From: zanussi@kernel.org
To: LKML <linux-kernel@vger.kernel.org>,
linux-rt-users <linux-rt-users@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>,
Carsten Emde <C.Emde@osadl.org>, John Kacur <jkacur@redhat.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Daniel Wagner <wagi@monom.org>, Tom Zanussi <zanussi@kernel.org>
Subject: [PATCH RT 13/25] lib/ubsan: Don't seralize UBSAN report
Date: Fri, 21 Feb 2020 15:24:41 -0600 [thread overview]
Message-ID: <979d699889bdefd12405df031feb27f4256d895d.1582320278.git.zanussi@kernel.org> (raw)
In-Reply-To: <cover.1582320278.git.zanussi@kernel.org>
In-Reply-To: <cover.1582320278.git.zanussi@kernel.org>
From: Julien Grall <julien.grall@arm.com>
v4.14.170-rt75-rc1 stable review patch.
If anyone has any objections, please let me know.
-----------
[ Upstream commmit 4702c28ac777b27acb499cbd5e8e787ce1a7d82d ]
At the moment, UBSAN report will be serialized using a spin_lock(). On
RT-systems, spinlocks are turned to rt_spin_lock and may sleep. This will
result to the following splat if the undefined behavior is in a context
that can sleep:
| BUG: sleeping function called from invalid context at /src/linux/kernel/locking/rtmutex.c:968
| in_atomic(): 1, irqs_disabled(): 128, pid: 3447, name: make
| 1 lock held by make/3447:
| #0: 000000009a966332 (&mm->mmap_sem){++++}, at: do_page_fault+0x140/0x4f8
| Preemption disabled at:
| [<ffff000011324a4c>] rt_mutex_futex_unlock+0x4c/0xb0
| CPU: 3 PID: 3447 Comm: make Tainted: G W 5.2.14-rt7-01890-ge6e057589653 #911
| Call trace:
| dump_backtrace+0x0/0x148
| show_stack+0x14/0x20
| dump_stack+0xbc/0x104
| ___might_sleep+0x154/0x210
| rt_spin_lock+0x68/0xa0
| ubsan_prologue+0x30/0x68
| handle_overflow+0x64/0xe0
| __ubsan_handle_add_overflow+0x10/0x18
| __lock_acquire+0x1c28/0x2a28
| lock_acquire+0xf0/0x370
| _raw_spin_lock_irqsave+0x58/0x78
| rt_mutex_futex_unlock+0x4c/0xb0
| rt_spin_unlock+0x28/0x70
| get_page_from_freelist+0x428/0x2b60
| __alloc_pages_nodemask+0x174/0x1708
| alloc_pages_vma+0x1ac/0x238
| __handle_mm_fault+0x4ac/0x10b0
| handle_mm_fault+0x1d8/0x3b0
| do_page_fault+0x1c8/0x4f8
| do_translation_fault+0xb8/0xe0
| do_mem_abort+0x3c/0x98
| el0_da+0x20/0x24
The spin_lock() will protect against multiple CPUs to output a report
together, I guess to prevent them to be interleaved. However, they can
still interleave with other messages (and even splat from __migth_sleep).
So the lock usefulness seems pretty limited. Rather than trying to
accomodate RT-system by switching to a raw_spin_lock(), the lock is now
completely dropped.
