From 188a81409ff7de1c5aae947a96356ddd8ff4aaa3 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Mon, 7 Apr 2014 15:39:44 -0700 Subject: [PATCH] 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 Acked-by: Ingo Molnar Cc: Tejun Heo Tested-by: Grygorii Strashko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/percpu.h | 39 +++++++++++++++++++++++++++++---------- lib/smp_processor_id.c | 18 ++++++++++++++---- 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 #include -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); -- 2.30.2