gdb/arm-linux-tdep.c: Handle Thumb2 signal trampolines

Recent versions of glibc have assembled the signal trampoline code
as Thumb2, which causes gdb to misinterpret them and a number of
testsuite tests to fail. Educate gdb about these trampolines and
get the tests running again.

gdb/ChangeLog:

2014-07-28  Will Newton  <will.newton@linaro.org>

	* arm-linux-tdep.c (THUMB2_SET_R7_SIGRETURN1): New define.
	(THUMB2_SET_R7_SIGRETURN2): Likewise.
	(THUMB2_SET_R7_RT_SIGRETURN1): Likewise.
	(THUMB2_SET_R7_RT_SIGRETURN2): Likewise.
	(THUMB2_EABI_SYSCALL): Likewise.
	(thumb2_eabi_linux_sigreturn_tramp_frame): Create new
	struct tramp_frame.
	(thumb2_eabi_linux_rt_sigreturn_tramp_frame): Likewise.
	(arm_linux_init_abi): Add Thumb2 tramp frame unwinders.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0ee72df..0b80869 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,15 @@
+2014-07-28  Will Newton  <will.newton@linaro.org>
+
+       * arm-linux-tdep.c (THUMB2_SET_R7_SIGRETURN1): New define.
+       (THUMB2_SET_R7_SIGRETURN2): Likewise.
+       (THUMB2_SET_R7_RT_SIGRETURN1): Likewise.
+       (THUMB2_SET_R7_RT_SIGRETURN2): Likewise.
+       (THUMB2_EABI_SYSCALL): Likewise.
+       (thumb2_eabi_linux_sigreturn_tramp_frame): Create new
+       struct tramp_frame.
+       (thumb2_eabi_linux_rt_sigreturn_tramp_frame): Likewise.
+       (arm_linux_init_abi): Add Thumb2 tramp frame unwinders.
+
 2014-07-27  Doug Evans  <xdje42@gmail.com>
 
        * guile/scm-param.c (pascm_print_param_smob): Fix output.

diff --git a/gdb/arm-linux-tdep.c b/gdb/arm-linux-tdep.c
index a96ea3f..4e17abd 100644 (file)
--- a/gdb/arm-linux-tdep.c
+++ b/gdb/arm-linux-tdep.c
@@ -246,6 +246,13 @@ static const gdb_byte arm_linux_thumb2_le_breakpoint[] = { 0xf0, 0xf7, 0x00, 0xa
 #define ARM_SET_R7_RT_SIGRETURN                0xe3a070ad
 #define ARM_EABI_SYSCALL               0xef000000
 
+/* Equivalent patterns for Thumb2.  */
+#define THUMB2_SET_R7_SIGRETURN1       0xf04f
+#define THUMB2_SET_R7_SIGRETURN2       0x0777
+#define THUMB2_SET_R7_RT_SIGRETURN1    0xf04f
+#define THUMB2_SET_R7_RT_SIGRETURN2    0x07ad
+#define THUMB2_EABI_SYSCALL            0xdf00
+
 /* OABI syscall restart trampoline, used for EABI executables too
    whenever OABI support has been enabled in the kernel.  */
 #define ARM_OABI_SYSCALL_RESTART_SYSCALL 0xef900000
@@ -444,6 +451,30 @@ static struct tramp_frame arm_eabi_linux_rt_sigreturn_tramp_frame = {
   arm_linux_rt_sigreturn_init
 };
 
+static struct tramp_frame thumb2_eabi_linux_sigreturn_tramp_frame = {
+  SIGTRAMP_FRAME,
+  2,
+  {
+    { THUMB2_SET_R7_SIGRETURN1, -1 },
+    { THUMB2_SET_R7_SIGRETURN2, -1 },
+    { THUMB2_EABI_SYSCALL, -1 },
+    { TRAMP_SENTINEL_INSN }
+  },
+  arm_linux_sigreturn_init
+};
+
+static struct tramp_frame thumb2_eabi_linux_rt_sigreturn_tramp_frame = {
+  SIGTRAMP_FRAME,
+  2,
+  {
+    { THUMB2_SET_R7_RT_SIGRETURN1, -1 },
+    { THUMB2_SET_R7_RT_SIGRETURN2, -1 },
+    { THUMB2_EABI_SYSCALL, -1 },
+    { TRAMP_SENTINEL_INSN }
+  },
+  arm_linux_rt_sigreturn_init
+};
+
 static struct tramp_frame arm_linux_restart_syscall_tramp_frame = {
   NORMAL_FRAME,
   4,
@@ -1416,6 +1447,10 @@ arm_linux_init_abi (struct gdbarch_info info,
   tramp_frame_prepend_unwinder (gdbarch,
                                &arm_eabi_linux_rt_sigreturn_tramp_frame);
   tramp_frame_prepend_unwinder (gdbarch,
+                               &thumb2_eabi_linux_sigreturn_tramp_frame);
+  tramp_frame_prepend_unwinder (gdbarch,
+                               &thumb2_eabi_linux_rt_sigreturn_tramp_frame);
+  tramp_frame_prepend_unwinder (gdbarch,
                                &arm_linux_restart_syscall_tramp_frame);
   tramp_frame_prepend_unwinder (gdbarch,
                                &arm_kernel_linux_restart_syscall_tramp_frame);