On 3/30/22 1:01 PM, Andy Shevchenko wrote:
On Wed, Mar 30, 2022 at 7:49 PM Sean Anderson <sean...@gmail.com> wrote:

We should only access console_devices[file][i] once we have checked that
i < cd_count[file]. Otherwise, we will access uninitialized memory at the end of
the loop. console_devices[file][i] should not be NULL, but putting the
assignment in the loop condition allows us to ensure that i is checked
beforehand. This isn't a bug, but it does make valgrind stop complaining.

Fixes: 400797cad3 ("IOMUX: Split out for_each_console_dev() helper macro")

Has this been tested? See below.

Yes.

...

  #define for_each_console_dev(i, file, dev)             \
-       for (i = 0, dev = console_devices[file][i];     \

When we enter the loop, the dev is assigned and perhaps valid

-            i < cd_count[file];                        \
-            i++, dev = console_devices[file][i])
+       for (i = 0; i < cd_count[file] &&               \

Not the case anymore.

The loop condition is evaluated before we enter the loop,
which includes the first assignment to dev.

--Sean

+               (dev = console_devices[file][i]); i++)




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