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kdb: core for kgdb back end (1 of 2)

Browse source 
This patch contains only the kdb core.  Because the change set was
large, it was split.  The next patch in the series includes the
instrumentation into the core kernel which are mainly helper functions
for kdb.

This work is directly derived from kdb v4.4 found at:

ftp://oss.sgi.com/projects/kdb/download/v4.4/

The kdb internals have been re-organized to make them mostly platform
independent and to connect everything to the debug core which is used by
gdbstub (which has long been known as kgdb).

The original version of kdb was 58,000 lines worth of changes to
support x86.  From that implementation only the kdb shell, and basic
commands for memory access, runcontrol, lsmod, and dmesg where carried
forward.

This is a generic implementation which aims to cover all the current
architectures using the kgdb core: ppc, arm, x86, mips, sparc, sh and
blackfin.  More archictectures can be added by implementing the
architecture specific kgdb functions.

[mort@sgi.com: Compile fix with hugepages enabled]
[mort@sgi.com: Clean breakpoint code renaming kdba_ -> kdb_]
[mort@sgi.com: fix new line after printing registers]
[mort@sgi.com: Remove the concept of global vs. local breakpoints]
[mort@sgi.com: Rework kdb_si_swapinfo to use more generic name]
[mort@sgi.com: fix the information dump macros, remove 'arch' from the names]
[sfr@canb.auug.org.au: include fixup to include linux/slab.h]

CC: linux-arch@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Martin Hicks <mort@sgi.com>
This commit is contained in:
Jason Wessel 2010-05-20 21:04:20 -05:00
parent e8861129d3
commit 5d5314d679
12 changed files with 5967 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

113
include/linux/kdb.h Normal file
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#ifndef _KDB_H
#define _KDB_H
/*
* Kernel Debugger Architecture Independent Global Headers
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2000-2007 Silicon Graphics, Inc. All Rights Reserved.
* Copyright (C) 2000 Stephane Eranian <eranian@hpl.hp.com>
* Copyright (C) 2009 Jason Wessel <jason.wessel@windriver.com>
*/
#ifdef CONFIG_KGDB_KDB
#include <linux/init.h>
#include <linux/sched.h>
#include <asm/atomic.h>
#define KDB_POLL_FUNC_MAX 5
/*
* kdb_initial_cpu is initialized to -1, and is set to the cpu
* number whenever the kernel debugger is entered.
*/
extern int kdb_initial_cpu;
extern atomic_t kdb_event;
/*
* kdb_diemsg
*
* Contains a pointer to the last string supplied to the
* kernel 'die' panic function.
*/
extern const char *kdb_diemsg;
#define KDB_FLAG_EARLYKDB (1 << 0) /* set from boot parameter kdb=early */
#define KDB_FLAG_CATASTROPHIC (1 << 1) /* A catastrophic event has occurred */
#define KDB_FLAG_CMD_INTERRUPT (1 << 2) /* Previous command was interrupted */
#define KDB_FLAG_NOIPI (1 << 3) /* Do not send IPIs */
#define KDB_FLAG_ONLY_DO_DUMP (1 << 4) /* Only do a dump, used when
* kdb is off */
#define KDB_FLAG_NO_CONSOLE (1 << 5) /* No console is available,
* kdb is disabled */
#define KDB_FLAG_NO_VT_CONSOLE (1 << 6) /* No VT console is available, do
* not use keyboard */
#define KDB_FLAG_NO_I8042 (1 << 7) /* No i8042 chip is available, do
* not use keyboard */
extern int kdb_flags; /* Global flags, see kdb_state for per cpu state */
extern void kdb_save_flags(void);
extern void kdb_restore_flags(void);
#define KDB_FLAG(flag) (kdb_flags & KDB_FLAG_##flag)
#define KDB_FLAG_SET(flag) ((void)(kdb_flags |= KDB_FLAG_##flag))
#define KDB_FLAG_CLEAR(flag) ((void)(kdb_flags &= ~KDB_FLAG_##flag))
/*
* External entry point for the kernel debugger. The pt_regs
* at the time of entry are supplied along with the reason for
* entry to the kernel debugger.
*/
typedef enum {
KDB_REASON_ENTER = 1, /* KDB_ENTER() trap/fault - regs valid */
KDB_REASON_ENTER_SLAVE, /* KDB_ENTER_SLAVE() trap/fault - regs valid */
KDB_REASON_BREAK, /* Breakpoint inst. - regs valid */
KDB_REASON_DEBUG, /* Debug Fault - regs valid */
KDB_REASON_OOPS, /* Kernel Oops - regs valid */
KDB_REASON_SWITCH, /* CPU switch - regs valid*/
KDB_REASON_KEYBOARD, /* Keyboard entry - regs valid */
KDB_REASON_NMI, /* Non-maskable interrupt; regs valid */
KDB_REASON_RECURSE, /* Recursive entry to kdb;
* regs probably valid */
KDB_REASON_SSTEP, /* Single Step trap. - regs valid */
} kdb_reason_t;
extern int kdb_printf(const char *, ...)
__attribute__ ((format (printf, 1, 2)));
typedef int (*kdb_printf_t)(const char *, ...)
__attribute__ ((format (printf, 1, 2)));
extern void kdb_init(int level);
/* Access to kdb specific polling devices */
typedef int (*get_char_func)(void);
extern get_char_func kdb_poll_funcs[];
extern int kdb_get_kbd_char(void);
static inline
int kdb_process_cpu(const struct task_struct *p)
{
unsigned int cpu = task_thread_info(p)->cpu;
if (cpu > num_possible_cpus())
cpu = 0;
return cpu;
}
/* kdb access to register set for stack dumping */
extern struct pt_regs *kdb_current_regs;
#else /* ! CONFIG_KGDB_KDB */
#define kdb_printf(...)
#define kdb_init(x)
#endif /* CONFIG_KGDB_KDB */
enum {
KDB_NOT_INITIALIZED,
KDB_INIT_EARLY,
KDB_INIT_FULL,
};
#endif /* !_KDB_H */

1
kernel/debug/Makefile
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#
obj-$(CONFIG_KGDB) += debug_core.o gdbstub.o
obj-$(CONFIG_KGDB_KDB) += kdb/

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kernel/debug/kdb/.gitignore vendored Normal file
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gen-kdb_cmds.c

24
kernel/debug/kdb/Makefile Normal file
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# This file is subject to the terms and conditions of the GNU General Public
# License. See the file "COPYING" in the main directory of this archive
# for more details.
#
# Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved.
# Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
#
CCVERSION := $(shell $(CC) -v 2>&1 | sed -ne '$$p')
obj-y := kdb_io.o kdb_main.o kdb_support.o kdb_bt.o gen-kdb_cmds.o kdb_bp.o kdb_debugger.o
clean-files := gen-kdb_cmds.c
quiet_cmd_gen-kdb = GENKDB $@
cmd_gen-kdb = $(AWK) 'BEGIN {print "\#include <linux/stddef.h>"; print "\#include <linux/init.h>"} \
/^\#/{next} \
/^[ \t]*$$/{next} \
{gsub(/"/, "\\\"", $$0); \
print "static __initdata char kdb_cmd" cmds++ "[] = \"" $$0 "\\n\";"} \
END {print "extern char *kdb_cmds[]; char __initdata *kdb_cmds[] = {"; for (i = 0; i < cmds; ++i) {print " kdb_cmd" i ","}; print(" NULL\n};");}' \
$(filter-out %/Makefile,$^) > $@#
$(obj)/gen-kdb_cmds.c: $(src)/kdb_cmds $(src)/Makefile
$(call cmd,gen-kdb)

