Messages in this thread | | | Date | Wed, 16 Nov 2011 21:52:36 +0000 | From | Ben Hutchings <> | Subject | Re: [PATCH 1/2] lockdep,rtmutex,bug: Show taint flags on error |
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Please could you ack or nak this?
Ben.
On Fri, Oct 28, 2011 at 04:36:55AM +0100, Ben Hutchings wrote: > Currently lock debugging is disabled when the kernel is tainted, with > a few exceptions. It is already recognised that this can be useful > for staging modules (TAINT_CRAP), but that also goes for out-of-tree > modules (TAINT_OOT_MODULE) so long as core kernel developers don't > have to spend time debugging them. Also, there are several reasons > for tainting that are unlikely to introduce false locking bug reports > (e.g. TAINT_FIRMWARE_WORKAROUND). > > Instead of disabling lock debugging, show the taint flags in all > lockdep and rtmutex-debug error messages. > > Signed-off-by: Ben Hutchings <ben@decadent.org.uk> > --- > kernel/lockdep.c | 23 +++++++++++++++-------- > kernel/panic.c | 10 ---------- > kernel/rtmutex-debug.c | 1 + > 3 files changed, 16 insertions(+), 18 deletions(-) > > diff --git a/kernel/lockdep.c b/kernel/lockdep.c > index e69434b..b2c4537 100644 > --- a/kernel/lockdep.c > +++ b/kernel/lockdep.c > @@ -567,11 +567,12 @@ static void lockdep_print_held_locks(struct task_struct *curr) > } > } > > -static void print_kernel_version(void) > +static void print_kernel_ident(void) > { > - printk("%s %.*s\n", init_utsname()->release, > + printk("%s %.*s %s\n", init_utsname()->release, > (int)strcspn(init_utsname()->version, " "), > - init_utsname()->version); > + init_utsname()->version, > + print_tainted()); > } > > static int very_verbose(struct lock_class *class) > @@ -1148,7 +1149,7 @@ print_circular_bug_header(struct lock_list *entry, unsigned int depth, > printk("\n"); > printk("======================================================\n"); > printk("[ INFO: possible circular locking dependency detected ]\n"); > - print_kernel_version(); > + print_kernel_ident(); > printk("-------------------------------------------------------\n"); > printk("%s/%d is trying to acquire lock:\n", > curr->comm, task_pid_nr(curr)); > @@ -1487,7 +1488,7 @@ print_bad_irq_dependency(struct task_struct *curr, > printk("======================================================\n"); > printk("[ INFO: %s-safe -> %s-unsafe lock order detected ]\n", > irqclass, irqclass); > - print_kernel_version(); > + print_kernel_ident(); > printk("------------------------------------------------------\n"); > printk("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] is trying to acquire:\n", > curr->comm, task_pid_nr(curr), > @@ -1716,7 +1717,7 @@ print_deadlock_bug(struct task_struct *curr, struct held_lock *prev, > printk("\n"); > printk("=============================================\n"); > printk("[ INFO: possible recursive locking detected ]\n"); > - print_kernel_version(); > + print_kernel_ident(); > printk("---------------------------------------------\n"); > printk("%s/%d is trying to acquire lock:\n", > curr->comm, task_pid_nr(curr)); > @@ -2223,7 +2224,7 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this, > printk("\n"); > printk("=================================\n"); > printk("[ INFO: inconsistent lock state ]\n"); > - print_kernel_version(); > + print_kernel_ident(); > printk("---------------------------------\n"); > > printk("inconsistent {%s} -> {%s} usage.