diff --git a/libc/src/ipc/ipc.c b/libc/src/ipc/ipc.c
index 4cc9da8..429e156 100644
--- a/libc/src/ipc/ipc.c
+++ b/libc/src/ipc/ipc.c
@@ -12,6 +12,7 @@
 #include "ipc/msg.h"
 #include "sys/stat.h"
 #include "io/debug.h"
+#include "stdio.h"
 
 _syscall3(void *, shmat, int, shmid, const void *, shmaddr, int, shmflg)
 
@@ -41,15 +42,22 @@ long semop(int semid, struct sembuf *sops, unsigned nsops)
         errno = EINVAL;
         return -1;
     }
-    // The process continues to try to perform the operation until it completes
-    // or receives an error.
-    while (1) {
-        // Calling the kernel-side function.
-        __inline_syscall3(__res, semop, semid, sops, nsops);
-        // If we get an error we stop the loop.
-        if (__res != OPERATION_NOT_ALLOWED)
-            break;
+
+    //this should be performed for each sops.
+    for (size_t i = 0; i < nsops; i++){
+       // The process continues to try to perform the operation until it completes
+        // or receives an error.
+        while (1) {
+            // Calling the kernel-side function.
+            __inline_syscall3(__res, semop, semid, &sops[i], 1);
+            // If we get an error we stop the loop.
+            if (__res != OPERATION_NOT_ALLOWED)
+                break;
+        }
+        //printf("op eseguita: %d\n", __res);
     }
+    
+    
     // Now, we can return the value.
     __syscall_return(long, __res);
 }
diff --git a/mentos/src/ipc/sem.c b/mentos/src/ipc/sem.c
index 5c2c538..87bd770 100644
--- a/mentos/src/ipc/sem.c
+++ b/mentos/src/ipc/sem.c
@@ -205,18 +205,18 @@ long sys_semop(int semid, struct sembuf *sops, unsigned nsops)
         /*If the operation is negative then we need to check for possible blocking operation*/
 
         /*if the value of the sem were to become negative then we return a special value*/
-        if (temp->sems[sops->sem_num].sem_val < (-nsops * (sops->sem_op))) {
+        if (temp->sems[sops->sem_num].sem_val < (-(sops->sem_op))) {
             return OPERATION_NOT_ALLOWED; //not allowed
         } else {
             /*otherwise we can modify the sem_val and all the other parameters of the semaphore*/
-            temp->sems[sops->sem_num].sem_val += (nsops * (sops->sem_op));
+            temp->sems[sops->sem_num].sem_val += (sops->sem_op);
             temp->sems[sops->sem_num].sem_pid = sys_getpid();
             temp->sem_ctime                   = sys_time(NULL);
             return 1; //allowed
         }
     } else {
         /*the operation is non negative so we can always do it*/
-        temp->sems[sops->sem_num].sem_val += (nsops * (sops->sem_op));
+        temp->sems[sops->sem_num].sem_val += (sops->sem_op);
         temp->sems[sops->sem_num].sem_pid = sys_getpid();
         temp->sem_ctime                   = sys_time(NULL);
         return 1; //allowed
diff --git a/programs/tests/t_semget.c b/programs/tests/t_semget.c
index 9d503f3..094b2cd 100644
--- a/programs/tests/t_semget.c
+++ b/programs/tests/t_semget.c
@@ -25,6 +25,7 @@ void semid_print(struct semid_ds *temp)
 int main()
 {
     struct sembuf op;
+    struct sembuf father[2];
     union semun arg;
     long ret, id;
     key_t key;
@@ -43,7 +44,7 @@ int main()
     //long id4 = semget(100, 2, IPC_CREAT | IPC_EXCL);  //need to return 101 (new semaphore)
 
     // Set the value of the semaphore in the structure.
-    arg.val = 1;
+    arg.val = 0;
     // Setting the semaphore value.
     printf("Set Value (%d): %d\n", id, arg.val);
     ret = semctl(id, 0, SETVAL, &arg);
@@ -54,12 +55,12 @@ int main()
 
     // Check if we successfully set the value of the semaphore.
     ret = semctl(id, 0, GETVAL, &arg);
-    printf("Check Value (%d): %d\n", id, ret);
+    printf("Check Value before(%d): %d\n", id, ret);
 
     // Create child process.
     if (!fork()) {
         // Make the child process sleep.
-        sleep(5);
+        sleep(2);
 
         // Initialize the operation structure.
         op.sem_num = 0; // Operate on semaphore 0.
@@ -70,31 +71,35 @@ int main()
 
         // Perform the operation.
         semop(id, &op, 1);
-
+        sleep(5);
+        semop(id, &op, 1);
         // Remove the semaphore.
-        semctl(id, 0, IPC_RMID, NULL);
+        //semctl(id, 0, IPC_RMID, NULL);
 
         // Exit with the child process.
         return 0;
     }
 
     // Initialize the operation structure.
-    op.sem_num = 0;  // Operate on semaphore 0.
-    op.sem_op  = -2; // Decrement value by 2.
-    op.sem_flg = 0;  // No flags.
+    father[0].sem_num = 0;  // Operate on semaphore 0.
+    father[0].sem_op  = -1; // Decrement value by 1.
+    father[0].sem_flg = 0;  // No flags.
+    father[1].sem_num = 0;  // Operate on semaphore 0.
+    father[1].sem_op  = -1; // Decrement value by 1.
+    father[1].sem_flg = 0;  // No flags.
 
     // We set the semaphore at the beginning at 1, and the child process will
     // increment the semaphore by 1, allowing us to decrement the semaphore by
     // 2.
 
     // Perform the operation.
-    if (semop(id, &op, 1) < 0) {
+    if (semop(id, father, 2) < 0) {
         printf("ERRORE\n");
     }
     
     // Check if we successfully set the value of the semaphore.
     ret = semctl(id, 0, GETVAL, &arg);
-    printf("Check Value (%d): %d\n", id, ret);
+    printf("Check Value after(%d): %d\n", id, ret);
 
     /*if ((semid = semctl(id, 0, IPC_RMID, 0)) == -1){
         printf("%d\n", errno);