| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Fri, 2 Aug 2013 14:09:34 -0700
From: David Daney <ddaney.cavm@...il.com>
To: Andrew Morton <akpm@...ux-foundation.org>,
linux-kernel@...r.kernel.org
Cc: David Daney <david.daney@...ium.com>
Subject: [PATCH 1/3] smp: Quit unconditionally enabling irq in on_each_cpu_mask and on_each_cpu_cond
From: David Daney <david.daney@...ium.com>
As in f21afc25f9ed (smp.h: Use local_irq_{save,restore}() in !SMP
version of on_each_cpu().), we don't want to enable irqs if they are
not already enabled. There are currently no known problematical
callers of these functions, but since it is a known failure pattern,
we preemptively fix them.
Since they are not trivial functions, make them non-inline by moving
them to up.c. This also makes it so we don't have to fix #include
dependancies for preempt_{disable,enable}.
Signed-off-by: David Daney <david.daney@...ium.com>
---
include/linux/smp.h | 62 ++++++++++++++---------------------------------------
kernel/up.c | 39 +++++++++++++++++++++++++++++++++
2 files changed, 55 insertions(+), 46 deletions(-)
diff --git a/include/linux/smp.h b/include/linux/smp.h
index c848876..3724a90 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -29,6 +29,22 @@ extern unsigned int total_cpus;
int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
int wait);
+/*
+ * Call a function on processors specified by mask, which might include
+ * the local one.
+ */
+void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
+ void *info, bool wait);
+
+/*
+ * Call a function on each processor for which the supplied function
+ * cond_func returns a positive value. This may include the local
+ * processor.
+ */
+void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
+ smp_call_func_t func, void *info, bool wait,
+ gfp_t gfp_flags);
+
#ifdef CONFIG_SMP
#include <linux/preempt.h>
@@ -101,22 +117,6 @@ static inline void call_function_init(void) { }
int on_each_cpu(smp_call_func_t func, void *info, int wait);
/*
- * Call a function on processors specified by mask, which might include
- * the local one.
- */
-void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
- void *info, bool wait);
-
-/*
- * Call a function on each processor for which the supplied function
- * cond_func returns a positive value. This may include the local
- * processor.
- */
-void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
- smp_call_func_t func, void *info, bool wait,
- gfp_t gfp_flags);
-
-/*
* Mark the boot cpu "online" so that it can call console drivers in
* printk() and can access its per-cpu storage.
*/
@@ -151,36 +151,6 @@ static inline int on_each_cpu(smp_call_func_t func, void *info, int wait)
return 0;
}
-/*
- * Note we still need to test the mask even for UP
- * because we actually can get an empty mask from
- * code that on SMP might call us without the local
- * CPU in the mask.
- */
-#define on_each_cpu_mask(mask, func, info, wait) \
- do { \
- if (cpumask_test_cpu(0, (mask))) { \
- local_irq_disable(); \
- (func)(info); \
- local_irq_enable(); \
- } \
- } while (0)
-/*
- * Preemption is disabled here to make sure the cond_func is called under the
- * same condtions in UP and SMP.
- */
-#define on_each_cpu_cond(cond_func, func, info, wait, gfp_flags)\
- do { \
- void *__info = (info); \
- preempt_disable(); \
- if ((cond_func)(0, __info)) { \
- local_irq_disable(); \
- (func)(__info); \
- local_irq_enable(); \
- } \
- preempt_enable(); \
- } while (0)
-
static inline void smp_send_reschedule(int cpu) { }
#define smp_prepare_boot_cpu() do {} while (0)
#define smp_call_function_many(mask, func, info, wait) \
diff --git a/kernel/up.c b/kernel/up.c
index c54c75e..144e572 100644
--- a/kernel/up.c
+++ b/kernel/up.c
@@ -19,3 +19,42 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
return 0;
}
EXPORT_SYMBOL(smp_call_function_single);
+
+/*
+ * Note we still need to test the mask even for UP
+ * because we actually can get an empty mask from
+ * code that on SMP might call us without the local
+ * CPU in the mask.
+ */
+void on_each_cpu_mask(const struct cpumask *mask,
+ smp_call_func_t func, void *info, bool wait)
+{
+ unsigned long flags;
+
+ if (cpumask_test_cpu(0, mask)) {
+ local_irq_save(flags);
+ func(info);
+ local_irq_restore(flags);
+ }
+}
+EXPORT_SYMBOL(on_each_cpu_mask);
+
+/*
+ * Preemption is disabled here to make sure the cond_func is called under the
+ * same condtions in UP and SMP.
+ */
+void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
+ smp_call_func_t func, void *info, bool wait,
+ gfp_t gfp_flags)
+{
+ unsigned long flags;
+
+ preempt_disable();
+ if (cond_func(0, info)) {
+ local_irq_save(flags);
+ func(info);
+ local_irq_restore(flags);
+ }
+ preempt_enable();
+}
+EXPORT_SYMBOL(on_each_cpu_cond);
--
1.7.11.7
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists