From: Greg KH <gregkh@linuxfoundation.org>
To: Rajat Jain <rajatja@google.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: PCI/AER sysfs files violate the rules of how sysfs works
Date: Fri, 21 Jun 2019 09:29:11 +0200 [thread overview]
Message-ID: <20190621072911.GA21600@kroah.com> (raw)
Hi,
When working on some documentation scripts to show the
Documentation/ABI/ files in an automated way, I ran across this "gem" of
a sysfs file: Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats
In it you describe how the files
/sys/bus/pci/devices/<dev>/aer_dev_correctable and
/sys/bus/pci/devices/<dev>/aer_dev_fatal and
/sys/bus/pci/devices/<dev>/aer_dev_nonfatal
all display a bunch of text on multiple lines.
This violates the "one value per sysfs file" rule, and should never have
been merged as-is :(
Please fix it up to be a lot of individual files if your really need all
of those different values.
Remember, sysfs files should never have to have a parser to read them
other than a simple "what is this single value", and you should NEVER
have fun macros like:
for (i = 0; i < ARRAY_SIZE(strings_array); i++) { \
if (strings_array[i]) \
str += sprintf(str, "%s %llu\n", \
strings_array[i], stats[i]); \
else if (stats[i]) \
str += sprintf(str, #stats_array "_bit[%d] %llu\n",\
i, stats[i]); \
} \
str += sprintf(str, "TOTAL_%s %llu\n", total_string, \
pdev->aer_stats->total_field); \
spit out sysfs information.
Note, I am all for not properly checking the length of the sysfs file
when writing to it, but that is ONLY because you "know" that a single
integer will never overflow anything. Here you are writing a ton of
different values, with no error checking at all. So just when I thought
it couldn't be any worse...
Please fix.
thanks,
greg k-h
next reply other threads:[~2019-06-21 7:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-21 7:29 Greg KH [this message]
2019-06-21 14:15 ` PCI/AER sysfs files violate the rules of how sysfs works Bjorn Helgaas
2019-06-21 14:44 ` Greg KH
2019-06-28 0:56 ` Rajat Jain
2019-06-28 8:44 ` Greg KH
[not found] ` <CACK8Z6GeAheLfmPcYXNnrTn1Rg7C-rndi_YCxiLsePapGCMmzw@mail.gmail.com>
2019-06-21 14:45 ` Greg Kroah-Hartman
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