect. So to be safe,
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* we clear out our breakpoints now in case
|
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* GDB is reconnecting.
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*/
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dbg_remove_all_break();
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remcom_out_buffer[0] = 'S';
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hex_byte_pack(&remcom_out_buffer[1], ks->signo);
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}
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static void gdb_get_regs_helper(struct kgdb_state *ks)
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{
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struct task_struct *thread;
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void *local_debuggerinfo;
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int i;
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thread = kgdb_usethread;
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if (!thread) {
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thread = kgdb_info[ks->cpu].task;
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local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo;
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} else {
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local_debuggerinfo = NULL;
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for_each_online_cpu(i) {
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/*
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* Try to find the task on some other
|
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* or possibly this node if we do not
|
|
* find the matching task then we try
|
|
* to approximate the results.
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*/
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if (thread == kgdb_info[i].task)
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local_debuggerinfo = kgdb_info[i].debuggerinfo;
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}
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}
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|
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/*
|
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* All threads that don't have debuggerinfo should be
|
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* in schedule() sleeping, since all other CPUs
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* are in kgdb_wait, and thus have debuggerinfo.
|
|
*/
|
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if (local_debuggerinfo) {
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pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo);
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} else {
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/*
|
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* Pull stuff saved during switch_to; nothing
|
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* else is accessible (or even particularly
|
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* relevant).
|
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*
|
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* This should be enough for a stack trace.
