| /* |
| * Kernel Debugger Architecture Independent Support Functions |
| * |
| * This file is subject to the terms and conditions of the GNU General Public |
| * License. See the file "COPYING" in the main directory of this archive |
| * for more details. |
| * |
| * Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved. |
| * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. |
| * 03/02/13 added new 2.5 kallsyms <xavier.bru@bull.net> |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/sched.h> |
| #include <linux/mm.h> |
| #include <linux/kallsyms.h> |
| #include <linux/stddef.h> |
| #include <linux/vmalloc.h> |
| #include <linux/ptrace.h> |
| #include <linux/highmem.h> |
| #include <linux/hardirq.h> |
| #include <linux/delay.h> |
| #include <linux/uaccess.h> |
| #include <linux/kdb.h> |
| #include <linux/slab.h> |
| #include <linux/ctype.h> |
| #include "kdb_private.h" |
| |
| /* |
| * kdbgetsymval - Return the address of the given symbol. |
| * |
| * Parameters: |
| * symname Character string containing symbol name |
| * symtab Structure to receive results |
| * Returns: |
| * 0 Symbol not found, symtab zero filled |
| * 1 Symbol mapped to module/symbol/section, data in symtab |
| */ |
| int kdbgetsymval(const char *symname, kdb_symtab_t *symtab) |
| { |
| kdb_dbg_printf(AR, "symname=%s, symtab=%px\n", symname, symtab); |
| memset(symtab, 0, sizeof(*symtab)); |
| symtab->sym_start = kallsyms_lookup_name(symname); |
| if (symtab->sym_start) { |
| kdb_dbg_printf(AR, "returns 1, symtab->sym_start=0x%lx\n", |
| symtab->sym_start); |
| return 1; |
| } |
| kdb_dbg_printf(AR, "returns 0\n"); |
| return 0; |
| } |
| EXPORT_SYMBOL(kdbgetsymval); |
| |
| /** |
| * kdbnearsym() - Return the name of the symbol with the nearest address |
| * less than @addr. |
| * @addr: Address to check for near symbol |
| * @symtab: Structure to receive results |
| * |
| * WARNING: This function may return a pointer to a single statically |
| * allocated buffer (namebuf). kdb's unusual calling context (single |
| * threaded, all other CPUs halted) provides us sufficient locking for |
| * this to be safe. The only constraint imposed by the static buffer is |
| * that the caller must consume any previous reply prior to another call |
| * to lookup a new symbol. |
| * |
| * Note that, strictly speaking, some architectures may re-enter the kdb |
| * trap if the system turns out to be very badly damaged and this breaks |
| * the single-threaded assumption above. In these circumstances successful |
| * continuation and exit from the inner trap is unlikely to work and any |
| * user attempting this receives a prominent warning before being allowed |
| * to progress. In these circumstances we remain memory safe because |
| * namebuf[KSYM_NAME_LEN-1] will never change from '\0' although we do |
| * tolerate the possibility of garbled symbol display from the outer kdb |
| * trap. |
| * |
| * Return: |
| * * 0 - No sections contain this address, symtab zero filled |
| * * 1 - Address mapped to module/symbol/section, data in symtab |
| */ |
| int kdbnearsym(unsigned long addr, kdb_symtab_t *symtab) |
| { |
| int ret = 0; |
