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authorChristoph Lameter <cl@linux.com>2014-04-07 15:39:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-07 16:36:14 -0700
commit188a81409ff7de1c5aae947a96356ddd8ff4aaa3 (patch)
tree7f2780e62f8a3b33c3cc6ef8b68ee05790909a8d
parent293b6a4c875c3b49853bff7de99954f49f59aa75 (diff)
percpu: add preemption checks to __this_cpu ops
We define a check function in order to avoid trouble with the include files. Then the higher level __this_cpu macros are modified to invoke the preemption check. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Tested-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/percpu.h39
-rw-r--r--lib/smp_processor_id.c18
2 files changed, 43 insertions, 14 deletions
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 4e4d2afcc0c7..e7a0b95ed527 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -173,6 +173,12 @@ extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
extern void __bad_size_call_parameter(void);
+#ifdef CONFIG_DEBUG_PREEMPT
+extern void __this_cpu_preempt_check(const char *op);
+#else
+static inline void __this_cpu_preempt_check(const char *op) { }
+#endif
+
#define __pcpu_size_call_return(stem, variable) \
({ typeof(variable) pscr_ret__; \
__verify_pcpu_ptr(&(variable)); \
@@ -725,18 +731,24 @@ do { \
/*
* Generic percpu operations for context that are safe from preemption/interrupts.
- * Checks will be added here soon.
*/
#ifndef __this_cpu_read
-# define __this_cpu_read(pcp) __pcpu_size_call_return(raw_cpu_read_, (pcp))
+# define __this_cpu_read(pcp) \
+ (__this_cpu_preempt_check("read"),__pcpu_size_call_return(raw_cpu_read_, (pcp)))
#endif
#ifndef __this_cpu_write
-# define __this_cpu_write(pcp, val) __pcpu_size_call(raw_cpu_write_, (pcp), (val))
+# define __this_cpu_write(pcp, val) \
+do { __this_cpu_preempt_check("write"); \
+ __pcpu_size_call(raw_cpu_write_, (pcp), (val)); \
+} while (0)
#endif
#ifndef __this_cpu_add
-# define __this_cpu_add(pcp, val) __pcpu_size_call(raw_cpu_add_, (pcp), (val))
+# define __this_cpu_add(pcp, val) \
+do { __this_cpu_preempt_check("add"); \
+ __pcpu_size_call(raw_cpu_add_, (pcp), (val)); \
+} while (0)
#endif
#ifndef __this_cpu_sub
@@ -752,16 +764,23 @@ do { \
#endif
#ifndef __this_cpu_and
-# define __this_cpu_and(pcp, val) __pcpu_size_call(raw_cpu_and_, (pcp), (val))
+# define __this_cpu_and(pcp, val) \
+do { __this_cpu_preempt_check("and"); \
+ __pcpu_size_call(raw_cpu_and_, (pcp), (val)); \
+} while (0)
+
#endif
#ifndef __this_cpu_or
-# define __this_cpu_or(pcp, val) __pcpu_size_call(raw_cpu_or_, (pcp), (val))
+# define __this_cpu_or(pcp, val) \
+do { __this_cpu_preempt_check("or"); \
+ __pcpu_size_call(raw_cpu_or_, (pcp), (val)); \
+} while (0)
#endif
#ifndef __this_cpu_add_return
# define __this_cpu_add_return(pcp, val) \
- __pcpu_size_call_return2(raw_cpu_add_return_, pcp, val)
+ (__this_cpu_preempt_check("add_return"),__pcpu_size_call_return2(raw_cpu_add_return_, pcp, val))
#endif
#define __this_cpu_sub_return(pcp, val) __this_cpu_add_return(pcp, -(typeof(pcp))(val))
@@ -770,17 +789,17 @@ do { \
#ifndef __this_cpu_xchg
# define __this_cpu_xchg(pcp, nval) \
- __pcpu_size_call_return2(raw_cpu_xchg_, (pcp), nval)
+ (__this_cpu_preempt_check("xchg"),__pcpu_size_call_return2(raw_cpu_xchg_, (pcp), nval))
#endif
#ifndef __this_cpu_cmpxchg
# define __this_cpu_cmpxchg(pcp, oval, nval) \
- __pcpu_size_call_return2(raw_cpu_cmpxchg_, pcp, oval, nval)
+ (__this_cpu_preempt_check("cmpxchg"),__pcpu_size_call_return2(raw_cpu_cmpxchg_, pcp, oval, nval))
#endif
#ifndef __this_cpu_cmpxchg_double
# define __this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
- __pcpu_double_call_return_bool(raw_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
+ (__this_cpu_preempt_check("cmpxchg_double"),__pcpu_double_call_return_bool(raw_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2)))
#endif
#endif /* __LINUX_PERCPU_H */
diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c
index 04abe53f12a1..1afec32de6f2 100644
--- a/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -7,7 +7,8 @@
#include <linux/kallsyms.h>
#include <linux/sched.h>
-notrace unsigned int debug_smp_processor_id(void)
+notrace static unsigned int check_preemption_disabled(const char *what1,
+ const char *what2)
{
int this_cpu = raw_smp_processor_id();
@@ -38,9 +39,9 @@ notrace unsigned int debug_smp_processor_id(void)
if (!printk_ratelimit())
goto out_enable;
- printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] "
- "code: %s/%d\n",
- preempt_count() - 1, current->comm, current->pid);
+ printk(KERN_ERR "BUG: using %s%s() in preemptible [%08x] code: %s/%d\n",
+ what1, what2, preempt_count() - 1, current->comm, current->pid);
+
print_symbol("caller is %s\n", (long)__builtin_return_address(0));
dump_stack();
@@ -50,5 +51,14 @@ out:
return this_cpu;
}
+notrace unsigned int debug_smp_processor_id(void)
+{
+ return check_preemption_disabled("smp_processor_id", "");
+}
EXPORT_SYMBOL(debug_smp_processor_id);
+notrace void __this_cpu_preempt_check(const char *op)
+{
+ check_preemption_disabled("__this_cpu_", op);
+}
+EXPORT_SYMBOL(__this_cpu_preempt_check);