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/*
* Kernel Debugger Architecture Independent Breakpoint Handler
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved.
* Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
*/
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/kdb.h>
#include <linux/kgdb.h>
#include <linux/smp.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include "kdb_private.h"
/*
* Table of kdb_breakpoints
*/
kdb_bp_t kdb_breakpoints[KDB_MAXBPT];
static void kdb_setsinglestep(struct pt_regs *regs)
{
KDB_STATE_SET(DOING_SS);
}
static char *kdb_rwtypes[] = {
"Instruction(i)",
"Instruction(Register)",
"Data Write",
"I/O",
"Data Access"
};
static char *kdb_bptype(kdb_bp_t *bp)
{
if (bp->bp_type < 0 || bp->bp_type > 4)
return "";
return kdb_rwtypes[bp->bp_type];
}
static int kdb_parsebp(int argc, const char **argv, int *nextargp, kdb_bp_t *bp)
{
int nextarg = *nextargp;
int diag;
bp->bph_length = 1;
if ((argc + 1) != nextarg) {
if (strnicmp(argv[nextarg], "datar", sizeof("datar")) == 0)
bp->bp_type = BP_ACCESS_WATCHPOINT;
else if (strnicmp(argv[nextarg], "dataw", sizeof("dataw")) == 0)
bp->bp_type = BP_WRITE_WATCHPOINT;
else if (strnicmp(argv[nextarg], "inst", sizeof("inst")) == 0)
bp->bp_type = BP_HARDWARE_BREAKPOINT;
else
return KDB_ARGCOUNT;
bp->bph_length = 1;
nextarg++;
if ((argc + 1) != nextarg) {
unsigned long len;
diag = kdbgetularg((char *)argv[nextarg],
&len);
if (diag)
return diag;
if (len > 8)
return KDB_BADLENGTH;
bp->bph_length = len;
nextarg++;
}
if ((argc + 1) != nextarg)
return KDB_ARGCOUNT;
}
*nextargp = nextarg;
return 0;
}
static int _kdb_bp_remove(kdb_bp_t *bp)
{
int ret = 1;
if (!bp->bp_installed)
return ret;
if (!bp->bp_type)
ret = dbg_remove_sw_break(bp->bp_addr);
else
ret = arch_kgdb_ops.remove_hw_breakpoint(bp->bp_addr,
bp->bph_length,
bp->bp_type);
if (ret == 0)
bp->bp_installed = 0;
return ret;
}
static void kdb_handle_bp(struct pt_regs *regs, kdb_bp_t *bp)
{
if (KDB_DEBUG(BP))
kdb_printf("regs->ip = 0x%lx\n", instruction_pointer(regs));
/*
* Setup single step
*/
kdb_setsinglestep(regs);
/*
* Reset delay attribute
*/
bp->bp_delay = 0;
bp->bp_delayed = 1;
}
static int _kdb_bp_install(struct pt_regs *regs, kdb_bp_t *bp)
{
int ret;
/*
* Install the breakpoint, if it is not already installed.
*/
if (KDB_DEBUG(BP))
kdb_printf("%s: bp_installed %d\n",
__func__, bp->bp_installed);
if (!KDB_STATE(SSBPT))
bp->bp_delay = 0;
if (bp->bp_installed)
return 1;
if (bp->bp_delay || (bp->bp_delayed && KDB_STATE(DOING_SS))) {
if (KDB_DEBUG(BP))
kdb_printf("%s: delayed bp\n", __func__);
kdb_handle_bp(regs, bp);
return 0;
}
if (!bp->bp_type)
ret = dbg_set_sw_break(bp->bp_addr);
else
ret = arch_kgdb_ops.set_hw_breakpoint(bp->bp_addr,
bp->bph_length,
bp->bp_type);
if (ret == 0) {
bp->bp_installed = 1;
} else {
kdb_printf("%s: failed to set breakpoint at 0x%lx\n",
__func__, bp->bp_addr);
return 1;
}
return 0;
}
/*
* kdb_bp_install
*
* Install kdb_breakpoints prior to returning from the
* kernel debugger. This allows the kdb_breakpoints to be set
* upon functions that are used internally by kdb, such as
* printk(). This function is only called once per kdb session.
*/
void kdb_bp_install(struct pt_regs *regs)
{
int i;
for (i = 0; i < KDB_MAXBPT; i++) {
kdb_bp_t *bp = &kdb_breakpoints[i];
if (KDB_DEBUG(BP)) {
kdb_printf("%s: bp %d bp_enabled %d\n",
__func__, i, bp->bp_enabled);
}
if (bp->bp_enabled)
_kdb_bp_install(regs, bp);
}
}
/*
* kdb_bp_remove
*
* Remove kdb_breakpoints upon entry to the kernel debugger.
*
* Parameters:
* None.
* Outputs:
* None.
* Returns:
* None.
* Locking:
* None.
* Remarks:
*/
void kdb_bp_remove(void)
{
int i;
for (i = KDB_MAXBPT - 1; i >= 0; i--) {
kdb_bp_t *bp = &kdb_breakpoints[i];
if (KDB_DEBUG(BP)) {
kdb_printf("%s: bp %d bp_enabled %d\n",
__func__, i, bp->bp_enabled);
}
if (bp->bp_enabled)
_kdb_bp_remove(bp);
}
}
/*
* kdb_printbp
*
* Internal function to format and print a breakpoint entry.
*
* Parameters:
* None.
* Outputs:
* None.
* Returns:
* None.
* Locking:
* None.
* Remarks:
*/
static void kdb_printbp(kdb_bp_t *bp, int i)
{
kdb_printf("%s ", kdb_bptype(bp));
kdb_printf("BP #%d at ", i);
kdb_symbol_print(bp->bp_addr, NULL, KDB_SP_DEFAULT);
if (bp->bp_enabled)
kdb_printf("\n is enabled");
else
kdb_printf("\n is disabled");
kdb_printf("\taddr at %016lx, hardtype=%d installed=%d\n",
bp->bp_addr, bp->bp_type, bp->bp_installed);
kdb_printf("\n");
}
/*
* kdb_bp
*
* Handle the bp commands.
*
* [bp|bph] <addr-expression> [DATAR|DATAW]
*
* Parameters:
* argc Count of arguments in argv
* argv Space delimited command line arguments
* Outputs:
* None.
* Returns:
* Zero for success, a kdb diagnostic if failure.
* Locking:
* None.
* Remarks:
*
* bp Set breakpoint on all cpus. Only use hardware assist if need.
* bph Set breakpoint on all cpus. Force hardware register
*/
static int kdb_bp(int argc, const char **argv)
{
int i, bpno;
kdb_bp_t *bp, *bp_check;
int diag;
int free;
char *symname = NULL;
long offset = 0ul;
int nextarg;
kdb_bp_t template = {0};
if (argc == 0) {
/*
* Display breakpoint table
*/
for (bpno = 0, bp = kdb_breakpoints; bpno < KDB_MAXBPT;
bpno++, bp++) {
if (bp->bp_free)
continue;
kdb_printbp(bp, bpno);
}
return 0;
}
nextarg = 1;
diag = kdbgetaddrarg(argc, argv, &nextarg, &template.bp_addr,
&offset, &symname);
if (diag)
return diag;
if (!template.bp_addr)
return KDB_BADINT;
/*
* Find an empty bp structure to allocate
*/
free = KDB_MAXBPT;
for (bpno = 0, bp = kdb_breakpoints; bpno < KDB_MAXBPT; bpno++, bp++) {
if (bp->bp_free)
break;
}
if (bpno == KDB_MAXBPT)
return KDB_TOOMANYBPT;
if (strcmp(argv[0], "bph") == 0) {
template.bp_type = BP_HARDWARE_BREAKPOINT;
diag = kdb_parsebp(argc, argv, &nextarg, &template);
if (diag)
return diag;
} else {
template.bp_type = BP_BREAKPOINT;
}
/*
* Check for clashing breakpoints.
*
* Note, in this design we can't have hardware breakpoints
* enabled for both read and write on the same address.
*/
for (i = 0, bp_check = kdb_breakpoints; i < KDB_MAXBPT;
i++, bp_check++) {
if (!bp_check->bp_free &&
bp_check->bp_addr == template.bp_addr) {
kdb_printf("You already have a breakpoint at "
kdb_bfd_vma_fmt0 "\n", template.bp_addr);
return KDB_DUPBPT;
}
}
template.bp_enabled = 1;
/*
* Actually allocate the breakpoint found earlier
*/
*bp = template;
bp->bp_free = 0;
kdb_printbp(bp, bpno);
return 0;
}
/*
* kdb_bc
*
* Handles the 'bc', 'be', and 'bd' commands
*
* [bd|bc|be] <breakpoint-number>
* [bd|bc|be] *
*
* Parameters:
* argc Count of arguments in argv
* argv Space delimited command line arguments
* Outputs:
* None.
* Returns:
* Zero for success, a kdb diagnostic for failure
* Locking:
* None.
* Remarks:
*/
static int kdb_bc(int argc, const char **argv)
{
unsigned long addr;
kdb_bp_t *bp = NULL;
int lowbp = KDB_MAXBPT;
int highbp = 0;
int done = 0;
int i;
int diag = 0;
int cmd; /* KDBCMD_B? */
#define KDBCMD_BC 0
#define KDBCMD_BE 1
#define KDBCMD_BD 2
if (strcmp(argv[0], "be") == 0)
cmd = KDBCMD_BE;
else if (strcmp(argv[0], "bd") == 0)
cmd = KDBCMD_BD;
else
cmd = KDBCMD_BC;
if (argc != 1)
return KDB_ARGCOUNT;
if (strcmp(argv[1], "*") == 0) {
lowbp = 0;
highbp = KDB_MAXBPT;
} else {
diag = kdbgetularg(argv[1], &addr);
if (diag)
return diag;
/*
* For addresses less than the maximum breakpoint number,
* assume that the breakpoint number is desired.
*/
if (addr < KDB_MAXBPT) {
bp = &kdb_breakpoints[addr];
lowbp = highbp = addr;
highbp++;
} else {
for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT;
i++, bp++) {
if (bp->bp_addr == addr) {
lowbp = highbp = i;
highbp++;
break;
}
}
}
}
/*
* Now operate on the set of breakpoints matching the input
* criteria (either '*' for all, or an individual breakpoint).
*/
for (bp = &kdb_breakpoints[lowbp], i = lowbp;
i < highbp;
i++, bp++) {
if (bp->bp_free)
continue;
done++;
switch (cmd) {
case KDBCMD_BC:
bp->bp_enabled = 0;
kdb_printf("Breakpoint %d at "
kdb_bfd_vma_fmt " cleared\n",
i, bp->bp_addr);
bp->bp_addr = 0;
bp->bp_free = 1;
break;
case KDBCMD_BE:
bp->bp_enabled = 1;
kdb_printf("Breakpoint %d at "
kdb_bfd_vma_fmt " enabled",
i, bp->bp_addr);
kdb_printf("\n");
break;
case KDBCMD_BD:
if (!bp->bp_enabled)
break;
bp->bp_enabled = 0;
kdb_printf("Breakpoint %d at "
kdb_bfd_vma_fmt " disabled\n",
i, bp->bp_addr);
break;
}
if (bp->bp_delay && (cmd == KDBCMD_BC || cmd == KDBCMD_BD)) {
bp->bp_delay = 0;
KDB_STATE_CLEAR(SSBPT);
}
}
return (!done) ? KDB_BPTNOTFOUND : 0;
}
/*
* kdb_ss
*
* Process the 'ss' (Single Step) and 'ssb' (Single Step to Branch)
* commands.
*
* ss
* ssb
*
* Parameters:
* argc Argument count
* argv Argument vector
* Outputs:
* None.
* Returns:
* KDB_CMD_SS[B] for success, a kdb error if failure.
* Locking:
* None.
* Remarks:
*
* Set the arch specific option to trigger a debug trap after the next
* instruction.
*
* For 'ssb', set the trace flag in the debug trap handler
* after printing the current insn and return directly without
* invoking the kdb command processor, until a branch instruction
* is encountered.
*/
static int kdb_ss(int argc, const char **argv)
{
int ssb = 0;
ssb = (strcmp(argv[0], "ssb") == 0);
if (argc != 0)
return KDB_ARGCOUNT;
/*
* Set trace flag and go.
*/
KDB_STATE_SET(DOING_SS);
if (ssb) {
KDB_STATE_SET(DOING_SSB);
return KDB_CMD_SSB;
}
return KDB_CMD_SS;
}
/* Initialize the breakpoint table and register breakpoint commands. */
void __init kdb_initbptab(void)
{
int i;
kdb_bp_t *bp;
/*
* First time initialization.
*/
memset(&kdb_breakpoints, '\0', sizeof(kdb_breakpoints));
for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++)
bp->bp_free = 1;
kdb_register_repeat("bp", kdb_bp, "[<vaddr>]",
"Set/Display breakpoints", 0, KDB_REPEAT_NO_ARGS);
kdb_register_repeat("bl", kdb_bp, "[<vaddr>]",
"Display breakpoints", 0, KDB_REPEAT_NO_ARGS);
if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)
kdb_register_repeat("bph", kdb_bp, "[<vaddr>]",
"[datar [length]|dataw [length]] Set hw brk", 0, KDB_REPEAT_NO_ARGS);
kdb_register_repeat("bc", kdb_bc, "<bpnum>",
"Clear Breakpoint", 0, KDB_REPEAT_NONE);
kdb_register_repeat("be", kdb_bc, "<bpnum>",
"Enable Breakpoint", 0, KDB_REPEAT_NONE);
kdb_register_repeat("bd", kdb_bc, "<bpnum>",
"Disable Breakpoint", 0, KDB_REPEAT_NONE);
kdb_register_repeat("ss", kdb_ss, "",
"Single Step", 1, KDB_REPEAT_NO_ARGS);
kdb_register_repeat("ssb", kdb_ss, "",
"Single step to branch/call", 0, KDB_REPEAT_NO_ARGS);
/*
* Architecture dependent initialization.
*/
}

