From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755689AbcHXNKB (ORCPT ); Wed, 24 Aug 2016 09:10:01 -0400 Received: from terminus.zytor.com ([198.137.202.10]:49080 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755091AbcHXNJ4 (ORCPT ); Wed, 24 Aug 2016 09:09:56 -0400 Date: Wed, 24 Aug 2016 06:08:09 -0700 From: tip-bot for Brian Gerst Message-ID: Cc: linux-kernel@vger.kernel.org, brgerst@gmail.com, torvalds@linux-foundation.org, mingo@kernel.org, luto@kernel.org, jpoimboe@redhat.com, dvlasenk@redhat.com, tglx@linutronix.de, hpa@zytor.com, bp@alien8.de, peterz@infradead.org Reply-To: dvlasenk@redhat.com, jpoimboe@redhat.com, linux-kernel@vger.kernel.org, mingo@kernel.org, torvalds@linux-foundation.org, luto@kernel.org, brgerst@gmail.com, peterz@infradead.org, bp@alien8.de, hpa@zytor.com, tglx@linutronix.de In-Reply-To: <1471106302-10159-4-git-send-email-brgerst@gmail.com> References: <1471106302-10159-4-git-send-email-brgerst@gmail.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/asm] sched/x86: Add 'struct inactive_task_frame' to better document the sleeping task stack frame Git-Commit-ID: 7b32aeadbc95d4a41402c1c0da6aa3ab51af4c10 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 7b32aeadbc95d4a41402c1c0da6aa3ab51af4c10 Gitweb: http://git.kernel.org/tip/7b32aeadbc95d4a41402c1c0da6aa3ab51af4c10 Author: Brian Gerst AuthorDate: Sat, 13 Aug 2016 12:38:18 -0400 Committer: Ingo Molnar CommitDate: Wed, 24 Aug 2016 12:27:41 +0200 sched/x86: Add 'struct inactive_task_frame' to better document the sleeping task stack frame Add 'struct inactive_task_frame', which defines the layout of the stack for a sleeping process. For now, the only defined field is the BP register (frame pointer). Signed-off-by: Brian Gerst Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1471106302-10159-4-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/stacktrace.h | 4 ++-- arch/x86/include/asm/switch_to.h | 5 +++++ arch/x86/kernel/kgdb.c | 3 ++- arch/x86/kernel/process.c | 3 ++- 4 files changed, 11 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h index 0944218..7646fb2 100644 --- a/arch/x86/include/asm/stacktrace.h +++ b/arch/x86/include/asm/stacktrace.h @@ -8,6 +8,7 @@ #include #include +#include extern int kstack_depth_to_print; @@ -70,8 +71,7 @@ stack_frame(struct task_struct *task, struct pt_regs *regs) return bp; } - /* bp is the last reg pushed by switch_to */ - return *(unsigned long *)task->thread.sp; + return ((struct inactive_task_frame *)task->thread.sp)->bp; } #else static inline unsigned long diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h index 14e4b20..ec689c6 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -30,6 +30,11 @@ static inline void prepare_switch_to(struct task_struct *prev, #endif } +/* data that is pointed to by thread.sp */ +struct inactive_task_frame { + unsigned long bp; +}; + #ifdef CONFIG_X86_32 #ifdef CONFIG_CC_STACKPROTECTOR diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index 5e3f294..8e36f24 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -50,6 +50,7 @@ #include #include #include +#include struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = { @@ -166,7 +167,7 @@ void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) gdb_regs[GDB_DX] = 0; gdb_regs[GDB_SI] = 0; gdb_regs[GDB_DI] = 0; - gdb_regs[GDB_BP] = *(unsigned long *)p->thread.sp; + gdb_regs[GDB_BP] = ((struct inactive_task_frame *)p->thread.sp)->bp; #ifdef CONFIG_X86_32 gdb_regs[GDB_DS] = __KERNEL_DS; gdb_regs[GDB_ES] = __KERNEL_DS; diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 62c0b0e..0115a4a 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -32,6 +32,7 @@ #include #include #include +#include /* * per-CPU TSS segments. Threads are completely 'soft' on Linux, @@ -556,7 +557,7 @@ unsigned long get_wchan(struct task_struct *p) if (sp < bottom || sp > top) return 0; - fp = READ_ONCE_NOCHECK(*(unsigned long *)sp); + fp = READ_ONCE_NOCHECK(((struct inactive_task_frame *)sp)->bp); do { if (fp < bottom || fp > top) return 0;