/* * 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 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "kdb_private.h" /* * kdbgetsymval - Return the address of the given symbol. * * Parameters: * symname Character string containing symbol name * symtab Structure to receive results * Returns: * 0 Symbol not found, symtab zero filled * 1 Symbol mapped to module/symbol/section, data in symtab */ int kdbgetsymval(const char *symname, kdb_symtab_t *symtab) { if (KDB_DEBUG(AR)) kdb_printf("kdbgetsymval: symname=%s, symtab=%px\n", symname, symtab); memset(symtab, 0, sizeof(*symtab)); symtab->sym_start = kallsyms_lookup_name(symname); if (symtab->sym_start) { if (KDB_DEBUG(AR)) kdb_printf("kdbgetsymval: returns 1, " "symtab->sym_start=0x%lx\n", symtab->sym_start); return 1; } if (KDB_DEBUG(AR)) kdb_printf("kdbgetsymval: returns 0\n"); return 0; } EXPORT_SYMBOL(kdbgetsymval); static char *kdb_name_table[100]; /* arbitrary size */ /* * kdbnearsym - Return the name of the symbol with the nearest address * less than 'addr'. * * Parameters: * addr Address to check for symbol near * symtab Structure to receive results * Returns: * 0 No sections contain this address, symtab zero filled * 1 Address mapped to module/symbol/section, data in symtab * Remarks: * 2.6 kallsyms has a "feature" where it unpacks the name into a * string. If that string is reused before the caller expects it * then the caller sees its string change without warning. To * avoid cluttering up the main kdb code with lots of kdb_strdup, * tests and kfree calls, kdbnearsym maintains an LRU list of the * last few unique strings. The list is sized large enough to * hold active strings, no kdb caller of kdbnearsym makes more * than ~20 later calls before using a saved value. */ int kdbnearsym(unsigned long addr, kdb_symtab_t *symtab) { int ret = 0; unsigned long symbolsize = 0; unsigned long offset = 0; #define knt1_size 128 /* must be >= kallsyms table size */ char *knt1 = NULL; if (KDB_DEBUG(AR)) kdb_printf("kdbnearsym: addr=0x%lx, symtab=%px\n", addr, symtab); memset(symtab, 0, sizeof(*symtab)); if (addr < 4096) goto out; knt1 = debug_kmalloc(knt1_size, GFP_ATOMIC); if (!knt1) { kdb_printf("kdbnearsym: addr=0x%lx cannot kmalloc knt1\n", addr); goto out; } symtab->sym_name = kallsyms_lookup(addr, &symbolsize , &offset, (char **)(&symtab->mod_name), knt1); if (offset > 8*1024*1024) { symtab->sym_name = NULL; addr = offset = symbolsize = 0; } symtab->sym_start = addr - offset; symtab->sym_end = symtab->sym_start + symbolsize; ret = symtab->sym_name != NULL && *(symtab->sym_name) != '\0'; if (ret) { int i; /* Another 2.6 kallsyms "feature". Sometimes the sym_name is * set but the buffer passed into kallsyms_lookup is not used, * so it contains garbage. The caller has to work out which * buffer needs to be saved. * * What was Rusty smoking when he wrote that code? */ if (symtab->sym_name != knt1) { strncpy(knt1, symtab->sym_name, knt1_size); knt1[knt1_size-1] = '\0'; } for (i = 0; i < ARRAY_SIZE(kdb_name_table); ++i) { if (kdb_name_table[i] && strcmp(kdb_name_table[i], knt1) == 0) break; } if (i >= ARRAY_SIZE(kdb_name_table)) { debug_kfree(kdb_name_table[0]); memmove(kdb_name_table, kdb_name_table+1, sizeof(kdb_name_table[0]) * (ARRAY_SIZE(kdb_name_table)-1)); } else { debug_kfree(knt1); knt1 = kdb_name_table[i]; memmove(kdb_name_table+i, kdb_name_table+i+1, sizeof(kdb_name_table[0]) * (ARRAY_SIZE(kdb_name_table)-i-1)); } i = ARRAY_SIZE(kdb_name_table) - 1; kdb_name_table[i] = knt1; symtab->sym_name = kdb_name_table[i]; knt1 = NULL; } if (symtab->mod_name == NULL) symtab->mod_name = "kernel"; if (KDB_DEBUG(AR)) kdb_printf("kdbnearsym: returns %d symtab->sym_start=0x%lx, " "symtab->mod_name=%px, symtab->sym_name=%px (%s)\n", ret, symtab->sym_start, symtab->mod_name, symtab->sym_name, symtab->sym_name); out: debug_kfree(knt1); return ret; } void kdbnearsym_cleanup(void) { int i; for (i = 0; i < ARRAY_SIZE(kdb_name_table); ++i) { if (kdb_name_table[i]) { debug_kfree(kdb_name_table[i]); kdb_name_table[i] = NULL; } } } static char ks_namebuf[KSYM_NAME_LEN+1], ks_namebuf_prev[KSYM_NAME_LEN+1]; /* * kallsyms_symbol_complete * * Parameters: * prefix_name prefix of a symbol name to lookup * max_len maximum length that can be returned * Returns: * Number of symbols which match the given prefix. * Notes: * prefix_name is changed to contain the longest unique prefix that * starts with this prefix (tab completion). */ int kallsyms_symbol_complete(char *prefix_name, int max_len) { loff_t pos = 0; int prefix_len = strlen(prefix_name), prev_len = 0; int i, number = 0; const char *name; while ((name = kdb_walk_kallsyms(&pos))) { if (strncmp(name, prefix_name, prefix_len) == 0) { strcpy(ks_namebuf, name); /* Work out the longest name that matches the prefix */ if (++number == 1) { prev_len = min_t(int, max_len-1, strlen(ks_namebuf)); memcpy(ks_namebuf_prev, ks_namebuf, prev_len); ks_namebuf_prev[prev_len] = '\0'; continue; } for (i = 0; i < prev_len; i++) { if (ks_namebuf[i] != ks_namebuf_prev[i]) { prev_len = i; ks_namebuf_prev[i] = '\0'; break; } } } } if (prev_len > prefix_len) memcpy(prefix_name, ks_namebuf_prev, prev_len+1); return number; } /* * kallsyms_symbol_next * * Parameters: * prefix_name prefix of a symbol name to lookup * flag 0 means search from the head, 1 means continue search. * 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 = probe_kernel_read((char *)res, (char *)addr, size); if (ret) { if (!KDB_STATE(SUPPRESS)) { kdb_printf("kdb_getarea: Bad address 0x%lx\n", addr); KDB_STATE_SET(SUPPRESS); } ret = KDB_BADADDR; } else { KDB_STATE_CLEAR(SUPPRESS); } return ret; } /* * kdb_putarea_size - Write an area of data. The kdb equivalent of * copy_to_user, with kdb messages for invalid addresses. * Inputs: * addr Address of the area to write to. * res Pointer to the area holding the data. * size Size of the area. * Returns: * 0 for success, < 0 for error. */ int kdb_putarea_size(unsigned long addr, void *res, size_t size) { int ret = probe_kernel_read((char *)addr, (char *)res, size); if (ret) { if (!KDB_STATE(SUPPRESS)) { kdb_printf("kdb_putarea: Bad address 0x%lx\n", addr); KDB_STATE_SET(SUPPRESS); } ret = KDB_BADADDR; } else { KDB_STATE_CLEAR(SUPPRESS); } return ret; } /* * kdb_getphys - Read data from a physical address. Validate the * address is in range, use kmap_atomic() to get data * similar to kdb_getarea() - but for phys addresses * Inputs: * res Pointer to the word to receive the result * addr Physical address of the area to copy * size Size of the area * Returns: * 0 for success, < 0 for error. */ static int kdb_getphys(void *res, unsigned long addr, size_t size) { unsigned long pfn; void *vaddr; struct page *page; pfn = (addr >> PAGE_SHIFT); if (!pfn_valid(pfn)) return 1; page = pfn_to_page(pfn); vaddr = kmap_atomic(page); 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 %px 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 %px size %d caller %px\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 %px size %d caller %px\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]; }