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/*
* Kernel Debugger Architecture Independent Stack Traceback
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved.
* Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
*/
#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/kdb.h>
#include <linux/nmi.h>
#include <asm/system.h>
#include "kdb_private.h"
static void kdb_show_stack(struct task_struct *p, void *addr)
{
int old_lvl = console_loglevel;
console_loglevel = 15;
kdb_set_current_task(p);
if (addr) {
show_stack((struct task_struct *)p, addr);
} else if (kdb_current_regs) {
#ifdef CONFIG_X86
show_stack(p, &kdb_current_regs->sp);
#else
show_stack(p, NULL);
#endif
} else {
show_stack(p, NULL);
}
console_loglevel = old_lvl;
}
/*
* kdb_bt
*
* This function implements the 'bt' command. Print a stack
* traceback.
*
* bt [<address-expression>] (addr-exp is for alternate stacks)
* btp <pid> Kernel stack for <pid>
* btt <address-expression> Kernel stack for task structure at
* <address-expression>
* bta [DRSTCZEUIMA] All useful processes, optionally
* filtered by state
* btc [<cpu>] The current process on one cpu,
* default is all cpus
*
* bt <address-expression> refers to a address on the stack, that location
* is assumed to contain a return address.
*
* btt <address-expression> refers to the address of a struct task.
*
* Inputs:
* argc argument count
* argv argument vector
* Outputs:
* None.
* Returns:
* zero for success, a kdb diagnostic if error
* Locking:
* none.
* Remarks:
* Backtrack works best when the code uses frame pointers. But even
* without frame pointers we should get a reasonable trace.
*
* mds comes in handy when examining the stack to do a manual traceback or
* to get a starting point for bt <address-expression>.
*/
static int
kdb_bt1(struct task_struct *p, unsigned long mask,
int argcount, int btaprompt)
{
char buffer[2];
if (kdb_getarea(buffer[0], (unsigned long)p) ||
kdb_getarea(buffer[0], (unsigned long)(p+1)-1))
return KDB_BADADDR;
if (!kdb_task_state(p, mask))
return 0;
kdb_printf("Stack traceback for pid %d\n", p->pid);
kdb_ps1(p);
kdb_show_stack(p, NULL);
if (btaprompt) {
kdb_getstr(buffer, sizeof(buffer),
"Enter <q> to end, <cr> to continue:");
if (buffer[0] == 'q') {
kdb_printf("\n");
return 1;
}
}
touch_nmi_watchdog();
return 0;
}
int
kdb_bt(int argc, const char **argv)
{
int diag;
int argcount = 5;
int btaprompt = 1;
int nextarg;
unsigned long addr;
long offset;
kdbgetintenv("BTARGS", &argcount); /* Arguments to print */
kdbgetintenv("BTAPROMPT", &btaprompt); /* Prompt after each
* proc in bta */
if (strcmp(argv[0], "bta") == 0) {
struct task_struct *g, *p;
unsigned long cpu;
unsigned long mask = kdb_task_state_string(argc ? argv[1] :
NULL);
if (argc == 0)
kdb_ps_suppressed();
/* Run the active tasks first */
for_each_online_cpu(cpu) {
p = kdb_curr_task(cpu);
if (kdb_bt1(p, mask, argcount, btaprompt))
return 0;
}
/* Now the inactive tasks */
kdb_do_each_thread(g, p) {
if (task_curr(p))
continue;
if (kdb_bt1(p, mask, argcount, btaprompt))
return 0;
} kdb_while_each_thread(g, p);
} else if (strcmp(argv[0], "btp") == 0) {
struct task_struct *p;
unsigned long pid;
if (argc != 1)
return KDB_ARGCOUNT;
diag = kdbgetularg((char *)argv[1], &pid);
if (diag)
return diag;
p = find_task_by_pid_ns(pid, &init_pid_ns);
if (p) {
kdb_set_current_task(p);
return kdb_bt1(p, ~0UL, argcount, 0);
}
kdb_printf("No process with pid == %ld found\n", pid);
return 0;
} else if (strcmp(argv[0], "btt") == 0) {
if (argc != 1)
return KDB_ARGCOUNT;
diag = kdbgetularg((char *)argv[1], &addr);
if (diag)
return diag;
kdb_set_current_task((struct task_struct *)addr);
return kdb_bt1((struct task_struct *)addr, ~0UL, argcount, 0);
} else if (strcmp(argv[0], "btc") == 0) {
unsigned long cpu = ~0;
struct task_struct *save_current_task = kdb_current_task;
char buf[80];
if (argc > 1)
return KDB_ARGCOUNT;
if (argc == 1) {
diag = kdbgetularg((char *)argv[1], &cpu);
if (diag)
return diag;
}
/* Recursive use of kdb_parse, do not use argv after
* this point */
argv = NULL;
if (cpu != ~0) {
if (cpu >= num_possible_cpus() || !cpu_online(cpu)) {
kdb_printf("no process for cpu %ld\n", cpu);
return 0;
}
sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu));
kdb_parse(buf);
return 0;
}
kdb_printf("btc: cpu status: ");
kdb_parse("cpu\n");
for_each_online_cpu(cpu) {
sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu));
kdb_parse(buf);
touch_nmi_watchdog();
}
kdb_set_current_task(save_current_task);
return 0;
} else {
if (argc) {
nextarg = 1;
diag = kdbgetaddrarg(argc, argv, &nextarg, &addr,
&offset, NULL);
if (diag)
return diag;
kdb_show_stack(kdb_current_task, (void *)addr);
return 0;
} else {
return kdb_bt1(kdb_current_task, ~0UL, argcount, 0);
}
}
/* NOTREACHED */
return 0;
}

35
kernel/debug/kdb/kdb_cmds Normal file
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# Initial commands for kdb, alter to suit your needs.
# These commands are executed in kdb_init() context, no SMP, no
# processes. Commands that require process data (including stack or
# registers) are not reliable this early. set and bp commands should
# be safe. Global breakpoint commands affect each cpu as it is booted.
# Standard debugging information for first level support, just type archkdb
# or archkdbcpu or archkdbshort at the kdb prompt.
defcmd dumpcommon "" "Common kdb debugging"
set BTAPROMPT 0
set LINES 10000
-summary
-cpu
-ps
-dmesg 600
-bt
endefcmd
defcmd dumpall "" "First line debugging"
set BTSYMARG 1
set BTARGS 9
pid R
-dumpcommon
-bta
endefcmd
defcmd dumpcpu "" "Same as dumpall but only tasks on cpus"
set BTSYMARG 1
set BTARGS 9
pid R
-dumpcommon
-btc
endefcmd

159
kernel/debug/kdb/kdb_debugger.c Normal file
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/*
* Created by: Jason Wessel <jason.wessel@windriver.com>
*
* Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kgdb.h>
#include <linux/kdb.h>
#include <linux/kdebug.h>
#include "kdb_private.h"
#include "../debug_core.h"
/*
* KDB interface to KGDB internals
*/
get_char_func kdb_poll_funcs[] = {
dbg_io_get_char,
NULL,
};
int kdb_stub(struct kgdb_state *ks)
{
int error = 0;
kdb_bp_t *bp;
unsigned long addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs);
kdb_reason_t reason = KDB_REASON_OOPS;
kdb_dbtrap_t db_result = KDB_DB_NOBPT;
int i;
if (KDB_STATE(REENTRY)) {
reason = KDB_REASON_SWITCH;
KDB_STATE_CLEAR(REENTRY);
addr = instruction_pointer(ks->linux_regs);
}
ks->pass_exception = 0;
if (atomic_read(&kgdb_setting_breakpoint))
reason = KDB_REASON_KEYBOARD;
for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) {
if ((bp->bp_enabled) && (bp->bp_addr == addr)) {
reason = KDB_REASON_BREAK;
db_result = KDB_DB_BPT;
if (addr != instruction_pointer(ks->linux_regs))
kgdb_arch_set_pc(ks->linux_regs, addr);
break;
}
}
if (reason == KDB_REASON_BREAK || reason == KDB_REASON_SWITCH) {
for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) {
if (bp->bp_free)
continue;
if (bp->bp_addr == addr) {
bp->bp_delay = 1;
bp->bp_delayed = 1;
/*
* SSBPT is set when the kernel debugger must single step a
* task in order to re-establish an instruction breakpoint
* which uses the instruction replacement mechanism. It is
* cleared by any action that removes the need to single-step
* the breakpoint.
*/
reason = KDB_REASON_BREAK;
db_result = KDB_DB_BPT;
KDB_STATE_SET(SSBPT);
break;
}
}
}
if (reason != KDB_REASON_BREAK && ks->ex_vector == 0 &&
ks->signo == SIGTRAP) {
reason = KDB_REASON_SSTEP;
db_result = KDB_DB_BPT;
}
/* Set initial kdb state variables */
KDB_STATE_CLEAR(KGDB_TRANS);
kdb_initial_cpu = ks->cpu;
kdb_current_task = kgdb_info[ks->cpu].task;
kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo;
/* Remove any breakpoints as needed by kdb and clear single step */
kdb_bp_remove();
KDB_STATE_CLEAR(DOING_SS);
KDB_STATE_CLEAR(DOING_SSB);
/* zero out any offline cpu data */
for_each_present_cpu(i) {
if (!cpu_online(i)) {
kgdb_info[i].debuggerinfo = NULL;
kgdb_info[i].task = NULL;
}
}
if (ks->err_code == DIE_OOPS || reason == KDB_REASON_OOPS) {
ks->pass_exception = 1;
KDB_FLAG_SET(CATASTROPHIC);
}
kdb_initial_cpu = ks->cpu;
if (KDB_STATE(SSBPT) && reason == KDB_REASON_SSTEP) {
KDB_STATE_CLEAR(SSBPT);
KDB_STATE_CLEAR(DOING_SS);
} else {
/* Start kdb main loop */
error = kdb_main_loop(KDB_REASON_ENTER, reason,
ks->err_code, db_result, ks->linux_regs);
}
/*
* Upon exit from the kdb main loop setup break points and restart
* the system based on the requested continue state
*/
kdb_initial_cpu = -1;
kdb_current_task = NULL;
kdb_current_regs = NULL;
kdbnearsym_cleanup();
if (error == KDB_CMD_KGDB) {
if (KDB_STATE(DOING_KGDB) || KDB_STATE(DOING_KGDB2)) {
/*
* This inteface glue which allows kdb to transition in into
* the gdb stub. In order to do this the '?' or '' gdb serial
* packet response is processed here. And then control is
* passed to the gdbstub.
*/
if (KDB_STATE(DOING_KGDB))
gdbstub_state(ks, "?");
else
gdbstub_state(ks, "");
KDB_STATE_CLEAR(DOING_KGDB);
KDB_STATE_CLEAR(DOING_KGDB2);
}
return DBG_PASS_EVENT;
}
kdb_bp_install(ks->linux_regs);
dbg_activate_sw_breakpoints();
/* Set the exit state to a single step or a continue */
if (KDB_STATE(DOING_SS))
gdbstub_state(ks, "s");
else
gdbstub_state(ks, "c");
KDB_FLAG_CLEAR(CATASTROPHIC);
/* Invoke arch specific exception handling prior to system resume */
kgdb_info[ks->cpu].ret_state = gdbstub_state(ks, "e");
if (ks->pass_exception)
kgdb_info[ks->cpu].ret_state = 1;
if (error == KDB_CMD_CPU) {
KDB_STATE_SET(REENTRY);
/*
* Force clear the single step bit because kdb emulates this
* differently vs the gdbstub
*/
kgdb_single_step = 0;
dbg_deactivate_sw_breakpoints();
return DBG_SWITCH_CPU_EVENT;
}
return kgdb_info[ks->cpu].ret_state;
}

