X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fsyscall.c;h=1fc68d2ca5d73319ebddb7f395106b2fc083ad57;hb=00a620843422e5c972aee0ada2181b811fc81b92;hp=ee7578051e2a12d3322cb6e3d9fd4ae2946da1a7;hpb=4b47b6a9070be168eb81fd204e4490d0f1d3be87;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/syscall.c b/src/bin/lttng-sessiond/syscall.c
index ee7578051..1fc68d2ca 100644
--- a/src/bin/lttng-sessiond/syscall.c
+++ b/src/bin/lttng-sessiond/syscall.c
@@ -16,6 +16,7 @@
  */
 
 #define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <common/bitfield.h>
 #include <common/common.h>
 #include <common/kernel-ctl/kernel-ctl.h>
@@ -35,7 +36,7 @@ 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.
+ * value is returned.
  */
 int syscall_init_table(void)
 {
@@ -72,7 +73,7 @@ int syscall_init_table(void)
 	}
 
 	while (fscanf(fp,
-				"syscall { index = %lu; \
+				"syscall { index = %zu; \
 				name = %" XSTR(SYSCALL_NAME_LEN) "[^;]; \
 				bitness = %u; };\n",
 				&index, name, &bitness) == 3) {
@@ -82,6 +83,14 @@ int syscall_init_table(void)
 
 			/* Double memory size. */
 			new_nbmem = max(index, nbmem << 1);
+			if (new_nbmem < nbmem) {
+				/* 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);
@@ -396,11 +405,15 @@ ssize_t syscall_list_channel(struct ltt_kernel_channel *kchan,
 			events = new_events;
 		}
 
+		rcu_read_lock();
 		ksyscall = lookup_syscall(syscalls_ht, syscall_table[i].name);
 		if (ksyscall) {
 			update_event_syscall_bitness(events, i, ksyscall->index);
+			rcu_read_unlock();
 			continue;
 		}
+		ksyscall = NULL;
+		rcu_read_unlock();
 
 		ret = add_syscall_to_ht(syscalls_ht, i, count);
 		if (ret < 0) {
@@ -420,7 +433,10 @@ ssize_t syscall_list_channel(struct ltt_kernel_channel *kchan,
 	return count;
 
 error:
+	rcu_read_lock();
 	destroy_syscall_ht(syscalls_ht);
+	rcu_read_unlock();
+
 	free(events);
 	return ret;
 }