Implement passing commandline strings

kernel/amd64/proc.h

@@ -12,6 +12,8 @@
 /* proc_map () base address */
 #define PROC_MAP_BASE 0x0000700000000000
 
+#define PROC_CMDLINE_BASE 0x0000100000000000
+
 /* Platform-dependent process data */
 struct proc_platformdata {
   uint8_t fx_env[512] ALIGNED(16);

kernel/proc/procgroup.c

@@ -3,6 +3,7 @@
 #include <libk/rbtree.h>
 #include <libk/std.h>
 #include <libk/string.h>
+#include <limine/requests.h>
 #include <mm/malloc.h>
 #include <mm/pmm.h>
 #include <proc/env.h>
@@ -132,6 +133,8 @@ bool procgroup_unmap(struct procgroup* procgroup, uintptr_t start_vaddr, size_t
 }
 
 struct procgroup* procgroup_create(void) {
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
   struct procgroup* procgroup = malloc(sizeof(*procgroup));
   if (procgroup == NULL) {
     return NULL;
@@ -156,6 +159,10 @@ struct procgroup* procgroup_create(void) {
   procgroup->pd.cr3_paddr = mm_alloc_user_pd_phys();
   procgroup->map_base = PROC_MAP_BASE;
 
+  procgroup->uvaddr_cmdline = procgroup_map(procgroup, PROC_CMDLINE_BASE, 1,
+                                            MM_PG_PRESENT | MM_PG_USER, &procgroup->paddr_cmdline);
+  memset((void*)((uintptr_t)hhdm->offset + procgroup->paddr_cmdline), 0, PROCGROUP_CMDLINE_MAX);
+
   if (proc_create_resource_mail(procgroup) == NULL) {
     id_alloc_fini(&procgroup->rid_alloc);
     free(procgroup);
@@ -214,6 +221,8 @@ static void procgroup_delete(struct procgroup* procgroup, struct reschedule_ctx*
 
   proc_env_cleanup(procgroup);
 
+  pmm_free(procgroup->paddr_cmdline, 1);
+
   pmm_free(procgroup->pd.cr3_paddr, 1);
 
   free(procgroup->tls.tls_tmpl);

kernel/proc/procgroup.h

@@ -5,14 +5,15 @@
 #include <libk/list.h>
 #include <libk/rbtree.h>
 #include <libk/std.h>
+#include <page_size.h>
 #include <proc/env.h>
 #include <proc/resource.h>
 #include <sync/spin_lock.h>
 #include <sys/mm.h>
 #include <sys/procgroup.h>
 
-#define PROCGROUP_VFS_HANDLES_MAX 256
-#define PROCGROUP_RESOURCES_MAX   256
+#define PROCGROUP_RESOURCES_MAX 256
+#define PROCGROUP_CMDLINE_MAX   PAGE_SIZE
 
 struct proc;
 struct reschedule_ctx;
@@ -36,6 +37,8 @@ struct procgroup {
   uintptr_t map_base;
   struct procgroup_tls tls;
   struct proc_env env;
+  uintptr_t uvaddr_cmdline;
+  uintptr_t paddr_cmdline;
 };
 
 struct procgroup* procgroup_create(void);

kernel/syscall/syscall.c

@@ -289,10 +289,11 @@ DEFINE_SYSCALL(sys_device_do) {
   return SYSRESULT(ret);
 }
 
-/* int exec (char* volume, char* path) */
+/* int exec (char* volume, char* path, char* cmdline) */
 DEFINE_SYSCALL(sys_exec) {
   uintptr_t uvaddr_volume = a1;
   uintptr_t uvaddr_path = a2;
+  uintptr_t uvaddr_cmdline = a3;
 
   struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
 
@@ -316,12 +317,21 @@ DEFINE_SYSCALL(sys_exec) {
 
   const char* volume = (const char*)((uintptr_t)hhdm->offset + out_paddr);
 
+  out_paddr = mm_v2p(&procgroup->pd, uvaddr_cmdline);
+
+  char* cmdline = (out_paddr != 0) ? (char*)((uintptr_t)hhdm->offset + out_paddr) : NULL;
+
   struct proc* new = proc_from_file(proc, volume, path, rctx);
 
   if (new == NULL) {
     return SYSRESULT(-ST_EXEC_ERROR);
   }
 
+  if (cmdline != NULL) {
+    void* cmdline_dest = (void*)((uintptr_t)hhdm->offset + new->procgroup->paddr_cmdline);
+    strncpy(cmdline_dest, cmdline, PAGE_SIZE);
+  }
+
   int pid = new->pid;
   new->exec_pid = pid1;
 
@@ -931,7 +941,14 @@ DEFINE_SYSCALL(sys_date_time) {
 
   date_time(dt);
 
-  return ST_OK;
+  return SYSRESULT(ST_OK);
+}
+
+/* const char* get_cmdline(void) */
+DEFINE_SYSCALL(sys_get_cmdline) {
+  struct procgroup* procgroup = proc->procgroup;
+
+  return SYSRESULT(procgroup->uvaddr_cmdline);
 }
 
 static syscall_handler_func_t handler_table[] = {
@@ -976,6 +993,7 @@ static syscall_handler_func_t handler_table[] = {
     [SYS_GET_VOLUME_INFO] = &sys_get_volume_info,
     [SYS_VOLUME_DELETE] = &sys_volume_delete,
     [SYS_DATE_TIME] = &sys_date_time,
+    [SYS_GET_CMDLINE] = &sys_get_cmdline,
 };
 
 syscall_handler_func_t syscall_find_handler(int syscall_num) {