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Move list of semaphores inside semid_ds structure.

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This commit is contained in:
Enrico Fraccaroli (Galfurian)
2023-05-24 13:31:44 -04:00
parent 1acec3e7b3
commit db050db01c
7 changed files with 103 additions and 120 deletions
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.gitignore
+3
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@@ -117,3 +117,6 @@ files/bin/**
# ISO creation files.
iso/boot/*.bin
# ClangD stuff.
.cache
.vscode/settings.json
Vendored
-8
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@@ -1,8 +0,0 @@
{
"files.associations": {
"*.h": "c",
"*.c": "c"
},
"cmake.configureOnOpen": false,
"C_Cpp.intelliSenseEngine" : "Tag Parser"
}
libc/inc/sys/sem.h
+2
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@@ -63,6 +63,8 @@ struct semid_ds {
time_t sem_otime;
/// @brief Last change time.
time_t sem_ctime;
/// @brief List of all the semaphores.
struct sem *sem_base;
/// @brief Number of semaphores in set.
unsigned short sem_nsems;
};
mentos/src/ipc/sem.c
+97 -105
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@@ -32,10 +32,10 @@
// ============================================================================
// Setup the logging for this file (do this before any other include).
#include "sys/kernel_levels.h" // Include kernel log levels.
#define __DEBUG_HEADER__ "[IPCsem]" ///< Change header.
#include "sys/kernel_levels.h" // Include kernel log levels.
#define __DEBUG_HEADER__ "[IPCsem]" ///< Change header.
#define __DEBUG_LEVEL__ LOGLEVEL_NOTICE ///< Set log level.
#include "io/debug.h" // Include debugging functions.
#include "io/debug.h" // Include debugging functions.
// ============================================================================
#include "sys/sem.h"
@@ -60,8 +60,6 @@ typedef struct {
int id;
/// @brief The semaphore data strcutre.
struct semid_ds semid;
/// @brief List of all the semaphores.
struct sem *sems;
/// Reference inside the list of semaphore management structures.
list_head list;
} sem_info_t;
@@ -106,11 +104,11 @@ static inline sem_info_t *__sem_info_alloc(key_t key, int nsems, int semflg)
// Clean the memory.
memset(sem_info, 0, sizeof(sem_info_t));
// Allocate the memory for semaphores.
sem_info->sems = (struct sem *)kmalloc(sizeof(struct sem) * nsems);
sem_info->semid.sem_base = (struct sem *)kmalloc(sizeof(struct sem) * nsems);
// Check the allocated memory.
assert(sem_info->sems && "Failed to allocate memory for a set of semaphores.");
assert(sem_info->semid.sem_base && "Failed to allocate memory for a set of semaphores.");
// Clean the memory.
memset(sem_info->sems, 0, sizeof(struct sem) * nsems);
memset(sem_info->semid.sem_base, 0, sizeof(struct sem) * nsems);
// Initialize its values.
sem_info->id = ++__sem_id;
sem_info->semid.sem_perm = register_ipc(key, semflg & 0x1FF);
@@ -118,10 +116,10 @@ static inline sem_info_t *__sem_info_alloc(key_t key, int nsems, int semflg)
sem_info->semid.sem_ctime = 0;
sem_info->semid.sem_nsems = nsems;
for (int i = 0; i < nsems; i++) {
sem_info->sems[i].sem_pid = sys_getpid();
sem_info->sems[i].sem_val = 0;
sem_info->sems[i].sem_ncnt = 0;
sem_info->sems[i].sem_zcnt = 0;
sem_info->semid.sem_base[i].sem_pid = sys_getpid();
sem_info->semid.sem_base[i].sem_val = 0;
sem_info->semid.sem_base[i].sem_ncnt = 0;
sem_info->semid.sem_base[i].sem_zcnt = 0;
}
// Return the semaphore management structure.
return sem_info;
@@ -133,7 +131,7 @@ static inline void __sem_info_dealloc(sem_info_t *sem_info)
{
assert(sem_info && "Received a NULL pointer.");
// Deallocate the array of semaphores.
kfree(sem_info->sems);
kfree(sem_info->semid.sem_base);
// Deallocate the semid memory.
