macos: update Mach routines for accessing page info

lib/std/c/darwin.zig

@@ -155,6 +155,7 @@ pub const vm_map_t = mach_port_t;
 pub const vm_map_read_t = mach_port_t;
 pub const vm_region_flavor_t = c_int;
 pub const vm_region_info_t = *c_int;
+pub const vm_region_recurse_info_t = *c_int;
 pub const mach_vm_address_t = usize;
 pub const vm_offset_t = usize;
 pub const mach_vm_size_t = u64;
@@ -193,13 +194,20 @@ pub extern "c" fn mach_vm_region(
     info_cnt: *mach_msg_type_number_t,
     object_name: *mach_port_t,
 ) kern_return_t;
-
+pub extern "c" fn mach_vm_region_recurse(
-pub const VM_REGION_BASIC_INFO_64 = 9;
+    target_task: vm_map_t,
-pub const VM_REGION_SUBMAP_SHORT_INFO_COUNT_64: mach_msg_type_number_t = @sizeOf(vm_region_submap_info_64) / @sizeOf(natural_t);
+    address: *mach_vm_address_t,
+    size: *mach_vm_size_t,
+    nesting_depth: *natural_t,
+    info: vm_region_recurse_info_t,
+    info_cnt: *mach_msg_type_number_t,
+) kern_return_t;
 
 pub const vm_inherit_t = u32;
 pub const memory_object_offset_t = u64;
 pub const vm_behavior_t = i32;
+pub const vm32_object_id_t = u32;
+pub const vm_object_id_t = u64;
 
 pub const VM_INHERIT_SHARE: vm_inherit_t = 0;
 pub const VM_INHERIT_COPY: vm_inherit_t = 1;
@@ -221,8 +229,47 @@ pub const VM_BEHAVIOR_REUSE: vm_behavior_t = 9;
 pub const VM_BEHAVIOR_CAN_REUSE: vm_behavior_t = 10;
 pub const VM_BEHAVIOR_PAGEOUT: vm_behavior_t = 11;
 
-pub const vm32_object_id_t = u32;
+pub const VM_REGION_BASIC_INFO_64 = 9;
-pub const vm_object_id_t = u64;
+pub const VM_REGION_EXTENDED_INFO = 13;
+pub const VM_REGION_TOP_INFO = 12;
+pub const VM_REGION_SUBMAP_INFO_COUNT_64: mach_msg_type_number_t = @sizeOf(vm_region_submap_info_64) / @sizeOf(natural_t);
+pub const VM_REGION_SUBMAP_SHORT_INFO_COUNT_64: mach_msg_type_number_t = @sizeOf(vm_region_submap_short_info_64) / @sizeOf(natural_t);
+pub const VM_REGION_BASIC_INFO_COUNT: mach_msg_type_number_t = @sizeOf(vm_region_basic_info_64) / @sizeOf(c_int);
+pub const VM_REGION_EXTENDED_INFO_COUNT: mach_msg_type_number_t = @sizeOf(vm_region_extended_info) / @sizeOf(natural_t);
+pub const VM_REGION_TOP_INFO_COUNT: mach_msg_type_number_t = @sizeOf(vm_region_top_info) / @sizeOf(natural_t);
+
+pub const vm_region_basic_info_64 = extern struct {
+    protection: vm_prot_t,
+    max_protection: vm_prot_t,
+    inheritance: vm_inherit_t,
+    shared: boolean_t,
+    reserved: boolean_t,
+    offset: memory_object_offset_t,
+    behavior: vm_behavior_t,
+    user_wired_count: u16,
+};
+
+pub const vm_region_extended_info = extern struct {
+    protection: vm_prot_t,
+    user_tag: u32,
+    pages_resident: u32,
+    pages_shared_now_private: u32,
+    pages_swapped_out: u32,
+    pages_dirtied: u32,
+    ref_count: u32,
+    shadow_depth: u16,
+    external_pager: u8,
+    share_mode: u8,
+    pages_reusable: u32,
+};
+
+pub const vm_region_top_info = extern struct {
+    obj_id: u32,
+    ref_count: u32,
+    private_pages_resident: u32,
+    shared_pages_resident: u32,
+    share_mode: u8,
+};
 
 pub const vm_region_submap_info_64 = extern struct {
     // present across protection
@@ -262,6 +309,34 @@ pub const vm_region_submap_info_64 = extern struct {
     object_id_full: vm_object_id_t,
 };
 
