From 461da1de5ee6ee7f4848840d296c28a60c8b50e7 Mon Sep 17 00:00:00 2001 From: Alexander Shmelev Date: Tue, 24 Jul 2007 21:44:48 -0700 Subject: [PATCH] [PATCH] Fix sparc32 memset() [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 Signed-off-by: Willy Tarreau --- arch/sparc/lib/memset.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/sparc/lib/memset.S b/arch/sparc/lib/memset.S index a65eba41097c..1c37ea892deb 100644 --- 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