From 66570ec9c465e3c6c5d6dbd7dd42e45041a39288 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Mon, 19 Sep 2016 11:15:51 -0400 Subject: [PATCH] fix undefined behavior in sched.h cpu_set_t usage since cpu sets can be dynamically allocated and have variable size, accessing their contents via ->__bits is not valid; performing pointer arithmetic outside the range of the size of the declared __bits array results in undefined beahavior. instead, only use cpu_set_t for fixed-size cpu set objects (instantiated by the caller) and as an abstract pointer type for dynamically allocated ones. perform all accesses simply by casting the abstract pointer type cpuset_t * back to unsigned long *. --- include/sched.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/include/sched.h b/include/sched.h index af82d6c9..d1cccb70 100644 --- a/include/sched.h +++ b/include/sched.h @@ -82,7 +82,7 @@ int sched_getaffinity(pid_t, size_t, cpu_set_t *); int sched_setaffinity(pid_t, size_t, const cpu_set_t *); #define __CPU_op_S(i, size, set, op) ( (i)/8U >= (size) ? 0 : \ - ((set)->__bits[(i)/8/sizeof(long)] op (1UL<<((i)%(8*sizeof(long))))) ) + (((unsigned long *)(set))[(i)/8/sizeof(long)] op (1UL<<((i)%(8*sizeof(long))))) ) #define CPU_SET_S(i, size, set) __CPU_op_S(i, size, set, |=) #define CPU_CLR_S(i, size, set) __CPU_op_S(i, size, set, &=~) @@ -94,8 +94,8 @@ static __inline void __CPU_##func##_S(size_t __size, cpu_set_t *__dest, \ { \ size_t __i; \ for (__i=0; __i<__size/sizeof(long); __i++) \ - __dest->__bits[__i] = __src1->__bits[__i] \ - op __src2->__bits[__i] ; \ + ((unsigned long *)__dest)[__i] = ((unsigned long *)__src1)[__i] \ + op ((unsigned long *)__src2)[__i] ; \ } __CPU_op_func_S(AND, &) -- GitLab