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memmod: register exception handler tables

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Otherwise recent WDK binaries fail on ARM64, where an exception handler
is used for trapping an illegal instruction when ARMv8.1 atomics are
being tested for functionality.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2021-08-05 14:56:48 +02:00
parent bad6caeb82
commit 3957e9b9dd
2 changed files with 19 additions and 0 deletions
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13
tun/wintun/memmod/memmod_windows.go
View file

@ -159,6 +159,16 @@ func (module *Module) finalizeSection(sectionData *sectionFinalizeData) error {
return nil
}
var rtlAddFunctionTable = windows.NewLazySystemDLL("ntdll.dll").NewProc("RtlAddFunctionTable")
func (module *Module) registerExceptionHandlers() {
directory := module.headerDirectory(IMAGE_DIRECTORY_ENTRY_EXCEPTION)
if directory.Size == 0 || directory.VirtualAddress == 0 {
return
}
rtlAddFunctionTable.Call(module.codeBase+uintptr(directory.VirtualAddress), uintptr(directory.Size)/unsafe.Sizeof(IMAGE_RUNTIME_FUNCTION_ENTRY{}), module.codeBase)
}
func (module *Module) finalizeSections() error {
sections := module.headers.Sections()
imageOffset := module.headers.OptionalHeader.imageOffset()
@ -500,6 +510,9 @@ func LoadLibrary(data []byte) (module *Module, err error) {
return
}
// Register exception tables, if they exist.
module.registerExceptionHandlers()
// TLS callbacks are executed BEFORE the main loading.
module.executeTLS()

6
tun/wintun/memmod/syscall_windows.go
View file

@ -370,6 +370,12 @@ const (
IMAGE_GUARD_CF_FUNCTION_TABLE_SIZE_SHIFT = 28
)
type IMAGE_RUNTIME_FUNCTION_ENTRY struct {
BeginAddress uint32
EndAddress uint32
UnwindInfoAddress uint32
}
const (
DLL_PROCESS_ATTACH = 1
DLL_THREAD_ATTACH = 2