[llvmlinux] [PATCH v2 for-3.10] tracing: x86: Mark TRACING_SUPPORT as BROKEN

Sedat Dilek sedat.dilek at gmail.com
Fri Jul 26 11:27:29 UTC 2013


On Fri, Jul 26, 2013 at 1:21 PM, Sedat Dilek <sedat.dilek at gmail.com> wrote:
> On Fri, Jul 26, 2013 at 1:18 PM, Jan-Simon Möller <dl9pf at gmx.de> wrote:
>> Considering it as local workaround.
>
> So, you can build w/ tracing-support enabled?
> Can you do some real tracing?
> Can you provide some logs and kernel-configs, please?
> What about other arches supported by llvmlinux?
> I am really interested in that!
>

Especially these kernel-config options on x86_64 arch:

CONFIG_KPROBES_ON_FTRACE=y
CONFIG_FTRACE=y <--- !!!
CONFIG_FUNCTION_TRACER=y <--- !!!
CONFIG_FTRACE_SYSCALLS=y
CONFIG_DYNAMIC_FTRACE=y <--- !!!
CONFIG_DYNAMIC_FTRACE_WITH_REGS=y
CONFIG_FTRACE_MCOUNT_RECORD=y

Thanks for testing in advance.

- Sedat -

> - Sedat -
>
>> --
>>
>> Dipl.-Ing.
>> Jan-Simon Möller
>>
>> jansimon.moeller at gmx.de
>> On Friday 26 July 2013 12:30:29 Sedat Dilek wrote:
>>> The build on x86_64 breaks with tracing support enabled.
>>>
>>> For more details see this thread on llvmlinux ML:
>>> "[arch/x86/kernel/head64.c] In function `early_make_pgtable': undefined
>>> reference to `mcount'"
>>>
>>> I tested also dropping changes to ftrace.h in 0033 from arch/x86_64/patches
>>> as suggested by pageexec from PaX Team, but the build is still broken.
>>>
>>> For now, I have disabled tracing support for x86 at all.
>>> It might be a good idea to do this for all supported arches.
>>>
>>> Tested with pre-built toolchain v3.3 (AMD64) from <llvm.org> against Linux
>>> v3.10.
>>>
>>> [1]
>>> http://git.linuxfoundation.org/?p=llvmlinux.git;a=blob;f=arch/x86_64/patche
>>> s/0033-Various-fixes-in-arch-x86-include-asm.patch
>>>
>>> Cc: PaX Team <pageexec at gmail.com>
>>> Signed-off-by: Sedat Dilek <sedat.dilek at gmail.com>
>>> ---
>>>  kernel/trace/Kconfig | 1 +
>>>  1 file changed, 1 insertion(+)
>>>
>>> diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
>>> index 015f85a..8ba949b 100644
>>> --- a/kernel/trace/Kconfig
>>> +++ b/kernel/trace/Kconfig
>>> @@ -125,6 +125,7 @@ config TRACING_SUPPORT
>>>       # irqflags tracing for your architecture.
>>>       depends on TRACE_IRQFLAGS_SUPPORT || PPC32
>>>       depends on STACKTRACE_SUPPORT
>>> +     depends on BROKEN && (X86_32 || X86_64)
>>>       default y
>>>
>>>  if TRACING_SUPPORT


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