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Re: [PATCH] newlib/configure.host: Turn off sti/cli for i386 setjmp for i386-rtems*
- From: Joel Sherrill <joel dot sherrill at oarcorp dot com>
- To: newlib at sourceware dot org
- Date: Fri, 26 Feb 2016 09:34:40 -0600
- Subject: Re: [PATCH] newlib/configure.host: Turn off sti/cli for i386 setjmp for i386-rtems*
- Authentication-results: sourceware.org; auth=none
- References: <1456433057-3036-1-git-send-email-joel at rtems dot org> <20160226104435 dot GA28180 at calimero dot vinschen dot de> <56D02ECE dot 9010303 at oarcorp dot com> <20160226152618 dot GD19219 at calimero dot vinschen dot de>
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
Support Available (256) 722-9985