789
kernel/debug/kdb/kdb_io.c Normal file
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/*
* Kernel Debugger Architecture Independent Console I/O handler
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 1999-2006 Silicon Graphics, Inc. All Rights Reserved.
* Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/ctype.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/kdev_t.h>
#include <linux/console.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/nmi.h>
#include <linux/delay.h>
#include <linux/kdb.h>
#include <linux/kallsyms.h>
#include "kdb_private.h"
#define CMD_BUFLEN 256
char kdb_prompt_str[CMD_BUFLEN];
static void kgdb_transition_check(char *buffer)
{
int slen = strlen(buffer);
if (strncmp(buffer, "$?#3f", slen) != 0 &&
strncmp(buffer, "$qSupported#37", slen) != 0 &&
strncmp(buffer, "+$qSupported#37", slen) != 0) {
KDB_STATE_SET(KGDB_TRANS);
kdb_printf("%s", buffer);
}
}
static int kdb_read_get_key(char *buffer, size_t bufsize)
{
#define ESCAPE_UDELAY 1000
#define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */
char escape_data[5]; /* longest vt100 escape sequence is 4 bytes */
char *ped = escape_data;
int escape_delay = 0;
get_char_func *f, *f_escape = NULL;
int key;
for (f = &kdb_poll_funcs[0]; ; ++f) {
if (*f == NULL) {
/* Reset NMI watchdog once per poll loop */
touch_nmi_watchdog();
f = &kdb_poll_funcs[0];
}
if (escape_delay == 2) {
*ped = '\0';
ped = escape_data;
--escape_delay;
}
if (escape_delay == 1) {
key = *ped++;
if (!*ped)
--escape_delay;
break;
}
key = (*f)();
if (key == -1) {
if (escape_delay) {
udelay(ESCAPE_UDELAY);
--escape_delay;
}
continue;
}
if (bufsize <= 2) {
if (key == '\r')
key = '\n';
*buffer++ = key;
*buffer = '\0';
return -1;
}
if (escape_delay == 0 && key == '\e') {
escape_delay = ESCAPE_DELAY;
ped = escape_data;
f_escape = f;
}
if (escape_delay) {
*ped++ = key;
if (f_escape != f) {
escape_delay = 2;
continue;
}
if (ped - escape_data == 1) {
/* \e */
continue;
} else if (ped - escape_data == 2) {
/* \e<something> */
if (key != '[')
escape_delay = 2;
continue;
} else if (ped - escape_data == 3) {
/* \e[<something> */
int mapkey = 0;
switch (key) {
case 'A': /* \e[A, up arrow */
mapkey = 16;
break;
case 'B': /* \e[B, down arrow */
mapkey = 14;
break;
case 'C': /* \e[C, right arrow */
mapkey = 6;
break;
case 'D': /* \e[D, left arrow */
mapkey = 2;
break;
case '1': /* dropthrough */
case '3': /* dropthrough */
/* \e[<1,3,4>], may be home, del, end */
case '4':
mapkey = -1;
break;
}
if (mapkey != -1) {
if (mapkey > 0) {
escape_data[0] = mapkey;
escape_data[1] = '\0';
}
escape_delay = 2;
}
continue;
} else if (ped - escape_data == 4) {
/* \e[<1,3,4><something> */
int mapkey = 0;
if (key == '~') {
switch (escape_data[2]) {
case '1': /* \e[1~, home */
mapkey = 1;
break;
case '3': /* \e[3~, del */
mapkey = 4;
break;
case '4': /* \e[4~, end */
mapkey = 5;
break;
}
}
if (mapkey > 0) {
escape_data[0] = mapkey;
escape_data[1] = '\0';
}
escape_delay = 2;
continue;
}
}
break; /* A key to process */
}
return key;
}
/*
* kdb_read
*
* This function reads a string of characters, terminated by
* a newline, or by reaching the end of the supplied buffer,
* from the current kernel debugger console device.
* Parameters:
* buffer - Address of character buffer to receive input characters.
* bufsize - size, in bytes, of the character buffer
* Returns:
* Returns a pointer to the buffer containing the received
* character string. This string will be terminated by a
* newline character.
* Locking:
* No locks are required to be held upon entry to this
* function. It is not reentrant - it relies on the fact
* that while kdb is running on only one "master debug" cpu.
* Remarks:
*
* The buffer size must be >= 2. A buffer size of 2 means that the caller only
* wants a single key.
*
* An escape key could be the start of a vt100 control sequence such as \e[D
* (left arrow) or it could be a character in its own right. The standard
* method for detecting the difference is to wait for 2 seconds to see if there
* are any other characters. kdb is complicated by the lack of a timer service
* (interrupts are off), by multiple input sources and by the need to sometimes
* return after just one key. Escape sequence processing has to be done as
* states in the polling loop.
*/
static char *kdb_read(char *buffer, size_t bufsize)
{
char *cp = buffer;
char *bufend = buffer+bufsize-2; /* Reserve space for newline
* and null byte */
char *lastchar;
char *p_tmp;
char tmp;
static char tmpbuffer[CMD_BUFLEN];
int len = strlen(buffer);
int len_tmp;
int tab = 0;
int count;
int i;
int diag, dtab_count;
int key;
diag = kdbgetintenv("DTABCOUNT", &dtab_count);
if (diag)
dtab_count = 30;
if (len > 0) {
cp += len;
if (*(buffer+len-1) == '\n')
cp--;
}
lastchar = cp;
*cp = '\0';
kdb_printf("%s", buffer);
poll_again:
key = kdb_read_get_key(buffer, bufsize);
if (key == -1)
return buffer;
if (key != 9)
tab = 0;
switch (key) {
case 8: /* backspace */
if (cp > buffer) {
if (cp < lastchar) {
memcpy(tmpbuffer, cp, lastchar - cp);
memcpy(cp-1, tmpbuffer, lastchar - cp);
}
*(--lastchar) = '\0';
--cp;
kdb_printf("\b%s \r", cp);
tmp = *cp;
*cp = '\0';
kdb_printf(kdb_prompt_str);
kdb_printf("%s", buffer);
*cp = tmp;
}
break;
case 13: /* enter */
*lastchar++ = '\n';
*lastchar++ = '\0';
kdb_printf("\n");
return buffer;
case 4: /* Del */
if (cp < lastchar) {
memcpy(tmpbuffer, cp+1, lastchar - cp - 1);
memcpy(cp, tmpbuffer, lastchar - cp - 1);
*(--lastchar) = '\0';
kdb_printf("%s \r", cp);
tmp = *cp;
*cp = '\0';
kdb_printf(kdb_prompt_str);
kdb_printf("%s", buffer);
*cp = tmp;
}
break;
case 1: /* Home */
if (cp > buffer) {
kdb_printf("\r");
kdb_printf(kdb_prompt_str);
cp = buffer;
}
break;
case 5: /* End */
if (cp < lastchar) {
kdb_printf("%s", cp);
cp = lastchar;
}
break;
case 2: /* Left */
if (cp > buffer) {
kdb_printf("\b");
--cp;
}
break;
case 14: /* Down */
memset(tmpbuffer, ' ',
strlen(kdb_prompt_str) + (lastchar-buffer));
*(tmpbuffer+strlen(kdb_prompt_str) +
(lastchar-buffer)) = '\0';
kdb_printf("\r%s\r", tmpbuffer);
*lastchar = (char)key;
*(lastchar+1) = '\0';
return lastchar;
case 6: /* Right */
if (cp < lastchar) {
kdb_printf("%c", *cp);
++cp;
}
break;
case 16: /* Up */
memset(tmpbuffer, ' ',
strlen(kdb_prompt_str) + (lastchar-buffer));
*(tmpbuffer+strlen(kdb_prompt_str) +
(lastchar-buffer)) = '\0';
kdb_printf("\r%s\r", tmpbuffer);
*lastchar = (char)key;
*(lastchar+1) = '\0';
return lastchar;
case 9: /* Tab */
if (tab < 2)
++tab;
p_tmp = buffer;
while (*p_tmp == ' ')
p_tmp++;
if (p_tmp > cp)
break;
memcpy(tmpbuffer, p_tmp, cp-p_tmp);
*(tmpbuffer + (cp-p_tmp)) = '\0';
p_tmp = strrchr(tmpbuffer, ' ');
if (p_tmp)
++p_tmp;
else
p_tmp = tmpbuffer;
len = strlen(p_tmp);
count = kallsyms_symbol_complete(p_tmp,
sizeof(tmpbuffer) -
(p_tmp - tmpbuffer));
if (tab == 2 && count > 0) {
kdb_printf("\n%d symbols are found.", count);
if (count > dtab_count) {
count = dtab_count;
kdb_printf(" But only first %d symbols will"
" be printed.\nYou can change the"
" environment variable DTABCOUNT.",
count);
}
kdb_printf("\n");
for (i = 0; i < count; i++) {
if (kallsyms_symbol_next(p_tmp, i) < 0)
break;
kdb_printf("%s ", p_tmp);
*(p_tmp + len) = '\0';
}
if (i >= dtab_count)
kdb_printf("...");
kdb_printf("\n");
kdb_printf(kdb_prompt_str);
kdb_printf("%s", buffer);
} else if (tab != 2 && count > 0) {
len_tmp = strlen(p_tmp);
strncpy(p_tmp+len_tmp, cp, lastchar-cp+1);
len_tmp = strlen(p_tmp);
strncpy(cp, p_tmp+len, len_tmp-len + 1);
len = len_tmp - len;
kdb_printf("%s", cp);
cp += len;
lastchar += len;
}
kdb_nextline = 1; /* reset output line number */
break;
default:
if (key >= 32 && lastchar < bufend) {
if (cp < lastchar) {
memcpy(tmpbuffer, cp, lastchar - cp);
memcpy(cp+1, tmpbuffer, lastchar - cp);
*++lastchar = '\0';
*cp = key;
kdb_printf("%s\r", cp);
++cp;
tmp = *cp;
*cp = '\0';
kdb_printf(kdb_prompt_str);
kdb_printf("%s", buffer);
*cp = tmp;
} else {
*++lastchar = '\0';
*cp++ = key;
/* The kgdb transition check will hide
* printed characters if we think that
* kgdb is connecting, until the check
* fails */
if (!KDB_STATE(KGDB_TRANS))
kgdb_transition_check(buffer);
else
kdb_printf("%c", key);
}
/* Special escape to kgdb */
if (lastchar - buffer >= 5 &&
strcmp(lastchar - 5, "$?#3f") == 0) {
strcpy(buffer, "kgdb");
KDB_STATE_SET(DOING_KGDB);
return buffer;
}
if (lastchar - buffer >= 14 &&
strcmp(lastchar - 14, "$qSupported#37") == 0) {
strcpy(buffer, "kgdb");
KDB_STATE_SET(DOING_KGDB2);
return buffer;
}
}
break;
}
goto poll_again;
}
/*
* kdb_getstr
*
* Print the prompt string and read a command from the
* input device.
*
* Parameters:
* buffer Address of buffer to receive command
* bufsize Size of buffer in bytes
