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1156 lines
26 KiB
1156 lines
26 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Kernel Debug Core |
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* |
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* Maintainer: Jason Wessel <[email protected]> |
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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 <[email protected]> |
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* Copyright (C) 2004 Pavel Machek <[email protected]> |
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* Copyright (C) 2004-2006 Tom Rini <[email protected]> |
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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 <[email protected]> |
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* |
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* Contributors at various stages not listed above: |
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* Jason Wessel ( [email protected] ) |
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* George Anzinger <[email protected]> |
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* Anurekh Saxena ([email protected]) |
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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 <[email protected]>, |
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* Tigran Aivazian <[email protected]> |
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*/ |
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|
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#include <linux/kernel.h> |
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#include <linux/sched/signal.h> |
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#include <linux/kgdb.h> |
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#include <linux/kdb.h> |
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#include <linux/serial_core.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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|
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#define KGDB_MAX_THREAD_QUERY 17 |
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|
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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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|
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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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/* |
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* GDB remote protocol parser: |
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*/ |
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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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|
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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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|
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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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/* |
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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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|
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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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|
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/* Now see what we get in reply. */ |
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ch = gdbstub_read_wait(); |
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|
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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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/* |
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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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|
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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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|
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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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|
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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 = copy_from_kernel_nofault(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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/* |
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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 copy_to_kernel_nofault(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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/* |
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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 overwritten 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 copy_to_kernel_nofault(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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|
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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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/* |
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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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|
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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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/* |
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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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* 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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|
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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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|
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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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|
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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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|
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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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|
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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 |
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* find the matching task then we try |
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* 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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*/ |
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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 */ |
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static void gdb_cmd_setregs(struct kgdb_state *ks) |
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{ |
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kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES); |
|
|
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if (kgdb_usethread && kgdb_usethread != current) { |
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error_packet(remcom_out_buffer, -EINVAL); |
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} else { |
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gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs); |
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strcpy(remcom_out_buffer, "OK"); |
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} |
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} |
|
|
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/* Handle the 'm' memory read bytes */ |
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static void gdb_cmd_memread(struct kgdb_state *ks) |
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{ |
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char *ptr = &remcom_in_buffer[1]; |
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unsigned long length; |
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unsigned long addr; |
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char *err; |
|
|
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if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' && |
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kgdb_hex2long(&ptr, &length) > 0) { |
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err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length); |
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if (!err) |
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error_packet(remcom_out_buffer, -EINVAL); |
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} else { |
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error_packet(remcom_out_buffer, -EINVAL); |
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} |
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} |
|
|
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/* Handle the 'M' memory write bytes */ |
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static void gdb_cmd_memwrite(struct kgdb_state *ks) |
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{ |
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int err = write_mem_msg(0); |
|
|
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if (err) |
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error_packet(remcom_out_buffer, err); |
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else |
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strcpy(remcom_out_buffer, "OK"); |
|
} |
|
|
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#if DBG_MAX_REG_NUM > 0 |
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static char *gdb_hex_reg_helper(int regnum, char *out) |
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{ |
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int i; |
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int offset = 0; |
|
|
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for (i = 0; i < regnum; i++) |
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offset += dbg_reg_def[i].size; |
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return kgdb_mem2hex((char *)gdb_regs + offset, out, |
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dbg_reg_def[i].size); |
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} |
|
|
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/* Handle the 'p' individual register get */ |
|
static void gdb_cmd_reg_get(struct kgdb_state *ks) |
|
{ |
|
unsigned long regnum; |
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char *ptr = &remcom_in_buffer[1]; |
|
|
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kgdb_hex2long(&ptr, ®num); |
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if (regnum >= DBG_MAX_REG_NUM) { |
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error_packet(remcom_out_buffer, -EINVAL); |
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return; |
|
} |
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gdb_get_regs_helper(ks); |
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gdb_hex_reg_helper(regnum, remcom_out_buffer); |
|
} |
|
|
|
/* Handle the 'P' individual register 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++ != '=' || |
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!(!kgdb_usethread || kgdb_usethread == current) || |
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!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++; |
|
} |
|
} |
|
|
|
for_each_process_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++; |
|
} |
|
|
|
*(--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_common_init_state(ks); |
|
kdb_parse(remcom_out_buffer); |
|
kdb_common_deinit_state(); |
|
|
|
strcpy(remcom_out_buffer, "OK"); |
|
} |
|
break; |
|
#endif |
|
#ifdef CONFIG_HAVE_ARCH_KGDB_QXFER_PKT |
|
case 'S': |
|
if (!strncmp(remcom_in_buffer, "qSupported:", 11)) |
|
strcpy(remcom_out_buffer, kgdb_arch_gdb_stub_feature); |
|
break; |
|
case 'X': |
|
if (!strncmp(remcom_in_buffer, "qXfer:", 6)) |
|
kgdb_arch_handle_qxfer_pkt(remcom_in_buffer, |
|
remcom_out_buffer); |
|
break; |
|
#endif |
|
default: |
|
break; |
|
} |
|
} |
|
|
|
/* 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 processing |
|
*/ |
|
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; |
|
} |
|
fallthrough; |
|
#endif |
|
case 'C': /* Exception passing */ |
|
tmp = gdb_cmd_exception_pass(ks); |
|
if (tmp > 0) |
|
goto default_handle; |
|
if (tmp == 0) |
|
break; |
|
fallthrough; /* 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; |
|
} |
|
fallthrough; /* 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': |
|
strscpy(remcom_in_buffer, cmd, sizeof(remcom_in_buffer)); |
|
return 0; |
|
case '$': |
|
strscpy(remcom_in_buffer, cmd, sizeof(remcom_in_buffer)); |
|
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(); |
|
}
|
|
|