• Tony Breeds's avatar
    powerpc: Work around gcc's -fno-omit-frame-pointer bug · 7563dc64
    Tony Breeds authored
    This bug is causing random crashes
    (http://bugzilla.kernel.org/show_bug.cgi?id=11414).
    
    -fno-omit-frame-pointer is only needed on powerpc when -pg is also
    supplied, and there is a gcc bug that causes incorrect code generation
    on 32-bit powerpc when -fno-omit-frame-pointer is used---it uses stack
    locations below the stack pointer, which is not allowed by the ABI
    because those locations can and sometimes do get corrupted by an
    interrupt.
    
    This ensures that CONFIG_FRAME_POINTER is only selected by ftrace.
    When CONFIG_FTRACE is enabled we also pass -mno-sched-epilog to work
    around the gcc codegen bug.
    
    Patch based on work by:
    	Andreas Schwab <schwab@suse.de>
    	Segher Boessenkool <segher@kernel.crashing.org>
    Signed-off-by: default avatarTony Breeds <tony@bakeyournoodle.com>
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    7563dc64
Makefile 7.35 KB