* prompt Pointer to string to use as prompt string
* Returns:
* Pointer to command buffer.
* Locking:
* None.
* Remarks:
* For SMP kernels, the processor number will be
* substituted for %d, %x or %o in the prompt.
*/
char *kdb_getstr(char *buffer, size_t bufsize, char *prompt)
{
if (prompt && kdb_prompt_str != prompt)
strncpy(kdb_prompt_str, prompt, CMD_BUFLEN);
kdb_printf(kdb_prompt_str);
kdb_nextline = 1; /* Prompt and input resets line number */
return kdb_read(buffer, bufsize);
}
/*
* kdb_input_flush
*
* Get rid of any buffered console input.
*
* Parameters:
* none
* Returns:
* nothing
* Locking:
* none
* Remarks:
* Call this function whenever you want to flush input. If there is any
* outstanding input, it ignores all characters until there has been no
* data for approximately 1ms.
*/
static void kdb_input_flush(void)
{
get_char_func *f;
int res;
int flush_delay = 1;
while (flush_delay) {
flush_delay--;
empty:
touch_nmi_watchdog();
for (f = &kdb_poll_funcs[0]; *f; ++f) {
res = (*f)();
if (res != -1) {
flush_delay = 1;
goto empty;
}
}
if (flush_delay)
mdelay(1);
}
}
/*
* kdb_printf
*
* Print a string to the output device(s).
*
* Parameters:
* printf-like format and optional args.
* Returns:
* 0
* Locking:
* None.
* Remarks:
* use 'kdbcons->write()' to avoid polluting 'log_buf' with
* kdb output.
*
* If the user is doing a cmd args | grep srch
* then kdb_grepping_flag is set.
* In that case we need to accumulate full lines (ending in \n) before
* searching for the pattern.
*/
static char kdb_buffer[256]; /* A bit too big to go on stack */
static char *next_avail = kdb_buffer;
static int size_avail;
static int suspend_grep;
/*
* search arg1 to see if it contains arg2
* (kdmain.c provides flags for ^pat and pat$)
*
* return 1 for found, 0 for not found
*/
static int kdb_search_string(char *searched, char *searchfor)
{
char firstchar, *cp;
int len1, len2;
/* not counting the newline at the end of "searched" */
len1 = strlen(searched)-1;
len2 = strlen(searchfor);
if (len1 < len2)
return 0;
if (kdb_grep_leading && kdb_grep_trailing && len1 != len2)
return 0;
if (kdb_grep_leading) {
if (!strncmp(searched, searchfor, len2))
return 1;
} else if (kdb_grep_trailing) {
if (!strncmp(searched+len1-len2, searchfor, len2))
return 1;
} else {
firstchar = *searchfor;
cp = searched;
while ((cp = strchr(cp, firstchar))) {
if (!strncmp(cp, searchfor, len2))
return 1;
cp++;
}
}
return 0;
}
int kdb_printf(const char *fmt, ...)
{
va_list ap;
int diag;
int linecount;
int logging, saved_loglevel = 0;
int got_printf_lock = 0;
int retlen = 0;
int fnd, len;
char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
char *moreprompt = "more> ";
struct console *c = console_drivers;
static DEFINE_SPINLOCK(kdb_printf_lock);
unsigned long uninitialized_var(flags);
preempt_disable();
/* Serialize kdb_printf if multiple cpus try to write at once.
* But if any cpu goes recursive in kdb, just print the output,
* even if it is interleaved with any other text.
*/
if (!KDB_STATE(PRINTF_LOCK)) {
KDB_STATE_SET(PRINTF_LOCK);
spin_lock_irqsave(&kdb_printf_lock, flags);
got_printf_lock = 1;
atomic_inc(&kdb_event);
} else {
__acquire(kdb_printf_lock);
}
diag = kdbgetintenv("LINES", &linecount);
if (diag || linecount <= 1)
linecount = 24;
diag = kdbgetintenv("LOGGING", &logging);
if (diag)
logging = 0;
if (!kdb_grepping_flag || suspend_grep) {
/* normally, every vsnprintf starts a new buffer */
next_avail = kdb_buffer;
size_avail = sizeof(kdb_buffer);
}
va_start(ap, fmt);
vsnprintf(next_avail, size_avail, fmt, ap);
va_end(ap);
/*
* If kdb_parse() found that the command was cmd xxx | grep yyy
* then kdb_grepping_flag is set, and kdb_grep_string contains yyy
*
* Accumulate the print data up to a newline before searching it.
* (vsnprintf does null-terminate the string that it generates)
*/
/* skip the search if prints are temporarily unconditional */
if (!suspend_grep && kdb_grepping_flag) {
cp = strchr(kdb_buffer, '\n');
if (!cp) {
/*
* Special cases that don't end with newlines
* but should be written without one:
* The "[nn]kdb> " prompt should
* appear at the front of the buffer.
*
* The "[nn]more " prompt should also be
* (MOREPROMPT -> moreprompt)
* written * but we print that ourselves,
* we set the suspend_grep flag to make
* it unconditional.
*
*/
if (next_avail == kdb_buffer) {
/*
* these should occur after a newline,
* so they will be at the front of the
* buffer
*/
cp2 = kdb_buffer;
len = strlen(kdb_prompt_str);
if (!strncmp(cp2, kdb_prompt_str, len)) {
/*
* We're about to start a new
* command, so we can go back
* to normal mode.
*/
kdb_grepping_flag = 0;
goto kdb_printit;
}
}
/* no newline; don't search/write the buffer
until one is there */
len = strlen(kdb_buffer);
next_avail = kdb_buffer + len;
size_avail = sizeof(kdb_buffer) - len;
goto kdb_print_out;
}
/*
* The newline is present; print through it or discard
* it, depending on the results of the search.
*/
cp++; /* to byte after the newline */
replaced_byte = *cp; /* remember what/where it was */
cphold = cp;
*cp = '\0'; /* end the string for our search */
/*
* We now have a newline at the end of the string
* Only continue with this output if it contains the
* search string.
*/
fnd = kdb_search_string(kdb_buffer, kdb_grep_string);
if (!fnd) {
/*
* At this point the complete line at the start
* of kdb_buffer can be discarded, as it does
* not contain what the user is looking for.
* Shift the buffer left.
*/
*cphold = replaced_byte;
strcpy(kdb_buffer, cphold);
len = strlen(kdb_buffer);
next_avail = kdb_buffer + len;
size_avail = sizeof(kdb_buffer) - len;
goto kdb_print_out;
}
/*
* at this point the string is a full line and
* should be printed, up to the null.
*/
}
kdb_printit:
/*
* Write to all consoles.
*/
retlen = strlen(kdb_buffer);
while (c) {
c->write(c, kdb_buffer, retlen);
touch_nmi_watchdog();
c = c->next;
}
if (logging) {
saved_loglevel = console_loglevel;
console_loglevel = 0;
printk(KERN_INFO "%s", kdb_buffer);
}
if (KDB_STATE(PAGER) && strchr(kdb_buffer, '\n'))
kdb_nextline++;
/* check for having reached the LINES number of printed lines */
if (kdb_nextline == linecount) {
char buf1[16] = "";
#if defined(CONFIG_SMP)
char buf2[32];
#endif
/* Watch out for recursion here. Any routine that calls
* kdb_printf will come back through here. And kdb_read
* uses kdb_printf to echo on serial consoles ...
*/
kdb_nextline = 1; /* In case of recursion */
/*
* Pause until cr.
*/
moreprompt = kdbgetenv("MOREPROMPT");
if (moreprompt == NULL)
moreprompt = "more> ";
#if defined(CONFIG_SMP)
if (strchr(moreprompt, '%')) {
sprintf(buf2, moreprompt, get_cpu());
put_cpu();
moreprompt = buf2;
}
#endif
kdb_input_flush();
c = console_drivers;
while (c) {
c->write(c, moreprompt, strlen(moreprompt));
touch_nmi_watchdog();
c = c->next;
}
if (logging)
printk("%s", moreprompt);
kdb_read(buf1, 2); /* '2' indicates to return
* immediately after getting one key. */
kdb_nextline = 1; /* Really set output line 1 */
/* empty and reset the buffer: */
kdb_buffer[0] = '\0';
next_avail = kdb_buffer;
size_avail = sizeof(kdb_buffer);
if ((buf1[0] == 'q') || (buf1[0] == 'Q')) {
/* user hit q or Q */
KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
KDB_STATE_CLEAR(PAGER);
/* end of command output; back to normal mode */
kdb_grepping_flag = 0;
kdb_printf("\n");
} else if (buf1[0] == ' ') {
kdb_printf("\n");
suspend_grep = 1; /* for this recursion */
} else if (buf1[0] == '\n') {
kdb_nextline = linecount - 1;
kdb_printf("\r");
suspend_grep = 1; /* for this recursion */
} else if (buf1[0] && buf1[0] != '\n') {
/* user hit something other than enter */
suspend_grep = 1; /* for this recursion */
kdb_printf("\nOnly 'q' or 'Q' are processed at more "
"prompt, input ignored\n");
} else if (kdb_grepping_flag) {
/* user hit enter */
suspend_grep = 1; /* for this recursion */
kdb_printf("\n");
}
kdb_input_flush();
}
/*
* For grep searches, shift the printed string left.
* replaced_byte contains the character that was overwritten with
* the terminating null, and cphold points to the null.
* Then adjust the notion of available space in the buffer.
*/
if (kdb_grepping_flag && !suspend_grep) {
*cphold = replaced_byte;
strcpy(kdb_buffer, cphold);
len = strlen(kdb_buffer);
next_avail = kdb_buffer + len;
size_avail = sizeof(kdb_buffer) - len;
}
kdb_print_out:
suspend_grep = 0; /* end of what may have been a recursive call */
if (logging)
console_loglevel = saved_loglevel;
if (KDB_STATE(PRINTF_LOCK) && got_printf_lock) {
got_printf_lock = 0;
spin_unlock_irqrestore(&kdb_printf_lock, flags);
KDB_STATE_CLEAR(PRINTF_LOCK);
atomic_dec(&kdb_event);
} else {
__release(kdb_printf_lock);
}
preempt_enable();
return retlen;
}

