--- /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 _GNU_SOURCE
+#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 and the syscall table is set to NULL.
+ */
+int syscall_init_table(void)
+{
+ int ret, fd, err;
+ size_t nbmem;
+ FILE *fp;
+ /* Syscall data from the kernel. */
+ size_t index;
+ 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 = -errno;
+ 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 = %lu; \
+ name = %" XSTR(SYSCALL_NAME_LEN) "[^;]; \
+ bitness = %u; };\n",
+ &index, name, &bitness) == 3) {
+ if (index >= nbmem ) {
+ struct syscall *new_list;
+ size_t new_nbmem;
+
+ /* Double memory size. */
+ new_nbmem = index << 1;
+
+ 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;
+ strncpy(syscall_table[index].name, name,
+ sizeof(syscall_table[index].name));
+ /*
+ DBG("Syscall name '%s' at index %" PRIu32 " of bitness %u",
+ syscall_table[index].name,
+ syscall_table[index].index,
+ syscall_table[index].bitness);
+ */
+ }
+
+ syscall_table_nb_entry = index;
+
+ 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;
+}
+
+/*
+ * Add enabled syscall to the events list using the given kernel channel.
+ *
+ * Return the number of entry of the events array that is different from size
+ * if the array grows. On error, return negative value and events is untouched.
+ */
+ssize_t syscall_list_channel(struct ltt_kernel_channel *kchan,
+ struct lttng_event **_events, size_t size)
+{
+ int err, i;
+ size_t new_size;
+ ssize_t ret, count;
+ char *mask = NULL;
+ uint32_t len;
+ struct lttng_event *events = NULL;
+ /* Hash table used to filter duplicate out. */
+ struct lttng_ht *syscalls_ht = NULL;
+
+ assert(kchan);
+
+ /* Get syscall mask from the kernel tracer. */
+ err = kernel_syscall_mask(kchan->fd, &mask, &len);
+ if (err < 0) {
+ ret = err;
+ goto error;
+ }
+
+ ret = init_syscall_ht(&syscalls_ht);
+ if (ret < 0) {
+ goto error;
+ }
+
+ count = new_size = size;
+ events = *_events;
+
+ for (i = 0; i < len; i++) {
+ unsigned char val;
+ struct syscall *ksyscall;
+
+ bitfield_read_be(mask, unsigned char, i, 1, &val);
+ if (!val) {
+ /* Syscall is disabled, continue the loop. */
+ continue;
+ }
+
+ /* Skip empty syscall. */
+ if (*syscall_table[i].name == '\0') {
+ continue;
+ }
+
+ /* Syscall is enabled thus add it to the events list. */
+
+ if (count >= new_size) {
+ struct lttng_event *new_events;
+
+ /* Get the maximum here since count can be 0. */
+ new_size = max(count << 1, 1);
+ DBG3("Listing syscall realloc events array from %zu to %zu", count,
+ new_size);
+ new_events = realloc(events, new_size * sizeof(*new_events));
+ if (!new_events) {
+ PERROR("realloc kernel events list");
+ ret = -ENOMEM;
+ goto error;
+ }
+ memset(new_events + count, 0,
+ (new_size - count) * sizeof(*new_events));
+ events = new_events;
+ }
+
+ 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, count);
+ if (ret < 0) {
+ goto error;
+ }
+
+ update_event_syscall_bitness(events, i, count);
+ strncpy(events[count].name, syscall_table[i].name,
+ sizeof(events[count].name));
+ events[count].enabled = 1;
+ events[count].type = LTTNG_KERNEL_SYSCALL;
+ count++;
+ }
+
+ *_events = events;
+
+ return count;
+
+error:
+ destroy_syscall_ht(syscalls_ht);
+ free(events);
+ return ret;
+}
projects / lttng-tools.git / blobdiff