On 2/26/2016 9:26 AM, Corinna Vinschen wrote:
> On Feb 26 04:54, Joel Sherrill wrote:
>>
>>
>> On 2/26/2016 4:44 AM, Corinna Vinschen wrote:
>>> On Feb 25 14:44, Joel Sherrill wrote:
>>>> When running RTEMS paravirtualized in user space, the cli/sti instructions
>>>> can't be used. But I can't see why they are needed in either user or
>>>> supervisor state. Turning the use of them off for RTEMS.
>>>>
>>>> This code is unmodified since the beginning of the repository, so I have
>>>> no insight into why it was done. I may even have been the one to add them.
>>>> Absolutely no idea except they aren't necessary.
>>>>
>>>> ---
>>>> newlib/configure.host | 2 ++
>>>> 1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/newlib/configure.host b/newlib/configure.host
>>>> index 5fa37d4..f6abb5c 100644
>>>> --- a/newlib/configure.host
>>>> +++ b/newlib/configure.host
>>>> @@ -592,6 +592,8 @@ case "${host}" in
>>>> newlib_cflags="${newlib_cflags} -DMALLOC_PROVIDED -DEXIT_PROVIDED -DSIGNAL_PROVIDED -DREENTRANT_SYSCALLS_PROVIDED -DHAVE_NANOSLEEP -DHAVE_BLKSIZE -DHAVE_FCNTL -DHAVE_ASSERT_FUNC"
>>>> # turn off unsupported items in posix directory
>>>> newlib_cflags="${newlib_cflags} -D_NO_GETLOGIN -D_NO_GETPWENT -D_NO_GETUT -D_NO_GETPASS -D_NO_SIGSET -D_NO_WORDEXP -D_NO_POPEN -D_NO_POSIX_SPAWN"
>>>> + # turn off using cli/sti in i386 setjmp/longjmp
>>>> + newlib_cflags="${newlib_cflags} -D_I386MACH_ALLOW_HW_INTERRUPTS"
>>>> ;;
>>>> # VxWorks supplies its own version of malloc, and the newlib one
>>>> # doesn't work because VxWorks does not have sbrk.
>>>
>>> Patch is ok, please apply.
>>>
>>> Would it make sense to enable _I386MACH_ALLOW_HW_INTERRUPTS by default
>>> on x86/x86_64?
>>
>> I can't see any downside. I spot checked other ports and no other port seemed to have comparable code. I would be OK with that. Where is it defaulted?
>
> I thought changing the definition from _I386MACH_ALLOW_HW_INTERRUPTS to,
> e.g, _I386MACH_DISABLE_HW_INTERRUPTS wouldn't hurt, as in the patch
> below.
>
> However, we might have to make sure how to handle explicitly mentioned
> ix86 systems (rdos, sco, netware). I know basically nothing about
> these.
I don't know about rdos but sco and netware would be running setjmp/longjmp
in user space and thus not be able to us the instructions.
Seems as though they would have complained if there were any users. :)
>> Also FWIW, I would like to see this resolved before the next newlib snapshot
>> so the RTEMS tools can include this. We are due for a tool update and I don't
>> want to impact users too much in a single month. :)
>
> For that it's probably better just to apply your patch as is for now.
OK. I will push it.
I am also happy with the intent to switch it off across the board.
>
> Corinna
>
>
> diff --git a/newlib/configure.host b/newlib/configure.host
> index 5fa37d4..9054230 100644
> --- a/newlib/configure.host
> +++ b/newlib/configure.host
> @@ -469,7 +469,6 @@ case "${host}" in
> default_newlib_io_pos_args="yes"
> #newlib_cflags="${newlib_cflags} -Werror" # DEBUGGING ONLY;BREAKS BUILD
> newlib_cflags="${newlib_cflags} -Wall"
> - newlib_cflags="${newlib_cflags} -D_I386MACH_ALLOW_HW_INTERRUPTS"
> newlib_cflags="${newlib_cflags} -DHAVE_FCNTL"
> newlib_cflags="${newlib_cflags} -DHAVE_GETOPT"
> newlib_cflags="${newlib_cflags} -D_NO_POSIX_SPAWN"
> diff --git a/newlib/libc/machine/i386/i386mach.h b/newlib/libc/machine/i386/i386mach.h
> index 23c3219..403d24b 100644
> --- a/newlib/libc/machine/i386/i386mach.h
> +++ b/newlib/libc/machine/i386/i386mach.h
> @@ -74,7 +74,7 @@
> #define SOTYPE_FUNCTION(sym)
> #endif
>
> -#ifdef _I386MACH_ALLOW_HW_INTERRUPTS
> +#ifndef _I386MACH_DISABLE_HW_INTERRUPTS
> #define __CLI
> #define __STI
> #else
> diff --git a/newlib/libc/machine/x86_64/x86_64mach.h b/newlib/libc/machine/x86_64/x86_64mach.h
> index 84cb2f8..05e6392 100644
> --- a/newlib/libc/machine/x86_64/x86_64mach.h
> +++ b/newlib/libc/machine/x86_64/x86_64mach.h
> @@ -104,7 +104,7 @@
> #define SOTYPE_FUNCTION(sym)
> #endif
>
> -#ifdef _I386MACH_ALLOW_HW_INTERRUPTS
> +#ifndef _I386MACH_DISABLE_HW_INTERRUPTS
> #define __CLI
> #define __STI
> #else
> diff --git a/newlib/libc/sys/linux/machine/i386/i386mach.h b/newlib/libc/sys/linux/machine/i386/i386mach.h
> index 23c3219..403d24b 100644
> --- a/newlib/libc/sys/linux/machine/i386/i386mach.h
> +++ b/newlib/libc/sys/linux/machine/i386/i386mach.h
> @@ -74,7 +74,7 @@
> #define SOTYPE_FUNCTION(sym)
> #endif
>
> -#ifdef _I386MACH_ALLOW_HW_INTERRUPTS
> +#ifndef _I386MACH_DISABLE_HW_INTERRUPTS
> #define __CLI
> #define __STI
> #else
> diff --git a/newlib/libm/machine/i386/i386mach.h b/newlib/libm/machine/i386/i386mach.h
> index 23c3219..403d24b 100644
> --- a/newlib/libm/machine/i386/i386mach.h
> +++ b/newlib/libm/machine/i386/i386mach.h
> @@ -74,7 +74,7 @@
> #define SOTYPE_FUNCTION(sym)
> #endif
>
> -#ifdef _I386MACH_ALLOW_HW_INTERRUPTS
> +#ifndef _I386MACH_DISABLE_HW_INTERRUPTS
> #define __CLI
> #define __STI
> #else
>
>
--
Joel Sherrill, Ph.D. Director of Research & Development
joel.sherrill@OARcorp.com On-Line Applications Research
Ask me about RTEMS: a free RTOS Huntsville AL 35806
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