+++ /dev/null
-/*
- * Copyright (C) 2014 - David Goulet <dgoulet@efficios.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License, version 2 only, as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 51
- * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-#define _LGPL_SOURCE
-#include <stdbool.h>
-
-#include <common/bitfield.h>
-#include <common/common.h>
-#include <common/kernel-ctl/kernel-ctl.h>
-
-#include "lttng-sessiond.h"
-#include "kernel.h"
-#include "syscall.h"
-#include "utils.h"
-
-/* Global syscall table. */
-struct syscall *syscall_table;
-
-/* Number of entry in the syscall table. */
-static size_t syscall_table_nb_entry;
-
-/*
- * Populate the system call table using the kernel tracer.
- *
- * Return 0 on success and the syscall table is allocated. On error, a negative
- * value is returned.
- */
-int syscall_init_table(void)
-{
- int ret, fd, err;
- size_t nbmem;
- FILE *fp;
- /* Syscall data from the kernel. */
- size_t index = 0;
- bool at_least_one_syscall = false;
- uint32_t bitness;
- char name[SYSCALL_NAME_LEN];
-
- DBG3("Syscall init system call table");
-
- fd = kernctl_syscall_list(kernel_tracer_fd);
- if (fd < 0) {
- ret = fd;
- PERROR("kernelctl syscall list");
- goto error_ioctl;
- }
-
- fp = fdopen(fd, "r");
- if (!fp) {
- ret = -errno;
- PERROR("syscall list fdopen");
- goto error_fp;
- }
-
- nbmem = SYSCALL_TABLE_INIT_SIZE;
- syscall_table = zmalloc(sizeof(struct syscall) * nbmem);
- if (!syscall_table) {
- ret = -errno;
- PERROR("syscall list zmalloc");
- goto error;
- }
-
- while (fscanf(fp,
- "syscall { index = %zu; \
- name = %" XSTR(SYSCALL_NAME_LEN) "[^;]; \
- bitness = %u; };\n",
- &index, name, &bitness) == 3) {
- at_least_one_syscall = true;
- if (index >= nbmem) {
- struct syscall *new_list;
- size_t new_nbmem;
-
- /* Double memory size. */
- new_nbmem = max(index + 1, nbmem << 1);
- if (new_nbmem > (SIZE_MAX / sizeof(*new_list))) {
- /* Overflow, stop everything, something went really wrong. */
- ERR("Syscall listing memory size overflow. Stopping");
- free(syscall_table);
- syscall_table = NULL;
- ret = -EINVAL;
- goto error;
- }
-
- DBG("Reallocating syscall table from %zu to %zu entries", nbmem,
- new_nbmem);
- new_list = realloc(syscall_table, new_nbmem * sizeof(*new_list));
- if (!new_list) {
- ret = -errno;
- PERROR("syscall list realloc");
- goto error;
- }
-
- /* Zero out the new memory. */
- memset(new_list + nbmem, 0,
- (new_nbmem - nbmem) * sizeof(*new_list));
- nbmem = new_nbmem;
- syscall_table = new_list;
- }
- syscall_table[index].index = index;
- syscall_table[index].bitness = bitness;
- if (lttng_strncpy(syscall_table[index].name, name,
- sizeof(syscall_table[index].name))) {
- ret = -EINVAL;
- free(syscall_table);
- syscall_table = NULL;
- goto error;
- }
- /*
- DBG("Syscall name '%s' at index %" PRIu32 " of bitness %u",
- syscall_table[index].name,
- syscall_table[index].index,
- syscall_table[index].bitness);
- */
- }
-
- /* Index starts at 0. */
- if (at_least_one_syscall) {
- syscall_table_nb_entry = index + 1;
- }
-
- ret = 0;
-
-error:
- err = fclose(fp);
- if (err) {
- PERROR("syscall list fclose");
- }
- return ret;
-
-error_fp:
- err = close(fd);
- if (err) {
- PERROR("syscall list close");
- }
-
-error_ioctl:
- return ret;
-}
-
-/*
- * Helper function for the list syscalls command that empty the temporary
- * syscall hashtable used to track duplicate between 32 and 64 bit arch.
- *
- * This empty the hash table and destroys it after. After this, the pointer is
- * unsuable. RCU read side lock MUST be acquired before calling this.
- */
-static void destroy_syscall_ht(struct lttng_ht *ht)
-{
- struct lttng_ht_iter iter;
- struct syscall *ksyscall;
-
- DBG3("Destroying syscall hash table.");
-
- if (!ht) {
- return;
- }
-
- cds_lfht_for_each_entry(ht->ht, &iter.iter, ksyscall, node.node) {
- int ret;
-
- ret = lttng_ht_del(ht, &iter);
- assert(!ret);
- free(ksyscall);
- }
- ht_cleanup_push(ht);
-}
-
-/*
- * Allocate the given hashtable pointer.
