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927 lines
24 KiB
927 lines
24 KiB
/* |
|
* Kernel Debugger Architecture Independent Support Functions |
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* |
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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 |
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* for more details. |
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* |
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* Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved. |
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* Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. |
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* 03/02/13 added new 2.5 kallsyms <[email protected]> |
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*/ |
|
|
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#include <stdarg.h> |
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#include <linux/types.h> |
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#include <linux/sched.h> |
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#include <linux/mm.h> |
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#include <linux/kallsyms.h> |
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#include <linux/stddef.h> |
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#include <linux/vmalloc.h> |
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#include <linux/ptrace.h> |
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#include <linux/module.h> |
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#include <linux/highmem.h> |
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#include <linux/hardirq.h> |
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#include <linux/delay.h> |
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#include <linux/uaccess.h> |
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#include <linux/kdb.h> |
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#include <linux/slab.h> |
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#include "kdb_private.h" |
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|
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/* |
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* kdbgetsymval - Return the address of the given symbol. |
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* |
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* Parameters: |
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* symname Character string containing symbol name |
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* symtab Structure to receive results |
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* Returns: |
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* 0 Symbol not found, symtab zero filled |
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* 1 Symbol mapped to module/symbol/section, data in symtab |
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*/ |
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int kdbgetsymval(const char *symname, kdb_symtab_t *symtab) |
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{ |
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if (KDB_DEBUG(AR)) |
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kdb_printf("kdbgetsymval: symname=%s, symtab=%p\n", symname, |
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symtab); |
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memset(symtab, 0, sizeof(*symtab)); |
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symtab->sym_start = kallsyms_lookup_name(symname); |
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if (symtab->sym_start) { |
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if (KDB_DEBUG(AR)) |
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kdb_printf("kdbgetsymval: returns 1, " |
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"symtab->sym_start=0x%lx\n", |
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symtab->sym_start); |
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return 1; |
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} |
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if (KDB_DEBUG(AR)) |
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kdb_printf("kdbgetsymval: returns 0\n"); |
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return 0; |
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} |
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EXPORT_SYMBOL(kdbgetsymval); |
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|
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static char *kdb_name_table[100]; /* arbitrary size */ |
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|
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/* |
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* kdbnearsym - Return the name of the symbol with the nearest address |
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* less than 'addr'. |
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* |
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* Parameters: |
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* addr Address to check for symbol near |
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* symtab Structure to receive results |
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* Returns: |
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* 0 No sections contain this address, symtab zero filled |
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* 1 Address mapped to module/symbol/section, data in symtab |
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* Remarks: |
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* 2.6 kallsyms has a "feature" where it unpacks the name into a |
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* string. If that string is reused before the caller expects it |
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* then the caller sees its string change without warning. To |
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* avoid cluttering up the main kdb code with lots of kdb_strdup, |
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* tests and kfree calls, kdbnearsym maintains an LRU list of the |
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* last few unique strings. The list is sized large enough to |
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* hold active strings, no kdb caller of kdbnearsym makes more |
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* than ~20 later calls before using a saved value. |
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*/ |
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int kdbnearsym(unsigned long addr, kdb_symtab_t *symtab) |
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{ |
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int ret = 0; |
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unsigned long symbolsize = 0; |
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unsigned long offset = 0; |
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#define knt1_size 128 /* must be >= kallsyms table size */ |
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char *knt1 = NULL; |
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|
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if (KDB_DEBUG(AR)) |
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kdb_printf("kdbnearsym: addr=0x%lx, symtab=%p\n", addr, symtab); |
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memset(symtab, 0, sizeof(*symtab)); |
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|
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if (addr < 4096) |
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goto out; |
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knt1 = debug_kmalloc(knt1_size, GFP_ATOMIC); |
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if (!knt1) { |
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kdb_printf("kdbnearsym: addr=0x%lx cannot kmalloc knt1\n", |
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addr); |
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goto out; |
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} |
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symtab->sym_name = kallsyms_lookup(addr, &symbolsize , &offset, |
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(char **)(&symtab->mod_name), knt1); |
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if (offset > 8*1024*1024) { |
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symtab->sym_name = NULL; |
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addr = offset = symbolsize = 0; |
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} |
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symtab->sym_start = addr - offset; |
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symtab->sym_end = symtab->sym_start + symbolsize; |
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ret = symtab->sym_name != NULL && *(symtab->sym_name) != '\0'; |
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|
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if (ret) { |
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int i; |
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/* Another 2.6 kallsyms "feature". Sometimes the sym_name is |
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* set but the buffer passed into kallsyms_lookup is not used, |
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* so it contains garbage. The caller has to work out which |
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* buffer needs to be saved. |
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* |
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* What was Rusty smoking when he wrote that code? |
