| Message ID | 1405994239-31834-2-git-send-email-yamada.m@jp.panasonic.com |
|---|---|
| State | Accepted |
| Headers | show |
On Tue, Jul 22, 2014 at 10:57:18AM +0900, Masahiro Yamada wrote: > 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 <yamada.m@jp.panasonic.com> > Cc: Jason Jin <Jason.jin@freescale.com> Applied to u-boot/master, thanks!
diff --git a/board/freescale/m5253demo/flash.c b/board/freescale/m5253demo/flash.c index 16bba59..071701d 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; } }
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 <yamada.m@jp.panasonic.com> Cc: Jason Jin <Jason.jin@freescale.com> --- board/freescale/m5253demo/flash.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)