From: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: devicetree-compiler-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: Tom Rini <trini-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>,
Frank Rowand
<frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: [PATCH] libfdt: Add FDT alignment check to fdt_check_header()
Date: Tue, 6 Apr 2021 14:07:12 -0500 [thread overview]
Message-ID: <20210406190712.2118098-1-robh@kernel.org> (raw)
Only checking the FDT alignment in fdt_ro_probe_() means that
fdt_check_header() can pass, but then subsequent API calls fail on
alignment checks. Let's add an alignment check to fdt_check_header() so
alignment errors are found up front.
Cc: Tom Rini <trini-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>
Cc: Frank Rowand <frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Signed-off-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
For background, the new alignment check triggered a crash in the
linux kernel. Yes, we should fix the error handling, but
fdt_check_header() shouldn't tell us the FDT is valid only to fail
later on.
Maybe we should move the check instead, but fdt_ro_probe_() and
fdt_check_header() already have a lot of the same checks.
libfdt/fdt.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/libfdt/fdt.c b/libfdt/fdt.c
index 3e893073da05..9fe7cf4b747d 100644
--- a/libfdt/fdt.c
+++ b/libfdt/fdt.c
@@ -90,6 +90,10 @@ int fdt_check_header(const void *fdt)
{
size_t hdrsize;
+ /* The device tree must be at an 8-byte aligned address */
+ if ((uintptr_t)fdt & 7)
+ return -FDT_ERR_ALIGNMENT;
+
if (fdt_magic(fdt) != FDT_MAGIC)
return -FDT_ERR_BADMAGIC;
if (!can_assume(LATEST)) {
--
2.27.0
next reply other threads:[~2021-04-06 19:07 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-06 19:07 Rob Herring [this message]
[not found] ` <20210406190712.2118098-1-robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2021-04-07 2:45 ` [PATCH] libfdt: Add FDT alignment check to fdt_check_header() David Gibson
2021-04-07 15:35 ` Simon Glass
[not found] ` <CAPnjgZ3fmzymABa4orPYxVQG4SaprSXZa+4AT9=yBYm8B6Md_Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2021-04-07 17:25 ` Rob Herring
[not found] ` <CAL_JsqK+h8v2PY9W2jzoAihFwb+7T0oqkoSKrtOSf1mgYfU1mA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2021-04-07 18:35 ` Simon Glass
2021-04-07 18:09 ` Tom Rini
2021-04-07 18:36 ` Simon Glass
[not found] ` <CAPnjgZ2rGyCVQwQ3aP+=wF99R+2C_POV1Y=18jd8eAd+sOqSZQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2021-04-07 18:39 ` Tom Rini
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