+pub const vm_region_submap_short_info_64 = extern struct {
+    // present access protection
+    protection: vm_prot_t,
+    // max avail through vm_prot
+    max_protection: vm_prot_t,
+    // behavior of map/obj on fork
+    inheritance: vm_inherit_t,
+    // offset into object/map
+    offset: memory_object_offset_t,
+    // user tag on map entry
+    user_tag: u32,
+    // obj/map mappers, etc
+    ref_count: u32,
+    // only for obj
+    shadow_depth: u16,
+    // only for obj
+    external_pager: u8,
+    // see enumeration
+    share_mode: u8,
+    //  submap vs obj
+    is_submap: boolean_t,
+    // access behavior hint
+    behavior: vm_behavior_t,
+    // obj/map name, not a handle
+    object_id: vm32_object_id_t,
+    user_wired_count: u16,
+};
+
 pub const thread_act_t = mach_port_t;
 pub const thread_state_t = *natural_t;
 pub const mach_port_array_t = *mach_port_t;
@@ -986,9 +1061,13 @@ pub const MAP = struct {
 };
 
 pub const MSF = struct {
-    pub const ASYNC = 1;
+    pub const ASYNC = 0x1;
-    pub const INVALIDATE = 2;
+    pub const INVALIDATE = 0x2;
-    pub const SYNC = 4;
+    // invalidate, leave mapped
+    pub const KILLPAGES = 0x4;
+    // deactivate, leave mapped
+    pub const DEACTIVATE = 0x8;
+    pub const SYNC = 0x10;
 };
 
 pub const SA = struct {

lib/std/os/darwin.zig

@@ -24,22 +24,63 @@ const mach_task = if (builtin.target.isDarwin()) struct {
             return self.port != 0;
         }
 
-        pub fn getCurrProtection(task: MachTask, address: u64, len: usize) MachError!std.c.vm_prot_t {
+        pub const RegionInfo = struct {
-            var base_addr = address;
+            pub const Tag = enum {
+                basic,
+                extended,
+                top,
+            };
+
+            base_addr: u64,
+            tag: Tag,
+            info: union {
+                basic: std.c.vm_region_basic_info_64,
+                extended: std.c.vm_region_extended_info,
+                top: std.c.vm_region_top_info,
+            },
+        };
+
+        pub fn getRegionInfo(
+            task: MachTask,
+            address: u64,
+            len: usize,
+            tag: RegionInfo.Tag,
+        ) MachError!RegionInfo {
+            var info: RegionInfo = .{
+                .base_addr = address,
+                .tag = tag,
+                .info = undefined,
+            };
+            switch (tag) {
+                .basic => info.info = .{ .basic = undefined },
+                .extended => info.info = .{ .extended = undefined },
+                .top => info.info = .{ .top = undefined },
+            }
             var base_len: std.c.mach_vm_size_t = if (len == 1) 2 else len;
             var objname: std.c.mach_port_t = undefined;
-            var info: std.c.vm_region_submap_info_64 = undefined;
+            var count: std.c.mach_msg_type_number_t = switch (tag) {
-            var count: std.c.mach_msg_type_number_t = std.c.VM_REGION_SUBMAP_SHORT_INFO_COUNT_64;
+                .basic => std.c.VM_REGION_BASIC_INFO_COUNT,
+                .extended => std.c.VM_REGION_EXTENDED_INFO_COUNT,
+                .top => std.c.VM_REGION_TOP_INFO_COUNT,
+            };
             switch (std.c.getKernError(std.c.mach_vm_region(
                 task.port,
-                &base_addr,
+                &info.base_addr,
                 &base_len,
-                std.c.VM_REGION_BASIC_INFO_64,
+                switch (tag) {
-                @ptrCast(std.c.vm_region_info_t, &info),
+                    .basic => std.c.VM_REGION_BASIC_INFO_64,
+                    .extended => std.c.VM_REGION_EXTENDED_INFO,
+                    .top => std.c.VM_REGION_TOP_INFO,
+                },
+                switch (tag) {
+                    .basic => @ptrCast(std.c.vm_region_info_t, &info.info.basic),
+                    .extended => @ptrCast(std.c.vm_region_info_t, &info.info.extended),
+                    .top => @ptrCast(std.c.vm_region_info_t, &info.info.top),
+                },
                 &count,
                 &objname,
             ))) {
-                .SUCCESS => return info.protection,
+                .SUCCESS => return info,
                 .FAILURE => return error.PermissionDenied,
                 else => |err| {
                     log.err("mach_vm_region kernel call failed with error code: {s}", .{@tagName(err)});
@@ -48,6 +89,67 @@ const mach_task = if (builtin.target.isDarwin()) struct {
             }
         }
 
