codegen: fix i686-unknown-linux-gnu

boj-rs · Dec 14, 2024 · 14cb9e3 · 14cb9e3
1 parent f2557bb
commit 14cb9e3
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Showing 2 changed files with 14 additions and 29 deletions.
diff --git a/basm-std/src/platform/codegen.rs b/basm-std/src/platform/codegen.rs
@@ -182,23 +182,14 @@ pub unsafe extern "win64" fn _basm_start() -> ! {
 }
 
 #[cfg(target_arch = "x86")]
-#[unsafe(no_mangle)]
-#[naked]
-#[unsafe(link_section = ".data")]
-unsafe extern "cdecl" fn _get_start_offset() -> ! {
-    unsafe {
-        naked_asm!("lea    eax, [_basm_start]", "ret");
-    }
+extern "cdecl" fn _get_start_offset() -> u32 {
+    _basm_start as u32
 }
 
 #[cfg(target_arch = "x86")]
-#[unsafe(no_mangle)]
-#[naked]
-#[unsafe(link_section = ".data")]
-unsafe extern "cdecl" fn _get_dynamic_section_offset() -> ! {
-    unsafe {
-        naked_asm!("lea    eax, [_DYNAMIC]", "ret");
-    }
+extern "cdecl" fn _get_dynamic_section_offset() -> u32 {
+    unsafe extern "C" { fn _DYNAMIC(); }
+    _DYNAMIC as u32
 }
 
 #[cfg(target_arch = "x86")]
@@ -227,17 +218,17 @@ pub unsafe extern "cdecl" fn _basm_start() -> ! {
             "3:",
             "call   4f",
             "4:",
-            "pop    ecx",                       // ecx = _basm_start + 36 (obtained by counting the opcode size in bytes)
-            "push   edx",                       // [esp + 0] = PLATFORM_DATA table
+            "pop    ebx",                       // ebx = _basm_start + 36 (obtained by counting the opcode size in bytes)
+            "push   edx",                       // [esp + 0] = PLATFORM_DATA table, stack is aligned
             "call   {2}",                       // eax = offset of _basm_start from the image base
-            "sub    ecx, eax",
-            "sub    ecx, 36",                   // ecx = the in-memory image base (i.e., __ehdr_start)
+            "sub    ebx, eax",
+            "sub    ebx, 36",                   // ebx = the in-memory image base (i.e., __ehdr_start)
             "call   {3}",                       // eax = offset of _DYNAMIC table from the image base
-            "add    eax, ecx",                  // eax = _DYNAMIC table
+            "lea    esi, [ebx + eax]",          // esi = _DYNAMIC table
             "sub    esp, 8",                    // For stack alignment
-            "push   eax",
-            "push   ecx",
-            "call   {0}",
+            "push   esi",
+            "push   ebx",
+            "call   {0}",                       // call loader::i686_elf::relocate
             "add    esp, 16",
             "call   {1}",
             "mov    esp, ebp",

diff --git a/basm/build.rs b/basm/build.rs
@@ -63,13 +63,7 @@ fn main() {
             link_args_basm.push("-fno-unwind-tables");
             link_args_basm.push("-fno-stack-protector");
             link_args_basm.push("-fno-plt");
-            if target == "i686-unknown-linux-gnu" {
-                // Prevent linker from putting data into text, which is non-writable and hence not relocatable.
-                // This prevents the hack for getting the _DYNAMIC symbol in the entrypoint.
-                link_args_basm.push("-Wl,--entry=_basm_start,--build-id=none,--gc-sections,--export-dynamic,--no-eh-frame-hdr,-z,norelro,-z,notext");
-            } else {
-                link_args_basm.push("-Wl,--entry=_basm_start,--build-id=none,--gc-sections,--export-dynamic,--no-eh-frame-hdr,-z,norelro");
-            }
+            link_args_basm.push("-Wl,--entry=_basm_start,--build-id=none,--gc-sections,--export-dynamic,--no-eh-frame-hdr,-z,norelro");
             link_args_basm_submit.push("-Wl,-z,max-page-size=128");
         }
         "aarch64-apple-darwin" => {