| unsigned long symbolsize = 0; |
| unsigned long offset = 0; |
| static char namebuf[KSYM_NAME_LEN]; |
| |
| kdb_dbg_printf(AR, "addr=0x%lx, symtab=%px\n", addr, symtab); |
| memset(symtab, 0, sizeof(*symtab)); |
| |
| if (addr < 4096) |
| goto out; |
| |
| symtab->sym_name = kallsyms_lookup(addr, &symbolsize , &offset, |
| (char **)(&symtab->mod_name), namebuf); |
| if (offset > 8*1024*1024) { |
| symtab->sym_name = NULL; |
| addr = offset = symbolsize = 0; |
| } |
| symtab->sym_start = addr - offset; |
| symtab->sym_end = symtab->sym_start + symbolsize; |
| ret = symtab->sym_name != NULL && *(symtab->sym_name) != '\0'; |
| |
| if (symtab->mod_name == NULL) |
| symtab->mod_name = "kernel"; |
| kdb_dbg_printf(AR, "returns %d symtab->sym_start=0x%lx, symtab->mod_name=%px, symtab->sym_name=%px (%s)\n", |
| ret, symtab->sym_start, symtab->mod_name, symtab->sym_name, symtab->sym_name); |
| out: |
| return ret; |
| } |
| |
| static char ks_namebuf[KSYM_NAME_LEN+1], ks_namebuf_prev[KSYM_NAME_LEN+1]; |
| |
| /* |
| * kallsyms_symbol_complete |
| * |
| * Parameters: |
| * prefix_name prefix of a symbol name to lookup |
| * max_len maximum length that can be returned |
| * Returns: |
| * Number of symbols which match the given prefix. |
| * Notes: |
| * prefix_name is changed to contain the longest unique prefix that |
| * starts with this prefix (tab completion). |
| */ |
| int kallsyms_symbol_complete(char *prefix_name, int max_len) |
| { |
| loff_t pos = 0; |
| int prefix_len = strlen(prefix_name), prev_len = 0; |
| int i, number = 0; |
| const char *name; |
| |
| while ((name = kdb_walk_kallsyms(&pos))) { |
| if (strncmp(name, prefix_name, prefix_len) == 0) { |
| strscpy(ks_namebuf, name, sizeof(ks_namebuf)); |
| /* Work out the longest name that matches the prefix */ |
| if (++number == 1) { |
| prev_len = min_t(int, max_len-1, |
| strlen(ks_namebuf)); |
| memcpy(ks_namebuf_prev, ks_namebuf, prev_len); |
| ks_namebuf_prev[prev_len] = '\0'; |
| continue; |
| } |
| for (i = 0; i < prev_len; i++) { |
| if (ks_namebuf[i] != ks_namebuf_prev[i]) { |
| prev_len = i; |
| ks_namebuf_prev[i] = '\0'; |
| break; |
| } |
| } |
| } |
| } |
| if (prev_len > prefix_len) |
| memcpy(prefix_name, ks_namebuf_prev, prev_len+1); |
| return number; |
| } |
| |
| /* |
| * kallsyms_symbol_next |
| * |
| * Parameters: |
| * prefix_name prefix of a symbol name to lookup |
| * flag 0 means search from the head, 1 means continue search. |
| * buf_size maximum length that can be written to prefix_name |
| * buffer |
| * Returns: |
| * 1 if a symbol matches the given prefix. |
| * 0 if no string found |
| */ |
| int kallsyms_symbol_next(char *prefix_name, int flag, int buf_size) |
| { |
| int prefix_len = strlen(prefix_name); |
| static loff_t pos; |
| const char *name; |
| |
| if (!flag) |
| pos = 0; |
| |
| while ((name = kdb_walk_kallsyms(&pos))) { |
| if (!strncmp(name, prefix_name, prefix_len)) |
| return strscpy(prefix_name, name, buf_size); |
| } |
| return 0; |
| } |
| |
| /* |
| * kdb_symbol_print - Standard method for printing a symbol name and offset. |
| * Inputs: |
| * addr Address to be printed. |