2845
kernel/debug/kdb/kdb_main.c Normal file
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301
kernel/debug/kdb/kdb_private.h Normal file
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#ifndef _KDBPRIVATE_H
#define _KDBPRIVATE_H
/*
* Kernel Debugger Architecture Independent Private Headers
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2000-2004 Silicon Graphics, Inc. All Rights Reserved.
* Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
*/
#include <linux/kgdb.h>
#include "../debug_core.h"
/* Kernel Debugger Error codes. Must not overlap with command codes. */
#define KDB_NOTFOUND (-1)
#define KDB_ARGCOUNT (-2)
#define KDB_BADWIDTH (-3)
#define KDB_BADRADIX (-4)
#define KDB_NOTENV (-5)
#define KDB_NOENVVALUE (-6)
#define KDB_NOTIMP (-7)
#define KDB_ENVFULL (-8)
#define KDB_ENVBUFFULL (-9)
#define KDB_TOOMANYBPT (-10)
#define KDB_TOOMANYDBREGS (-11)
#define KDB_DUPBPT (-12)
#define KDB_BPTNOTFOUND (-13)
#define KDB_BADMODE (-14)
#define KDB_BADINT (-15)
#define KDB_INVADDRFMT (-16)
#define KDB_BADREG (-17)
#define KDB_BADCPUNUM (-18)
#define KDB_BADLENGTH (-19)
#define KDB_NOBP (-20)
#define KDB_BADADDR (-21)
/* Kernel Debugger Command codes. Must not overlap with error codes. */
#define KDB_CMD_GO (-1001)
#define KDB_CMD_CPU (-1002)
#define KDB_CMD_SS (-1003)
#define KDB_CMD_SSB (-1004)
#define KDB_CMD_KGDB (-1005)
#define KDB_CMD_KGDB2 (-1006)
/* Internal debug flags */
#define KDB_DEBUG_FLAG_BP 0x0002 /* Breakpoint subsystem debug */
#define KDB_DEBUG_FLAG_BB_SUMM 0x0004 /* Basic block analysis, summary only */
#define KDB_DEBUG_FLAG_AR 0x0008 /* Activation record, generic */
#define KDB_DEBUG_FLAG_ARA 0x0010 /* Activation record, arch specific */
#define KDB_DEBUG_FLAG_BB 0x0020 /* All basic block analysis */
#define KDB_DEBUG_FLAG_STATE 0x0040 /* State flags */
#define KDB_DEBUG_FLAG_MASK 0xffff /* All debug flags */
#define KDB_DEBUG_FLAG_SHIFT 16 /* Shift factor for dbflags */
#define KDB_DEBUG(flag) (kdb_flags & \
(KDB_DEBUG_FLAG_##flag << KDB_DEBUG_FLAG_SHIFT))
#define KDB_DEBUG_STATE(text, value) if (KDB_DEBUG(STATE)) \
kdb_print_state(text, value)
#if BITS_PER_LONG == 32
#define KDB_PLATFORM_ENV "BYTESPERWORD=4"
#define kdb_machreg_fmt "0x%lx"
#define kdb_machreg_fmt0 "0x%08lx"
#define kdb_bfd_vma_fmt "0x%lx"
#define kdb_bfd_vma_fmt0 "0x%08lx"
#define kdb_elfw_addr_fmt "0x%x"
#define kdb_elfw_addr_fmt0 "0x%08x"
#define kdb_f_count_fmt "%d"
#elif BITS_PER_LONG == 64
#define KDB_PLATFORM_ENV "BYTESPERWORD=8"
#define kdb_machreg_fmt "0x%lx"
#define kdb_machreg_fmt0 "0x%016lx"
#define kdb_bfd_vma_fmt "0x%lx"
#define kdb_bfd_vma_fmt0 "0x%016lx"
#define kdb_elfw_addr_fmt "0x%x"
#define kdb_elfw_addr_fmt0 "0x%016x"
#define kdb_f_count_fmt "%ld"
#endif
/*
* KDB_MAXBPT describes the total number of breakpoints
* supported by this architecure.
*/
#define KDB_MAXBPT 16
/* Maximum number of arguments to a function */
#define KDB_MAXARGS 16
typedef enum {
KDB_REPEAT_NONE = 0, /* Do not repeat this command */
KDB_REPEAT_NO_ARGS, /* Repeat the command without arguments */
KDB_REPEAT_WITH_ARGS, /* Repeat the command including its arguments */
} kdb_repeat_t;
typedef int (*kdb_func_t)(int, const char **);
/* Symbol table format returned by kallsyms. */
typedef struct __ksymtab {
unsigned long value; /* Address of symbol */
const char *mod_name; /* Module containing symbol or
* "kernel" */
unsigned long mod_start;
unsigned long mod_end;
const char *sec_name; /* Section containing symbol */
unsigned long sec_start;
unsigned long sec_end;
const char *sym_name; /* Full symbol name, including
* any version */
unsigned long sym_start;
unsigned long sym_end;
} kdb_symtab_t;
extern int kallsyms_symbol_next(char *prefix_name, int flag);
extern int kallsyms_symbol_complete(char *prefix_name, int max_len);
/* Exported Symbols for kernel loadable modules to use. */
extern int kdb_register(char *, kdb_func_t, char *, char *, short);
extern int kdb_register_repeat(char *, kdb_func_t, char *, char *,
short, kdb_repeat_t);
extern int kdb_unregister(char *);
extern int kdb_getarea_size(void *, unsigned long, size_t);
extern int kdb_putarea_size(unsigned long, void *, size_t);
/*
* Like get_user and put_user, kdb_getarea and kdb_putarea take variable
* names, not pointers. The underlying *_size functions take pointers.
*/
#define kdb_getarea(x, addr) kdb_getarea_size(&(x), addr, sizeof((x)))
#define kdb_putarea(addr, x) kdb_putarea_size(addr, &(x), sizeof((x)))
extern int kdb_getphysword(unsigned long *word,
unsigned long addr, size_t size);
extern int kdb_getword(unsigned long *, unsigned long, size_t);
extern int kdb_putword(unsigned long, unsigned long, size_t);
extern int kdbgetularg(const char *, unsigned long *);
extern int kdb_set(int, const char **);
extern char *kdbgetenv(const char *);
extern int kdbgetintenv(const char *, int *);
extern int kdbgetaddrarg(int, const char **, int*, unsigned long *,
long *, char **);
extern int kdbgetsymval(const char *, kdb_symtab_t *);
extern int kdbnearsym(unsigned long, kdb_symtab_t *);
extern void kdbnearsym_cleanup(void);
extern char *kdb_strdup(const char *str, gfp_t type);
extern void kdb_symbol_print(unsigned long, const kdb_symtab_t *, unsigned int);
/* Routine for debugging the debugger state. */
extern void kdb_print_state(const char *, int);
extern int kdb_state;
#define KDB_STATE_KDB 0x00000001 /* Cpu is inside kdb */
#define KDB_STATE_LEAVING 0x00000002 /* Cpu is leaving kdb */
#define KDB_STATE_CMD 0x00000004 /* Running a kdb command */
#define KDB_STATE_KDB_CONTROL 0x00000008 /* This cpu is under
* kdb control */
#define KDB_STATE_HOLD_CPU 0x00000010 /* Hold this cpu inside kdb */
#define KDB_STATE_DOING_SS 0x00000020 /* Doing ss command */
#define KDB_STATE_DOING_SSB 0x00000040 /* Doing ssb command,
* DOING_SS is also set */
#define KDB_STATE_SSBPT 0x00000080 /* Install breakpoint
* after one ss, independent of
* DOING_SS */
#define KDB_STATE_REENTRY 0x00000100 /* Valid re-entry into kdb */
#define KDB_STATE_SUPPRESS 0x00000200 /* Suppress error messages */
#define KDB_STATE_PAGER 0x00000400 /* pager is available */
#define KDB_STATE_GO_SWITCH 0x00000800 /* go is switching
* back to initial cpu */
#define KDB_STATE_PRINTF_LOCK 0x00001000 /* Holds kdb_printf lock */
#define KDB_STATE_WAIT_IPI 0x00002000 /* Waiting for kdb_ipi() NMI */
#define KDB_STATE_RECURSE 0x00004000 /* Recursive entry to kdb */
#define KDB_STATE_IP_ADJUSTED 0x00008000 /* Restart IP has been
* adjusted */
#define KDB_STATE_GO1 0x00010000 /* go only releases one cpu */
#define KDB_STATE_KEYBOARD 0x00020000 /* kdb entered via
* keyboard on this cpu */
#define KDB_STATE_KEXEC 0x00040000 /* kexec issued */
#define KDB_STATE_DOING_KGDB 0x00080000 /* kgdb enter now issued */
#define KDB_STATE_DOING_KGDB2 0x00100000 /* kgdb enter now issued */
#define KDB_STATE_KGDB_TRANS 0x00200000 /* Transition to kgdb */
#define KDB_STATE_ARCH 0xff000000 /* Reserved for arch
* specific use */
#define KDB_STATE(flag) (kdb_state & KDB_STATE_##flag)
#define KDB_STATE_SET(flag) ((void)(kdb_state |= KDB_STATE_##flag))
#define KDB_STATE_CLEAR(flag) ((void)(kdb_state &= ~KDB_STATE_##flag))
extern int kdb_nextline; /* Current number of lines displayed */
typedef struct _kdb_bp {
unsigned long bp_addr; /* Address breakpoint is present at */
unsigned int bp_free:1; /* This entry is available */
unsigned int bp_enabled:1; /* Breakpoint is active in register */
unsigned int bp_type:4; /* Uses hardware register */
unsigned int bp_installed:1; /* Breakpoint is installed */
unsigned int bp_delay:1; /* Do delayed bp handling */
unsigned int bp_delayed:1; /* Delayed breakpoint */
unsigned int bph_length; /* HW break length */
} kdb_bp_t;
#ifdef CONFIG_KGDB_KDB
extern kdb_bp_t kdb_breakpoints[/* KDB_MAXBPT */];
/* The KDB shell command table */
typedef struct _kdbtab {
char *cmd_name; /* Command name */
kdb_func_t cmd_func; /* Function to execute command */
char *cmd_usage; /* Usage String for this command */
char *cmd_help; /* Help message for this command */
short cmd_flags; /* Parsing flags */
short cmd_minlen; /* Minimum legal # command
* chars required */
kdb_repeat_t cmd_repeat; /* Does command auto repeat on enter? */
} kdbtab_t;
extern int kdb_bt(int, const char **); /* KDB display back trace */
/* KDB breakpoint management functions */
extern void kdb_initbptab(void);
extern void kdb_bp_install(struct pt_regs *);
extern void kdb_bp_remove(void);
typedef enum {
KDB_DB_BPT, /* Breakpoint */
KDB_DB_SS, /* Single-step trap */
KDB_DB_SSB, /* Single step to branch */
KDB_DB_SSBPT, /* Single step over breakpoint */
KDB_DB_NOBPT /* Spurious breakpoint */
} kdb_dbtrap_t;
extern int kdb_main_loop(kdb_reason_t, kdb_reason_t,
int, kdb_dbtrap_t, struct pt_regs *);
/* Miscellaneous functions and data areas */
extern int kdb_grepping_flag;
extern char kdb_grep_string[];
extern int kdb_grep_leading;
extern int kdb_grep_trailing;
extern char *kdb_cmds[];
extern void kdb_syslog_data(char *syslog_data[]);
extern unsigned long kdb_task_state_string(const char *);
extern char kdb_task_state_char (const struct task_struct *);
extern unsigned long kdb_task_state(const struct task_struct *p,
unsigned long mask);
extern void kdb_ps_suppressed(void);
extern void kdb_ps1(const struct task_struct *p);
extern int kdb_parse(const char *cmdstr);
extern void kdb_print_nameval(const char *name, unsigned long val);
extern void kdb_send_sig_info(struct task_struct *p, struct siginfo *info);
extern void kdb_meminfo_proc_show(void);
extern const char *kdb_walk_kallsyms(loff_t *pos);
extern char *kdb_getstr(char *, size_t, char *);
/* Defines for kdb_symbol_print */
#define KDB_SP_SPACEB 0x0001 /* Space before string */
#define KDB_SP_SPACEA 0x0002 /* Space after string */
#define KDB_SP_PAREN 0x0004 /* Parenthesis around string */
#define KDB_SP_VALUE 0x0008 /* Print the value of the address */
#define KDB_SP_SYMSIZE 0x0010 /* Print the size of the symbol */
#define KDB_SP_NEWLINE 0x0020 /* Newline after string */
#define KDB_SP_DEFAULT (KDB_SP_VALUE|KDB_SP_PAREN)
#define KDB_TSK(cpu) kgdb_info[cpu].task
#define KDB_TSKREGS(cpu) kgdb_info[cpu].debuggerinfo
extern struct task_struct *kdb_curr_task(int);
#define kdb_task_has_cpu(p) (task_curr(p))
/* Simplify coexistence with NPTL */
#define kdb_do_each_thread(g, p) do_each_thread(g, p)
#define kdb_while_each_thread(g, p) while_each_thread(g, p)
#define GFP_KDB (in_interrupt() ? GFP_ATOMIC : GFP_KERNEL)
extern void *debug_kmalloc(size_t size, gfp_t flags);
extern void debug_kfree(void *);
extern void debug_kusage(void);
extern void kdb_set_current_task(struct task_struct *);
extern struct task_struct *kdb_current_task;
#ifdef CONFIG_MODULES
extern struct list_head *kdb_modules;
#endif /* CONFIG_MODULES */
extern char kdb_prompt_str[];
#define KDB_WORD_SIZE ((int)sizeof(unsigned long))
#endif /* CONFIG_KGDB_KDB */
#endif /* !_KDBPRIVATE_H */