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*/ |
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if (symtab->sym_name != knt1) { |
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strncpy(knt1, symtab->sym_name, knt1_size); |
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knt1[knt1_size-1] = '\0'; |
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} |
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for (i = 0; i < ARRAY_SIZE(kdb_name_table); ++i) { |
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if (kdb_name_table[i] && |
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strcmp(kdb_name_table[i], knt1) == 0) |
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break; |
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} |
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if (i >= ARRAY_SIZE(kdb_name_table)) { |
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debug_kfree(kdb_name_table[0]); |
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memcpy(kdb_name_table, kdb_name_table+1, |
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sizeof(kdb_name_table[0]) * |
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(ARRAY_SIZE(kdb_name_table)-1)); |
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} else { |
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debug_kfree(knt1); |
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knt1 = kdb_name_table[i]; |
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memcpy(kdb_name_table+i, kdb_name_table+i+1, |
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sizeof(kdb_name_table[0]) * |
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(ARRAY_SIZE(kdb_name_table)-i-1)); |
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} |
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i = ARRAY_SIZE(kdb_name_table) - 1; |
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kdb_name_table[i] = knt1; |
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symtab->sym_name = kdb_name_table[i]; |
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knt1 = NULL; |
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} |
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|
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if (symtab->mod_name == NULL) |
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symtab->mod_name = "kernel"; |
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if (KDB_DEBUG(AR)) |
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kdb_printf("kdbnearsym: returns %d symtab->sym_start=0x%lx, " |
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"symtab->mod_name=%p, symtab->sym_name=%p (%s)\n", ret, |
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symtab->sym_start, symtab->mod_name, symtab->sym_name, |
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symtab->sym_name); |
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|
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out: |
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debug_kfree(knt1); |
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return ret; |
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} |
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|
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void kdbnearsym_cleanup(void) |
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{ |
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int i; |
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for (i = 0; i < ARRAY_SIZE(kdb_name_table); ++i) { |
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if (kdb_name_table[i]) { |
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debug_kfree(kdb_name_table[i]); |
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kdb_name_table[i] = NULL; |
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} |
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} |
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} |
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|
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static char ks_namebuf[KSYM_NAME_LEN+1], ks_namebuf_prev[KSYM_NAME_LEN+1]; |
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|
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/* |
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* kallsyms_symbol_complete |
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* |
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* Parameters: |
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* prefix_name prefix of a symbol name to lookup |
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* max_len maximum length that can be returned |
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* Returns: |
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* Number of symbols which match the given prefix. |
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* Notes: |
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* prefix_name is changed to contain the longest unique prefix that |
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* starts with this prefix (tab completion). |
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*/ |
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int kallsyms_symbol_complete(char *prefix_name, int max_len) |
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{ |
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loff_t pos = 0; |
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int prefix_len = strlen(prefix_name), prev_len = 0; |
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int i, number = 0; |
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const char *name; |
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|
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while ((name = kdb_walk_kallsyms(&pos))) { |
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if (strncmp(name, prefix_name, prefix_len) == 0) { |
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strcpy(ks_namebuf, name); |
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/* Work out the longest name that matches the prefix */ |
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if (++number == 1) { |
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prev_len = min_t(int, max_len-1, |
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strlen(ks_namebuf)); |
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memcpy(ks_namebuf_prev, ks_namebuf, prev_len); |
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ks_namebuf_prev[prev_len] = '\0'; |
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continue; |
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} |
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for (i = 0; i < prev_len; i++) { |
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if (ks_namebuf[i] != ks_namebuf_prev[i]) { |
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prev_len = i; |
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ks_namebuf_prev[i] = '\0'; |
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break; |
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} |
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} |
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} |
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} |
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if (prev_len > prefix_len) |
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memcpy(prefix_name, ks_namebuf_prev, prev_len+1); |
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return number; |
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} |
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|
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/* |
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* kallsyms_symbol_next |
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* |
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* Parameters: |
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* prefix_name prefix of a symbol name to lookup |
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* flag 0 means search from the head, 1 means continue search. |
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* Returns: |
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* 1 if a symbol matches the given prefix. |
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* 0 if no string found |
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*/ |
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int kallsyms_symbol_next(char *prefix_name, int flag) |
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{ |
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int prefix_len = strlen(prefix_name); |
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static loff_t pos; |
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const char *name; |
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|
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if (!flag) |
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pos = 0; |
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|
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while ((name = kdb_walk_kallsyms(&pos))) { |
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if (strncmp(name, prefix_name, prefix_len) == 0) { |
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strncpy(prefix_name, name, strlen(name)+1); |
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return 1; |
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} |
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} |
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return 0; |
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} |
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|
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/* |