kfree(sem_info);
}
@@ -305,14 +303,14 @@ 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 (((int)sem_info->sems[sops->sem_num].sem_val + (int)sops->sem_op) < 0) {
if (((int)sem_info->semid.sem_base[sops->sem_num].sem_val + (int)sops->sem_op) < 0) {
// The value would become negative, we cannot perform the operation.
return -EAGAIN;
}
// Update the semaphore value.
sem_info->sems[sops->sem_num].sem_val += sops->sem_op;
sem_info->semid.sem_base[sops->sem_num].sem_val += sops->sem_op;
// Update the pid of the process that did last op.
sem_info->sems[sops->sem_num].sem_pid = sys_getpid();
sem_info->semid.sem_base[sops->sem_num].sem_pid = sys_getpid();
// Update the time.
sem_info->semid.sem_ctime = sys_time(NULL);
return 0;
@@ -321,6 +319,7 @@ long sys_semop(int semid, struct sembuf *sops, unsigned nsops)
long sys_semctl(int semid, int semnum, int cmd, union semun *arg)
{
sem_info_t *sem_info = NULL;
task_struct *task = NULL;
// Search for the semaphore.
sem_info = __list_find_sem_info_by_id(semid);
// The semaphore set doesn't exist.
@@ -328,15 +327,14 @@ long sys_semctl(int semid, int semnum, int cmd, union semun *arg)
pr_err("The semaphore set doesn't exist.\n");
return -EINVAL;
}
// Get the calling task.
task_struct *task = scheduler_get_current_process();
task = scheduler_get_current_process();
assert(task && "Failed to get the current running process.");
switch (cmd) {
// Remove the semaphore set; any processes blocked is awakened (errno set to
// EIDRM); no argument required.
case IPC_RMID:
if (cmd == IPC_RMID) {
// Remove the semaphore set; any processes blocked is awakened (errno set to
// EIDRM); no argument required.
if ((sem_info->semid.sem_perm.uid != task->uid) && (sem_info->semid.sem_perm.cuid != task->uid)) {
pr_err("The calling process is not the creator or the owner of the semaphore set.\n");
return -EPERM;
@@ -345,11 +343,10 @@ long sys_semctl(int semid, int semnum, int cmd, union semun *arg)
__list_remove_sem_info(sem_info);
// Delete the set.
__sem_info_dealloc(sem_info);
break;
} else if (cmd == SETVAL) {
// The value of the semnum-th semaphore in the set is initialized to the
// value specified in arg.val.
// The value of the semnum-th semaphore in the set is initialized to the
// value specified in arg.val.
case SETVAL:
// Check if the index is valid.
if ((semnum < 0) || (semnum >= (sem_info->semid.sem_nsems))) {
pr_err("Semaphore number out of bound (%d not in [%d, %d])\n", semnum, 0, sem_info->semid.sem_nsems);
@@ -371,14 +368,13 @@ long sys_semctl(int semid, int semnum, int cmd, union semun *arg)
return -EACCES;
}
// Setting the value.
sem_info->sems[semnum].sem_val = arg->val;
sem_info->semid.sem_base[semnum].sem_val = arg->val;
// Update the last change time.
sem_info->semid.sem_ctime = sys_time(NULL);
return 0;
} else if (cmd == SETALL) {
// Initialize all semaphore in the set referred to by semid, using the
// values supplied in the array pointed to by arg.array.
// Initialize all semaphore in the set referred to by semid, using the
// values supplied in the array pointed to by arg.array.
case SETALL:
// Check if the argument is a null pointer.
if (!arg) {
pr_err("The argument is NULL.\n");
@@ -396,15 +392,14 @@ long sys_semctl(int semid, int semnum, int cmd, union semun *arg)
}
// Setting the values.
for (unsigned i = 0; i < sem_info->semid.sem_nsems; ++i) {
sem_info->sems[i].sem_val = arg->array[i];
sem_info->semid.sem_base[i].sem_val = arg->array[i];
}
// Update the last change time.
sem_info->semid.sem_ctime = sys_time(NULL);
return 0;
} else if (cmd == IPC_STAT) {
// Place a copy of the semid_ds data structure in the buffer pointed to by
// arg.buf.
