Kernel: Pass name+length to set_mmap_name() and remove SmapDisabler

Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/33025a8049e

Kernel/Process.cpp

@@ -208,17 +208,24 @@ Region* Process::region_containing(const Range& range)
     return nullptr;
 }
 
-int Process::sys$set_mmap_name(void* addr, size_t size, const char* name)
+int Process::sys$set_mmap_name(const Syscall::SC_set_mmap_name_params* user_params)
 {
-    SmapDisabler disabler;
-    if (!validate_read_str(name))
+    if (!validate_read_typed(user_params))
         return -EFAULT;
-    auto* region = region_from_range({ VirtualAddress((u32)addr), size });
+
+    Syscall::SC_set_mmap_name_params params;
+    copy_from_user(&params, user_params, sizeof(params));
+
+    if (!validate_read(params.name, params.name_length))
+        return -EFAULT;
+    auto name = copy_string_from_user(params.name, params.name_length);
+
+    auto* region = region_from_range({ VirtualAddress((u32)params.addr), params.size });
     if (!region)
         return -EINVAL;
     if (!region->is_mmap())
         return -EPERM;
-    region->set_name(String(name));
+    region->set_name(name);
     return 0;
 }
 

Kernel/Process.h

@@ -136,7 +136,7 @@ public:
     pid_t sys$waitpid(pid_t, int* wstatus, int options);
     void* sys$mmap(const Syscall::SC_mmap_params*);
     int sys$munmap(void*, size_t size);
-    int sys$set_mmap_name(void*, size_t, const char*);
+    int sys$set_mmap_name(const Syscall::SC_set_mmap_name_params*);
     int sys$mprotect(void*, size_t, int prot);
     int sys$madvise(void*, size_t, int advice);
     int sys$purge(int mode);

Kernel/Syscall.h

@@ -298,6 +298,13 @@ struct SC_realpath_params {
     size_t buffer_size;
 };
 
+struct SC_set_mmap_name_params {
+    void* addr;
+    size_t size;
+    const char* name;
+    size_t name_length;
+};
+
 void initialize();
 int sync();
 

Libraries/LibC/mman.cpp

@@ -2,6 +2,7 @@
 #include <errno.h>
 #include <mman.h>
 #include <stdio.h>
+#include <string.h>
 
 extern "C" {
 
@@ -41,7 +42,12 @@ int mprotect(void* addr, size_t size, int prot)
 
 int set_mmap_name(void* addr, size_t size, const char* name)
 {
-    int rc = syscall(SC_set_mmap_name, addr, size, name);
+    if (!name) {
+        errno = EFAULT;
+        return -1;
+    }
+    Syscall::SC_set_mmap_name_params params { addr, size, name, strlen(name) };
+    int rc = syscall(SC_set_mmap_name, &params);
     __RETURN_WITH_ERRNO(rc, rc, -1);
 }
 
@@ -50,5 +56,4 @@ int madvise(void* address, size_t size, int advice)
     int rc = syscall(SC_madvise, address, size, advice);
     __RETURN_WITH_ERRNO(rc, rc, -1);
 }
-
 }