557 lines
14 KiB
C
557 lines
14 KiB
C
/*
|
|
* 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 <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/highmem.h>
|
|
#include <linux/hardirq.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/kdb.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/ctype.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)
|
|
{
|
|
kdb_dbg_printf(AR, "symname=%s, symtab=%px\n", symname, symtab);
|
|
memset(symtab, 0, sizeof(*symtab));
|
|
symtab->sym_start = kallsyms_lookup_name(symname);
|
|
if (symtab->sym_start) {
|
|
kdb_dbg_printf(AR, "returns 1, symtab->sym_start=0x%lx\n",
|
|
symtab->sym_start);
|
|
return 1;
|
|
}
|
|
kdb_dbg_printf(AR, "returns 0\n");
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(kdbgetsymval);
|
|
|
|
/**
|
|
* kdbnearsym() - Return the name of the symbol with the nearest address
|
|
* less than @addr.
|
|
* @addr: Address to check for near symbol
|
|
* @symtab: Structure to receive results
|
|
*
|
|
* WARNING: This function may return a pointer to a single statically
|
|
* allocated buffer (namebuf). kdb's unusual calling context (single
|
|
* threaded, all other CPUs halted) provides us sufficient locking for
|
|
* this to be safe. The only constraint imposed by the static buffer is
|
|
* that the caller must consume any previous reply prior to another call
|
|
* to lookup a new symbol.
|
|
*
|
|
* Note that, strictly speaking, some architectures may re-enter the kdb
|
|
* trap if the system turns out to be very badly damaged and this breaks
|
|
* the single-threaded assumption above. In these circumstances successful
|
|
* continuation and exit from the inner trap is unlikely to work and any
|
|
* user attempting this receives a prominent warning before being allowed
|
|
* to progress. In these circumstances we remain memory safe because
|
|
* namebuf[KSYM_NAME_LEN-1] will never change from '\0' although we do
|
|
* tolerate the possibility of garbled symbol display from the outer kdb
|
|
* trap.
|
|
*
|
|
* Return:
|
|
* * 0 - No sections contain this address, symtab zero filled
|
|
* * 1 - Address mapped to module/symbol/section, data in symtab
|
|
*/
|
|
int kdbnearsym(unsigned long addr, kdb_symtab_t *symtab)
|
|
{
|
|
int ret = 0;
|
|
unsigned long symbolsize = 0;
|
|
unsigned long offset = 0;
|
|
static char namebuf[KSYM_NAME_LEN];
|
|
|
|
kdb_dbg_printf(AR, "addr=0x%lx, symtab=%px\n", addr, symtab);
|
|
memset(symtab, 0, sizeof(*symtab));
|
|
|
|
if (addr < 4096)
|
|
goto out;
|
|
|
|
symtab->sym_name = kallsyms_lookup(addr, &symbolsize , &offset,
|
|
(char **)(&symtab->mod_name), namebuf);
|
|
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 (symtab->mod_name == NULL)
|
|
symtab->mod_name = "kernel";
|
|
kdb_dbg_printf(AR, "returns %d symtab->sym_start=0x%lx, symtab->mod_name=%px, symtab->sym_name=%px (%s)\n",
|
|
ret, symtab->sym_start, symtab->mod_name, symtab->sym_name, symtab->sym_name);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
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) {
|
|
strscpy(ks_namebuf, name, sizeof(ks_namebuf));
|
|
/* 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.
|
|
* buf_size maximum length that can be written to prefix_name
|
|
* buffer
|
|
* Returns:
|
|
* 1 if a symbol matches the given prefix.
|
|
* 0 if no string found
|
|
*/
|
|
int kallsyms_symbol_next(char *prefix_name, int flag, int buf_size)
|
|
{
|
|
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))
|
|
return strscpy(prefix_name, name, buf_size);
|
|
}
|
|
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 = copy_from_kernel_nofault((char *)res, (char *)addr, size);
|
|
if (ret) {
|
|
if (!KDB_STATE(SUPPRESS)) {
|
|
kdb_func_printf("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 = copy_to_kernel_nofault((char *)addr, (char *)res, size);
|
|
if (ret) {
|
|
if (!KDB_STATE(SUPPRESS)) {
|
|
kdb_func_printf("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);
|
|
memcpy(res, vaddr + (addr & (PAGE_SIZE - 1)), size);
|
|
kunmap_atomic(vaddr);
|
|
|
|
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;
|
|
}
|
|
fallthrough;
|
|
default:
|
|
diag = KDB_BADWIDTH;
|
|
kdb_func_printf("bad width %zu\n", 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;
|
|
}
|
|
fallthrough;
|
|
default:
|
|
diag = KDB_BADWIDTH;
|
|
kdb_func_printf("bad width %zu\n", 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;
|
|
}
|
|
fallthrough;
|
|
default:
|
|
diag = KDB_BADWIDTH;
|
|
kdb_func_printf("bad width %zu\n", size);
|
|
}
|
|
return diag;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
unsigned long tmp;
|
|
char state;
|
|
int cpu;
|
|
|
|
if (!p ||
|
|
copy_from_kernel_nofault(&tmp, (char *)p, sizeof(unsigned long)))
|
|
return 'E';
|
|
|
|
state = task_state_to_char((struct task_struct *) p);
|
|
|
|
if (is_idle_task(p)) {
|
|
/* Idle task. Is it really idle, apart from the kdb
|
|
* interrupt? */
|
|
cpu = kdb_process_cpu(p);
|
|
if (!kdb_task_has_cpu(p) || kgdb_info[cpu].irq_depth == 1) {
|
|
if (cpu != kdb_initial_cpu)
|
|
state = '-'; /* idle task */
|
|
}
|
|
} else if (!p->mm && strchr("IMS", state)) {
|
|
state = tolower(state); /* 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 set of characters used to select processes; both NULL
|
|
* and the empty string mean adopt a default filter, which
|
|
* is to suppress sleeping system daemons and the idle tasks
|
|
* Returns:
|
|
* True if the process matches at least one criteria defined by the mask.
|
|
*/
|
|
bool kdb_task_state(const struct task_struct *p, const char *mask)
|
|
{
|
|
char state = kdb_task_state_char(p);
|
|
|
|
/* If there is no mask, then we will filter code that runs when the
|
|
* scheduler is idling and any system daemons that are currently
|
|
* sleeping.
|
|
*/
|
|
if (!mask || mask[0] == '\0')
|
|
return !strchr("-ims", state);
|
|
|
|
/* A is a special case that matches all states */
|
|
if (strchr(mask, 'A'))
|
|
return true;
|
|
|
|
return strchr(mask, state);
|
|
}
|
|
|
|
/* 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];
|
|
}
|