From patchwork Wed Jun 24 12:44:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Simek X-Patchwork-Id: 242862 List-Id: U-Boot discussion From: michal.simek at xilinx.com (Michal Simek) Date: Wed, 24 Jun 2020 14:44:20 +0200 Subject: [PATCH] arm64: zynqmp: Fix set_fdtfile() not to break u-boots DTB Message-ID: <5192ad3001c704c47cb578746f3200aab1dabd94.1593002658.git.michal.simek@xilinx.com> Origin function was calling strsep which replaced delimiter ',' by a null byte ('\0'). Operation was done directly on FDT which ends up with the following behavior: ZynqMP> printenv fdtfile fdtfile=xilinx/zynqmp.dtb ZynqMP> fdt addr $fdtcontroladdr ZynqMP> fdt print / compatible compatible = "xlnx", "zynqmp" As is visible fdtfile was correctly composed but a null byte caused that xlnx was separated from zynqmp. This hasn't been spotted because in all Xilinx DTs there are at least 3 compatible string and only the first one was affected by this issue. But for systems which only had one compatible string "xlnx,zynqmp" it was causing an issue when U-Boot's DT was used by Linux kernel. The patch removes strsep calling and strchr is called instead which just locate the first char after deliminator ',' (variable called "name"). And using this pointer in fdtfile composing. Fixes: 91d7e0c47f51 ("arm64: zynqmp: Create fdtfile from compatible string") Signed-off-by: Michal Simek Reported-by: Igor Lantsman Signed-off-by: Igor Lantsman --- board/xilinx/zynqmp/zynqmp.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/board/xilinx/zynqmp/zynqmp.c b/board/xilinx/zynqmp/zynqmp.c index ebb71729081d..8a4df6fc1ab6 100644 --- a/board/xilinx/zynqmp/zynqmp.c +++ b/board/xilinx/zynqmp/zynqmp.c @@ -541,23 +541,30 @@ static int set_fdtfile(void) char *compatible, *fdtfile; const char *suffix = ".dtb"; const char *vendor = "xilinx/"; + int fdt_compat_len; if (env_get("fdtfile")) return 0; - compatible = (char *)fdt_getprop(gd->fdt_blob, 0, "compatible", NULL); - if (compatible) { + compatible = (char *)fdt_getprop(gd->fdt_blob, 0, "compatible", + &fdt_compat_len); + if (compatible && fdt_compat_len) { + char *name; + debug("Compatible: %s\n", compatible); - /* Discard vendor prefix */ - strsep(&compatible, ","); + name = strchr(compatible, ','); + if (!name) + return -EINVAL; + + name++; - fdtfile = calloc(1, strlen(vendor) + strlen(compatible) + + fdtfile = calloc(1, strlen(vendor) + strlen(name) + strlen(suffix) + 1); if (!fdtfile) return -ENOMEM; - sprintf(fdtfile, "%s%s%s", vendor, compatible, suffix); + sprintf(fdtfile, "%s%s%s", vendor, name, suffix); env_set("fdtfile", fdtfile); free(fdtfile);