[PATCH 0/2] MR1576: ntdll: Get TEB from signal stack pointer in init_handler.

[PATCH 1/2] ntdll: Get TEB from signal stack pointer in init_handler.

[Jacek Caban]

From: Jacek Caban

We can't use NtCurrentTeb before setting %fs base.
---
 dlls/ntdll/unix/signal_x86_64.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/dlls/ntdll/unix/signal_x86_64.c b/dlls/ntdll/unix/signal_x86_64.c
index cc070dda5ae..8541dc9ccaf 100644
--- a/dlls/ntdll/unix/signal_x86_64.c
+++ b/dlls/ntdll/unix/signal_x86_64.c
@@ -440,6 +440,13 @@ static inline struct amd64_thread_data *amd64_thread_data(void)
     return (struct amd64_thread_data *)ntdll_get_thread_data()->cpu_data;
 }

+static inline TEB *get_current_teb(void)
+{
+    unsigned long rsp;
+    __asm__( "movq %%rsp,%0" : "=r" (rsp) );
+    return (TEB *)(rsp & ~signal_stack_mask);
+}
+
 static BOOL is_inside_syscall( const ucontext_t *sigcontext )
 {
     return ((char *)RSP_sig(sigcontext) >= (char *)ntdll_get_thread_data()->kernel_stack &&
@@ -806,7 +813,11 @@ static inline void set_sigcontext( const CONTEXT *context, ucontext_t *sigcontex
 static inline void init_handler( const ucontext_t *sigcontext )
 {
 #ifdef __linux__
-    if (fs32_sel) arch_prctl( ARCH_SET_FS, amd64_thread_data()->pthread_teb );
+    if (fs32_sel)
+    {
+        struct ntdll_thread_data *thread_data = (struct ntdll_thread_data *)&get_current_teb()->GdiTebBatch;
+        arch_prctl( ARCH_SET_FS, ((struct amd64_thread_data *)thread_data->cpu_data)->pthread_teb );
+    }
 #endif
 }

[PATCH 2/2] ntdll: Call init_handler in usr1_handler.

[Jacek Caban]

From: Jacek Caban

It's needed before is_inside_syscall accesses TEB.
---
 dlls/ntdll/unix/signal_x86_64.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/dlls/ntdll/unix/signal_x86_64.c b/dlls/ntdll/unix/signal_x86_64.c
index 8541dc9ccaf..e22654f6d29 100644
--- a/dlls/ntdll/unix/signal_x86_64.c
+++ b/dlls/ntdll/unix/signal_x86_64.c
@@ -2158,6 +2158,7 @@ static void usr1_handler( int signal, siginfo_t *siginfo, void *ucontext )
 {
     struct xcontext context;

+    init_handler( ucontext );
     if (is_inside_syscall( ucontext ))
     {
         DECLSPEC_ALIGN(64) XSTATE xs;