From 18f01d4462f861b3ca300944fb66322214040416 Mon Sep 17 00:00:00 2001 From: Brian Swetland Date: Tue, 8 Apr 2008 22:34:46 -0700 Subject: [PATCH] kernel_debugger_core: add interrupt-context debugger core MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This provides kernel_debugger() which can be called from an interrupt context low level debugger wedge to execute commands that inspect kernel state. It doesn't do much on its own. Signed-off-by: Brian Swetland kernel_debugger_core: Add sysrq command. sysrq will run the sysrq command and dump what was added to the kernel log while the command ran. Signed-off-by: Brian Swetland Signed-off-by: Arve Hjønnevåg --- drivers/misc/Kconfig | 7 ++++ drivers/misc/Makefile | 1 + drivers/misc/kernel_debugger.c | 79 +++++++++++++++++++++++++++++++++++++++++ include/linux/kernel_debugger.h | 41 +++++++++++++++++++++ 4 files changed, 128 insertions(+) create mode 100644 drivers/misc/kernel_debugger.c create mode 100644 include/linux/kernel_debugger.h diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index b87c5e5b10eb..6ccb11d62971 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -203,6 +203,13 @@ config ENCLOSURE_SERVICES driver (SCSI/ATA) which supports enclosures or a SCSI enclosure device (SES) to use these services. +config KERNEL_DEBUGGER_CORE + bool "Kernel Debugger Core" + default n + ---help--- + Generic kernel debugging command processor used by low level + (interrupt context) platform-specific debuggers. + config SGI_XP tristate "Support communication between SGI SSIs" depends on NET diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index 8d2b1af3ae16..3e781db84b54 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_PHANTOM) += phantom.o obj-$(CONFIG_ANDROID_PMEM) += pmem.o obj-$(CONFIG_SGI_IOC4) += ioc4.o obj-$(CONFIG_ENCLOSURE_SERVICES) += enclosure.o +obj-$(CONFIG_KERNEL_DEBUGGER_CORE) += kernel_debugger.o obj-$(CONFIG_KGDB_TESTS) += kgdbts.o obj-$(CONFIG_SGI_XP) += sgi-xp/ obj-$(CONFIG_SGI_GRU) += sgi-gru/ diff --git a/drivers/misc/kernel_debugger.c b/drivers/misc/kernel_debugger.c new file mode 100644 index 000000000000..44c19fd2f264 --- /dev/null +++ b/drivers/misc/kernel_debugger.c @@ -0,0 +1,79 @@ +/* drivers/android/kernel_debugger.c + * + * Guts of the kernel debugger. + * Needs something to actually push commands to it. + * + * Copyright (C) 2007-2008 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include +#include +#include +#include +#include +#include + +#define dprintf(fmt...) (ctxt->printf(ctxt->cookie, fmt)) + +static void do_ps(struct kdbg_ctxt *ctxt) +{ + struct task_struct *g, *p; + unsigned state; + static const char stat_nam[] = "RSDTtZX"; + + dprintf("pid ppid prio task pc\n"); + read_lock(&tasklist_lock); + do_each_thread(g, p) { + state = p->state ? __ffs(p->state) + 1 : 0; + dprintf("%5d %5d %4d ", p->pid, p->parent->pid, p->prio); + dprintf("%-13.13s %c", p->comm, + state >= sizeof(stat_nam) ? '?' : stat_nam[state]); + if (state == TASK_RUNNING) + dprintf(" running\n"); + else + dprintf(" %08lx\n", thread_saved_pc(p)); + } while_each_thread(g, p); + read_unlock(&tasklist_lock); +} + +int log_buf_copy(char *dest, int idx, int len); +extern int do_syslog(int type, char __user *bug, int count); +static void do_sysrq(struct kdbg_ctxt *ctxt, char rq) +{ + char buf[128]; + int ret; + int idx = 0; + do_syslog(5 /* clear */, NULL, 0); + handle_sysrq(rq, NULL); + while (1) { + ret = log_buf_copy(buf, idx, sizeof(buf) - 1); + if (ret <= 0) + break; + buf[ret] = 0; + dprintf("%s", buf); + idx += ret; + } +} + +int kernel_debugger(struct kdbg_ctxt *ctxt, char *cmd) +{ + if (!strcmp(cmd, "ps")) + do_ps(ctxt); + if (!strcmp(cmd, "sysrq")) + do_sysrq(ctxt, 'h'); + if (!strncmp(cmd, "sysrq ", 6)) + do_sysrq(ctxt, cmd[6]); + + return 0; +} + diff --git a/include/linux/kernel_debugger.h b/include/linux/kernel_debugger.h new file mode 100644 index 000000000000..b4dbfe99d79e --- /dev/null +++ b/include/linux/kernel_debugger.h @@ -0,0 +1,41 @@ +/* + * include/linux/kernel_debugger.h + * + * Copyright (C) 2008 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef _LINUX_KERNEL_DEBUGGER_H_ +#define _LINUX_KERNEL_DEBUGGER_H_ + +struct kdbg_ctxt { + int (*printf)(void *cookie, const char *fmt, ...); + void *cookie; +}; + +/* kernel_debugger() is called from IRQ context and should + * use the kdbg_ctxt.printf to write output (do NOT call + * printk, do operations not safe from IRQ context, etc). + * + * kdbg_ctxt.printf will return -1 if there is not enough + * buffer space or if you are being aborted. In this case + * you must return as soon as possible. + * + * Return non-zero if more data is available -- if buffer + * space ran and you had to stop, but could print more, + * for example. + * + * Additional calls where cmd is "more" will be made if + * the additional data is desired. + */ +int kernel_debugger(struct kdbg_ctxt *ctxt, char *cmd); + +#endif -- 2.11.0