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*/
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sleeping_thread_to_gdb_regs(gdb_regs, thread);
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}
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}
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|
|
/* Handle the 'g' get registers request */
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static void gdb_cmd_getregs(struct kgdb_state *ks)
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{
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gdb_get_regs_helper(ks);
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kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES);
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}
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|
|
/* Handle the 'G' set registers request */
|
|
static void gdb_cmd_setregs(struct kgdb_state *ks)
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{
|
|
kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES);
|
|
|
|
if (kgdb_usethread && kgdb_usethread != current) {
|
|
error_packet(remcom_out_buffer, -EINVAL);
|
|
} else {
|
|
gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs);
|
|
strcpy(remcom_out_buffer, "OK");
|
|
}
|
|
}
|
|
|
|
/* Handle the 'm' memory read bytes */
|
|
static void gdb_cmd_memread(struct kgdb_state *ks)
|
|
{
|
|
char *ptr = &remcom_in_buffer[1];
|
|
unsigned long length;
|
|
unsigned long addr;
|
|
char *err;
|
|
|
|
if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' &&
|
|
kgdb_hex2long(&ptr, &length) > 0) {
|
|
err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length);
|
|
if (!err)
|
|
error_packet(remcom_out_buffer, -EINVAL);
|
|
} else {
|
|
error_packet(remcom_out_buffer, -EINVAL);
|
|
}
|
|
}
|
|
|
|
/* Handle the 'M' memory write bytes */
|
|
static void gdb_cmd_memwrite(struct kgdb_state *ks)
|
|
{
|
|
int err = write_mem_msg(0);
|
|
|
|
if (err)
|
|
error_packet(remcom_out_buffer, err);
|
|
else
|
|
strcpy(remcom_out_buffer, "OK");
|
|
}
|
|
|
|
#if DBG_MAX_REG_NUM > 0
|
|
static char *gdb_hex_reg_helper(int regnum, char *out)
|
|
{
|
|
int i;
|
|
int offset = 0;
|
|
|
|
for (i = 0; i < regnum; i++)
|
|
offset += dbg_reg_def[i].size;
|
|
return kgdb_mem2hex((char *)gdb_regs + offset, out,
|
|
dbg_reg_def[i].size);
|
|
}
|
|
|
|
/* Handle the 'p' individual regster get */
|
|
static void gdb_cmd_reg_get(struct kgdb_state *ks)
|
|
{
|
|
unsigned long regnum;
|
|
char *ptr = &remcom_in_buffer[1];
|
|
|
|
kgdb_hex2long(&ptr, ®num);
|
|
if (regnum >= DBG_MAX_REG_NUM) {
|
|
error_packet(remcom_out_buffer, -EINVAL);
|
|
return;
|
|
}
|
|
gdb_get_regs_helper(ks);
|
|
gdb_hex_reg_helper(regnum, remcom_out_buffer);
|
|
}
|
|
|
|
/* Handle the 'P' individual regster set */
|
|
static void gdb_cmd_reg_set(struct kgdb_state *ks)
|
|
{
|
|
unsigned long regnum;
|
|
char *ptr = &remcom_in_buffer[1];
|
|
int i = 0;
|
|
|
|
kgdb_hex2long(&ptr, ®num);
|
|
if (*ptr++ != '=' ||
|
|
!(!kgdb_usethread || kgdb_usethread == current) ||
|
|
!dbg_get_reg(regnum, gdb_regs, ks->linux_regs)) {
|
|
error_packet(remcom_out_buffer, -EINVAL);
|
|
return;
|
|
}
|
|
memset(gdb_regs, 0, sizeof(gdb_regs));
|
|
while (i < sizeof(gdb_regs) * 2)
|
|
if (hex_to_bin(ptr[i]) >= 0)
