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Modernize manual memzero implementation

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Instead of using volatile pointers to prevent the compiler from
optimizing the call away, use a memory barrier.
This requires support for embedded assembly, which should be fine after
the recent requirement bumps.
This commit is contained in:
Christian Göttsche
2023-01-24 15:44:35 +01:00
committed by Iker Pedrosa
parent 90ead3cfb8
commit e0d79ee032
1 changed files with 2 additions and 4 deletions
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6
lib/defines.h
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@ -54,10 +54,8 @@
#else /* !HAVE_MEMSET_S && HAVE_EXPLICIT_BZERO */ #else /* !HAVE_MEMSET_S && HAVE_EXPLICIT_BZERO */
static inline void memzero(void *ptr, size_t size) static inline void memzero(void *ptr, size_t size)
{ {
volatile unsigned char * volatile p = ptr; ptr = memset(ptr, '\0', size);
while (size--) { __asm__ __volatile__ ("" : : "r"(ptr) : "memory");
*p++ = '\0';
}
} }
#endif /* !HAVE_MEMSET_S && !HAVE_EXPLICIT_BZERO */ #endif /* !HAVE_MEMSET_S && !HAVE_EXPLICIT_BZERO */