// Place a copy of the semid_ds data structure in the buffer pointed to by
// arg.buf.
case IPC_STAT:
// Check if the argument is a null pointer.
if (!arg) {
pr_err("The argument is NULL.\n");
@@ -422,11 +417,10 @@ long sys_semctl(int semid, int semnum, int cmd, union semun *arg)
}
// Copying all the data.
memcpy(arg->buf, &sem_info->semid, sizeof(struct semid_ds));
return 0;
} else if (cmd == GETALL) {
// Retrieve the values of all of the semaphores in the set referred to by
// semid, placing them in the array pointed to by arg.array.
// Retrieve the values of all of the semaphores in the set referred to by
// semid, placing them in the array pointed to by arg.array.
case GETALL:
// Check if the argument is a null pointer.
if (!arg) {
pr_err("The argument is NULL.\n");
@@ -438,79 +432,77 @@ long sys_semctl(int semid, int semnum, int cmd, union semun *arg)
return -EINVAL;
}
for (unsigned i = 0; i < sem_info->semid.sem_nsems; ++i) {
arg->array[i] = sem_info->sems[i].sem_val;
arg->array[i] = sem_info->semid.sem_base[i].sem_val;
}
return 0;
// Returns the value of the semnum-th semaphore in the set specified by
// semid; no argument required.
case GETVAL:
// Check if the index is valid.
if ((semnum < 0) || (semnum >= (sem_info->semid.sem_nsems))) {
pr_err("Semaphore number out of bound (%d not in [%d, %d])\n", semnum, 0, sem_info->semid.sem_nsems);
return -EINVAL;
}
// Check permissions.
if (!ipc_valid_permissions(O_RDONLY, &sem_info->semid.sem_perm)) {
pr_err("The calling process does not have read permission to access the set.\n");
return -EACCES;
}
return sem_info->sems[semnum].sem_val;
// Return the process ID of the last process to perform a semop on the
// semnum-th semaphore.
case GETPID:
// Check if the index is valid.
if ((semnum < 0) || (semnum >= (sem_info->semid.sem_nsems))) {
pr_err("Semaphore number out of bound (%d not in [%d, %d])\n", semnum, 0, sem_info->semid.sem_nsems);
return -EINVAL;
}
// Check permissions.
if (!ipc_valid_permissions(O_RDONLY, &sem_info->semid.sem_perm)) {
pr_err("The calling process does not have read permission to access the set.\n");
return -EACCES;
}
return sem_info->sems[semnum].sem_pid;
// Return the number of processes currently waiting for the resources to
// become available.
case GETNCNT:
// Check if the index is valid.
if ((semnum < 0) || (semnum >= (sem_info->semid.sem_nsems))) {
pr_err("Semaphore number out of bound (%d not in [%d, %d])\n", semnum, 0, sem_info->semid.sem_nsems);
return -EINVAL;
}
// Check permissions.
if (!ipc_valid_permissions(O_RDONLY, &sem_info->semid.sem_perm)) {
pr_err("The calling process does not have read permission to access the set.\n");
return -EACCES;
}
return sem_info->sems[semnum].sem_ncnt;
// Return the number of processes currently waiting for the value of the
// semnum-th semaphore to become 0.
case GETZCNT:
// Check if the index is valid.
if ((semnum < 0) || (semnum >= (sem_info->semid.sem_nsems))) {
pr_err("Semaphore number out of bound (%d not in [%d, %d])\n", semnum, 0, sem_info->semid.sem_nsems);
return -EINVAL;
}
// Check permissions.
if (!ipc_valid_permissions(O_RDONLY, &sem_info->semid.sem_perm)) {
pr_err("The calling process does not have read permission to access the set.\n");
return -EACCES;
}
return sem_info->sems[semnum].sem_zcnt;
} else if (cmd == GETVAL) {
// Returns the value of the semnum-th semaphore in the set specified by
// semid; no argument required.
case SEM_STAT:
// Check if the index is valid.
if ((semnum < 0) || (semnum >= (sem_info->semid.sem_nsems))) {
pr_err("Semaphore number out of bound (%d not in [%d, %d])\n", semnum, 0, sem_info->semid.sem_nsems);
return -EINVAL;
}
// Check permissions.
if (!ipc_valid_permissions(O_RDONLY, &sem_info->semid.sem_perm)) {
pr_err("The calling process does not have read permission to access the set.\n");
return -EACCES;
}
return sem_info->semid.sem_base[semnum].sem_val;
} else if (cmd == GETPID) {
// Return the process ID of the last process to perform a semop on the
// semnum-th semaphore.
