From: Alexander Shmelev [SPARC32]: Fix bug in sparc optimized memset. Sparc optimized memset (arch/sparc/lib/memset.S) does not fill last byte of the memory area, if area size is less than 8 bytes and start address is not word (4-bytes) aligned. Here is code chunk where bug located: /* %o0 - memory address, %o1 - size, %g3 - value */ 8: add %o0, 1, %o0 subcc %o1, 1, %o1 bne,a 8b stb %g3, [%o0 - 1] This code should write byte every loop iteration, but last time delay instruction stb is not executed because branch instruction sets "annul" bit. Patch replaces bne,a by bne instruction. Error can be reproduced by simple kernel module: -------------------- #include #include #include #include #include static void do_memset(void **p, int size) { memset(p, 0x00, size); } static int __init memset_test_init(void) { char fooc[8]; int *fooi; memset(fooc, 0xba, sizeof(fooc)); do_memset((void**)(fooc + 3), 1); fooi = (int*) fooc; printk("%08X %08X\n", fooi[0], fooi[1]); return -1; } static void __exit memset_test_cleanup(void) { return; } module_init(memset_test_init); module_exit(memset_test_cleanup); MODULE_LICENSE("GPL"); EXPORT_NO_SYMBOLS; ------------------------ Signed-off-by: Alexander Shmelev Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- arch/sparc/lib/memset.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/sparc/lib/memset.S +++ b/arch/sparc/lib/memset.S @@ -162,7 +162,7 @@ __bzero: 8: add %o0, 1, %o0 subcc %o1, 1, %o1 - bne,a 8b + bne 8b EX(stb %g3, [%o0 - 1], add %o1, 1) 0: retl -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/