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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#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/string.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){ size_t n = strlen(str) + 1; char *s = kmalloc(n, type); if (!s) return NULL; memcpy(s, str, n); return s;}
/* * kdb_strdup_dequote - same as kdb_strdup(), but trims surrounding quotes from * the input string if present. * Remarks: * Quotes are only removed if there is both a leading and a trailing quote. */char *kdb_strdup_dequote(const char *str, gfp_t type){ size_t len = strlen(str); char *s;
if (str[0] == '"' && len > 1 && str[len - 1] == '"') { /* trim both leading and trailing quotes */ str++; len -= 2; }
len++; /* add space for NUL terminator */
s = kmalloc(len, type); if (!s) return NULL;
memcpy(s, str, len - 1); s[len - 1] = '\0';
return s;}
/* * 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_local_page() 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_local_page(page); memcpy(res, vaddr + (addr & (PAGE_SIZE - 1)), size); kunmap_local(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);}