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* kdb_symbol_print - Standard method for printing a symbol name and offset. |
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* Inputs: |
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* addr Address to be printed. |
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* symtab Address of symbol data, if NULL this routine does its |
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* own lookup. |
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* punc Punctuation for string, bit field. |
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* Remarks: |
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* The string and its punctuation is only printed if the address |
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* is inside the kernel, except that the value is always printed |
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* when requested. |
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*/ |
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void kdb_symbol_print(unsigned long addr, const kdb_symtab_t *symtab_p, |
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unsigned int punc) |
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{ |
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kdb_symtab_t symtab, *symtab_p2; |
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if (symtab_p) { |
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symtab_p2 = (kdb_symtab_t *)symtab_p; |
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} else { |
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symtab_p2 = &symtab; |
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kdbnearsym(addr, symtab_p2); |
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} |
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if (!(symtab_p2->sym_name || (punc & KDB_SP_VALUE))) |
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return; |
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if (punc & KDB_SP_SPACEB) |
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kdb_printf(" "); |
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if (punc & KDB_SP_VALUE) |
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kdb_printf(kdb_machreg_fmt0, addr); |
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if (symtab_p2->sym_name) { |
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if (punc & KDB_SP_VALUE) |
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kdb_printf(" "); |
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if (punc & KDB_SP_PAREN) |
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kdb_printf("("); |
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if (strcmp(symtab_p2->mod_name, "kernel")) |
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kdb_printf("[%s]", symtab_p2->mod_name); |
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kdb_printf("%s", symtab_p2->sym_name); |
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if (addr != symtab_p2->sym_start) |
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kdb_printf("+0x%lx", addr - symtab_p2->sym_start); |
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if (punc & KDB_SP_SYMSIZE) |
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kdb_printf("/0x%lx", |
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symtab_p2->sym_end - symtab_p2->sym_start); |
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if (punc & KDB_SP_PAREN) |
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kdb_printf(")"); |
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} |
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if (punc & KDB_SP_SPACEA) |
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kdb_printf(" "); |
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if (punc & KDB_SP_NEWLINE) |
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kdb_printf("\n"); |
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} |
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|
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/* |
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* kdb_strdup - kdb equivalent of strdup, for disasm code. |
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* Inputs: |
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* str The string to duplicate. |
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* type Flags to kmalloc for the new string. |
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* Returns: |
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* Address of the new string, NULL if storage could not be allocated. |
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* Remarks: |
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* This is not in lib/string.c because it uses kmalloc which is not |
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* available when string.o is used in boot loaders. |
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*/ |
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char *kdb_strdup(const char *str, gfp_t type) |
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{ |
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int n = strlen(str)+1; |
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char *s = kmalloc(n, type); |
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if (!s) |
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return NULL; |
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return strcpy(s, str); |
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} |
|
|
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/* |
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* kdb_getarea_size - Read an area of data. The kdb equivalent of |
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* copy_from_user, with kdb messages for invalid addresses. |
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* Inputs: |
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* res Pointer to the area to receive the result. |
|
* addr Address of the area to copy. |
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* size Size of the area. |
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* Returns: |
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* 0 for success, < 0 for error. |
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*/ |
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int kdb_getarea_size(void *res, unsigned long addr, size_t size) |
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{ |
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int ret = probe_kernel_read((char *)res, (char *)addr, size); |
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if (ret) { |
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if (!KDB_STATE(SUPPRESS)) { |
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kdb_printf("kdb_getarea: Bad address 0x%lx\n", addr); |
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KDB_STATE_SET(SUPPRESS); |
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} |
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ret = KDB_BADADDR; |
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} else { |
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KDB_STATE_CLEAR(SUPPRESS); |
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} |
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return ret; |
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} |
|
|
|
/* |
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* kdb_putarea_size - Write an area of data. The kdb equivalent of |
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* 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: |
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* 0 for success, < 0 for error. |
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*/ |
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int kdb_putarea_size(unsigned long addr, void *res, size_t size) |
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{ |
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int ret = probe_kernel_read((char *)addr, (char *)res, size); |
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if (ret) { |
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if (!KDB_STATE(SUPPRESS)) { |
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kdb_printf("kdb_putarea: Bad address 0x%lx\n", addr); |
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KDB_STATE_SET(SUPPRESS); |
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} |
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ret = KDB_BADADDR; |
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} else { |
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KDB_STATE_CLEAR(SUPPRESS); |
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} |
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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. |
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*/ |
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static int kdb_getphys(void *res, unsigned long addr, size_t size) |
|
{ |
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unsigned long pfn; |
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void *vaddr; |
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struct page *page; |
|
|
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pfn = (addr >> PAGE_SHIFT); |
|
if (!pfn_valid(pfn)) |
|
return 1; |
|
page = pfn_to_page(pfn); |
|
vaddr = kmap_atomic(page); |
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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; |
|
} |
|
/* 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 careful 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 (is_idle_task(p)) { |
|
/* 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]; |
|
}
|
|
|