927
kernel/debug/kdb/kdb_support.c Normal file
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@ -0,0 +1,927 @@
/*
* Kernel Debugger Architecture Independent Support Functions
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved.
* Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
* 03/02/13 added new 2.5 kallsyms <xavier.bru@bull.net>
*/
#include <stdarg.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/kallsyms.h>
#include <linux/stddef.h>
#include <linux/vmalloc.h>
#include <linux/ptrace.h>
#include <linux/module.h>
#include <linux/highmem.h>
#include <linux/hardirq.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/kdb.h>
#include <linux/slab.h>
#include "kdb_private.h"
/*
* kdbgetsymval - Return the address of the given symbol.
*
* Parameters:
* symname Character string containing symbol name
* symtab Structure to receive results
* Returns:
* 0 Symbol not found, symtab zero filled
* 1 Symbol mapped to module/symbol/section, data in symtab
*/
int kdbgetsymval(const char *symname, kdb_symtab_t *symtab)
{
if (KDB_DEBUG(AR))
kdb_printf("kdbgetsymval: symname=%s, symtab=%p\n", symname,
symtab);
memset(symtab, 0, sizeof(*symtab));
symtab->sym_start = kallsyms_lookup_name(symname);
if (symtab->sym_start) {
if (KDB_DEBUG(AR))
kdb_printf("kdbgetsymval: returns 1, "
"symtab->sym_start=0x%lx\n",
symtab->sym_start);
return 1;
}
if (KDB_DEBUG(AR))
kdb_printf("kdbgetsymval: returns 0\n");
return 0;
}
EXPORT_SYMBOL(kdbgetsymval);
static char *kdb_name_table[100]; /* arbitrary size */
/*
* kdbnearsym - Return the name of the symbol with the nearest address
* less than 'addr'.
*
* Parameters:
* addr Address to check for symbol near
* symtab Structure to receive results
* Returns:
* 0 No sections contain this address, symtab zero filled
* 1 Address mapped to module/symbol/section, data in symtab
* Remarks:
* 2.6 kallsyms has a "feature" where it unpacks the name into a
* string. If that string is reused before the caller expects it
* then the caller sees its string change without warning. To
* avoid cluttering up the main kdb code with lots of kdb_strdup,
* tests and kfree calls, kdbnearsym maintains an LRU list of the
* last few unique strings. The list is sized large enough to
* hold active strings, no kdb caller of kdbnearsym makes more
* than ~20 later calls before using a saved value.
*/
int kdbnearsym(unsigned long addr, kdb_symtab_t *symtab)
{
int ret = 0;
unsigned long symbolsize;
unsigned long offset;
#define knt1_size 128 /* must be >= kallsyms table size */
char *knt1 = NULL;
if (KDB_DEBUG(AR))
kdb_printf("kdbnearsym: addr=0x%lx, symtab=%p\n", addr, symtab);
memset(symtab, 0, sizeof(*symtab));
if (addr < 4096)
goto out;
knt1 = debug_kmalloc(knt1_size, GFP_ATOMIC);
if (!knt1) {
kdb_printf("kdbnearsym: addr=0x%lx cannot kmalloc knt1\n",
addr);
goto out;
}
symtab->sym_name = kallsyms_lookup(addr, &symbolsize , &offset,
(char **)(&symtab->mod_name), knt1);
if (offset > 8*1024*1024) {
symtab->sym_name = NULL;
addr = offset = symbolsize = 0;
}
symtab->sym_start = addr - offset;
symtab->sym_end = symtab->sym_start + symbolsize;
ret = symtab->sym_name != NULL && *(symtab->sym_name) != '\0';
if (ret) {
int i;
/* Another 2.6 kallsyms "feature". Sometimes the sym_name is
* set but the buffer passed into kallsyms_lookup is not used,
* so it contains garbage. The caller has to work out which
* buffer needs to be saved.
*
* What was Rusty smoking when he wrote that code?
*/
if (symtab->sym_name != knt1) {
strncpy(knt1, symtab->sym_name, knt1_size);
knt1[knt1_size-1] = '\0';
}
for (i = 0; i < ARRAY_SIZE(kdb_name_table); ++i) {
if (kdb_name_table[i] &&
strcmp(kdb_name_table[i], knt1) == 0)
break;
}
if (i >= ARRAY_SIZE(kdb_name_table)) {
debug_kfree(kdb_name_table[0]);
memcpy(kdb_name_table, kdb_name_table+1,
sizeof(kdb_name_table[0]) *
(ARRAY_SIZE(kdb_name_table)-1));
} else {
debug_kfree(knt1);
knt1 = kdb_name_table[i];
memcpy(kdb_name_table+i, kdb_name_table+i+1,
sizeof(kdb_name_table[0]) *
(ARRAY_SIZE(kdb_name_table)-i-1));
}
i = ARRAY_SIZE(kdb_name_table) - 1;
kdb_name_table[i] = knt1;
symtab->sym_name = kdb_name_table[i];
knt1 = NULL;
}
if (symtab->mod_name == NULL)
symtab->mod_name = "kernel";
if (KDB_DEBUG(AR))
kdb_printf("kdbnearsym: returns %d symtab->sym_start=0x%lx, "
"symtab->mod_name=%p, symtab->sym_name=%p (%s)\n", ret,
symtab->sym_start, symtab->mod_name, symtab->sym_name,
symtab->sym_name);
out:
debug_kfree(knt1);
return ret;
}
void kdbnearsym_cleanup(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(kdb_name_table); ++i) {
if (kdb_name_table[i]) {
debug_kfree(kdb_name_table[i]);
kdb_name_table[i] = NULL;
}
}
}
static char ks_namebuf[KSYM_NAME_LEN+1], ks_namebuf_prev[KSYM_NAME_LEN+1];
/*
* kallsyms_symbol_complete
*
* Parameters:
* prefix_name prefix of a symbol name to lookup
* max_len maximum length that can be returned
* Returns:
* Number of symbols which match the given prefix.
* Notes:
* prefix_name is changed to contain the longest unique prefix that
* starts with this prefix (tab completion).
*/
int kallsyms_symbol_complete(char *prefix_name, int max_len)
{
loff_t pos = 0;
int prefix_len = strlen(prefix_name), prev_len = 0;
int i, number = 0;
const char *name;
while ((name = kdb_walk_kallsyms(&pos))) {
if (strncmp(name, prefix_name, prefix_len) == 0) {
strcpy(ks_namebuf, name);
/* Work out the longest name that matches the prefix */
if (++number == 1) {
prev_len = min_t(int, max_len-1,
strlen(ks_namebuf));
memcpy(ks_namebuf_prev, ks_namebuf, prev_len);
ks_namebuf_prev[prev_len] = '\0';
continue;
}
for (i = 0; i < prev_len; i++) {
if (ks_namebuf[i] != ks_namebuf_prev[i]) {
prev_len = i;
ks_namebuf_prev[i] = '\0';
break;
}
}
}
}
if (prev_len > prefix_len)
memcpy(prefix_name, ks_namebuf_prev, prev_len+1);
return number;
}
/*
* kallsyms_symbol_next
*
* Parameters:
* prefix_name prefix of a symbol name to lookup
* flag 0 means search from the head, 1 means continue search.
* Returns:
* 1 if a symbol matches the given prefix.
* 0 if no string found
*/
int kallsyms_symbol_next(char *prefix_name, int flag)
{
int prefix_len = strlen(prefix_name);
static loff_t pos;
const char *name;
if (!flag)
pos = 0;
while ((name = kdb_walk_kallsyms(&pos))) {
if (strncmp(name, prefix_name, prefix_len) == 0) {
strncpy(prefix_name, name, strlen(name)+1);
return 1;
}
}
return 0;
}
/*
* kdb_symbol_print - Standard method for printing a symbol name and offset.
* Inputs:
* addr Address to be printed.
* symtab Address of symbol data, if NULL this routine does its
* own lookup.
* punc Punctuation for string, bit field.
* Remarks:
* The string and its punctuation is only printed if the address
* is inside the kernel, except that the value is always printed
* when requested.
*/
void kdb_symbol_print(unsigned long addr, const kdb_symtab_t *symtab_p,
unsigned int punc)
{
kdb_symtab_t symtab, *symtab_p2;
if (symtab_p) {
symtab_p2 = (kdb_symtab_t *)symtab_p;
} else {
symtab_p2 = &symtab;
kdbnearsym(addr, symtab_p2);
}
if (!(symtab_p2->sym_name || (punc & KDB_SP_VALUE)))
return;
if (punc & KDB_SP_SPACEB)
kdb_printf(" ");
if (punc & KDB_SP_VALUE)
kdb_printf(kdb_machreg_fmt0, addr);
if (symtab_p2->sym_name) {
if (punc & KDB_SP_VALUE)
kdb_printf(" ");
if (punc & KDB_SP_PAREN)
kdb_printf("(");
if (strcmp(symtab_p2->mod_name, "kernel"))
kdb_printf("[%s]", symtab_p2->mod_name);
kdb_printf("%s", symtab_p2->sym_name);
if (addr != symtab_p2->sym_start)
kdb_printf("+0x%lx", addr - symtab_p2->sym_start);
if (punc & KDB_SP_SYMSIZE)
kdb_printf("/0x%lx",
symtab_p2->sym_end - symtab_p2->sym_start);
if (punc & KDB_SP_PAREN)
kdb_printf(")");
}
if (punc & KDB_SP_SPACEA)
kdb_printf(" ");
if (punc & KDB_SP_NEWLINE)
kdb_printf("\n");
}
/*
* kdb_strdup - kdb equivalent of strdup, for disasm code.
* Inputs:
* str The string to duplicate.
* type Flags to kmalloc for the new string.
* Returns:
* Address of the new string, NULL if storage could not be allocated.
* Remarks:
* This is not in lib/string.c because it uses kmalloc which is not
* available when string.o is used in boot loaders.
*/
char *kdb_strdup(const char *str, gfp_t type)
{
int n = strlen(str)+1;
char *s = kmalloc(n, type);
if (!s)
return NULL;
return strcpy(s, str);
}
/*
* kdb_getarea_size - Read an area of data. The kdb equivalent of
* copy_from_user, with kdb messages for invalid addresses.
* Inputs:
* res Pointer to the area to receive the result.
* addr Address of the area to copy.
* size Size of the area.
* Returns:
* 0 for success, < 0 for error.
*/
int kdb_getarea_size(void *res, unsigned long addr, size_t size)
{
int ret = probe_kernel_read((char *)res, (char *)addr, size);
if (ret) {
if (!KDB_STATE(SUPPRESS)) {
kdb_printf("kdb_getarea: Bad address 0x%lx\n", addr);
KDB_STATE_SET(SUPPRESS);
}
ret = KDB_BADADDR;
} else {
KDB_STATE_CLEAR(SUPPRESS);
}
return ret;
}
/*
* kdb_putarea_size - Write an area of data. The kdb equivalent of
* copy_to_user, with kdb messages for invalid addresses.
* Inputs:
* addr Address of the area to write to.
* res Pointer to the area holding the data.
* size Size of the area.
* Returns:
* 0 for success, < 0 for error.
*/
int kdb_putarea_size(unsigned long addr, void *res, size_t size)
{
int ret = probe_kernel_read((char *)addr, (char *)res, size);
if (ret) {
if (!KDB_STATE(SUPPRESS)) {
kdb_printf("kdb_putarea: Bad address 0x%lx\n", addr);
KDB_STATE_SET(SUPPRESS);
}
ret = KDB_BADADDR;
} else {
KDB_STATE_CLEAR(SUPPRESS);
}
return ret;
}
/*
* kdb_getphys - Read data from a physical address. Validate the
* address is in range, use kmap_atomic() to get data
* similar to kdb_getarea() - but for phys addresses
* Inputs:
* res Pointer to the word to receive the result
* addr Physical address of the area to copy
* size Size of the area
* Returns:
* 0 for success, < 0 for error.
*/
static int kdb_getphys(void *res, unsigned long addr, size_t size)
{
unsigned long pfn;
void *vaddr;
struct page *page;
pfn = (addr >> PAGE_SHIFT);
if (!pfn_valid(pfn))
return 1;
page = pfn_to_page(pfn);
vaddr = kmap_atomic(page, KM_KDB);
memcpy(res, vaddr + (addr & (PAGE_SIZE - 1)), size);
kunmap_atomic(vaddr, KM_KDB);
return 0;
}
/*
* kdb_getphysword
* Inputs:
* word Pointer to the word to receive the result.
* addr Address of the area to copy.
* size Size of the area.
* Returns:
* 0 for success, < 0 for error.
*/
int kdb_getphysword(unsigned long *word, unsigned long addr, size_t size)
{
int diag;
__u8 w1;
__u16 w2;
__u32 w4;
__u64 w8;
*word = 0; /* Default value if addr or size is invalid */
switch (size) {
case 1:
diag = kdb_getphys(&w1, addr, sizeof(w1));
if (!diag)
*word = w1;
break;
case 2:
diag = kdb_getphys(&w2, addr, sizeof(w2));
if (!diag)
*word = w2;
break;
case 4:
diag = kdb_getphys(&w4, addr, sizeof(w4));
if (!diag)
*word = w4;
break;
case 8:
if (size <= sizeof(*word)) {
diag = kdb_getphys(&w8, addr, sizeof(w8));
if (!diag)
*word = w8;
break;
}
/* drop through */
default:
diag = KDB_BADWIDTH;
kdb_printf("kdb_getphysword: bad width %ld\n", (long) size);
}
return diag;
}
/*
* kdb_getword - Read a binary value. Unlike kdb_getarea, this treats
* data as numbers.
* Inputs:
* word Pointer to the word to receive the result.
* addr Address of the area to copy.
* size Size of the area.
* Returns:
* 0 for success, < 0 for error.
*/
int kdb_getword(unsigned long *word, unsigned long addr, size_t size)
{
int diag;
__u8 w1;
__u16 w2;
__u32 w4;
__u64 w8;
*word = 0; /* Default value if addr or size is invalid */
switch (size) {
case 1:
diag = kdb_getarea(w1, addr);
if (!diag)