Link: https://lkml.kernel.org/r/20190920100835.14999-1-julien.grall@arm.com
Reported-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Conflicts:
lib/ubsan.c
---
lib/ubsan.c | 76 ++++++++++++++++++++++---------------------------------------
1 file changed, 27 insertions(+), 49 deletions(-)
diff --git a/lib/ubsan.c b/lib/ubsan.c
index c652b4a820cc..f94cfb3a41ed 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -147,26 +147,21 @@ static bool location_is_valid(struct source_location *loc)
{
return loc->file_name != NULL;
}
-
-static DEFINE_SPINLOCK(report_lock);
-
-static void ubsan_prologue(struct source_location *location,
- unsigned long *flags)
+static void ubsan_prologue(struct source_location *location)
{
current->in_ubsan++;
- spin_lock_irqsave(&report_lock, *flags);
pr_err("========================================"
"========================================\n");
print_source_location("UBSAN: Undefined behaviour in", location);
}
-static void ubsan_epilogue(unsigned long *flags)
+static void ubsan_epilogue(void)
{
dump_stack();
pr_err("========================================"
"========================================\n");
- spin_unlock_irqrestore(&report_lock, *flags);
+
current->in_ubsan--;
}
@@ -175,14 +170,13 @@ static void handle_overflow(struct overflow_data *data, void *lhs,
{
struct type_descriptor *type = data->type;
- unsigned long flags;
char lhs_val_str[VALUE_LENGTH];
char rhs_val_str[VALUE_LENGTH];
if (suppress_report(&data->location))
return;
- ubsan_prologue(&data->location, &flags);
+ ubsan_prologue(&data->location);
val_to_string(lhs_val_str, sizeof(lhs_val_str), type, lhs);
val_to_string(rhs_val_str, sizeof(rhs_val_str), type, rhs);
@@ -194,7 +188,7 @@ static void handle_overflow(struct overflow_data *data, void *lhs,
rhs_val_str,
type->type_name);
- ubsan_epilogue(&flags);
+ ubsan_epilogue();
}
void __ubsan_handle_add_overflow(struct overflow_data *data,
@@ -222,20 +216,19 @@ EXPORT_SYMBOL(__ubsan_handle_mul_overflow);
void __ubsan_handle_negate_overflow(struct overflow_data *data,
void *old_val)
{
- unsigned long flags;
char old_val_str[VALUE_LENGTH];
if (suppress_report(&data->location))
return;
- ubsan_prologue(&data->location, &flags);
+ ubsan_prologue(&data->location);
val_to_string(old_val_str, sizeof(old_val_str), data->type, old_val);
pr_err("negation of %s cannot be represented in type %s:\n",
old_val_str, data->type->type_name);
- ubsan_epilogue(&flags);
+ ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_negate_overflow);
@@ -243,13 +236,12 @@ EXPORT_SYMBOL(__ubsan_handle_negate_overflow);
void __ubsan_handle_divrem_overflow(struct overflow_data *data,
void *lhs, void *rhs)
{
- unsigned long flags;
char rhs_val_str[VALUE_LENGTH];
if (suppress_report(&data->location))
return;
- ubsan_prologue(&data->location, &flags);
+ ubsan_prologue(&data->location);
val_to_string(rhs_val_str, sizeof(rhs_val_str), data->type, rhs);
@@ -259,58 +251,52 @@ void __ubsan_handle_divrem_overflow(struct overflow_data *data,
else
pr_err("division by zero\n");
- ubsan_epilogue(&flags);
+ ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_divrem_overflow);
static void handle_null_ptr_deref(struct type_mismatch_data_common *data)
{
- unsigned long flags;
-
if (suppress_report(data->location))
return;
- ubsan_prologue(data->location, &flags);
+ ubsan_prologue(data->location);
pr_err("%s null pointer of type %s\n",
type_check_kinds[data->type_check_kind],
data->type->type_name);
- ubsan_epilogue(&flags);
+ ubsan_epilogue();
}
static void handle_misaligned_access(struct type_mismatch_data_common *data,
unsigned long ptr)
{
- unsigned long flags;
-
if (suppress_report(data->location))
return;
- ubsan_prologue(data->location, &flags);
