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use unsigned int to do byte swap (misaligned memory access) #113

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Merged
merged 1 commit into from
Dec 7, 2023
Merged

use unsigned int to do byte swap (misaligned memory access) #113

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55 changes: 35 additions & 20 deletions src/drivers/common/ncx.m4
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Original file line number Diff line number Diff line change
Expand Up @@ -878,13 +878,37 @@ typedef long ix_int;
#endif


#if USHORT_MAX == X_UINT_MAX
typedef ushort ix_uint;
#define SIZEOF_IX_UINT SIZEOF_USHORT
#define IX_UINT_MAX USHORT_MAX
#elif UINT_MAX >= X_UINT_MAX
typedef uint ix_uint;
#define SIZEOF_IX_UINT SIZEOF_UINT
#define IX_UINT_MAX UINT_MAX
#elif ULONG_MAX >= X_UINT_MAX
typedef ulong ix_uint;
#define SIZEOF_IX_UINT SIZEOF_ULONG
#define IX_UINT_MAX ULONG_MAX
#else
#error "ix_uint implementation"
#endif


static void
get_ix_int(const void *xp, ix_int *ip)
{
#ifdef WORDS_BIGENDIAN
memcpy(ip, xp, 4);
#else
ix_int tmp;

/* must use unsigned type to do byte swap. Otherwise, we may get error
* message below when using "-fsanitize=undefined" compile flag:
* runtime error: left shift of 1618607871 by 8 places cannot be
* represented in type 'int'
*/

ix_uint tmp;
memcpy(&tmp, xp, 4);
*ip = SWAP4(tmp);
#endif
Expand All @@ -896,8 +920,16 @@ put_ix_int(void *xp, const ix_int *ip)
#ifdef WORDS_BIGENDIAN
memcpy(xp, ip, 4);
#else
ix_int xtmp, itmp = *ip;
xtmp = SWAP4(itmp);

/* must use unsigned type to do byte swap. Otherwise, we may get error
* message below when using "-fsanitize=undefined" compile flag:
* runtime error: left shift of 1618607871 by 8 places cannot be
* represented in type 'int'
*/

ix_uint xtmp;
memcpy(&xtmp, ip, 4);
xtmp = SWAP4(xtmp);
memcpy(xp, &xtmp, 4);
#endif
}
Expand Down Expand Up @@ -962,23 +994,6 @@ NCX_PUT1F(int, double)

/* external NC_UINT ---------------------------------------------------------*/

#if USHORT_MAX == X_UINT_MAX
typedef ushort ix_uint;
#define SIZEOF_IX_UINT SIZEOF_USHORT
#define IX_UINT_MAX USHORT_MAX
#elif UINT_MAX >= X_UINT_MAX
typedef uint ix_uint;
#define SIZEOF_IX_UINT SIZEOF_UINT
#define IX_UINT_MAX UINT_MAX
#elif ULONG_MAX >= X_UINT_MAX
typedef ulong ix_uint;
#define SIZEOF_IX_UINT SIZEOF_ULONG
#define IX_UINT_MAX ULONG_MAX
#else
#error "ix_uint implementation"
#endif


static void
get_ix_uint(const void *xp, ix_uint *ip)
{
Expand Down