44 lines
1.7 KiB
Diff
44 lines
1.7 KiB
Diff
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From 66570ec9c465e3c6c5d6dbd7dd42e45041a39288 Mon Sep 17 00:00:00 2001
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From: Rich Felker <dalias@aerifal.cx>
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Date: Mon, 19 Sep 2016 11:15:51 -0400
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Subject: fix undefined behavior in sched.h cpu_set_t usage
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since cpu sets can be dynamically allocated and have variable size,
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accessing their contents via ->__bits is not valid; performing pointer
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arithmetic outside the range of the size of the declared __bits array
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results in undefined beahavior. instead, only use cpu_set_t for
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fixed-size cpu set objects (instantiated by the caller) and as an
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abstract pointer type for dynamically allocated ones. perform all
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accesses simply by casting the abstract pointer type cpuset_t * back
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to unsigned long *.
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---
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include/sched.h | 6 +++---
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1 file changed, 3 insertions(+), 3 deletions(-)
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diff --git a/include/sched.h b/include/sched.h
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index af82d6c..d1cccb7 100644
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--- a/include/sched.h
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+++ b/include/sched.h
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@@ -82,7 +82,7 @@ int sched_getaffinity(pid_t, size_t, cpu_set_t *);
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int sched_setaffinity(pid_t, size_t, const cpu_set_t *);
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#define __CPU_op_S(i, size, set, op) ( (i)/8U >= (size) ? 0 : \
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- ((set)->__bits[(i)/8/sizeof(long)] op (1UL<<((i)%(8*sizeof(long))))) )
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+ (((unsigned long *)(set))[(i)/8/sizeof(long)] op (1UL<<((i)%(8*sizeof(long))))) )
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#define CPU_SET_S(i, size, set) __CPU_op_S(i, size, set, |=)
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#define CPU_CLR_S(i, size, set) __CPU_op_S(i, size, set, &=~)
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@@ -94,8 +94,8 @@ static __inline void __CPU_##func##_S(size_t __size, cpu_set_t *__dest, \
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{ \
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size_t __i; \
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for (__i=0; __i<__size/sizeof(long); __i++) \
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- __dest->__bits[__i] = __src1->__bits[__i] \
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- op __src2->__bits[__i] ; \
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+ ((unsigned long *)__dest)[__i] = ((unsigned long *)__src1)[__i] \
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+ op ((unsigned long *)__src2)[__i] ; \
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}
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__CPU_op_func_S(AND, &)
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--
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