syscalltbl.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * System call table mapper
  4 *
  5 * (C) 2016 Arnaldo Carvalho de Melo <acme@redhat.com>
  6 */
  7
  8#include "syscalltbl.h"
  9#include <stdlib.h>
 10#include <asm/bitsperlong.h>
 11#include <linux/compiler.h>
 12#include <linux/kernel.h>
 13#include <linux/zalloc.h>
 14
 15#include <string.h>
 16#include "string2.h"
 17
 18#include "trace/beauty/generated/syscalltbl.c"
 19
 20static const struct syscalltbl *find_table(int e_machine)
 21{
 22	static const struct syscalltbl *last_table;
 23	static int last_table_machine = EM_NONE;
 24
 25	/* Tables only exist for EM_SPARC. */
 26	if (e_machine == EM_SPARCV9)
 27		e_machine = EM_SPARC;
 28
 29	if (last_table_machine == e_machine && last_table != NULL)
 30		return last_table;
 31
 32	for (size_t i = 0; i < ARRAY_SIZE(syscalltbls); i++) {
 33		const struct syscalltbl *entry = &syscalltbls[i];
 34
 35		if (entry->e_machine != e_machine && entry->e_machine != EM_NONE)
 36			continue;
 37
 38		last_table = entry;
 39		last_table_machine = e_machine;
 40		return entry;
 41	}
 42	return NULL;
 43}
 44
 45const char *syscalltbl__name(int e_machine, int id)
 46{
 47	const struct syscalltbl *table = find_table(e_machine);
 48
 49	if (e_machine == EM_MIPS && id > 1000) {
 50		/*
 51		 * MIPS may encode the N32/64/O32 type in the high part of
 52		 * syscall number. Mask this off if present. See the values of
 53		 * __NR_N32_Linux, __NR_64_Linux, __NR_O32_Linux and __NR_Linux.
 54		 */
 55		id = id % 1000;
 56	}
 57	if (table && id >= 0 && id < table->num_to_name_len)
 58		return table->num_to_name[id];
 59	return NULL;
 60}
 61
 62struct syscall_cmp_key {
 63	const char *name;
 64	const char *const *tbl;
 65};
 66
 67static int syscallcmpname(const void *vkey, const void *ventry)
 68{
 69	const struct syscall_cmp_key *key = vkey;
 70	const uint16_t *entry = ventry;
 71
 72	return strcmp(key->name, key->tbl[*entry]);
 73}
 74
 75int syscalltbl__id(int e_machine, const char *name)
 76{
 77	const struct syscalltbl *table = find_table(e_machine);
 78	struct syscall_cmp_key key;
 79	const uint16_t *id;
 80
 81	if (!table)
 82		return -1;
 83
 84	key.name = name;
 85	key.tbl = table->num_to_name;
 86	id = bsearch(&key, table->sorted_names, table->sorted_names_len,
 87		     sizeof(table->sorted_names[0]), syscallcmpname);
 88
 89	return id ? *id : -1;
 90}
 91
 92int syscalltbl__num_idx(int e_machine)
 93{
 94	const struct syscalltbl *table = find_table(e_machine);
 95
 96	if (!table)
 97		return 0;
 98
 99	return table->sorted_names_len;
100}
101
102int syscalltbl__id_at_idx(int e_machine, int idx)
103{
104	const struct syscalltbl *table = find_table(e_machine);
105
106	if (!table)
107		return -1;
108
109	assert(idx >= 0 && idx < table->sorted_names_len);
110	return table->sorted_names[idx];
111}
112
113int syscalltbl__strglobmatch_next(int e_machine, const char *syscall_glob, int *idx)
114{
115	const struct syscalltbl *table = find_table(e_machine);
116
117	for (int i = *idx + 1; table && i < table->sorted_names_len; ++i) {
118		const char *name = table->num_to_name[table->sorted_names[i]];
119
120		if (strglobmatch(name, syscall_glob)) {
121			*idx = i;
122			return table->sorted_names[i];
123		}
124	}
125
126	return -1;
127}
128
129int syscalltbl__strglobmatch_first(int e_machine, const char *syscall_glob, int *idx)
130{
131	*idx = -1;
132	return syscalltbl__strglobmatch_next(e_machine, syscall_glob, idx);
133}