|
|
i++;
|
|
else
|
|
break;
|
|
i = i / 2;
|
|
kgdb_hex2mem(ptr, (char *)gdb_regs, i);
|
|
dbg_set_reg(regnum, gdb_regs, ks->linux_regs);
|
|
strcpy(remcom_out_buffer, "OK");
|
|
}
|
|
#endif /* DBG_MAX_REG_NUM > 0 */
|
|
|
|
/* Handle the 'X' memory binary write bytes */
|
|
static void gdb_cmd_binwrite(struct kgdb_state *ks)
|
|
{
|
|
int err = write_mem_msg(1);
|
|
|
|
if (err)
|
|
error_packet(remcom_out_buffer, err);
|
|
else
|
|
strcpy(remcom_out_buffer, "OK");
|
|
}
|
|
|
|
/* Handle the 'D' or 'k', detach or kill packets */
|
|
static void gdb_cmd_detachkill(struct kgdb_state *ks)
|
|
{
|
|
int error;
|
|
|
|
/* The detach case */
|
|
if (remcom_in_buffer[0] == 'D') {
|
|
error = dbg_remove_all_break();
|
|
if (error < 0) {
|
|
error_packet(remcom_out_buffer, error);
|
|
} else {
|
|
strcpy(remcom_out_buffer, "OK");
|
|
kgdb_connected = 0;
|
|
}
|
|
put_packet(remcom_out_buffer);
|
|
} else {
|
|
/*
|
|
* Assume the kill case, with no exit code checking,
|
|
* trying to force detach the debugger:
|
|
*/
|
|
dbg_remove_all_break();
|
|
kgdb_connected = 0;
|
|
}
|
|
}
|
|
|
|
/* Handle the 'R' reboot packets */
|
|
static int gdb_cmd_reboot(struct kgdb_state *ks)
|
|
{
|
|
/* For now, only honor R0 */
|
|
if (strcmp(remcom_in_buffer, "R0") == 0) {
|
|
printk(KERN_CRIT "Executing emergency reboot\n");
|
|
strcpy(remcom_out_buffer, "OK");
|
|
put_packet(remcom_out_buffer);
|
|
|
|
/*
|
|
* Execution should not return from
|
|
* machine_emergency_restart()
|
|
*/
|
|
machine_emergency_restart();
|
|
kgdb_connected = 0;
|
|
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Handle the 'q' query packets */
|
|
static void gdb_cmd_query(struct kgdb_state *ks)
|
|
{
|
|
struct task_struct *g;
|
|
struct task_struct *p;
|
|
unsigned char thref[BUF_THREAD_ID_SIZE];
|
|
char *ptr;
|
|
int i;
|
|
int cpu;
|
|
int finished = 0;
|
|
|
|
switch (remcom_in_buffer[1]) {
|
|
case 's':
|
|
case 'f':
|
|
if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10))
|
|
break;
|
|
|
|
i = 0;
|
|
remcom_out_buffer[0] = 'm';
|
|
ptr = remcom_out_buffer + 1;
|
|
if (remcom_in_buffer[1] == 'f') {
|
|
/* Each cpu is a shadow thread */
|
|
for_each_online_cpu(cpu) {
|
|
ks->thr_query = 0;
|
|
int_to_threadref(thref, -cpu - 2);
|
|
ptr = pack_threadid(ptr, thref);
|
|
*(ptr++) = ',';
|
|
i++;
|
|
}
|
|
}
|
|
|
|
do_each_thread(g, p) {
|
|
if (i >= ks->thr_query && !finished) {
|
|
int_to_threadref(thref, p->pid);
|
|
ptr = pack_threadid(ptr, thref);
|
|
*(ptr++) = ',';
|
|
ks->thr_query++;
|
|
if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0)
|
|
finished = 1;
|
|
}
|
|
i++;
|
|
} while_each_thread(g, p);
|
|
|
|
*(--ptr) = '\0';
|
|
break;
|
|
|
|
case 'C':
|
|
/* Current thread id */
|
|
strcpy(remcom_out_buffer, "QC");
|
|
ks->threadid = shadow_pid(current->pid);
|
|
int_to_threadref(thref, ks->threadid);
|
|
pack_threadid(remcom_out_buffer + 2, thref);
|
|
break;
|
|
case 'T':
|
|
if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16))
|
|
break;
|
|
|
|
ks->threadid = 0;
|
|
ptr = remcom_in_buffer + 17;
|
|
kgdb_hex2long(&ptr, &ks->threadid);
|
|
if (!getthread(ks->linux_regs, ks->threadid)) {
|
|
error_packet(remcom_out_buffer, -EINVAL);
|
|
break;
|
|
}
|
|
if ((int)ks->threadid > 0) {
|
|
kgdb_mem2hex(getthread(ks->linux_regs,
|
|
