[igt-dev] [PATCH i-g-t] lib/igt_edid: Allocate raw 8-bytes for VSDB

Khem Raj raj.khem at gmail.com
Sat Feb 27 22:10:41 UTC 2021


hdmi_vsdb is an element of cea_vsdb which makes the size of cea_vsdb to
be 8 ( 3bytes ieee_oui ) + ( 5bytes hdmi_vsdb struct), its true that we
only use 7 bytes technically we can only allocate 7byte array but since
we are writing to elements of hdmi_vsdb struct which is sitting at offet
4-8 in cea_vsdb, compiler thinks we have an element which is out of
array bounds since out allocated size is 7bytes

This errors out
../git/lib/igt_edid.c:365:13: error: array subscript 'struct hdmi_vsdb[0]' is partly outside array bounds of 'char[7]' [-Werror=array-bounds]
  365 |         hdmi->src_phy_addr[0] = 0x10;
      |             ^~

allocating one extra byte matches with size of cea_vsdb and compiler is
happy

Signed-off-by: Khem Raj <raj.khem at gmail.com>
---
 lib/igt_edid.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/igt_edid.c b/lib/igt_edid.c
index 1c85486d..ce09cc47 100644
--- a/lib/igt_edid.c
+++ b/lib/igt_edid.c
@@ -351,7 +351,7 @@ void cea_sad_init_pcm(struct cea_sad *sad, int channels,
 const struct cea_vsdb *cea_vsdb_get_hdmi_default(size_t *size)
 {
 	/* We'll generate a VSDB with 2 extension fields. */
-	static char raw[CEA_VSDB_HDMI_MIN_SIZE + 2] = {0};
+	static char raw[CEA_VSDB_HDMI_MIN_SIZE + 3] = {0};
 	struct cea_vsdb *vsdb;
 	struct hdmi_vsdb *hdmi;
 
-- 
2.30.1



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