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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>
This commit is contained in:
Christoph Lameter 2014-04-07 15:39:44 -07:00 committed by Linus Torvalds
parent 293b6a4c87
commit 188a81409f
2 changed files with 43 additions and 14 deletions
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39
include/linux/percpu.h
View File

@ -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 */

18
lib/smp_processor_id.c
View File

@ -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);