From: Masahiro Yamada Date: Tue, 22 Jul 2014 01:57:18 +0000 (+0900) Subject: m68k: fix an undefined behavior warning of M5253DEMO board X-Git-Tag: v2014.10-rc1~83 X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=61f06b143e92de70272627b4cd23d7b1e5af256e;p=u-boot m68k: fix an undefined behavior warning of M5253DEMO board The latest GCC is so clever that it reports more warnings than old ones did: ------------------------------>8------------------------------ board/freescale/m5253demo/flash.c: In function 'flash_get_offsets': board/freescale/m5253demo/flash.c:65:23: warning: iteration 2047u invokes undefined behavior [-Waggressive-loop-optimizations] info->start[k + 1] = info->start[k] + CONFIG_SYS_SST_SECTSZ; ^ board/freescale/m5253demo/flash.c:64:3: note: containing loop for (k = 0, j = 0; j < CONFIG_SYS_SST_SECT; j++, k++) { ^ ------------------------------8<------------------------------ The cause of the warning is like this: The for statement iterates 2048 times in flash_get_offsets() func. (Notice CONFIG_SYS_SST_SECT is defined as 2048) The last iteration does info->start[2048] = info->start[2047] + CONFIG_SYS_SST_SECTSZ; causing an undefined behavior. (Please note the array size of info->start is 2048. CONFIG_SYS_MAX_FLASH_SECT is defined as 2048 for this board.) This commit fixes that so as not to overrun the info->start array. Signed-off-by: Masahiro Yamada Cc: Jason Jin --- diff --git a/board/freescale/m5253demo/flash.c b/board/freescale/m5253demo/flash.c index 16bba59ba8..071701d234 100644 --- a/board/freescale/m5253demo/flash.c +++ b/board/freescale/m5253demo/flash.c @@ -56,14 +56,16 @@ ulong flash_init(void) int flash_get_offsets(ulong base, flash_info_t * info) { - int j, k; + int i; if ((info->flash_id & FLASH_VENDMASK) == FLASH_MAN_SST) { info->start[0] = base; - for (k = 0, j = 0; j < CONFIG_SYS_SST_SECT; j++, k++) { - info->start[k + 1] = info->start[k] + CONFIG_SYS_SST_SECTSZ; - info->protect[k] = 0; + info->protect[0] = 0; + for (i = 1; i < CONFIG_SYS_SST_SECT; i++) { + info->start[i] = info->start[i - 1] + + CONFIG_SYS_SST_SECTSZ; + info->protect[i] = 0; } }