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625 lines
16 KiB
625 lines
16 KiB
/* |
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* 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 |
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* 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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|
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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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kdb_dbg_printf(AR, "symname=%s, symtab=%px\n", symname, 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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kdb_dbg_printf(AR, "returns 1, 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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kdb_dbg_printf(AR, "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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/** |
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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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* @addr: Address to check for near symbol |
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* @symtab: Structure to receive results |
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* |
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* WARNING: This function may return a pointer to a single statically |
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* allocated buffer (namebuf). kdb's unusual calling context (single |
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* threaded, all other CPUs halted) provides us sufficient locking for |
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* this to be safe. The only constraint imposed by the static buffer is |
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* that the caller must consume any previous reply prior to another call |
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* to lookup a new symbol. |
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* |
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* Note that, strictly speaking, some architectures may re-enter the kdb |
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* trap if the system turns out to be very badly damaged and this breaks |
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* the single-threaded assumption above. In these circumstances successful |
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* continuation and exit from the inner trap is unlikely to work and any |
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* user attempting this receives a prominent warning before being allowed |
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* to progress. In these circumstances we remain memory safe because |
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* namebuf[KSYM_NAME_LEN-1] will never change from '\0' although we do |
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* tolerate the possibility of garbled symbol display from the outer kdb |
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* trap. |
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* |
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* Return: |
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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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*/ |
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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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static char namebuf[KSYM_NAME_LEN]; |
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kdb_dbg_printf(AR, "addr=0x%lx, symtab=%px\n", addr, symtab); |
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memset(symtab, 0, sizeof(*symtab)); |
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if (addr < 4096) |
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goto out; |
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symtab->sym_name = kallsyms_lookup(addr, &symbolsize , &offset, |
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(char **)(&symtab->mod_name), namebuf); |
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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 (symtab->mod_name == NULL) |
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symtab->mod_name = "kernel"; |
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kdb_dbg_printf(AR, "returns %d symtab->sym_start=0x%lx, symtab->mod_name=%px, symtab->sym_name=%px (%s)\n", |
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ret, symtab->sym_start, symtab->mod_name, symtab->sym_name, symtab->sym_name); |
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out: |
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return ret; |
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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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while ((name = kdb_walk_kallsyms(&pos))) { |
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if (strncmp(name, prefix_name, prefix_len) == 0) { |
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strscpy(ks_namebuf, name, sizeof(ks_namebuf)); |
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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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* 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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* buf_size maximum length that can be written to prefix_name |
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* buffer |
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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, int buf_size) |
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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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if (!flag) |
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pos = 0; |
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while ((name = kdb_walk_kallsyms(&pos))) { |
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if (!strncmp(name, prefix_name, prefix_len)) |
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return strscpy(prefix_name, name, buf_size); |
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} |
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return 0; |
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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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* 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. |
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* 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 = copy_from_kernel_nofault((char *)res, (char *)addr, size); |
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if (ret) { |
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if (!KDB_STATE(SUPPRESS)) { |
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kdb_func_printf("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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/* |
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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. |
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* Inputs: |
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* addr Address of the area to write to. |
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* res Pointer to the area holding the data. |
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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_putarea_size(unsigned long addr, void *res, size_t size) |
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{ |
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int ret = copy_from_kernel_nofault((char *)addr, (char *)res, size); |
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if (ret) { |
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if (!KDB_STATE(SUPPRESS)) { |
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kdb_func_printf("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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/* |
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* kdb_getphys - Read data from a physical address. Validate the |
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* address is in range, use kmap_atomic() to get data |
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* similar to kdb_getarea() - but for phys addresses |
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* Inputs: |
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* res Pointer to the word to receive the result |
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* addr Physical 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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static int kdb_getphys(void *res, unsigned long addr, size_t size) |
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{ |
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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); |
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if (!pfn_valid(pfn)) |
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return 1; |
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page = pfn_to_page(pfn); |
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vaddr = kmap_atomic(page); |
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memcpy(res, vaddr + (addr & (PAGE_SIZE - 1)), size); |
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kunmap_atomic(vaddr); |
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return 0; |
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} |
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/* |
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* kdb_getphysword |
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* Inputs: |
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* word Pointer to the word to receive the result. |
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* 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_getphysword(unsigned long *word, unsigned long addr, size_t size) |
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{ |
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int diag; |
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__u8 w1; |
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__u16 w2; |
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__u32 w4; |
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__u64 w8; |
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*word = 0; /* Default value if addr or size is invalid */ |
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|
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switch (size) { |
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case 1: |
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diag = kdb_getphys(&w1, addr, sizeof(w1)); |
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if (!diag) |
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*word = w1; |
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break; |
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case 2: |
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diag = kdb_getphys(&w2, addr, sizeof(w2)); |
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if (!diag) |
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*word = w2; |
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break; |
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case 4: |
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diag = kdb_getphys(&w4, addr, sizeof(w4)); |
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if (!diag) |
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*word = w4; |
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break; |
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case 8: |
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if (size <= sizeof(*word)) { |
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diag = kdb_getphys(&w8, addr, sizeof(w8)); |
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if (!diag) |
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*word = w8; |
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break; |
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} |
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fallthrough; |
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default: |
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diag = KDB_BADWIDTH; |
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kdb_func_printf("bad width %zu\n", size); |
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} |
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return diag; |
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} |
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/* |
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* kdb_getword - Read a binary value. Unlike kdb_getarea, this treats |
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* data as numbers. |
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* Inputs: |
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* word Pointer to the word to receive the result. |
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* 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_getword(unsigned long *word, unsigned long addr, size_t size) |
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{ |
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int diag; |
