__startcontext marks the bottom of the call stack of the contexts created
by makecontext.
+2016-08-15 Andreas Schwab <schwab@suse.de>
+
+ [BZ #20435]
+ * sysdeps/unix/sysv/linux/arm/setcontext.S (__startcontext): Mark
+ as .cantunwind.
+
2016-08-12 Joseph Myers <joseph@codesourcery.com>
* sysdeps/powerpc/fpu/fsetexcptflg.c (__fesetexceptflag): Add
/* Called when a makecontext() context returns. Start the
context in R4 or fall through to exit(). */
+ /* Unwind descriptors are looked up based on PC - 2, so we have to
+ make sure to mark the instruction preceding the __startcontext
+ label as .cantunwind. */
+ .fnstart
+ .cantunwind
+ nop
ENTRY(__startcontext)
movs r0, r4
bne PLTJMP(__setcontext)
@ New context was 0 - exit
b PLTJMP(HIDDEN_JUMPTARGET(exit))
+ .fnend
END(__startcontext)
#ifdef PIC