vmbase: Export linker-defined MemoryRegions & VAs
Group all linker-defined variables in a private module.
Export the memory regions defined by the linker as safe Range<usize>.
Export __stack_chk_guard as a safe static &u64.
Bug: 238050226
Test: atest vmbase_example.integration_test
Change-Id: I401ac4af949e283f78fbc576db19339e38ed3942
diff --git a/vmbase/example/src/layout.rs b/vmbase/example/src/layout.rs
index c0c4fab..4c3af6d 100644
--- a/vmbase/example/src/layout.rs
+++ b/vmbase/example/src/layout.rs
@@ -17,72 +17,59 @@
use aarch64_paging::paging::{MemoryRegion, VirtualAddress};
use core::arch::asm;
use core::ops::Range;
+use vmbase::layout;
use vmbase::println;
+use vmbase::STACK_CHK_GUARD;
/// The first 1 GiB of memory are used for MMIO.
pub const DEVICE_REGION: MemoryRegion = MemoryRegion::new(0, 0x40000000);
+fn into_va_range(r: Range<usize>) -> Range<VirtualAddress> {
+ VirtualAddress(r.start)..VirtualAddress(r.end)
+}
+
/// Memory reserved for the DTB.
pub fn dtb_range() -> Range<VirtualAddress> {
- unsafe {
- VirtualAddress(&dtb_begin as *const u8 as usize)
- ..VirtualAddress(&dtb_end as *const u8 as usize)
- }
+ into_va_range(layout::dtb_range())
}
/// Executable code.
pub fn text_range() -> Range<VirtualAddress> {
- unsafe {
- VirtualAddress(&text_begin as *const u8 as usize)
- ..VirtualAddress(&text_end as *const u8 as usize)
- }
+ into_va_range(layout::text_range())
}
/// Read-only data.
pub fn rodata_range() -> Range<VirtualAddress> {
- unsafe {
- VirtualAddress(&rodata_begin as *const u8 as usize)
- ..VirtualAddress(&rodata_end as *const u8 as usize)
- }
+ into_va_range(layout::rodata_range())
}
/// Initialised writable data.
pub fn data_range() -> Range<VirtualAddress> {
- unsafe {
- VirtualAddress(&data_begin as *const u8 as usize)
- ..VirtualAddress(&data_end as *const u8 as usize)
- }
+ into_va_range(layout::data_range())
}
/// Zero-initialised writable data.
pub fn bss_range() -> Range<VirtualAddress> {
- unsafe {
- VirtualAddress(&bss_begin as *const u8 as usize)
- ..VirtualAddress(&bss_end as *const u8 as usize)
- }
+ into_va_range(layout::bss_range())
}
/// Writable data region for the stack.
pub fn boot_stack_range() -> Range<VirtualAddress> {
- unsafe {
- VirtualAddress(&boot_stack_begin as *const u8 as usize)
- ..VirtualAddress(&boot_stack_end as *const u8 as usize)
- }
+ into_va_range(layout::boot_stack_range())
}
/// Writable data, including the stack.
pub fn writable_region() -> MemoryRegion {
- unsafe {
- MemoryRegion::new(&data_begin as *const u8 as usize, &boot_stack_end as *const u8 as usize)
- }
+ let r = layout::writable_region();
+ MemoryRegion::new(r.start, r.end)
}
fn data_load_address() -> VirtualAddress {
- unsafe { VirtualAddress(&data_lma as *const u8 as usize) }
+ VirtualAddress(layout::data_load_address())
}
fn binary_end() -> VirtualAddress {
- unsafe { VirtualAddress(&bin_end as *const u8 as usize) }
+ VirtualAddress(layout::binary_end())
}
pub fn print_addresses() {
@@ -124,23 +111,5 @@
/// Value of __stack_chk_guard.
pub fn stack_chk_guard() -> u64 {
- unsafe { __stack_chk_guard }
-}
-
-extern "C" {
- static dtb_begin: u8;
- static dtb_end: u8;
- static text_begin: u8;
- static text_end: u8;
- static rodata_begin: u8;
- static rodata_end: u8;
- static data_begin: u8;
- static data_end: u8;
- static data_lma: u8;
- static bin_end: u8;
- static bss_begin: u8;
- static bss_end: u8;
- static boot_stack_begin: u8;
- static boot_stack_end: u8;
- static __stack_chk_guard: u64;
+ *STACK_CHK_GUARD
}
diff --git a/vmbase/src/layout.rs b/vmbase/src/layout.rs
new file mode 100644
index 0000000..b0a5173
--- /dev/null
+++ b/vmbase/src/layout.rs
@@ -0,0 +1,66 @@
+// Copyright 2022, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Memory layout.
