From a9f7d0a7a7b134004b92092831bdefc6faf8213c Mon Sep 17 00:00:00 2001 From: Jeff Johnston Date: Wed, 2 Jul 2008 18:17:48 +0000 Subject: 2008-07-02 Jeff Johnston * libc/machine/mips/strncpy.c (strncpy): Fix logic so unaligned source data is taken care of before loop unrolling. --- newlib/libc/machine/mips/strncpy.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'newlib/libc/machine/mips/strncpy.c') diff --git a/newlib/libc/machine/mips/strncpy.c b/newlib/libc/machine/mips/strncpy.c index a2ceb2c77..324c45209 100644 --- a/newlib/libc/machine/mips/strncpy.c +++ b/newlib/libc/machine/mips/strncpy.c @@ -82,6 +82,26 @@ strncpy (char *dst0, const char *src0, size_t count) dst = (unsigned char *)dst0; src = (unsigned const char *)src0; + /* Take care of any odd bytes in the source data because we + * want to unroll where we read ahead 2 or 4 bytes at a time and then + * check each byte for the null terminator. This can result in + * a segfault for the case where the source pointer is unaligned, + * the null terminator is in valid memory, but reading 2 or 4 bytes at a + * time blindly eventually goes outside of valid memory. */ + while ((src & (UNROLL_FACTOR - 1)) != 0 && count > 0) + { + *dst++ = ch = *src++; + --count; + if (ch == '\0') + { + end = dst + count; + while (dst != end) + *dst++ = '\0'; + + return dst0; + } + } + if (__builtin_expect (count >= 4, 1)) { odd_bytes = (count & (UNROLL_FACTOR - 1)); -- cgit v1.2.3