+ ubsan_prologue(data->location);
pr_err("%s misaligned address %p for type %s\n",
type_check_kinds[data->type_check_kind],
(void *)ptr, data->type->type_name);
pr_err("which requires %ld byte alignment\n", data->alignment);
- ubsan_epilogue(&flags);
+ ubsan_epilogue();
}
static void handle_object_size_mismatch(struct type_mismatch_data_common *data,
unsigned long ptr)
{
- unsigned long flags;
-
if (suppress_report(data->location))
return;
- ubsan_prologue(data->location, &flags);
+ ubsan_prologue(data->location);
pr_err("%s address %p with insufficient space\n",
type_check_kinds[data->type_check_kind],
(void *) ptr);
pr_err("for an object of type %s\n", data->type->type_name);
- ubsan_epilogue(&flags);
+ ubsan_epilogue();
}
static void ubsan_type_mismatch_common(struct type_mismatch_data_common *data,
@@ -356,12 +342,10 @@ EXPORT_SYMBOL(__ubsan_handle_type_mismatch_v1);
void __ubsan_handle_nonnull_return(struct nonnull_return_data *data)
{
- unsigned long flags;
-
if (suppress_report(&data->location))
return;
- ubsan_prologue(&data->location, &flags);
+ ubsan_prologue(&data->location);
pr_err("null pointer returned from function declared to never return null\n");
@@ -369,49 +353,46 @@ void __ubsan_handle_nonnull_return(struct nonnull_return_data *data)
print_source_location("returns_nonnull attribute specified in",
&data->attr_location);
- ubsan_epilogue(&flags);
+ ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_nonnull_return);
void __ubsan_handle_vla_bound_not_positive(struct vla_bound_data *data,
void *bound)
{
- unsigned long flags;
char bound_str[VALUE_LENGTH];
if (suppress_report(&data->location))
return;
- ubsan_prologue(&data->location, &flags);
+ ubsan_prologue(&data->location);
val_to_string(bound_str, sizeof(bound_str), data->type, bound);
pr_err("variable length array bound value %s <= 0\n", bound_str);
- ubsan_epilogue(&flags);
+ ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_vla_bound_not_positive);
void __ubsan_handle_out_of_bounds(struct out_of_bounds_data *data, void *index)
{
- unsigned long flags;
char index_str[VALUE_LENGTH];
if (suppress_report(&data->location))
return;
- ubsan_prologue(&data->location, &flags);
+ ubsan_prologue(&data->location);
val_to_string(index_str, sizeof(index_str), data->index_type, index);
pr_err("index %s is out of range for type %s\n", index_str,
data->array_type->type_name);
- ubsan_epilogue(&flags);
+ ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_out_of_bounds);
void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
void *lhs, void *rhs)
{
- unsigned long flags;
struct type_descriptor *rhs_type = data->rhs_type;
struct type_descriptor *lhs_type = data->lhs_type;
char rhs_str[VALUE_LENGTH];
@@ -420,7 +401,7 @@ void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
if (suppress_report(&data->location))
return;
- ubsan_prologue(&data->location, &flags);
+ ubsan_prologue(&data->location);
val_to_string(rhs_str, sizeof(rhs_str), rhs_type, rhs);
val_to_string(lhs_str, sizeof(lhs_str), lhs_type, lhs);
@@ -443,18 +424,16 @@ void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
lhs_str, rhs_str,
lhs_type->type_name);
- ubsan_epilogue(&flags);
+ ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds);
void __ubsan_handle_builtin_unreachable(struct unreachable_data *data)
{
- unsigned long flags;
-
- ubsan_prologue(&data->location, &flags);
+ ubsan_prologue(&data->location);
pr_err("calling __builtin_unreachable()\n");
- ubsan_epilogue(&flags);
+ ubsan_epilogue();
panic("can't return from __builtin_unreachable()");
}
EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);
@@ -462,19 +441,18 @@ EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);
