tree-wide: be more careful with the type of array sizes

Previously we were a bit sloppy with the index and size types of arrays,
we'd regularly use unsigned. While I don't think this ever resulted in
real issues I think we should be more careful there and follow a
stricter regime: unless there's a strong reason not to use size_t for
array sizes and indexes, size_t it should be. Any allocations we do
ultimately will use size_t anyway, and converting forth and back between
unsigned and size_t will always be a source of problems.

Note that on 32bit machines "unsigned" and "size_t" are equivalent, and
on 64bit machines our arrays shouldn't grow that large anyway, and if
they do we have a problem, however that kind of overly large allocation
we have protections for usually, but for overflows we do not have that
so much, hence let's add it.

So yeah, it's a story of the current code being already "good enough",
but I think some extra type hygiene is better.

This patch tries to be comprehensive, but it probably isn't and I missed
a few cases. But I guess we can cover that later as we notice it. Among
smaller fixes, this changes:

1. strv_length()' return type becomes size_t

2. the unit file changes array size becomes size_t

3. DNS answer and query array sizes become size_t

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=76745

1 files changed, 6 insertions, 6 deletions

diff --git a/src/core/namespace.h b/src/core/namespace.h
index ac97f9f373..d8e4682255 100644
--- a/src/core/namespace.h
+++ b/src/core/namespace.h
@@ -78,9 +78,9 @@ int setup_namespace(
                 char **inaccessible_paths,
                 char **empty_directories,
                 const BindMount *bind_mounts,
-                unsigned n_bind_mounts,
+                size_t n_bind_mounts,
                 const TemporaryFileSystem *temporary_filesystems,
-                unsigned n_temporary_filesystems,
+                size_t n_temporary_filesystems,
                 const char *tmp_dir,
                 const char *var_tmp_dir,
                 ProtectHome protect_home,
@@ -103,11 +103,11 @@ const char* protect_system_to_string(ProtectSystem p) _const_;
 ProtectSystem protect_system_from_string(const char *s) _pure_;
 ProtectSystem parse_protect_system_or_bool(const char *s);
 
-void bind_mount_free_many(BindMount *b, unsigned n);
-int bind_mount_add(BindMount **b, unsigned *n, const BindMount *item);
+void bind_mount_free_many(BindMount *b, size_t n);
+int bind_mount_add(BindMount **b, size_t *n, const BindMount *item);
 
-void temporary_filesystem_free_many(TemporaryFileSystem *t, unsigned n);
-int temporary_filesystem_add(TemporaryFileSystem **t, unsigned *n,
+void temporary_filesystem_free_many(TemporaryFileSystem *t, size_t n);
+int temporary_filesystem_add(TemporaryFileSystem **t, size_t *n,
                              const char *path, const char *options);
 
 const char* namespace_type_to_string(NamespaceType t) _const_;