ks->threadid)->comm,
|
|
remcom_out_buffer, 16);
|
|
} else {
|
|
static char tmpstr[23 + BUF_THREAD_ID_SIZE];
|
|
|
|
sprintf(tmpstr, "shadowCPU%d",
|
|
(int)(-ks->threadid - 2));
|
|
kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr));
|
|
}
|
|
break;
|
|
#ifdef CONFIG_KGDB_KDB
|
|
case 'R':
|
|
if (strncmp(remcom_in_buffer, "qRcmd,", 6) == 0) {
|
|
int len = strlen(remcom_in_buffer + 6);
|
|
|
|
if ((len % 2) != 0) {
|
|
strcpy(remcom_out_buffer, "E01");
|
|
break;
|
|
}
|
|
kgdb_hex2mem(remcom_in_buffer + 6,
|
|
remcom_out_buffer, len);
|
|
len = len / 2;
|
|
remcom_out_buffer[len++] = 0;
|
|
|
|
kdb_parse(remcom_out_buffer);
|
|
strcpy(remcom_out_buffer, "OK");
|
|
}
|
|
break;
|
|
#endif
|
|
}
|
|
}
|
|
|
|
/* Handle the 'H' task query packets */
|
|
static void gdb_cmd_task(struct kgdb_state *ks)
|
|
{
|
|
struct task_struct *thread;
|
|
char *ptr;
|
|
|
|
switch (remcom_in_buffer[1]) {
|
|
case 'g':
|
|
ptr = &remcom_in_buffer[2];
|
|
kgdb_hex2long(&ptr, &ks->threadid);
|
|
thread = getthread(ks->linux_regs, ks->threadid);
|
|
if (!thread && ks->threadid > 0) {
|
|
error_packet(remcom_out_buffer, -EINVAL);
|
|
break;
|
|
}
|
|
kgdb_usethread = thread;
|
|
ks->kgdb_usethreadid = ks->threadid;
|
|
strcpy(remcom_out_buffer, "OK");
|
|
break;
|
|
case 'c':
|
|
ptr = &remcom_in_buffer[2];
|
|
kgdb_hex2long(&ptr, &ks->threadid);
|
|
if (!ks->threadid) {
|
|
kgdb_contthread = NULL;
|
|
} else {
|
|
thread = getthread(ks->linux_regs, ks->threadid);
|
|
if (!thread && ks->threadid > 0) {
|
|
error_packet(remcom_out_buffer, -EINVAL);
|
|
break;
|
|
}
|
|
kgdb_contthread = thread;
|
|
}
|
|
strcpy(remcom_out_buffer, "OK");
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Handle the 'T' thread query packets */
|
|
static void gdb_cmd_thread(struct kgdb_state *ks)
|
|
{
|
|
char *ptr = &remcom_in_buffer[1];
|
|
struct task_struct *thread;
|
|
|
|
kgdb_hex2long(&ptr, &ks->threadid);
|
|
thread = getthread(ks->linux_regs, ks->threadid);
|
|
if (thread)
|
|
strcpy(remcom_out_buffer, "OK");
|
|
else
|
|
error_packet(remcom_out_buffer, -EINVAL);
|
|
}
|
|
|
|
/* Handle the 'z' or 'Z' breakpoint remove or set packets */
|
|
static void gdb_cmd_break(struct kgdb_state *ks)
|
|
{
|
|
/*
|
|
* Since GDB-5.3, it's been drafted that '0' is a software
|
|
* breakpoint, '1' is a hardware breakpoint, so let's do that.
|
|
*/
|
|
char *bpt_type = &remcom_in_buffer[1];
|
|
char *ptr = &remcom_in_buffer[2];
|
|
unsigned long addr;
|
|
unsigned long length;
|
|
int error = 0;
|
|
|
|
if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') {
|
|
/* Unsupported */
|
|
if (*bpt_type > '4')
|
|
return;
|
|
} else {
|
|
if (*bpt_type != '0' && *bpt_type != '1')
|
|
/* Unsupported. */
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Test if this is a hardware breakpoint, and
|
|
* if we support it:
|
|
*/
|
|
if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT))
|
|
/* Unsupported. */
|
|
return;
|
|
|
|
if (*(ptr++) != ',') {
|
|
error_packet(remcom_out_buffer, -EINVAL);
|
|
return;
|
|
}
|
|
if (!kgdb_hex2long(&ptr, &addr)) {
|
|
error_packet(remcom_out_buffer, -EINVAL);
|
|
return;
|
|
}
|
|
if (*(ptr++) != ',' ||
|
|
!kgdb_hex2long(&ptr, &length)) {
|
|
error_packet(remcom_out_buffer, -EINVAL);
|
|
return;
|
|
}
|
|
|
|
if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0')
