Attempt to load jit frames

Author: alexcrichton

src/backtrace/dbghelp.rs

@@ -93,6 +93,32 @@ pub unsafe fn trace(cb: &mut FnMut(&super::Frame) -> bool) {
         Err(()) => return, // oh well...
     };
 
+    // On x86_64 (and probably ARM64? need to verify at some point) we opt to
+    // not use the default `Sym*` functions from dbghelp for getting the
+    // function table and module base. Instead we use the
+    // `RtlLookupFunctionEntry` function in kernel32 which will account for JIT
+    // compiler frames as well. These should be equivalent, but using `Rtl*`
+    // allows us to backtrace through JIT frames.
+    cfg_if::cfg_if! {
+        if #[cfg(target_arch = "x86_64")] {
+            use core::ptr;
+
+            unsafe extern "system" fn function_table_access(_process: HANDLE, addr: DWORD64) -> PVOID {
+                let mut base = 0;
+                RtlLookupFunctionEntry(addr, &mut base, ptr::null_mut()).cast()
+            }
+
+            unsafe extern "system" fn get_module_base(_process: HANDLE, addr: DWORD64) -> DWORD64 {
+                let mut base = 0;
+                RtlLookupFunctionEntry(addr, &mut base, ptr::null_mut());
+                base
+            }
+        } else {
+            let function_table_access = dbghelp.SymFunctionTableAccess64();
+            let get_module_base = dbghelp.SymGetModuleBase64();
+        }
+    }
+
     // Attempt to use `StackWalkEx` if we can, but fall back to `StackWalk64`
     // since it's in theory supported on more systems.
     match (*dbghelp.dbghelp()).StackWalkEx() {
@@ -113,8 +139,8 @@ pub unsafe fn trace(cb: &mut FnMut(&super::Frame) -> bool) {
                 frame_ptr,
                 &mut context.0 as *mut CONTEXT as *mut _,
                 None,
-                Some(dbghelp.SymFunctionTableAccess64()),
-                Some(dbghelp.SymGetModuleBase64()),
+                Some(function_table_access),
+                Some(get_module_base),
                 None,
                 0,
             ) == TRUE
@@ -141,8 +167,8 @@ pub unsafe fn trace(cb: &mut FnMut(&super::Frame) -> bool) {
                 frame_ptr,
                 &mut context.0 as *mut CONTEXT as *mut _,
                 None,
-                Some(dbghelp.SymFunctionTableAccess64()),
-                Some(dbghelp.SymGetModuleBase64()),
+                Some(function_table_access),
+                Some(get_module_base),
                 None,
             ) == TRUE
             {

src/windows.rs

@@ -35,6 +35,8 @@ cfg_if::cfg_if! {
         pub type HINSTANCE = *mut c_void;
         pub type FARPROC = *mut c_void;
         pub type LPSECURITY_ATTRIBUTES = *mut c_void;
+        pub type PRUNTIME_FUNCTION = *mut c_void;
+        pub type PUNWIND_HISTORY_TABLE = *mut c_void;
     }
 }
 
@@ -152,9 +154,12 @@ macro_rules! ffi {
         ffi!($($rest)*);
     );
 
-    (extern "system" { $(pub fn $name:ident($($args:tt)*) -> $ret:ty;)* } $($rest:tt)*) => (
+    (extern "system" { $($(#[$attr:meta])* pub fn $name:ident($($args:tt)*) -> $ret:ty;)* } $($rest:tt)*) => (
         extern "system" {
-            $(pub fn $name($($args)*) -> $ret;)*
+            $(
+                $(#[$attr])*
+                pub fn $name($($args)*) -> $ret;
+            )*
         }
 
         $(
@@ -371,6 +376,12 @@ ffi! {
             dwMilliseconds: DWORD,
             bAlertable: BOOL,
         ) -> DWORD;
+        #[cfg(target_arch = "x86_64")]
+        pub fn RtlLookupFunctionEntry(
+            ControlPc: DWORD64,
+            ImageBase: PDWORD64,
+            HistoryTable: PUNWIND_HISTORY_TABLE,
+        ) -> PRUNTIME_FUNCTION;
     }
 }