From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxim Kuvyrkov Subject: Re: [PATCH] Define sigcontext ABI of ColdFire Date: Wed, 23 Sep 2009 01:37:31 +0400 Message-ID: <4AB9439B.6050006@codesourcery.com> References: <4AB360DC.9030902@codesourcery.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------050905030803090404040401" Return-path: Received: from mail.codesourcery.com ([65.74.133.4]:37662 "EHLO mail.codesourcery.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752530AbZIVVhh (ORCPT ); Tue, 22 Sep 2009 17:37:37 -0400 In-Reply-To: <4AB360DC.9030902@codesourcery.com> Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: Geert Uytterhoeven Cc: Andreas Schwab , linux-m68k@vger.kernel.org This is a multi-part message in MIME format. --------------050905030803090404040401 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Maxim Kuvyrkov wrote: > The following patch define sigcontext ABI of ColdFire. ... > --- a/arch/m68k/kernel/signal.c > +++ b/arch/m68k/kernel/signal.c > @@ -897,9 +897,15 @@ static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info, > > /* Set up to return from userspace. */ > err |= __put_user(frame->retcode, &frame->pretcode); > +#ifdef __mcoldfire__ > + /* move.w #,d0; trap #0 */ > + err |= __put_user(0x303c0000 + __NR_rt_sigreturn, > + (long __user *)(frame->retcode + 0)); > +#else > /* moveq #,d0; notb d0; trap #0 */ > err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16), > (long __user *)(frame->retcode + 0)); > +#endif > err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4)); > > if (err) This turned out to be buggy: move.w will only set the lower 16 bits of %d0 so if the signal handler leaves something in the high-order bits, then the trampoline will trap into a non-existent syscall. The attached patch fixes this; nothing else in it has changed since the initial revision. I was lured into thinking that the above sequence is OK by m68knommu's version of the trampoline. Arch/m68knommu/kernel/entry.S uses "move #__NR_rt_sigreturn,%d0" which assembles into "move.w". This is too is buggy and I'm also attaching the fix for the nommu version. Regards, -- Maxim K. CodeSourcery --------------050905030803090404040401 Content-Type: text/plain; x-mac-type="0"; x-mac-creator="0"; name="0001-Define-sigcontext-ABI-of-ColdFire.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="0001-Define-sigcontext-ABI-of-ColdFire.patch" >>From bafb4e11ac13ea3095d9e8510f9a58c4cdc0481d Mon Sep 17 00:00:00 2001 From: Maxim Kuvyrkov Date: Wed, 23 Sep 2009 01:22:43 +0400 Subject: [PATCH 1/2] Define sigcontext ABI of ColdFire The following patch defines sigcontext ABI of ColdFire. Due to ISA restrictions ColdFire needs different rt_sigreturn trampoline. And due to ColdFire FP registers being 8-bytes instead of 12-bytes on m68k, sigcontext and fpregset structures should be updated. Regarding the sc_fpstate[16+6*8] field, it would've been enough 16 bytes to store ColdFire's FP state. To accomodate GLIBC's libSegFault it would'be been enough 6*8 bytes (room for the 6 non-call-clobbered FP registers). I set it to 16+6*8 to provide some extra space for any future changes in the ColdFire FPU. Signed-off-by: Maxim Kuvyrkov --- arch/m68k/include/asm/sigcontext.h | 6 ++++++ arch/m68k/include/asm/ucontext.h | 4 ++++ arch/m68k/kernel/signal.c | 7 +++++++ 3 files changed, 17 insertions(+), 0 deletions(-) diff --git a/arch/m68k/include/asm/sigcontext.h b/arch/m68k/include/asm/sigcontext.h index 523db2a..1320eaa 100644 --- a/arch/m68k/include/asm/sigcontext.h +++ b/arch/m68k/include/asm/sigcontext.h @@ -15,9 +15,15 @@ struct sigcontext { unsigned long sc_pc; unsigned short sc_formatvec; #ifndef __uClinux__ +# ifdef __mcoldfire__ + unsigned long sc_fpregs[2][2]; /* room for two fp registers */ + unsigned long sc_fpcntl[3]; + unsigned char sc_fpstate[16+6*8]; +# else unsigned long sc_fpregs[2*3]; /* room for two fp registers */ unsigned long sc_fpcntl[3]; unsigned char sc_fpstate[216]; +# endif #endif }; diff --git a/arch/m68k/include/asm/ucontext.h b/arch/m68k/include/asm/ucontext.h index e4e2266..00dcc51 100644 --- a/arch/m68k/include/asm/ucontext.h +++ b/arch/m68k/include/asm/ucontext.h @@ -7,7 +7,11 @@ typedef greg_t gregset_t[NGREG]; typedef struct fpregset { int f_fpcntl[3]; +#ifdef __mcoldfire__ + int f_fpregs[8][2]; +#else int f_fpregs[8*3]; +#endif } fpregset_t; struct mcontext { diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c index de2d05d..4b38753 100644 --- a/arch/m68k/kernel/signal.c +++ b/arch/m68k/kernel/signal.c @@ -897,10 +897,17 @@ static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info, /* Set up to return from userspace. */ err |= __put_user(frame->retcode, &frame->pretcode); +#ifdef __mcoldfire__ + /* movel #__NR_rt_sigreturn,d0; trap #0 */ + err |= __put_user(0x203c0000, (long __user *)(frame->retcode + 0)); + err |= __put_user(0x00004e40 + (__NR_rt_sigreturn << 16), + (long __user *)(frame->retcode + 4)); +#else /* moveq #,d0; notb d0; trap #0 */ err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16), (long __user *)(frame->retcode + 0)); err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4)); +#endif if (err) goto give_sigsegv; -- 1.6.4 --------------050905030803090404040401 Content-Type: text/plain; x-mac-type="0"; x-mac-creator="0"; name="0002-Fix-m68k-uclinux-s-rt_sigreturn-trampoline.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename*0="0002-Fix-m68k-uclinux-s-rt_sigreturn-trampoline.patch" >>From ac003b05af17bb48e6acffd454cae6fdf6e80737 Mon Sep 17 00:00:00 2001 From: Maxim Kuvyrkov Date: Wed, 23 Sep 2009 01:25:44 +0400 Subject: [PATCH 2/2] Fix m68k-uclinux's rt_sigreturn trampoline Signed-off-by: Maxim Kuvyrkov --- arch/m68knommu/kernel/entry.S | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/m68knommu/kernel/entry.S b/arch/m68knommu/kernel/entry.S index f56faa5..2717605 100644 --- a/arch/m68knommu/kernel/entry.S +++ b/arch/m68knommu/kernel/entry.S @@ -145,6 +145,6 @@ ENTRY(ret_from_user_signal) trap #0 ENTRY(ret_from_user_rt_signal) - move #__NR_rt_sigreturn,%d0 + movel #__NR_rt_sigreturn,%d0 trap #0 -- 1.6.4 --------------050905030803090404040401--