Revision dbf520a9d7d4d5ba28d2947be11e34099a5e3e20 authored by Paul Walmsley on 31 March 2013, 00:04:40 UTC, committed by Linus Torvalds on 31 March 2013, 18:38:33 UTC
This reverts commit 6aa9707099c4b25700940eb3d016f16c4434360d. Commit 6aa9707099c4 ("lockdep: check that no locks held at freeze time") causes problems with NFS root filesystems. The failures were noticed on OMAP2 and 3 boards during kernel init: [ BUG: swapper/0/1 still has locks held! ] 3.9.0-rc3-00344-ga937536 #1 Not tainted ------------------------------------- 1 lock held by swapper/0/1: #0: (&type->s_umount_key#13/1){+.+.+.}, at: [<c011e84c>] sget+0x248/0x574 stack backtrace: rpc_wait_bit_killable __wait_on_bit out_of_line_wait_on_bit __rpc_execute rpc_run_task rpc_call_sync nfs_proc_get_root nfs_get_root nfs_fs_mount_common nfs_try_mount nfs_fs_mount mount_fs vfs_kern_mount do_mount sys_mount do_mount_root mount_root prepare_namespace kernel_init_freeable kernel_init Although the rootfs mounts, the system is unstable. Here's a transcript from a PM test: http://www.pwsan.com/omap/testlogs/test_v3.9-rc3/20130317194234/pm/37xxevm/37xxevm_log.txt Here's what the test log should look like: http://www.pwsan.com/omap/testlogs/test_v3.8/20130218214403/pm/37xxevm/37xxevm_log.txt Mailing list discussion is here: http://lkml.org/lkml/2013/3/4/221 Deal with this for v3.9 by reverting the problem commit, until folks can figure out the right long-term course of action. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Mandeep Singh Baines <msb@chromium.org> Cc: Jeff Layton <jlayton@redhat.com> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: <maciej.rutecki@gmail.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ben Chan <benchan@chromium.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 13d2080
process.c
/*
* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2008-2009 PetaLogix
* Copyright (C) 2006 Atmark Techno, Inc.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/tick.h>
#include <linux/bitops.h>
#include <linux/ptrace.h>
#include <asm/pgalloc.h>
#include <linux/uaccess.h> /* for USER_DS macros */
#include <asm/cacheflush.h>
void show_regs(struct pt_regs *regs)
{
pr_info(" Registers dump: mode=%X\r\n", regs->pt_mode);
pr_info(" r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n",
regs->r1, regs->r2, regs->r3, regs->r4);
pr_info(" r5=%08lX, r6=%08lX, r7=%08lX, r8=%08lX\n",
regs->r5, regs->r6, regs->r7, regs->r8);
pr_info(" r9=%08lX, r10=%08lX, r11=%08lX, r12=%08lX\n",
regs->r9, regs->r10, regs->r11, regs->r12);
pr_info(" r13=%08lX, r14=%08lX, r15=%08lX, r16=%08lX\n",
regs->r13, regs->r14, regs->r15, regs->r16);
pr_info(" r17=%08lX, r18=%08lX, r19=%08lX, r20=%08lX\n",
regs->r17, regs->r18, regs->r19, regs->r20);
pr_info(" r21=%08lX, r22=%08lX, r23=%08lX, r24=%08lX\n",
regs->r21, regs->r22, regs->r23, regs->r24);
pr_info(" r25=%08lX, r26=%08lX, r27=%08lX, r28=%08lX\n",
regs->r25, regs->r26, regs->r27, regs->r28);
pr_info(" r29=%08lX, r30=%08lX, r31=%08lX, rPC=%08lX\n",
regs->r29, regs->r30, regs->r31, regs->pc);
pr_info(" msr=%08lX, ear=%08lX, esr=%08lX, fsr=%08lX\n",
regs->msr, regs->ear, regs->esr, regs->fsr);
}
void (*pm_power_off)(void) = NULL;
EXPORT_SYMBOL(pm_power_off);
static int hlt_counter = 1;
void disable_hlt(void)
{
hlt_counter++;
}
EXPORT_SYMBOL(disable_hlt);
void enable_hlt(void)
{
hlt_counter--;
}
EXPORT_SYMBOL(enable_hlt);
static int __init nohlt_setup(char *__unused)
{
hlt_counter = 1;
return 1;
}
__setup("nohlt", nohlt_setup);
static int __init hlt_setup(char *__unused)
{
hlt_counter = 0;
return 1;
}
__setup("hlt", hlt_setup);
void default_idle(void)
{
if (likely(hlt_counter)) {