+
+use crate::linker;
+use core::ops::Range;
+use core::ptr::addr_of;
+
+/// Memory reserved for the DTB.
+pub fn dtb_range() -> Range<usize> {
+ unsafe { (addr_of!(linker::dtb_begin) as usize)..(addr_of!(linker::dtb_end) as usize) }
+}
+
+/// Executable code.
+pub fn text_range() -> Range<usize> {
+ unsafe { (addr_of!(linker::text_begin) as usize)..(addr_of!(linker::text_end) as usize) }
+}
+
+/// Read-only data.
+pub fn rodata_range() -> Range<usize> {
+ unsafe { (addr_of!(linker::rodata_begin) as usize)..(addr_of!(linker::rodata_end) as usize) }
+}
+
+/// Initialised writable data.
+pub fn data_range() -> Range<usize> {
+ unsafe { (addr_of!(linker::data_begin) as usize)..(addr_of!(linker::data_end) as usize) }
+}
+
+/// Zero-initialised writable data.
+pub fn bss_range() -> Range<usize> {
+ unsafe { (addr_of!(linker::bss_begin) as usize)..(addr_of!(linker::bss_end) as usize) }
+}
+
+/// Writable data region for the stack.
+pub fn boot_stack_range() -> Range<usize> {
+ unsafe {
+ (addr_of!(linker::boot_stack_begin) as usize)..(addr_of!(linker::boot_stack_end) as usize)
+ }
+}
+
+/// Writable data, including the stack.
+pub fn writable_region() -> Range<usize> {
+ data_range().start..boot_stack_range().end
+}
+
+/// Read-write data (original).
+pub fn data_load_address() -> usize {
+ unsafe { addr_of!(linker::data_lma) as usize }
+}
+
+/// End of the binary image.
+pub fn binary_end() -> usize {
+ unsafe { addr_of!(linker::bin_end) as usize }
+}
diff --git a/vmbase/src/lib.rs b/vmbase/src/lib.rs
index 9c9417a..a012442 100644
--- a/vmbase/src/lib.rs
+++ b/vmbase/src/lib.rs
@@ -18,6 +18,8 @@
pub mod console;
mod entry;
+pub mod layout;
+mod linker;
pub mod logger;
pub mod power;
pub mod uart;
@@ -31,6 +33,9 @@
reboot()
}
+/// Reference to __stack_chk_guard.
+pub static STACK_CHK_GUARD: &u64 = unsafe { &linker::__stack_chk_guard };
+
#[no_mangle]
extern "C" fn __stack_chk_fail() -> ! {
panic!("stack guard check failed");
diff --git a/vmbase/src/linker.rs b/vmbase/src/linker.rs
new file mode 100644
index 0000000..f4baae8
--- /dev/null
+++ b/vmbase/src/linker.rs
@@ -0,0 +1,48 @@
+// Copyright 2022, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Linker-defined symbols.
+
+extern "C" {
+ /// Stack canary value
+ pub static __stack_chk_guard: u64;
+ /// First byte beyond the pre-loaded binary.
+ pub static bin_end: u8;
+ /// First byte of the `.stack` section.
+ pub static boot_stack_begin: u8;
+ /// First byte beyond the `.stack` section.
+ pub static boot_stack_end: u8;
+ /// First byte of the `.bss` section.
+ pub static bss_begin: u8;
+ /// First byte beyond the `.bss` section.
+ pub static bss_end: u8;
+ /// First byte of the (loaded) `.data` section.
+ pub static data_begin: u8;
+ /// First byte beyond the (loaded) `.data` section.
+ pub static data_end: u8;
+ /// First byte of the pre-loaded `.data` section.
+ pub static data_lma: u8;
+ /// First byte of the `.dtb` section.
+ pub static dtb_begin: u8;
+ /// First byte beyond the `.dtb` section.
+ pub static dtb_end: u8;
+ /// First byte of the `.rodata` section.
+ pub static rodata_begin: u8;
+ /// First byte beyond the `.rodata` section.
+ pub static rodata_end: u8;
+ /// First byte of the `.text` section.
+ pub static text_begin: u8;
+ /// First byte beyond the `.text` section.
+ pub static text_end: u8;
+}