void __ubsan_handle_load_invalid_value(struct invalid_value_data *data,
void *val)
{
- unsigned long flags;
char val_str[VALUE_LENGTH];
if (suppress_report(&data->location))
return;
- ubsan_prologue(&data->location, &flags);
+ ubsan_prologue(&data->location);
val_to_string(val_str, sizeof(val_str), data->type, val);
pr_err("load of value %s is not a valid value for type %s\n",
val_str, data->type->type_name);
- ubsan_epilogue(&flags);
+ ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
--
2.14.1
next prev parent reply other threads:[~2020-02-21 21:26 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-21 21:24 [PATCH RT 00/25] Linux v4.14.170-rt75-rc1 zanussi
2020-02-21 21:24 ` [PATCH RT 01/25] Fix wrong-variable use in irq_set_affinity_notifier zanussi
2020-02-21 21:24 ` [PATCH RT 02/25] x86: preempt: Check preemption level before looking at lazy-preempt zanussi
2020-02-21 21:24 ` [PATCH RT 03/25] sched/deadline: Ensure inactive_timer runs in hardirq context zanussi
2020-02-24 8:33 ` Sebastian Andrzej Siewior
2020-02-25 14:50 ` Juri Lelli
2020-02-21 21:24 ` [PATCH RT 04/25] i2c: hix5hd2: Remove IRQF_ONESHOT zanussi
2020-02-21 21:24 ` [PATCH RT 05/25] i2c: exynos5: " zanussi
2020-02-21 21:24 ` [PATCH RT 06/25] sched: migrate_dis/enable: Use sleeping_lock…() to annotate sleeping points zanussi
2020-02-21 21:24 ` [PATCH RT 07/25] sched: __set_cpus_allowed_ptr: Check cpus_mask, not cpus_ptr zanussi
2020-02-21 21:24 ` [PATCH RT 08/25] sched: Remove dead __migrate_disabled() check zanussi
2020-02-21 21:24 ` [PATCH RT 09/25] sched: migrate disable: Protect cpus_ptr with lock zanussi
2020-02-21 21:24 ` [PATCH RT 10/25] lib/smp_processor_id: Don't use cpumask_equal() zanussi
2020-02-21 21:24 ` [PATCH RT 11/25] futex: Make the futex_hash_bucket spinlock_t again and bring back its old state zanussi
2020-02-21 21:24 ` [PATCH RT 12/25] locking/rtmutex: Clean ->pi_blocked_on in the error case zanussi
2020-02-21 21:24 ` zanussi [this message]
2020-02-21 21:24 ` [PATCH RT 14/25] kmemleak: Change the lock of kmemleak_object to raw_spinlock_t zanussi
2020-02-21 21:24 ` [PATCH RT 15/25] sched: migrate_enable: Use select_fallback_rq() zanussi
2020-02-24 9:43 ` Sebastian Andrzej Siewior
2020-02-24 15:31 ` Tom Zanussi
2020-02-24 16:05 ` Sebastian Andrzej Siewior
2020-02-24 22:15 ` Scott Wood
2020-02-21 21:24 ` [PATCH RT 16/25] Revert "ARM: Initialize split page table locks for vector page" zanussi
2020-02-21 21:24 ` [PATCH RT 17/25] x86/fpu: Don't cache access to fpu_fpregs_owner_ctx zanussi
2020-02-24 8:55 ` Sebastian Andrzej Siewior
2020-02-24 15:12 ` Tom Zanussi
2020-02-21 21:24 ` [PATCH RT 18/25] locking: Make spinlock_t and rwlock_t a RCU section on RT zanussi
2020-02-21 21:24 ` [PATCH RT 19/25] userfaultfd: Use a seqlock instead of seqcount zanussi
2020-02-24 9:03 ` Sebastian Andrzej Siewior
2020-02-24 15:14 ` Tom Zanussi
2020-02-24 16:17 ` Steven Rostedt
2020-02-21 21:24 ` [PATCH RT 20/25] kmemleak: Cosmetic changes zanussi
2020-02-24 9:12 ` Sebastian Andrzej Siewior
2020-02-24 15:18 ` Tom Zanussi
2020-02-24 15:52 ` Sebastian Andrzej Siewior
2020-02-21 21:24 ` [PATCH RT 21/25] smp: Use smp_cond_func_t as type for the conditional function zanussi
2020-02-24 9:52 ` Sebastian Andrzej Siewior
2020-02-24 15:34 ` Tom Zanussi
2020-02-21 21:24 ` [PATCH RT 22/25] mm/memcontrol: Move misplaced local_unlock_irqrestore() zanussi
2020-02-24 9:55 ` Sebastian Andrzej Siewior
2020-02-21 21:24 ` [PATCH RT 23/25] locallock: Include header for the `current' macro zanussi
2020-02-21 21:24 ` [PATCH RT 24/25] sched: Provide migrate_disable/enable() inlines zanussi
2020-02-21 21:24 ` [PATCH RT 25/25] Linux 4.14.170-rt75-rc1 zanussi
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