// Check if the index is valid.
if ((semnum < 0) || (semnum >= (sem_info->semid.sem_nsems))) {
pr_err("Semaphore number out of bound (%d not in [%d, %d])\n", semnum, 0, sem_info->semid.sem_nsems);
return -EINVAL;
}
// Check permissions.
if (!ipc_valid_permissions(O_RDONLY, &sem_info->semid.sem_perm)) {
pr_err("The calling process does not have read permission to access the set.\n");
return -EACCES;
}
return sem_info->semid.sem_base[semnum].sem_pid;
} else if (cmd == GETNCNT) {
// Return the number of processes currently waiting for the resources to
// become available.
// Check if the index is valid.
if ((semnum < 0) || (semnum >= (sem_info->semid.sem_nsems))) {
pr_err("Semaphore number out of bound (%d not in [%d, %d])\n", semnum, 0, sem_info->semid.sem_nsems);
return -EINVAL;
}
// Check permissions.
if (!ipc_valid_permissions(O_RDONLY, &sem_info->semid.sem_perm)) {
pr_err("The calling process does not have read permission to access the set.\n");
return -EACCES;
}
return sem_info->semid.sem_base[semnum].sem_ncnt;
} else if (cmd == GETZCNT) {
// Return the number of processes currently waiting for the value of the
// semnum-th semaphore to become 0.
// Check if the index is valid.
if ((semnum < 0) || (semnum >= (sem_info->semid.sem_nsems))) {
pr_err("Semaphore number out of bound (%d not in [%d, %d])\n", semnum, 0, sem_info->semid.sem_nsems);
return -EINVAL;
}
// Check permissions.
if (!ipc_valid_permissions(O_RDONLY, &sem_info->semid.sem_perm)) {
pr_err("The calling process does not have read permission to access the set.\n");
return -EACCES;
}
return sem_info->semid.sem_base[semnum].sem_zcnt;
} else if (cmd == SEM_STAT) {
pr_err("Not implemented.\n");
return -ENOSYS;
case SEM_INFO:
} else if (cmd == SEM_INFO) {
pr_err("Not implemented.\n");
return -ENOSYS;
// Not a valid argument.
default:
} else {
return -EINVAL;
}
return 0;
}
mentos/src/ipc/shm.c
-1
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@@ -412,7 +412,6 @@ ssize_t procipc_shm_read(vfs_file_t *file, char *buf, off_t offset, size_t nbyte
return -ENOENT;
}
size_t buffer_len = 0, read_pos = 0, write_count = 0, ret = 0;
struct semid_ds *entry = NULL;
char buffer[BUFSIZ];
// Prepare a buffer.
programs/ipcs.c
-2
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@@ -74,8 +74,6 @@ int main(int argc, char **argv)
ret = semctl(semid, 0, IPC_STAT, &temp);
// Check if we succeded.
if (!ret) {
//ret = semctl(atoi(argv[2]), 0, GETNSEMS, NULL);
//temp.buf->sems = (struct sem *)malloc(sizeof(struct sem) * ret);
printf("key semid owner perms nsems\n");
printf("%10d %10d %10d %10d %d\n", sem.sem_perm.key, semid, sem.sem_perm.uid, sem.sem_perm.mode, sem.sem_nsems);
return 0;
programs/ps.c
-3
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@@ -53,9 +53,6 @@ static inline void __iterate_proc_dirs(int proc_fd)
strcat(absolute_path, "/stat");
// Open the `/proc/<pid>/stat` file.
if ((stat_fd = open(absolute_path, O_RDONLY, 0)) == -1) {
printf("Failed to open `%s`: ", absolute_path);
perror(NULL);
putchar('\n');
continue;
}
// Reset the stat buffer.