- *
- * Return 0 on success else a negative LTTNG error value.
- */
-static int init_syscall_ht(struct lttng_ht **ht)
-{
- int ret;
-
- *ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
- if (!*ht) {
- ret = -LTTNG_ERR_NOMEM;
- } else {
- ret = 0;
- }
-
- return ret;
-}
-
-/*
- * Lookup a syscall in the given hash table by name.
- *
- * Return syscall object if found or else NULL.
- */
-static struct syscall *lookup_syscall(struct lttng_ht *ht, const char *name)
-{
- struct lttng_ht_node_str *node;
- struct lttng_ht_iter iter;
- struct syscall *ksyscall = NULL;
-
- assert(ht);
- assert(name);
-
- lttng_ht_lookup(ht, (void *) name, &iter);
- node = lttng_ht_iter_get_node_str(&iter);
- if (node) {
- ksyscall = caa_container_of(node, struct syscall, node);
- }
-
- return ksyscall;
-}
-
-/*
- * Using the given syscall object in the events array with the bitness of the
- * syscall at index in the syscall table.
- */
-static void update_event_syscall_bitness(struct lttng_event *events,
- unsigned int index, unsigned int syscall_index)
-{
- assert(events);
-
- if (syscall_table[index].bitness == 32) {
- events[syscall_index].flags |= LTTNG_EVENT_FLAG_SYSCALL_32;
- } else {
- events[syscall_index].flags |= LTTNG_EVENT_FLAG_SYSCALL_64;
- }
-}
-
-/*
- * Allocate and initialize syscall object and add it to the given hashtable.
- *
- * Return 0 on success else -LTTNG_ERR_NOMEM.
- */
-static int add_syscall_to_ht(struct lttng_ht *ht, unsigned int index,
- unsigned int syscall_index)
-{
- int ret;
- struct syscall *ksyscall;
-
- assert(ht);
-
- ksyscall = zmalloc(sizeof(*ksyscall));
- if (!ksyscall) {
- ret = -LTTNG_ERR_NOMEM;
- goto error;
- }
-
- strncpy(ksyscall->name, syscall_table[index].name,
- sizeof(ksyscall->name));
- ksyscall->bitness = syscall_table[index].bitness;
- ksyscall->index = syscall_index;
- lttng_ht_node_init_str(&ksyscall->node, ksyscall->name);
- lttng_ht_add_unique_str(ht, &ksyscall->node);
- ret = 0;
-
-error:
- return ret;
-}
-
-/*
- * List syscalls present in the kernel syscall global array, allocate and
- * populate the events structure with them. Skip the empty syscall name.
- *
- * Return the number of entries in the array else a negative value.
- */
-ssize_t syscall_table_list(struct lttng_event **_events)
-{
- int i, index = 0;
- ssize_t ret;
- struct lttng_event *events;
- /* Hash table used to filter duplicate out. */
- struct lttng_ht *syscalls_ht = NULL;
-
- assert(_events);
-
- DBG("Syscall table listing.");
-
- rcu_read_lock();
-
- /*
- * Allocate at least the number of total syscall we have even if some of
- * them might not be valid. The count below will make sure to return the
- * right size of the events array.
- */
- events = zmalloc(syscall_table_nb_entry * sizeof(*events));
- if (!events) {
- PERROR("syscall table list zmalloc");
- ret = -LTTNG_ERR_NOMEM;
- goto error;
- }
-
- ret = init_syscall_ht(&syscalls_ht);
- if (ret < 0) {
- goto error;
- }
-
- for (i = 0; i < syscall_table_nb_entry; i++) {
- struct syscall *ksyscall;
-
- /* Skip empty syscalls. */
- if (*syscall_table[i].name == '\0') {
- continue;
- }
-
- ksyscall = lookup_syscall(syscalls_ht, syscall_table[i].name);
- if (ksyscall) {
- update_event_syscall_bitness(events, i, ksyscall->index);
- continue;
- }
-
- ret = add_syscall_to_ht(syscalls_ht, i, index);
- if (ret < 0) {
- goto error;
- }
-
- /* Copy the event information in the event's array. */
- strncpy(events[index].name, syscall_table[i].name,
- sizeof(events[index].name));
- update_event_syscall_bitness(events, i, index);
- events[index].type = LTTNG_EVENT_SYSCALL;
- /* This makes the command line not print the enabled/disabled field. */
- events[index].enabled = -1;
- index++;
- }
-
- destroy_syscall_ht(syscalls_ht);
- *_events = events;
- rcu_read_unlock();
- return index;
-
-error:
- destroy_syscall_ht(syscalls_ht);
- free(events);
- rcu_read_unlock();
- return ret;
-}
projects / lttng-tools.git / blobdiff