| * symtab Address of symbol data, if NULL this routine does its |
| * own lookup. |
| * punc Punctuation for string, bit field. |
| * Remarks: |
| * The string and its punctuation is only printed if the address |
| * is inside the kernel, except that the value is always printed |
| * when requested. |
| */ |
| void kdb_symbol_print(unsigned long addr, const kdb_symtab_t *symtab_p, |
| unsigned int punc) |
| { |
| kdb_symtab_t symtab, *symtab_p2; |
| if (symtab_p) { |
| symtab_p2 = (kdb_symtab_t *)symtab_p; |
| } else { |
| symtab_p2 = &symtab; |
| kdbnearsym(addr, symtab_p2); |
| } |
| if (!(symtab_p2->sym_name || (punc & KDB_SP_VALUE))) |
| return; |
| if (punc & KDB_SP_SPACEB) |
| kdb_printf(" "); |
| if (punc & KDB_SP_VALUE) |
| kdb_printf(kdb_machreg_fmt0, addr); |
| if (symtab_p2->sym_name) { |
| if (punc & KDB_SP_VALUE) |
| kdb_printf(" "); |
| if (punc & KDB_SP_PAREN) |
| kdb_printf("("); |
| if (strcmp(symtab_p2->mod_name, "kernel")) |
| kdb_printf("[%s]", symtab_p2->mod_name); |
| kdb_printf("%s", symtab_p2->sym_name); |
| if (addr != symtab_p2->sym_start) |
| kdb_printf("+0x%lx", addr - symtab_p2->sym_start); |
| if (punc & KDB_SP_SYMSIZE) |
| kdb_printf("/0x%lx", |
| symtab_p2->sym_end - symtab_p2->sym_start); |
| if (punc & KDB_SP_PAREN) |
| kdb_printf(")"); |
| } |
| if (punc & KDB_SP_SPACEA) |
| kdb_printf(" "); |
| if (punc & KDB_SP_NEWLINE) |
| kdb_printf("\n"); |
| } |
| |
| /* |
| * kdb_strdup - kdb equivalent of strdup, for disasm code. |
| * Inputs: |
| * str The string to duplicate. |
| * type Flags to kmalloc for the new string. |
| * Returns: |
| * Address of the new string, NULL if storage could not be allocated. |
| * Remarks: |
| * This is not in lib/string.c because it uses kmalloc which is not |
| * available when string.o is used in boot loaders. |
| */ |
| char *kdb_strdup(const char *str, gfp_t type) |
| { |
| int n = strlen(str)+1; |
| char *s = kmalloc(n, type); |
| if (!s) |
| return NULL; |
| return strcpy(s, str); |
| } |
| |
| /* |
| * kdb_getarea_size - Read an area of data. The kdb equivalent of |
| * copy_from_user, with kdb messages for invalid addresses. |
| * Inputs: |
| * res Pointer to the area to receive the result. |
| * addr Address of the area to copy. |
| * size Size of the area. |
| * Returns: |
| * 0 for success, < 0 for error. |
| */ |
| int kdb_getarea_size(void *res, unsigned long addr, size_t size) |
| { |
| int ret = copy_from_kernel_nofault((char *)res, (char *)addr, size); |
| if (ret) { |
| if (!KDB_STATE(SUPPRESS)) { |
| kdb_func_printf("Bad address 0x%lx\n", addr); |
| KDB_STATE_SET(SUPPRESS); |
| } |
| ret = KDB_BADADDR; |
| } else { |
| KDB_STATE_CLEAR(SUPPRESS); |
| } |
| return ret; |
| } |
| |
| /* |
| * kdb_putarea_size - Write an area of data. The kdb equivalent of |
| * copy_to_user, with kdb messages for invalid addresses. |
| * Inputs: |
| * addr Address of the area to write to. |
| * res Pointer to the area holding the data. |
| * size Size of the area. |
| * Returns: |
| * 0 for success, < 0 for error. |
| */ |
| int kdb_putarea_size(unsigned long addr, void *res, size_t size) |
| { |
| int ret = copy_to_kernel_nofault((char *)addr, (char *)res, size); |
