* [PATCHv2 5/6] jump label: detect %c support for ARM [not found] <1327757725-10114-1-git-send-email-rabin@rab.in> @ 2012-01-28 13:35 ` Rabin Vincent 2012-02-07 16:18 ` Rabin Vincent 2012-02-20 17:21 ` Russell King - ARM Linux 0 siblings, 2 replies; 5+ messages in thread From: Rabin Vincent @ 2012-01-28 13:35 UTC (permalink / raw) To: linux-arm-kernel; +Cc: Rabin Vincent, Jason Baron, linux-kernel Some versions of ARM GCC which do support asm goto, have problems handling the the %c specifier. Since we need the %c to support jump labels on ARM, detect that too in the asm goto detection script to avoid build errors with these versions. http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637 Cc: Jason Baron <jbaron@redhat.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Rabin Vincent <rabin@rab.in> --- scripts/gcc-goto.sh | 18 +++++++++++++++++- 1 files changed, 17 insertions(+), 1 deletions(-) diff --git a/scripts/gcc-goto.sh b/scripts/gcc-goto.sh index 98cffcb..9b744de 100644 --- a/scripts/gcc-goto.sh +++ b/scripts/gcc-goto.sh @@ -2,4 +2,20 @@ # Test for gcc 'asm goto' support # Copyright (C) 2010, Jason Baron <jbaron@redhat.com> -echo "int main(void) { entry: asm goto (\"\"::::entry); return 0; }" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" +cat << "END" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" +int main(void) +{ +#ifdef __arm__ + /* + * Not related to asm goto, but used by jump label + * and broken on some ARM GCC versions (see GCC Bug 48637). + */ + static struct { int dummy; int state; } tp; + asm ("@ %c0" :: "i" (&tp.state)); +#endif + +entry: + asm goto ("" :::: entry); + return 0; +} +END -- 1.7.8.3 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCHv2 5/6] jump label: detect %c support for ARM 2012-01-28 13:35 ` [PATCHv2 5/6] jump label: detect %c support for ARM Rabin Vincent @ 2012-02-07 16:18 ` Rabin Vincent 2012-02-07 18:04 ` Jason Baron 2012-02-20 17:21 ` Russell King - ARM Linux 1 sibling, 1 reply; 5+ messages in thread From: Rabin Vincent @ 2012-02-07 16:18 UTC (permalink / raw) To: Jason Baron; +Cc: LKML, linux-arm-kernel Jason, On Sat, Jan 28, 2012 at 19:05, Rabin Vincent <rabin@rab.in> wrote: > Some versions of ARM GCC which do support asm goto, have problems > handling the the %c specifier. Since we need the %c to support jump > labels on ARM, detect that too in the asm goto detection script to avoid > build errors with these versions. > > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637 > > Cc: Jason Baron <jbaron@redhat.com> > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Rabin Vincent <rabin@rab.in> Could you please ack this patch if it's OK for you? Then I could try to send it via rmk's ARM patch system along with the rest of the series. Thanks. > --- > scripts/gcc-goto.sh | 18 +++++++++++++++++- > 1 files changed, 17 insertions(+), 1 deletions(-) > > diff --git a/scripts/gcc-goto.sh b/scripts/gcc-goto.sh > index 98cffcb..9b744de 100644 > --- a/scripts/gcc-goto.sh > +++ b/scripts/gcc-goto.sh > @@ -2,4 +2,20 @@ > # Test for gcc 'asm goto' support > # Copyright (C) 2010, Jason Baron <jbaron@redhat.com> > > -echo "int main(void) { entry: asm goto (\"\"::::entry); return 0; }" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" > +cat << "END" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" > +int main(void) > +{ > +#ifdef __arm__ > + /* > + * Not related to asm goto, but used by jump label > + * and broken on some ARM GCC versions (see GCC Bug 48637). > + */ > + static struct { int dummy; int state; } tp; > + asm ("@ %c0" :: "i" (&tp.state)); > +#endif > + > +entry: > + asm goto ("" :::: entry); > + return 0; > +} > +END > -- > 1.7.8.3 > ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCHv2 5/6] jump label: detect %c support for ARM 2012-02-07 16:18 ` Rabin Vincent @ 2012-02-07 18:04 ` Jason Baron 0 siblings, 0 replies; 5+ messages in thread From: Jason Baron @ 2012-02-07 18:04 UTC (permalink / raw) To: Rabin Vincent; +Cc: LKML, linux-arm-kernel On Tue, Feb 07, 2012 at 09:48:24PM +0530, Rabin Vincent wrote: > Jason, > > On Sat, Jan 28, 2012 at 19:05, Rabin Vincent <rabin@rab.in> wrote: > > Some versions of ARM GCC which do support asm goto, have problems > > handling