|
|
error = dbg_set_sw_break(addr);
|
|
else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0')
|
|
error = dbg_remove_sw_break(addr);
|
|
else if (remcom_in_buffer[0] == 'Z')
|
|
error = arch_kgdb_ops.set_hw_breakpoint(addr,
|
|
(int)length, *bpt_type - '0');
|
|
else if (remcom_in_buffer[0] == 'z')
|
|
error = arch_kgdb_ops.remove_hw_breakpoint(addr,
|
|
(int) length, *bpt_type - '0');
|
|
|
|
if (error == 0)
|
|
strcpy(remcom_out_buffer, "OK");
|
|
else
|
|
error_packet(remcom_out_buffer, error);
|
|
}
|
|
|
|
/* Handle the 'C' signal / exception passing packets */
|
|
static int gdb_cmd_exception_pass(struct kgdb_state *ks)
|
|
{
|
|
/* C09 == pass exception
|
|
* C15 == detach kgdb, pass exception
|
|
*/
|
|
if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') {
|
|
|
|
ks->pass_exception = 1;
|
|
remcom_in_buffer[0] = 'c';
|
|
|
|
} else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') {
|
|
|
|
ks->pass_exception = 1;
|
|
remcom_in_buffer[0] = 'D';
|
|
dbg_remove_all_break();
|
|
kgdb_connected = 0;
|
|
return 1;
|
|
|
|
} else {
|
|
gdbstub_msg_write("KGDB only knows signal 9 (pass)"
|
|
" and 15 (pass and disconnect)\n"
|
|
"Executing a continue without signal passing\n", 0);
|
|
remcom_in_buffer[0] = 'c';
|
|
}
|
|
|
|
/* Indicate fall through */
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* This function performs all gdbserial command procesing
|
|
*/
|
|
int gdb_serial_stub(struct kgdb_state *ks)
|
|
{
|
|
int error = 0;
|
|
int tmp;
|
|
|
|
/* Initialize comm buffer and globals. */
|
|
memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
|
|
kgdb_usethread = kgdb_info[ks->cpu].task;
|
|
ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
|
|
ks->pass_exception = 0;
|
|
|
|
if (kgdb_connected) {
|
|
unsigned char thref[BUF_THREAD_ID_SIZE];
|
|
char *ptr;
|
|
|
|
/* Reply to host that an exception has occurred */
|
|
ptr = remcom_out_buffer;
|
|
*ptr++ = 'T';
|
|
ptr = hex_byte_pack(ptr, ks->signo);
|
|
ptr += strlen(strcpy(ptr, "thread:"));
|
|
int_to_threadref(thref, shadow_pid(current->pid));
|
|
ptr = pack_threadid(ptr, thref);
|
|
*ptr++ = ';';
|
|
put_packet(remcom_out_buffer);
|
|
}
|
|
|
|
while (1) {
|
|
error = 0;
|
|
|
|
/* Clear the out buffer. */
|
|
memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
|
|
|
|
get_packet(remcom_in_buffer);
|
|
|
|
switch (remcom_in_buffer[0]) {
|
|
case '?': /* gdbserial status */
|
|
gdb_cmd_status(ks);
|
|
break;
|
|
case 'g': /* return the value of the CPU registers */
|
|
gdb_cmd_getregs(ks);
|
|
break;
|
|
case 'G': /* set the value of the CPU registers - return OK */
|
|
gdb_cmd_setregs(ks);
|
|
break;
|
|
case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
|
|
gdb_cmd_memread(ks);
|
|
break;
|
|
case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */
|
|
gdb_cmd_memwrite(ks);
|
|
break;
|
|
#if DBG_MAX_REG_NUM > 0
|
|
case 'p': /* pXX Return gdb register XX (in hex) */
|
|
gdb_cmd_reg_get(ks);
|
|
break;
|
|
case 'P': /* PXX=aaaa Set gdb register XX to aaaa (in hex) */
|
|
gdb_cmd_reg_set(ks);
|
|
break;
|
|
#endif /* DBG_MAX_REG_NUM > 0 */
|
|
case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */
|
|
gdb_cmd_binwrite(ks);
|
|
break;
|
|
/* kill or detach. KGDB should treat this like a
|
|
* continue.