| if (ret) { |
| if (!KDB_STATE(SUPPRESS)) { |
| kdb_func_printf("Bad address 0x%lx\n", addr); |
| KDB_STATE_SET(SUPPRESS); |
| } |
| ret = KDB_BADADDR; |
| } else { |
| KDB_STATE_CLEAR(SUPPRESS); |
| } |
| return ret; |
| } |
| |
| /* |
| * kdb_getphys - Read data from a physical address. Validate the |
| * address is in range, use kmap_atomic() to get data |
| * similar to kdb_getarea() - but for phys addresses |
| * Inputs: |
| * res Pointer to the word to receive the result |
| * addr Physical address of the area to copy |
| * size Size of the area |
| * Returns: |
| * 0 for success, < 0 for error. |
| */ |
| static int kdb_getphys(void *res, unsigned long addr, size_t size) |
| { |
| unsigned long pfn; |
| void *vaddr; |
| struct page *page; |
| |
| pfn = (addr >> PAGE_SHIFT); |
| if (!pfn_valid(pfn)) |
| return 1; |
| page = pfn_to_page(pfn); |
| vaddr = kmap_atomic(page); |
| memcpy(res, vaddr + (addr & (PAGE_SIZE - 1)), size); |
| kunmap_atomic(vaddr); |
| |
| return 0; |
| } |
| |
| /* |
| * kdb_getphysword |
| * Inputs: |
| * word Pointer to the word to receive the result. |
| * addr Address of the area to copy. |
| * size Size of the area. |
| * Returns: |
| * 0 for success, < 0 for error. |
| */ |
| int kdb_getphysword(unsigned long *word, unsigned long addr, size_t size) |
| { |
| int diag; |
| __u8 w1; |
| __u16 w2; |
| __u32 w4; |
| __u64 w8; |
| *word = 0; /* Default value if addr or size is invalid */ |
| |
| switch (size) { |
| case 1: |
| diag = kdb_getphys(&w1, addr, sizeof(w1)); |
| if (!diag) |
| *word = w1; |
| break; |
| case 2: |
| diag = kdb_getphys(&w2, addr, sizeof(w2)); |
| if (!diag) |
| *word = w2; |
| break; |
| case 4: |
| diag = kdb_getphys(&w4, addr, sizeof(w4)); |
| if (!diag) |
| *word = w4; |
| break; |
| case 8: |
| if (size <= sizeof(*word)) { |
| diag = kdb_getphys(&w8, addr, sizeof(w8)); |
| if (!diag) |
| *word = w8; |
| break; |
| } |
| fallthrough; |
| default: |
| diag = KDB_BADWIDTH; |
| kdb_func_printf("bad width %zu\n", size); |
| } |
| return diag; |
| } |
| |
| /* |
| * kdb_getword - Read a binary value. Unlike kdb_getarea, this treats |
| * data as numbers. |
| * Inputs: |
| * word Pointer to the word to receive the result. |
| * addr Address of the area to copy. |
| * size Size of the area. |
| * Returns: |
| * 0 for success, < 0 for error. |
| */ |
| int kdb_getword(unsigned long *word, unsigned long addr, size_t size) |
| { |
| int diag; |
| __u8 w1; |
| __u16 w2; |
| __u32 w4; |
| __u64 w8; |
| *word = 0; /* Default value if addr or size is invalid */ |
| switch (size) { |
| case 1: |
| diag = kdb_getarea(w1, addr); |
| if (!diag) |
| *word = w1; |
| break; |
| case 2: |
| diag = kdb_getarea(w2, addr); |
| if (!diag) |
| *word = w2; |
| break; |
| case 4: |
| diag = kdb_getarea(w4, addr); |
| if (!diag) |
| *word = w4; |
| break; |
| case 8: |
| if (size <= sizeof(*word)) { |
| diag = kdb_getarea(w8, addr); |
| if (!diag) |
| *word = w8; |
| break; |
| } |
| fallthrough; |
| default: |
| diag = KDB_BADWIDTH; |
| kdb_func_printf("bad width %zu\n", size); |
| } |
| return diag; |
| } |
| |
| /* |
| * kdb_putword - Write a binary value. Unlike kdb_putarea, this |