*word = w1;
break;
case 2:
diag = kdb_getarea(w2, addr);
if (!diag)
*word = w2;
break;
case 4:
diag = kdb_getarea(w4, addr);
if (!diag)
*word = w4;
break;
case 8:
if (size <= sizeof(*word)) {
diag = kdb_getarea(w8, addr);
if (!diag)
*word = w8;
break;
}
/* drop through */
default:
diag = KDB_BADWIDTH;
kdb_printf("kdb_getword: bad width %ld\n", (long) size);
}
return diag;
}
/*
* kdb_putword - Write a binary value. Unlike kdb_putarea, this
* treats data as numbers.
* Inputs:
* addr Address of the area to write to..
* word The value to set.
* size Size of the area.
* Returns:
* 0 for success, < 0 for error.
*/
int kdb_putword(unsigned long addr, unsigned long word, size_t size)
{
int diag;
__u8 w1;
__u16 w2;
__u32 w4;
__u64 w8;
switch (size) {
case 1:
w1 = word;
diag = kdb_putarea(addr, w1);
break;
case 2:
w2 = word;
diag = kdb_putarea(addr, w2);
break;
case 4:
w4 = word;
diag = kdb_putarea(addr, w4);
break;
case 8:
if (size <= sizeof(word)) {
w8 = word;
diag = kdb_putarea(addr, w8);
break;
}
/* drop through */
default:
diag = KDB_BADWIDTH;
kdb_printf("kdb_putword: bad width %ld\n", (long) size);
}
return diag;
}
/*
* kdb_task_state_string - Convert a string containing any of the
* letters DRSTCZEUIMA to a mask for the process state field and
* return the value. If no argument is supplied, return the mask
* that corresponds to environment variable PS, DRSTCZEU by
* default.
* Inputs:
* s String to convert
* Returns:
* Mask for process state.
* Notes:
* The mask folds data from several sources into a single long value, so
* be carefull not to overlap the bits. TASK_* bits are in the LSB,
* special cases like UNRUNNABLE are in the MSB. As of 2.6.10-rc1 there
* is no overlap between TASK_* and EXIT_* but that may not always be
* true, so EXIT_* bits are shifted left 16 bits before being stored in
* the mask.
*/
/* unrunnable is < 0 */
#define UNRUNNABLE (1UL << (8*sizeof(unsigned long) - 1))
#define RUNNING (1UL << (8*sizeof(unsigned long) - 2))
#define IDLE (1UL << (8*sizeof(unsigned long) - 3))
#define DAEMON (1UL << (8*sizeof(unsigned long) - 4))
unsigned long kdb_task_state_string(const char *s)
{
long res = 0;
if (!s) {
s = kdbgetenv("PS");
if (!s)
s = "DRSTCZEU"; /* default value for ps */
}
while (*s) {
switch (*s) {
case 'D':
res |= TASK_UNINTERRUPTIBLE;
break;
case 'R':
res |= RUNNING;
break;
case 'S':
res |= TASK_INTERRUPTIBLE;
break;
case 'T':
res |= TASK_STOPPED;
break;
case 'C':
res |= TASK_TRACED;
break;
case 'Z':
res |= EXIT_ZOMBIE << 16;
break;
case 'E':
res |= EXIT_DEAD << 16;
break;
case 'U':
res |= UNRUNNABLE;
break;
case 'I':
res |= IDLE;
break;
case 'M':
res |= DAEMON;
break;
case 'A':
res = ~0UL;
break;
default:
kdb_printf("%s: unknown flag '%c' ignored\n",
__func__, *s);
break;
}
++s;
}
return res;
}
/*
* kdb_task_state_char - Return the character that represents the task state.
* Inputs:
* p struct task for the process
* Returns:
* One character to represent the task state.
*/
char kdb_task_state_char (const struct task_struct *p)
{
int cpu;
char state;
unsigned long tmp;
if (!p || probe_kernel_read(&tmp, (char *)p, sizeof(unsigned long)))
return 'E';
cpu = kdb_process_cpu(p);
state = (p->state == 0) ? 'R' :
(p->state < 0) ? 'U' :
(p->state & TASK_UNINTERRUPTIBLE) ? 'D' :
(p->state & TASK_STOPPED) ? 'T' :
(p->state & TASK_TRACED) ? 'C' :
(p->exit_state & EXIT_ZOMBIE) ? 'Z' :
(p->exit_state & EXIT_DEAD) ? 'E' :
(p->state & TASK_INTERRUPTIBLE) ? 'S' : '?';
if (p->pid == 0) {
/* Idle task. Is it really idle, apart from the kdb
* interrupt? */
if (!kdb_task_has_cpu(p) || kgdb_info[cpu].irq_depth == 1) {
if (cpu != kdb_initial_cpu)
state = 'I'; /* idle task */
}
} else if (!p->mm && state == 'S') {
state = 'M'; /* sleeping system daemon */
}
return state;
}
/*
* kdb_task_state - Return true if a process has the desired state
* given by the mask.
* Inputs:
* p struct task for the process
* mask mask from kdb_task_state_string to select processes
* Returns:
* True if the process matches at least one criteria defined by the mask.
*/
unsigned long kdb_task_state(const struct task_struct *p, unsigned long mask)
{
char state[] = { kdb_task_state_char(p), '\0' };
return (mask & kdb_task_state_string(state)) != 0;
}
/*
* kdb_print_nameval - Print a name and its value, converting the
* value to a symbol lookup if possible.
* Inputs:
* name field name to print
* val value of field
*/
void kdb_print_nameval(const char *name, unsigned long val)
{
kdb_symtab_t symtab;
kdb_printf(" %-11.11s ", name);
if (kdbnearsym(val, &symtab))
kdb_symbol_print(val, &symtab,
KDB_SP_VALUE|KDB_SP_SYMSIZE|KDB_SP_NEWLINE);
else
kdb_printf("0x%lx\n", val);
}
/* Last ditch allocator for debugging, so we can still debug even when
* the GFP_ATOMIC pool has been exhausted. The algorithms are tuned
* for space usage, not for speed. One smallish memory pool, the free
* chain is always in ascending address order to allow coalescing,
* allocations are done in brute force best fit.
*/
struct debug_alloc_header {
u32 next; /* offset of next header from start of pool */
u32 size;
void *caller;
};
/* The memory returned by this allocator must be aligned, which means
* so must the header size. Do not assume that sizeof(struct
* debug_alloc_header) is a multiple of the alignment, explicitly
* calculate the overhead of this header, including the alignment.
* The rest of this code must not use sizeof() on any header or
* pointer to a header.
*/
#define dah_align 8
#define dah_overhead ALIGN(sizeof(struct debug_alloc_header), dah_align)
static u64 debug_alloc_pool_aligned[256*1024/dah_align]; /* 256K pool */
static char *debug_alloc_pool = (char *)debug_alloc_pool_aligned;
static u32 dah_first, dah_first_call = 1, dah_used, dah_used_max;
/* Locking is awkward. The debug code is called from all contexts,
* including non maskable interrupts. A normal spinlock is not safe
* in NMI context. Try to get the debug allocator lock, if it cannot
* be obtained after a second then give up. If the lock could not be
* previously obtained on this cpu then only try once.
*
* sparse has no annotation for "this function _sometimes_ acquires a
* lock", so fudge the acquire/release notation.
*/
static DEFINE_SPINLOCK(dap_lock);
static int get_dap_lock(void)
__acquires(dap_lock)
{
static int dap_locked = -1;
int count;
if (dap_locked == smp_processor_id())
count = 1;
else
count = 1000;
while (1) {
if (spin_trylock(&dap_lock)) {
dap_locked = -1;
return 1;
}
if (!count--)
break;
udelay(1000);
}
dap_locked = smp_processor_id();
__acquire(dap_lock);
return 0;
}
void *debug_kmalloc(size_t size, gfp_t flags)
{
unsigned int rem, h_offset;
struct debug_alloc_header *best, *bestprev, *prev, *h;
void *p = NULL;
if (!get_dap_lock()) {
__release(dap_lock); /* we never actually got it */
return NULL;
}
h = (struct debug_alloc_header *)(debug_alloc_pool + dah_first);
if (dah_first_call) {
h->size = sizeof(debug_alloc_pool_aligned) - dah_overhead;
dah_first_call = 0;
}
size = ALIGN(size, dah_align);
prev = best = bestprev = NULL;
while (1) {
if (h->size >= size && (!best || h->size < best->size)) {
best = h;
bestprev = prev;
if (h->size == size)
break;
}
if (!h->next)
break;
prev = h;
h = (struct debug_alloc_header *)(debug_alloc_pool + h->next);
}
if (!best)
goto out;
rem = best->size - size;
/* The pool must always contain at least one header */
if (best->next == 0 && bestprev == NULL && rem < dah_overhead)
goto out;
if (rem >= dah_overhead) {
best->size = size;
h_offset = ((char *)best - debug_alloc_pool) +
dah_overhead + best->size;
h = (struct debug_alloc_header *)(debug_alloc_pool + h_offset);
h->size = rem - dah_overhead;
h->next = best->next;
} else
h_offset = best->next;
best->caller = __builtin_return_address(0);
dah_used += best->size;
dah_used_max = max(dah_used, dah_used_max);
if (bestprev)
bestprev->next = h_offset;
else
dah_first = h_offset;
p = (char *)best + dah_overhead;
memset(p, POISON_INUSE, best->size - 1);
*((char *)p + best->size - 1) = POISON_END;
out:
spin_unlock(&dap_lock);
return p;
}
void debug_kfree(void *p)
{
struct debug_alloc_header *h;
unsigned int h_offset;
if (!p)
return;
if ((char *)p < debug_alloc_pool ||
(char *)p >= debug_alloc_pool + sizeof(debug_alloc_pool_aligned)) {
kfree(p);
return;
}
if (!get_dap_lock()) {
__release(dap_lock); /* we never actually got it */
return; /* memory leak, cannot be helped */
}
h = (struct debug_alloc_header *)((char *)p - dah_overhead);
memset(p, POISON_FREE, h->size - 1);
*((char *)p + h->size - 1) = POISON_END;
h->caller = NULL;
dah_used -= h->size;
h_offset = (char *)h - debug_alloc_pool;
if (h_offset < dah_first) {
h->next = dah_first;
dah_first = h_offset;
} else {
struct debug_alloc_header *prev;
unsigned int prev_offset;
prev = (struct debug_alloc_header *)(debug_alloc_pool +
dah_first);
while (1) {
if (!prev->next || prev->next > h_offset)
break;
prev = (struct debug_alloc_header *)
(debug_alloc_pool + prev->next);
}
prev_offset = (char *)prev - debug_alloc_pool;
if (prev_offset + dah_overhead + prev->size == h_offset) {
prev->size += dah_overhead + h->size;
memset(h, POISON_FREE, dah_overhead - 1);
*((char *)h + dah_overhead - 1) = POISON_END;
h = prev;
h_offset = prev_offset;
} else {
h->next = prev->next;
prev->next = h_offset;
}
}
if (h_offset + dah_overhead + h->size == h->next) {
struct debug_alloc_header *next;
next = (struct debug_alloc_header *)
(debug_alloc_pool + h->next);
h->size += dah_overhead + next->size;
h->next = next->next;
memset(next, POISON_FREE, dah_overhead - 1);
*((char *)next + dah_overhead - 1) = POISON_END;
}
spin_unlock(&dap_lock);
}
void debug_kusage(void)
{
struct debug_alloc_header *h_free, *h_used;
#ifdef CONFIG_IA64
/* FIXME: using dah for ia64 unwind always results in a memory leak.
* Fix that memory leak first, then set debug_kusage_one_time = 1 for
* all architectures.
*/
static int debug_kusage_one_time;
#else
static int debug_kusage_one_time = 1;
#endif
if (!get_dap_lock()) {
__release(dap_lock); /* we never actually got it */
return;
}
h_free = (struct debug_alloc_header *)(debug_alloc_pool + dah_first);
if (dah_first == 0 &&
(h_free->size == sizeof(debug_alloc_pool_aligned) - dah_overhead ||
dah_first_call))
goto out;
if (!debug_kusage_one_time)
goto out;
debug_kusage_one_time = 0;
kdb_printf("%s: debug_kmalloc memory leak dah_first %d\n",
__func__, dah_first);
if (dah_first) {
h_used = (struct debug_alloc_header *)debug_alloc_pool;
kdb_printf("%s: h_used %p size %d\n", __func__, h_used,
h_used->size);
}
do {
h_used = (struct debug_alloc_header *)
((char *)h_free + dah_overhead + h_free->size);
kdb_printf("%s: h_used %p size %d caller %p\n",
__func__, h_used, h_used->size, h_used->caller);
h_free = (struct debug_alloc_header *)
(debug_alloc_pool + h_free->next);
} while (h_free->next);
h_used = (struct debug_alloc_header *)
((char *)h_free + dah_overhead + h_free->size);
if ((char *)h_used - debug_alloc_pool !=
sizeof(debug_alloc_pool_aligned))
kdb_printf("%s: h_used %p size %d caller %p\n",
__func__, h_used, h_used->size, h_used->caller);
out:
spin_unlock(&dap_lock);
}
/* Maintain a small stack of kdb_flags to allow recursion without disturbing
* the global kdb state.
*/
static int kdb_flags_stack[4], kdb_flags_index;
void kdb_save_flags(void)
{
BUG_ON(kdb_flags_index >= ARRAY_SIZE(kdb_flags_stack));
kdb_flags_stack[kdb_flags_index++] = kdb_flags;
}
void kdb_restore_flags(void)
{
BUG_ON(kdb_flags_index <= 0);
kdb_flags = kdb_flags_stack[--kdb_flags_index];
}