the the %c specifier. Since we need the %c to support jump > > labels on ARM, detect that too in the asm goto detection script to avoid > > build errors with these versions. > > > > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637 > > > > Cc: Jason Baron <jbaron@redhat.com> > > Cc: linux-kernel@vger.kernel.org > > Signed-off-by: Rabin Vincent <rabin@rab.in> > > Could you please ack this patch if it's OK for you? Then I could try to > send it via rmk's ARM patch system along with the rest of the series. > > Thanks. > > > --- > > scripts/gcc-goto.sh | 18 +++++++++++++++++- > > 1 files changed, 17 insertions(+), 1 deletions(-) > > > > diff --git a/scripts/gcc-goto.sh b/scripts/gcc-goto.sh > > index 98cffcb..9b744de 100644 > > --- a/scripts/gcc-goto.sh > > +++ b/scripts/gcc-goto.sh > > @@ -2,4 +2,20 @@ > > # Test for gcc 'asm goto' support > > # Copyright (C) 2010, Jason Baron <jbaron@redhat.com> > > > > -echo "int main(void) { entry: asm goto (\"\"::::entry); return 0; }" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" > > +cat << "END" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" > > +int main(void) > > +{ > > +#ifdef __arm__ > > + /* > > + * Not related to asm goto, but used by jump label > > + * and broken on some ARM GCC versions (see GCC Bug 48637). > > + */ > > + static struct { int dummy; int state; } tp; > > + asm ("@ %c0" :: "i" (&tp.state)); > > +#endif > > + > > +entry: > > + asm goto ("" :::: entry); > > + return 0; > > +} > > +END > > -- > > 1.7.8.3 > > Sure, patch works for me. Acked-by: Jason Baron <jbaron@redhat.com> ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCHv2 5/6] jump label: detect %c support for ARM 2012-01-28 13:35 ` [PATCHv2 5/6] jump label: detect %c support for ARM Rabin Vincent 2012-02-07 16:18 ` Rabin Vincent @ 2012-02-20 17:21 ` Russell King - ARM Linux 2012-02-22 13:32 ` Rabin Vincent 1 sibling, 1 reply; 5+ messages in thread From: Russell King - ARM Linux @ 2012-02-20 17:21 UTC (permalink / raw) To: Rabin Vincent; +Cc: linux-arm-kernel, Jason Baron, linux-kernel On Sat, Jan 28, 2012 at 07:05:24PM +0530, Rabin Vincent wrote: > Some versions of ARM GCC which do support asm goto, have problems > handling the the %c specifier. Since we need the %c to support jump > labels on ARM, detect that too in the asm goto detection script to avoid > build errors with these versions. I'm not sure how this detects properly working %c support. %c support has been rather flakey on ARM for some time, I'm not sure which version of gcc was fixed for it. > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637 > > Cc: Jason Baron <jbaron@redhat.com> > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Rabin Vincent <rabin@rab.in> > --- > scripts/gcc-goto.sh | 18 +++++++++++++++++- > 1 files changed, 17 insertions(+), 1 deletions(-) > > diff --git a/scripts/gcc-goto.sh b/scripts/gcc-goto.sh > index 98cffcb..9b744de 100644 > --- a/scripts/gcc-goto.sh > +++ b/scripts/gcc-goto.sh > @@ -2,4 +2,20 @@ > # Test for gcc 'asm goto' support > # Copyright (C) 2010, Jason Baron <jbaron@redhat.com> > > -echo "int main(void) { entry: asm goto (\"\"::::entry); return 0; }" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" > +cat << "END" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" > +int main(void) > +{ > +#ifdef __arm__ > + /* > + * Not related to asm goto, but used by jump label > + * and broken on some ARM GCC versions (see GCC Bug 48637). > + */ > + static struct { int dummy; int state; } tp; > + asm ("@ %c0" :: "i" (&tp.state)); While this detects the presence of the ICE, previous compilers included the '#' before the constant, which leads to problems. I think a better check would be: asm(".long %c0" :: "i" (&tp.state)); to make sure that it spits out something purely numeric, rather than something prefixed with a '#'. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCHv2 5/6] jump label: detect %c support for ARM 2012-02-20 17:21 ` Russell King - ARM Linux @ 2012-02-22 13:32 ` Rabin Vincent 0 siblings, 0 replies; 5+ messages in thread From: Rabin Vincent @ 2012-02-22 13:32 UTC (permalink / raw) To: Russell King - ARM Linux; +Cc: linux-arm-kernel, Jason Baron, linux-kernel On Mon, Feb 20, 2012 at 05:21:58PM +0000, Russell King - ARM Linux wrote: > On Sat, Jan 28, 2012 at 07:05:24PM +0530, Rabin Vincent wrote: > > Some versions of ARM GCC which do support asm goto, have problems > > handling the the %c specifier. Since we need the %c to support jump > > labels on ARM, detect that too in the asm goto detection script to avoid > > build errors with these versions. > > I'm not sure how this detects properly working %c support. %c support > has been rather flakey on ARM for some time, I'm not sure which version > of gcc was fixed for it. Right, it only detects that %c on a sym+offset doesn't ICE, which was what it had been doing since atleast version 4.3. The assumption was that since asm goto was only added in ~4.5, all older compilers (regardless of their state of %c support) would choke (as we want them to) on the existing second half of this script. I have added the change you suggested below. > > > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637 > > > > Cc: Jason Baron <jbaron@redhat.com> > > Cc: linux-kernel@vger.kernel.org > > Signed-off-by: Rabin Vincent <rabin@rab.in> > > --- > > scripts/gcc-goto.sh | 18 +++++++++++++++++- > > 1 files changed, 17 insertions(+), 1 deletions(-) > > > > diff --git a/scripts/gcc-goto.sh b/scripts/gcc-goto.sh > > index 98cffcb..9b744de 100644 > > --- a/scripts/gcc-goto.sh > > +++ b/scripts/gcc-goto.sh > > @@ -2,4 +2,20 @@ > > # Test for gcc 'asm goto' support > > # Copyright (C) 2010, Jason Baron <jbaron@redhat.com> > > > > -echo "int main(void) { entry: asm goto (\"\"::::entry); return 0; }" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" > > +cat << "END" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" > > +int main(void) > > +{ > > +#ifdef __arm__ > > + /* > > + * Not related to asm goto, but used by jump label > > + * and broken on some ARM GCC versions (see GCC Bug 48637). > > + */ > > + static struct { int dummy; int state; } tp; > > + asm ("@ %c0" :: "i" (&tp.state)); > > While this detects the presence of the ICE, previous compilers included > the '#' before the constant, which leads to problems. I think a better > check would be: > asm(".long %c0" :: "i" (&tp.state)); > > to make sure that it spits out something purely numeric, rather than > something prefixed with a '#'. OK, done: 8<---------------- >From f3a3bd64f72720def5cfbaedf6ff83ca54f1644b Mon Sep 17 00:00:00 2001 From: Rabin Vincent <rabin@rab.in> Date: Wed, 23 Nov 2011 20:05:09 +0530 Subject: [PATCH] jump label: detect %c support for ARM Some versions of ARM GCC which do support asm goto, do not support the %c specifier. Since we need the %c to support jump labels on ARM, detect that too in the asm goto detection script to avoid build errors with these versions. http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637 Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Rabin Vincent <rabin@rab.in> --- scripts/gcc-goto.sh | 18 +++++++++++++++++- 1 files changed, 17 insertions(+), 1 deletions(-) diff --git a/scripts/gcc-goto.sh b/scripts/gcc-goto.sh index 98cffcb..a2af2e8 100644 --- a/scripts/gcc-goto.sh +++ b/scripts/gcc-goto.sh @@ -2,4 +2,20 @@ # Test for gcc 'asm goto' support # Copyright (C) 2010, Jason Baron <jbaron@redhat.com> -echo "int main(void) { entry: asm goto (\"\"::::entry); return 0; }" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" +cat << "END" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" +int main(void) +{ +#ifdef __arm__ + /* + * Not related to asm goto, but used by jump label + * and broken on some ARM GCC versions (see GCC Bug 48637). + */ + static struct { int dummy; int state; } tp; + asm (".long %c0" :: "i" (&tp.state)); +#endif + +entry: + asm goto ("" :::: entry); + return 0; +} +END -- 1.7.9 ^ permalink raw reply related [flat|nested] 5+ messages in thread
end of thread, other threads:[~2012-02-22 13:35 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <1327757725-10114-1-git-send-email-rabin@rab.in> 2012-01-28 13:35 ` [PATCHv2 5/6] jump label: detect %c support for ARM Rabin Vincent 2012-02-07 16:18 ` Rabin Vincent 2012-02-07 18:04 ` Jason Baron 2012-02-20 17:21 ` Russell King - ARM Linux 2012-02-22 13:32 ` Rabin Vincent
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