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__u8 w1; |
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__u16 w2; |
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__u32 w4; |
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__u64 w8; |
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*word = 0; /* Default value if addr or size is invalid */ |
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switch (size) { |
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case 1: |
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diag = kdb_getarea(w1, addr); |
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if (!diag) |
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*word = w1; |
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break; |
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case 2: |
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diag = kdb_getarea(w2, addr); |
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if (!diag) |
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*word = w2; |
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break; |
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case 4: |
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diag = kdb_getarea(w4, addr); |
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if (!diag) |
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*word = w4; |
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break; |
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case 8: |
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if (size <= sizeof(*word)) { |
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diag = kdb_getarea(w8, addr); |
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if (!diag) |
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*word = w8; |
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break; |
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} |
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fallthrough; |
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default: |
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diag = KDB_BADWIDTH; |
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kdb_func_printf("bad width %zu\n", size); |
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} |
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return diag; |
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} |
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|
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/* |
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* kdb_putword - Write a binary value. Unlike kdb_putarea, this |
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* treats data as numbers. |
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* Inputs: |
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* addr Address of the area to write to.. |
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* word The value to set. |
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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_putword(unsigned long addr, unsigned long word, size_t size) |
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{ |
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int diag; |
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__u8 w1; |
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__u16 w2; |
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__u32 w4; |
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__u64 w8; |
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switch (size) { |
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case 1: |
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w1 = word; |
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diag = kdb_putarea(addr, w1); |
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break; |
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case 2: |
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w2 = word; |
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diag = kdb_putarea(addr, w2); |
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break; |
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case 4: |
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w4 = word; |
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diag = kdb_putarea(addr, w4); |
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break; |
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case 8: |
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if (size <= sizeof(word)) { |
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w8 = word; |
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diag = kdb_putarea(addr, w8); |
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break; |
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} |
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fallthrough; |
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default: |
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diag = KDB_BADWIDTH; |
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kdb_func_printf("bad width %zu\n", size); |
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} |
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return diag; |
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} |
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|
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/* |
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* kdb_task_state_string - Convert a string containing any of the |
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* letters DRSTCZEUIMA to a mask for the process state field and |
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* return the value. If no argument is supplied, return the mask |
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* that corresponds to environment variable PS, DRSTCZEU by |
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* default. |
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* Inputs: |
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* s String to convert |
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* Returns: |
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* Mask for process state. |
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* Notes: |
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* The mask folds data from several sources into a single long value, so |
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* be careful not to overlap the bits. TASK_* bits are in the LSB, |
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* special cases like UNRUNNABLE are in the MSB. As of 2.6.10-rc1 there |
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* is no overlap between TASK_* and EXIT_* but that may not always be |
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* true, so EXIT_* bits are shifted left 16 bits before being stored in |
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* the mask. |
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*/ |
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|
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/* unrunnable is < 0 */ |
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#define UNRUNNABLE (1UL << (8*sizeof(unsigned long) - 1)) |
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#define RUNNING (1UL << (8*sizeof(unsigned long) - 2)) |
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#define IDLE (1UL << (8*sizeof(unsigned long) - 3)) |
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#define DAEMON (1UL << (8*sizeof(unsigned long) - 4)) |
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|
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unsigned long kdb_task_state_string(const char *s) |
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{ |
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long res = 0; |
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if (!s) { |
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s = kdbgetenv("PS"); |
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if (!s) |
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s = "DRSTCZEU"; /* default value for ps */ |
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} |
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while (*s) { |
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switch (*s) { |
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case 'D': |
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res |= TASK_UNINTERRUPTIBLE; |
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break; |
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case 'R': |
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res |= RUNNING; |
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break; |
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case 'S': |
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res |= TASK_INTERRUPTIBLE; |
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break; |
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case 'T': |
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res |= TASK_STOPPED; |
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break; |
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case 'C': |
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res |= TASK_TRACED; |
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break; |
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case 'Z': |
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res |= EXIT_ZOMBIE << 16; |
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break; |
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case 'E': |
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res |= EXIT_DEAD << 16; |
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break; |
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case 'U': |
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res |= UNRUNNABLE; |
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break; |
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case 'I': |
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res |= IDLE; |
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break; |
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case 'M': |
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res |= DAEMON; |
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break; |
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case 'A': |
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res = ~0UL; |
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break; |
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default: |
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kdb_func_printf("unknown flag '%c' ignored\n", *s); |
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break; |
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} |
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++s; |
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} |
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return res; |
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} |
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|
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/* |
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* kdb_task_state_char - Return the character that represents the task state. |
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* Inputs: |
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* p struct task for the process |
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* Returns: |
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* One character to represent the task state. |
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*/ |
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char kdb_task_state_char (const struct task_struct *p) |
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{ |
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unsigned int p_state; |
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unsigned long tmp; |
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char state; |
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int cpu; |
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|
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if (!p || |
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copy_from_kernel_nofault(&tmp, (char *)p, sizeof(unsigned long))) |
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return 'E'; |
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|
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cpu = kdb_process_cpu(p); |
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p_state = READ_ONCE(p->__state); |
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state = (p_state == 0) ? 'R' : |
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(p_state < 0) ? 'U' : |
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(p_state & TASK_UNINTERRUPTIBLE) ? 'D' : |
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(p_state & TASK_STOPPED) ? 'T' : |
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(p_state & TASK_TRACED) ? 'C' : |
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(p->exit_state & EXIT_ZOMBIE) ? 'Z' : |
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(p->exit_state & EXIT_DEAD) ? 'E' : |
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(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; |
|
} |
|
|
|
/* 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]; |
|
}
|
|
|