\n", > @@ -2288,7 +2289,7 @@ print_irq_inversion_bug(struct task_struct *curr, > printk("\n"); > printk("=========================================================\n"); > printk("[ INFO: possible irq lock inversion dependency detected ]\n"); > - print_kernel_version(); > + print_kernel_ident(); > printk("---------------------------------------------------------\n"); > printk("%s/%d just changed the state of lock:\n", > curr->comm, task_pid_nr(curr)); > @@ -3169,6 +3170,7 @@ print_unlock_inbalance_bug(struct task_struct *curr, struct lockdep_map *lock, > printk("\n"); > printk("=====================================\n"); > printk("[ BUG: bad unlock balance detected! ]\n"); > + print_kernel_ident(); > printk("-------------------------------------\n"); > printk("%s/%d is trying to release lock (", > curr->comm, task_pid_nr(curr)); > @@ -3613,6 +3615,7 @@ print_lock_contention_bug(struct task_struct *curr, struct lockdep_map *lock, > printk("\n"); > printk("=================================\n"); > printk("[ BUG: bad contention detected! ]\n"); > + print_kernel_ident(); > printk("---------------------------------\n"); > printk("%s/%d is trying to contend lock (", > curr->comm, task_pid_nr(curr)); > @@ -3987,6 +3990,7 @@ print_freed_lock_bug(struct task_struct *curr, const void *mem_from, > printk("\n"); > printk("=========================\n"); > printk("[ BUG: held lock freed! ]\n"); > + print_kernel_ident(); > printk("-------------------------\n"); > printk("%s/%d is freeing memory %p-%p, with a lock still held there!\n", > curr->comm, task_pid_nr(curr), mem_from, mem_to-1); > @@ -4044,6 +4048,7 @@ static void print_held_locks_bug(struct task_struct *curr) > printk("\n"); > printk("=====================================\n"); > printk("[ BUG: lock held at task exit time! ]\n"); > + print_kernel_ident(); > printk("-------------------------------------\n"); > printk("%s/%d is exiting with locks still held!\n", > curr->comm, task_pid_nr(curr)); > @@ -4141,6 +4146,7 @@ void lockdep_sys_exit(void) > printk("\n"); > printk("================================================\n"); > printk("[ BUG: lock held when returning to user space! ]\n"); > + print_kernel_ident(); > printk("------------------------------------------------\n"); > printk("%s/%d is leaving the kernel with locks still held!\n", > curr->comm, curr->pid); > @@ -4160,6 +4166,7 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s) > printk("\n"); > printk("===============================\n"); > printk("[ INFO: suspicious RCU usage. ]\n"); > + print_kernel_ident(); > printk("-------------------------------\n"); > printk("%s:%d %s!\n", file, line, s); > printk("\nother info that might help us debug this:\n\n"); > diff --git a/kernel/panic.c b/kernel/panic.c > index b2659360..ad03fb5 100644 > --- a/kernel/panic.c > +++ b/kernel/panic.c > @@ -233,16 +233,6 @@ unsigned long get_taint(void) > > void add_taint(unsigned flag) > { > - /* > - * Can't trust the integrity of the kernel anymore. > - * We don't call directly debug_locks_off() because the issue > - * is not necessarily serious enough to set oops_in_progress to 1 > - * Also we want to keep up lockdep for staging development and > - * post-warning case. > - */ > - if (flag != TAINT_CRAP && flag != TAINT_WARN && __debug_locks_off()) > - printk(KERN_WARNING "Disabling lock debugging due to kernel taint\n"); > - > set_bit(flag, &tainted_mask); > } > EXPORT_SYMBOL(add_taint); > diff --git a/kernel/rtmutex-debug.c b/kernel/rtmutex-debug.c > index a2e7e72..077257f 100644 > --- a/kernel/rtmutex-debug.c > +++ b/kernel/rtmutex-debug.c > @@ -101,6 +101,7 @@ void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter) > > printk("\n============================================\n"); > printk( "[ BUG: circular locking deadlock detected! ]\n"); > + printk("%s\n", print_tainted()); > printk( "--------------------------------------------\n"); > printk("%s/%d is deadlocking current task %s/%d\n\n", > task->comm, task_pid_nr(task), > -- > 1.7.7 > > >
-- Ben Hutchings We get into the habit of living before acquiring the habit of thinking. - Albert Camus
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