|
|
*/
|
|
case 'D': /* Debugger detach */
|
|
case 'k': /* Debugger detach via kill */
|
|
gdb_cmd_detachkill(ks);
|
|
goto default_handle;
|
|
case 'R': /* Reboot */
|
|
if (gdb_cmd_reboot(ks))
|
|
goto default_handle;
|
|
break;
|
|
case 'q': /* query command */
|
|
gdb_cmd_query(ks);
|
|
break;
|
|
case 'H': /* task related */
|
|
gdb_cmd_task(ks);
|
|
break;
|
|
case 'T': /* Query thread status */
|
|
gdb_cmd_thread(ks);
|
|
break;
|
|
case 'z': /* Break point remove */
|
|
case 'Z': /* Break point set */
|
|
gdb_cmd_break(ks);
|
|
break;
|
|
#ifdef CONFIG_KGDB_KDB
|
|
case '3': /* Escape into back into kdb */
|
|
if (remcom_in_buffer[1] == '\0') {
|
|
gdb_cmd_detachkill(ks);
|
|
return DBG_PASS_EVENT;
|
|
}
|
|
#endif
|
|
case 'C': /* Exception passing */
|
|
tmp = gdb_cmd_exception_pass(ks);
|
|
if (tmp > 0)
|
|
goto default_handle;
|
|
if (tmp == 0)
|
|
break;
|
|
/* Fall through on tmp < 0 */
|
|
case 'c': /* Continue packet */
|
|
case 's': /* Single step packet */
|
|
if (kgdb_contthread && kgdb_contthread != current) {
|
|
/* Can't switch threads in kgdb */
|
|
error_packet(remcom_out_buffer, -EINVAL);
|
|
break;
|
|
}
|
|
dbg_activate_sw_breakpoints();
|
|
/* Fall through to default processing */
|
|
default:
|
|
default_handle:
|
|
error = kgdb_arch_handle_exception(ks->ex_vector,
|
|
ks->signo,
|
|
ks->err_code,
|
|
remcom_in_buffer,
|
|
remcom_out_buffer,
|
|
ks->linux_regs);
|
|
/*
|
|
* Leave cmd processing on error, detach,
|
|
* kill, continue, or single step.
|
|
*/
|
|
if (error >= 0 || remcom_in_buffer[0] == 'D' ||
|
|
remcom_in_buffer[0] == 'k') {
|
|
error = 0;
|
|
goto kgdb_exit;
|
|
}
|
|
|
|
}
|
|
|
|
/* reply to the request */
|
|
put_packet(remcom_out_buffer);
|
|
}
|
|
|
|
kgdb_exit:
|
|
if (ks->pass_exception)
|
|
error = 1;
|
|
return error;
|
|
}
|
|
|
|
int gdbstub_state(struct kgdb_state *ks, char *cmd)
|
|
{
|
|
int error;
|
|
|
|
switch (cmd[0]) {
|
|
case 'e':
|
|
error = kgdb_arch_handle_exception(ks->ex_vector,
|
|
ks->signo,
|
|
ks->err_code,
|
|
remcom_in_buffer,
|
|
remcom_out_buffer,
|
|
ks->linux_regs);
|
|
return error;
|
|
case 's':
|
|
case 'c':
|
|
strcpy(remcom_in_buffer, cmd);
|
|
return 0;
|
|
case '$':
|
|
strcpy(remcom_in_buffer, cmd);
|
|
gdbstub_use_prev_in_buf = strlen(remcom_in_buffer);
|
|
gdbstub_prev_in_buf_pos = 0;
|
|
return 0;
|
|
}
|
|
dbg_io_ops->write_char('+');
|
|
put_packet(remcom_out_buffer);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* gdbstub_exit - Send an exit message to GDB
|
|
* @status: The exit code to report.
|
|
*/
|
|
void gdbstub_exit(int status)
|
|
{
|
|
unsigned char checksum, ch, buffer[3];
|
|
int loop;
|
|
|
|
if (!kgdb_connected)
|
|
return;
|
|
kgdb_connected = 0;
|
|
|
|
if (!dbg_io_ops || dbg_kdb_mode)
|
|
return;
|
|
|
|
buffer[0] = 'W';
|
|
buffer[1] = hex_asc_hi(status);
|
|
buffer[2] = hex_asc_lo(status);
|
|
|
|
dbg_io_ops->write_char('$');
|
|
checksum = 0;
|
|
|
|
for (loop = 0; loop < 3; loop++) {
|
|
ch = buffer[loop];
|
|
checksum += ch;
|
|
dbg_io_ops->write_char(ch);
|
|
}
|
|
|
|
dbg_io_ops->write_char('#');
|
|
dbg_io_ops->write_char(hex_asc_hi(checksum));
|
|
dbg_io_ops->write_char(hex_asc_lo(checksum));
|
|
|
|
/* make sure the output is flushed, lest the bootloader clobber it */
|
|
if (dbg_io_ops->flush)
|
|
dbg_io_ops->flush();
|
|
}
|