local_irq_disable();
stop_critical_timings();
cpu_relax();
start_critical_timings();
local_irq_enable();
} else {
clear_thread_flag(TIF_POLLING_NRFLAG);
smp_mb__after_clear_bit();
local_irq_disable();
while (!need_resched())
cpu_sleep();
local_irq_enable();
set_thread_flag(TIF_POLLING_NRFLAG);
}
}
void cpu_idle(void)
{
set_thread_flag(TIF_POLLING_NRFLAG);
/* endless idle loop with no priority at all */
while (1) {
tick_nohz_idle_enter();
rcu_idle_enter();
while (!need_resched())
default_idle();
rcu_idle_exit();
tick_nohz_idle_exit();
schedule_preempt_disabled();
check_pgt_cache();
}
}
void flush_thread(void)
{
}
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p)
{
struct pt_regs *childregs = task_pt_regs(p);
struct thread_info *ti = task_thread_info(p);
if (unlikely(p->flags & PF_KTHREAD)) {
/* if we're creating a new kernel thread then just zeroing all
* the registers. That's OK for a brand new thread.*/
memset(childregs, 0, sizeof(struct pt_regs));
memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
ti->cpu_context.r1 = (unsigned long)childregs;
ti->cpu_context.r20 = (unsigned long)usp; /* fn */
ti->cpu_context.r19 = (unsigned long)arg;
childregs->pt_mode = 1;
local_save_flags(childregs->msr);
#ifdef CONFIG_MMU
ti->cpu_context.msr = childregs->msr & ~MSR_IE;
#endif
ti->cpu_context.r15 = (unsigned long)ret_from_kernel_thread - 8;
return 0;
}
*childregs = *current_pt_regs();
if (usp)
childregs->r1 = usp;
memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
ti->cpu_context.r1 = (unsigned long)childregs;
#ifndef CONFIG_MMU
ti->cpu_context.msr = (unsigned long)childregs->msr;
#else
childregs->msr |= MSR_UMS;
/* we should consider the fact that childregs is a copy of the parent
* regs which were saved immediately after entering the kernel state
* before enabling VM. This MSR will be restored in switch_to and
* RETURN() and we want to have the right machine state there
* specifically this state must have INTs disabled before and enabled
* after performing rtbd
* compose the right MSR for RETURN(). It will work for switch_to also
* excepting for VM and UMS
* don't touch UMS , CARRY and cache bits
* right now MSR is a copy of parent one */
childregs->msr &= ~MSR_EIP;
childregs->msr |= MSR_IE;
childregs->msr &= ~MSR_VM;
childregs->msr |= MSR_VMS;
childregs->msr |= MSR_EE; /* exceptions will be enabled*/
ti->cpu_context.msr = (childregs->msr|MSR_VM);
ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
ti->cpu_context.msr &= ~MSR_IE;
#endif
ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;
/*
* r21 is the thread reg, r10 is 6th arg to clone
* which contains TLS area
*/
if (clone_flags & CLONE_SETTLS)
childregs->r21 = childregs->r10;
return 0;
}
#ifndef CONFIG_MMU
/*
* Return saved PC of a blocked thread.
*/
unsigned long thread_saved_pc(struct task_struct *tsk)
{
struct cpu_context *ctx =
&(((struct thread_info *)(tsk->stack))->cpu_context);
/* Check whether the thread is blocked in resume() */
if (in_sched_functions(ctx->r15))
return (unsigned long)ctx->r15;
else
return ctx->r14;
}
#endif
unsigned long get_wchan(struct task_struct *p)
{
/* TBD (used by procfs) */
return 0;
}
/* Set up a thread for executing a new program */
void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
{
regs->pc = pc;
regs->r1 = usp;
regs->pt_mode = 0;
#ifdef CONFIG_MMU
regs->msr |= MSR_UMS;
regs->msr &= ~MSR_VM;
#endif
}
#ifdef CONFIG_MMU
#include <linux/elfcore.h>
/*
* Set up a thread for executing a new program
*/
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
{
return 0; /* MicroBlaze has no separate FPU registers */
}
#endif /* CONFIG_MMU */
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