+        pub const RegionSubmapInfo = struct {
+            pub const Tag = enum {
+                short,
+                full,
+            };
+
+            tag: Tag,
+            base_addr: u64,
+            info: union {
+                short: std.c.vm_region_submap_short_info_64,
+                full: std.c.vm_region_submap_info_64,
+            },
+        };
+
+        pub fn getRegionSubmapInfo(
+            task: MachTask,
+            address: u64,
+            len: usize,
+            nesting_depth: u32,
+            tag: RegionSubmapInfo.Tag,
+        ) MachError!RegionSubmapInfo {
+            var info: RegionSubmapInfo = .{
+                .base_addr = address,
+                .tag = tag,
+                .info = undefined,
+            };
+            switch (tag) {
+                .short => info.info = .{ .short = undefined },
+                .full => info.info = .{ .full = undefined },
+            }
+            var nesting = nesting_depth;
+            var base_len: std.c.mach_vm_size_t = if (len == 1) 2 else len;
+            var count: std.c.mach_msg_type_number_t = switch (tag) {
+                .short => std.c.VM_REGION_SUBMAP_SHORT_INFO_COUNT_64,
+                .full => std.c.VM_REGION_SUBMAP_INFO_COUNT_64,
+            };
+            switch (std.c.getKernError(std.c.mach_vm_region_recurse(
+                task.port,
+                &info.base_addr,
+                &base_len,
+                &nesting,
+                switch (tag) {
+                    .short => @ptrCast(std.c.vm_region_recurse_info_t, &info.info.short),
+                    .full => @ptrCast(std.c.vm_region_recurse_info_t, &info.info.full),
+                },
+                &count,
+            ))) {
+                .SUCCESS => return info,
+                .FAILURE => return error.PermissionDenied,
+                else => |err| {
+                    log.err("mach_vm_region kernel call failed with error code: {s}", .{@tagName(err)});
+                    return error.Unexpected;
+                },
+            }
+        }
+
+        pub fn getCurrProtection(task: MachTask, address: u64, len: usize) MachError!std.c.vm_prot_t {
+            const info = try task.getRegionSubmapInfo(address, len, 0, .short);
+            return info.info.short.protection;
+        }
+
         pub fn setMaxProtection(task: MachTask, address: u64, len: usize, prot: std.c.vm_prot_t) MachError!void {
             return task.setProtectionImpl(address, len, true, prot);
         }
@@ -216,4 +318,8 @@ const mach_task = if (builtin.target.isDarwin()) struct {
         }
         return MachTask{ .port = port };
     }
+
+    pub fn machTaskForSelf() MachTask {
+        return .{ .port = std.c.mach_task_self() };
+    }
 } else struct {};