| * treats data as numbers. |
| * Inputs: |
| * addr Address of the area to write to.. |
| * word The value to set. |
| * size Size of the area. |
| * Returns: |
| * 0 for success, < 0 for error. |
| */ |
| int kdb_putword(unsigned long addr, unsigned long word, size_t size) |
| { |
| int diag; |
| __u8 w1; |
| __u16 w2; |
| __u32 w4; |
| __u64 w8; |
| switch (size) { |
| case 1: |
| w1 = word; |
| diag = kdb_putarea(addr, w1); |
| break; |
| case 2: |
| w2 = word; |
| diag = kdb_putarea(addr, w2); |
| break; |
| case 4: |
| w4 = word; |
| diag = kdb_putarea(addr, w4); |
| break; |
| case 8: |
| if (size <= sizeof(word)) { |
| w8 = word; |
| diag = kdb_putarea(addr, w8); |
| break; |
| } |
| fallthrough; |
| default: |
| diag = KDB_BADWIDTH; |
| kdb_func_printf("bad width %zu\n", size); |
| } |
| return diag; |
| } |
| |
| |
| |
| /* |
| * kdb_task_state_char - Return the character that represents the task state. |
| * Inputs: |
| * p struct task for the process |
| * Returns: |
| * One character to represent the task state. |
| */ |
| char kdb_task_state_char (const struct task_struct *p) |
| { |
| unsigned long tmp; |
| char state; |
| int cpu; |
| |
| if (!p || |
| copy_from_kernel_nofault(&tmp, (char *)p, sizeof(unsigned long))) |
| return 'E'; |
| |
| state = task_state_to_char((struct task_struct *) p); |
| |
| if (is_idle_task(p)) { |
| /* Idle task. Is it really idle, apart from the kdb |
| * interrupt? */ |
| cpu = kdb_process_cpu(p); |
| if (!kdb_task_has_cpu(p) || kgdb_info[cpu].irq_depth == 1) { |
| if (cpu != kdb_initial_cpu) |
| state = '-'; /* idle task */ |
| } |
| } else if (!p->mm && strchr("IMS", state)) { |
| state = tolower(state); /* sleeping system daemon */ |
| } |
| return state; |
| } |
| |
| /* |
| * kdb_task_state - Return true if a process has the desired state |
| * given by the mask. |
| * Inputs: |
| * p struct task for the process |
| * mask set of characters used to select processes; both NULL |
| * and the empty string mean adopt a default filter, which |
| * is to suppress sleeping system daemons and the idle tasks |
| * Returns: |
| * True if the process matches at least one criteria defined by the mask. |
| */ |
| bool kdb_task_state(const struct task_struct *p, const char *mask) |
| { |
| char state = kdb_task_state_char(p); |
| |
| /* If there is no mask, then we will filter code that runs when the |
| * scheduler is idling and any system daemons that are currently |
| * sleeping. |
| */ |
| if (!mask || mask[0] == '\0') |
| return !strchr("-ims", state); |
| |
| /* A is a special case that matches all states */ |
| if (strchr(mask, 'A')) |
| return true; |
| |
| return strchr(mask, state); |
| } |
| |
| /* Maintain a small stack of kdb_flags to allow recursion without disturbing |
| * the global kdb state. |
| */ |
| |
| static int kdb_flags_stack[4], kdb_flags_index; |
| |
| void kdb_save_flags(void) |
| { |
| BUG_ON(kdb_flags_index >= ARRAY_SIZE(kdb_flags_stack)); |
| kdb_flags_stack[kdb_flags_index++] = kdb_flags; |
| } |
| |
| void kdb_restore_flags(void) |
| { |
| BUG_ON(kdb_flags_index <= 0); |
| kdb_flags = kdb_flags_stack[--kdb_flags_index]; |
| } |