Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933127AbcDYQwB (ORCPT ); Mon, 25 Apr 2016 12:52:01 -0400 Received: from mail-ob0-f178.google.com ([209.85.214.178]:35944 "EHLO mail-ob0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754398AbcDYQv7 (ORCPT ); Mon, 25 Apr 2016 12:51:59 -0400 MIME-Version: 1.0 In-Reply-To: <1461600763-3534-2-git-send-email-dsafonov@virtuozzo.com> References: <1461600763-3534-1-git-send-email-dsafonov@virtuozzo.com> <1461600763-3534-2-git-send-email-dsafonov@virtuozzo.com> From: Andy Lutomirski Date: Mon, 25 Apr 2016 09:51:38 -0700 Message-ID: Subject: Re: [RFC 2/3] x86/coredump: use core regs, rather that TIF_IA32 flag To: Dmitry Safonov , Oleg Nesterov Cc: "linux-kernel@vger.kernel.org" , Dmitry Safonov <0x7f454c46@gmail.com>, Andy Lutomirski , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Alexander Viro , X86 ML , Linux FS Devel Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4648 Lines: 115 On Mon, Apr 25, 2016 at 9:12 AM, Dmitry Safonov wrote: > As we have here core registers, use them to determine application's > mode and sizes of register set and elf_prstatus. Looks fine to me, but I'm not that familiar with this code. Oleg? > > Cc: Andy Lutomirski > Cc: Ingo Molnar > Cc: Thomas Gleixner > Cc: "H. Peter Anvin" > Cc: Alexander Viro > Cc: x86@kernel.org > Cc: linux-fsdevel@vger.kernel.org > Signed-off-by: Dmitry Safonov > --- > arch/x86/include/asm/compat.h | 8 ++++---- > fs/binfmt_elf.c | 18 ++++++++++-------- > 2 files changed, 14 insertions(+), 12 deletions(-) > > diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h > index 5a3b2c119ed0..d0b517fc77ff 100644 > --- a/arch/x86/include/asm/compat.h > +++ b/arch/x86/include/asm/compat.h > @@ -264,10 +264,10 @@ struct compat_shmid64_ds { > #ifdef CONFIG_X86_X32_ABI > typedef struct user_regs_struct compat_elf_gregset_t; > > -#define PR_REG_SIZE(S) (test_thread_flag(TIF_IA32) ? 68 : 216) > -#define PRSTATUS_SIZE(S) (test_thread_flag(TIF_IA32) ? 144 : 296) > -#define SET_PR_FPVALID(S,V) \ > - do { *(int *) (((void *) &((S)->pr_reg)) + PR_REG_SIZE(0)) = (V); } \ > +#define PR_REG_SIZE(S, R) (!user_64bit_mode(R) ? 68 : 216) > +#define PRSTATUS_SIZE(S, R) (!user_64bit_mode(R) ? 144 : 296) > +#define SET_PR_FPVALID(S, V, R) \ > + do { *(int *) (((void *) &((S)->pr_reg)) + PR_REG_SIZE(0, R)) = (V); } \ > while (0) > > #define COMPAT_USE_64BIT_TIME \ > diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c > index 81381cc0dd17..6be281ef34f9 100644 > --- a/fs/binfmt_elf.c > +++ b/fs/binfmt_elf.c > @@ -1621,11 +1621,11 @@ static void do_thread_regset_writeback(struct task_struct *task, > } > > #ifndef PR_REG_SIZE > -#define PR_REG_SIZE(S) sizeof(S) > +#define PR_REG_SIZE(S, R) sizeof(S) > #endif > > #ifndef PRSTATUS_SIZE > -#define PRSTATUS_SIZE(S) sizeof(S) > +#define PRSTATUS_SIZE(S, R) sizeof(S) > #endif > > #ifndef PR_REG_PTR > @@ -1633,12 +1633,13 @@ static void do_thread_regset_writeback(struct task_struct *task, > #endif > > #ifndef SET_PR_FPVALID > -#define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V)) > +#define SET_PR_FPVALID(S, V, R) ((S)->pr_fpvalid = (V)) > #endif > > static int fill_thread_core_info(struct elf_thread_core_info *t, > const struct user_regset_view *view, > - long signr, size_t *total) > + long signr, size_t *total, > + struct pt_regs *regs __maybe_unused) > { > unsigned int i; > > @@ -1650,11 +1651,11 @@ static int fill_thread_core_info(struct elf_thread_core_info *t, > */ > fill_prstatus(&t->prstatus, t->task, signr); > (void) view->regsets[0].get(t->task, &view->regsets[0], > - 0, PR_REG_SIZE(t->prstatus.pr_reg), > + 0, PR_REG_SIZE(t->prstatus.pr_reg, regs), > PR_REG_PTR(&t->prstatus), NULL); > > fill_note(&t->notes[0], "CORE", NT_PRSTATUS, > - PRSTATUS_SIZE(t->prstatus), &t->prstatus); > + PRSTATUS_SIZE(t->prstatus, regs), &t->prstatus); > *total += notesize(&t->notes[0]); > > do_thread_regset_writeback(t->task, &view->regsets[0]); > @@ -1684,7 +1685,7 @@ static int fill_thread_core_info(struct elf_thread_core_info *t, > regset->core_note_type, > size, data); > else { > - SET_PR_FPVALID(&t->prstatus, 1); > + SET_PR_FPVALID(&t->prstatus, 1, regs); > fill_note(&t->notes[i], "CORE", > NT_PRFPREG, size, data); > } > @@ -1770,7 +1771,8 @@ static int fill_note_info(struct elfhdr *elf, int phdrs, > * Now fill in each thread's information. > */ > for (t = info->thread; t != NULL; t = t->next) > - if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size)) > + if (!fill_thread_core_info(t, view, siginfo->si_signo, > + &info->size, regs)) > return 0; > > /* > -- > 2.8.0 > -- Andy Lutomirski AMA Capital Management, LLC