[PATCH v10 2/4] ntdll: Avoid calling abort_thread from the signal stack.

[Rémi Bernon]

From: Rémi Bernon

---
 dlls/ntdll/unix/signal_arm.c    |  8 +++++++-
 dlls/ntdll/unix/signal_arm64.c  |  8 +++++++-
 dlls/ntdll/unix/signal_i386.c   | 12 ++++++++++--
 dlls/ntdll/unix/signal_x86_64.c | 15 ++++++++++++---
 4 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/dlls/ntdll/unix/signal_arm.c b/dlls/ntdll/unix/signal_arm.c
index 1fc52632147..b15beba672b 100644
--- a/dlls/ntdll/unix/signal_arm.c
+++ b/dlls/ntdll/unix/signal_arm.c
@@ -1471,7 +1471,13 @@ static void abrt_handler( int signal, siginfo_t *siginfo, void *sigcontext )
  */
 static void quit_handler( int signal, siginfo_t *siginfo, void *sigcontext )
 {
-    abort_thread(0);
+    UINT_PTR *stack = (void *)SP_sig(sigcontext);
+
+    if (!is_inside_syscall( stack )) stack = (void *)arm_thread_data()->syscall_frame;
+
+    SP_sig(sigcontext)      = stack;
+    REGn_sig(0, sigcontext) = 0;
+    PC_sig(sigcontext)      = (ULONG_PTR)abort_thread;
 }

diff --git a/dlls/ntdll/unix/signal_arm64.c b/dlls/ntdll/unix/signal_arm64.c
index 813853cdf70..c1c8419a51f 100644
--- a/dlls/ntdll/unix/signal_arm64.c
+++ b/dlls/ntdll/unix/signal_arm64.c
@@ -1443,7 +1443,13 @@ static void abrt_handler( int signal, siginfo_t *siginfo, void *sigcontext )
  */
 static void quit_handler( int signal, siginfo_t *siginfo, void *sigcontext )
 {
-    abort_thread(0);
+    UINT_PTR *stack = (void *)SP_sig(sigcontext);
+
+    if (!is_inside_syscall( stack )) stack = (void *)arm64_thread_data()->syscall_frame;
+
+    SP_sig(sigcontext)      = stack;
+    REGn_sig(0, sigcontext) = 0;
+    PC_sig(sigcontext)      = (ULONG_PTR)abort_thread;
 }

diff --git a/dlls/ntdll/unix/signal_i386.c b/dlls/ntdll/unix/signal_i386.c
index f0847913da0..a380c231d2f 100644
--- a/dlls/ntdll/unix/signal_i386.c
+++ b/dlls/ntdll/unix/signal_i386.c
@@ -2065,8 +2065,16 @@ static void abrt_handler( int signal, siginfo_t *siginfo, void *sigcontext )
  */
 static void quit_handler( int signal, siginfo_t *siginfo, void *sigcontext )
 {
-    init_handler( sigcontext );
-    abort_thread(0);
+    ucontext_t *ucontext = init_handler( sigcontext );
+    UINT_PTR *stack = (void *)ESP_sig(ucontext);
+
+    if (!is_inside_syscall( stack )) stack = (void *)x86_thread_data()->syscall_frame;
+
+    *(--stack) = 0;
+    *(--stack) = 0;
+    *(--stack) = 0xdeadbabe;  /* return address */
+    ESP_sig(ucontext) = (DWORD)stack;
+    EIP_sig(ucontext) = (DWORD)abort_thread;
 }

diff --git a/dlls/ntdll/unix/signal_x86_64.c b/dlls/ntdll/unix/signal_x86_64.c
index 4453039208e..975a98c109f 100644
--- a/dlls/ntdll/unix/signal_x86_64.c
+++ b/dlls/ntdll/unix/signal_x86_64.c
@@ -2172,10 +2172,19 @@ static void abrt_handler( int signal, siginfo_t *siginfo, void *sigcontext )
  *
  * Handler for SIGQUIT.
  */
-static void quit_handler( int signal, siginfo_t *siginfo, void *ucontext )
+static void quit_handler( int signal, siginfo_t *siginfo, void *sigcontext )
 {
-    init_handler( ucontext );
-    abort_thread(0);
+    ucontext_t *ucontext = init_handler( sigcontext );
+    UINT_PTR *stack = (void *)RSP_sig(ucontext);
+
+    if (!is_inside_syscall( stack )) stack = (void *)amd64_thread_data()->syscall_frame;
+
+    *(--stack) = 0xdeadbabe;  /* return address */
+    RDI_sig(ucontext) = 0;
+    RSP_sig(ucontext) = (UINT_PTR)stack;
+    RIP_sig(ucontext) = (UINT_PTR)abort_thread;
+
+    leave_handler( sigcontext );
 }