question about "acpi, nfit: validate ars_status output buffer size"

Hi Dan,

It's really hard to understand commit 82aa37cf0986 ("acpi, nfit:
validate ars_status output buffer size") from Dec 6, 2016.

drivers/acpi/nfit/core.c
139 /* No ARS performed for the current boot */
140 if (status = NFIT_ARS_STATUS_NONE)
141 return -EAGAIN;
142
143 /*

   144                   * ARS interrupted, either we overflowed or some other
   145                   * agent wants the scan to stop.  If we didn't overflow
   146                   * then just continue with the returned results.
   147                   */

148 if (status = NFIT_ARS_STATUS_INTR) {
149 if (ars_status->out_length >= 40 && (ars_status->flags
150 & NFIT_ARS_F_OVERFLOW))

When I read the commit message, it implies that we're being more strict about what we process but actually this is && instead of || so we're being less strict.

The commit message doesn't really describe the user visible effects of this bug. I'm not an expert on ACPI and I have grepped the source but can't figure it out.

Also this isn't aligned the normal way. It should be:

				if (ars_status->out_length >= 40 &&
				    (ars_status->flags & NFIT_ARS_F_OVERFLOW))

151 return -ENOSPC;
152 return 0;
153 }

regards,
dan carpenter

Oh wow... I was only reading that one chunk of the commit and I realized that as soon as I scrolled down. I'm an idiot.

regards,
dan carpenter

Dan, you probably hit the wrong mailing list :-)

Marcelo

Gar... I'm on a role today. :P

regards,
dan carpenter