[PATCH v3 0/2] MR4793: ntdll/tests: Restore x86-64 #AC exception test in test_exceptions().

[Jinoh Kang (＠iamahuman)]

The old code did memory-indirect jmp with a misaligned operand address.

--
  v3: ntdll/tests: Restore x86-64 #AC exception test in test_exceptions().

https://gitlab.winehq.org/wine/wine/-/merge_requests/4793

[PATCH v3 1/2] ntdll/tests: Avoid misaligned load in exception handler code in run_exception_test_flags().

[Jinoh Kang]

From: Jinoh Kang

This is required for testing EH behavior on alignment check (#AC)
exceptions.
---
 dlls/ntdll/tests/exception.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/dlls/ntdll/tests/exception.c b/dlls/ntdll/tests/exception.c
index bac571b2733..87bee9d8e93 100644
--- a/dlls/ntdll/tests/exception.c
+++ b/dlls/ntdll/tests/exception.c
@@ -3193,7 +3193,7 @@ static void run_exception_test_flags(void *handler, const void* context,
                                const void *code, unsigned int code_size,
                                DWORD access, DWORD handler_flags)
 {
-    unsigned char buf[8 + 6 + 8 + 8];
+    unsigned char buf[2 + 8 + 2 + 8 + 8];
     RUNTIME_FUNCTION runtime_func;
     UNWIND_INFO *unwind = (UNWIND_INFO *)buf;
     void (*func)(void) = code_mem;
@@ -3212,11 +3212,13 @@ static void run_exception_test_flags(void *handler, const void* context,
     *(ULONG *)&buf[4] = 0x1010;
     *(const void **)&buf[8] = context;

-    /* jmp near */
-    buf[16] = 0xff;
-    buf[17] = 0x25;
-    *(ULONG *)&buf[18] = 0;
-    *(void **)&buf[22] = handler;
+    /* movabs $<handler>, %rax */
+    buf[16] = 0x48;
+    buf[17] = 0xb8;
+    *(void **)&buf[18] = handler;
+    /* jmp *%rax */
+    buf[26] = 0xff;
+    buf[27] = 0xe0;

memcpy((unsigned char *)code_mem + 0x1000, buf, sizeof(buf));
     memcpy(code_mem, code, code_size);

[PATCH v3 2/2] ntdll/tests: Restore x86-64 #AC exception test in test_exceptions().

[Jinoh Kang]

From: Jinoh Kang

---
 dlls/ntdll/tests/exception.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/dlls/ntdll/tests/exception.c b/dlls/ntdll/tests/exception.c
index 87bee9d8e93..4f9e0b51519 100644
--- a/dlls/ntdll/tests/exception.c
+++ b/dlls/ntdll/tests/exception.c
@@ -3439,8 +3439,13 @@ static DWORD WINAPI align_check_handler( EXCEPTION_RECORD *rec, ULONG64 frame,
 #ifdef __GNUC__
     __asm__ volatile( "pushfq; andl $~0x40000,(%rsp); popfq" );
 #endif
-    ok (!(context->EFlags & 0x40000), "eflags has AC bit set\n");
+    ok (!!(context->EFlags & 0x40000), "eflags has AC bit unset\n");
     got_exception++;
+    if (got_exception != 1)
+    {
+        ok(broken(1) /* win7 */, "exception should occur only once");
+        context->EFlags &= ~0x40000;
+    }
     return ExceptionContinueExecution;
 }

@@ -3581,12 +3586,10 @@ static void test_exceptions(void)
     ok(got_exception == 3, "expected 3 single step exceptions, got %d\n", got_exception);

/* test alignment exceptions */
-    if (0)  /* broken on Windows */
-    {
     got_exception = 0;
     run_exception_test(align_check_handler, NULL, align_check_code, sizeof(align_check_code), 0);
-    ok(got_exception == 0, "got %d alignment faults, expected 0\n", got_exception);
-    }
+    todo_wine
+    ok(got_exception == 1 || broken(got_exception == 2) /* win7 */, "got %d alignment faults, expected 1\n", got_exception);

/* test direction flag */
     got_exception = 0;