From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: David Hunt <david.hunt@intel.com>, dev@dpdk.org
Cc: stable@dpdk.org
Subject: Re: [dpdk-stable] [PATCH] lib/power: fix governor storage to trim newlines
Date: Fri, 29 Mar 2019 16:25:47 +0000 [thread overview]
Message-ID: <abf8228d-9c7d-d4b6-753e-44fe8077c20e@intel.com> (raw)
In-Reply-To: <20190329161142.39787-1-david.hunt@intel.com>
On 29-Mar-19 4:11 PM, David Hunt wrote:
> Currently the Power Libray stores the governor name with an embedded
> newline read from the scaling_governor sysfs file. This patch strips
> it out.
>
> Fixes: 445c6528b55f ("power: common interface for guest and host")
> Cc: stable@dpdk.org
>
> Signed-off-by: David Hunt <david.hunt@intel.com>
> ---
> lib/librte_power/power_acpi_cpufreq.c | 4 ++++
> lib/librte_power/power_pstate_cpufreq.c | 4 ++++
> 2 files changed, 8 insertions(+)
>
> diff --git a/lib/librte_power/power_acpi_cpufreq.c b/lib/librte_power/power_acpi_cpufreq.c
> index 45412f0b9..c2febdf06 100644
> --- a/lib/librte_power/power_acpi_cpufreq.c
> +++ b/lib/librte_power/power_acpi_cpufreq.c
> @@ -147,6 +147,10 @@ power_set_governor_userspace(struct rte_power_info *pi)
>
> s = fgets(buf, sizeof(buf), f);
> FOPS_OR_NULL_GOTO(s, out);
> + buf[BUFSIZ-1] = '\0';
> + if (strlen(buf))
> + /* Strip off terminating '\n' */
> + strtok(buf, "\n");
I have a feeling that either strlen or strtok here is unnecessary.
If it's always terminating - you can just use strlen return value and
overwrite the '\n' without going over the string the second time - you
know where the string ends!
You have already written null-terminator to the end of the buffer, so it
can't overflow on strtok, so you don't really need strlen either,
because the string will either:
1) be empty (in which case strtok does nothing)
2) contain text + newline (in which case you cut off the newline and
leave the text - no need for strlen), or
3) contain just a newline (which would make it empty after strtok)
Did you mean to only cut off the newline off the strings that have stuff
other than newline? That would be the only case where using strlen would
make sense - in which case, not only the check is wrong, but you could
also replace it with a simple 'if (buf[0] != '\n')' check instead of strlen.
--
Thanks,
Anatoly
next prev parent reply other threads:[~2019-03-29 16:25 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-29 16:11 David Hunt
2019-03-29 16:24 ` [dpdk-stable] [dpdk-dev] " Bruce Richardson
2019-03-29 16:25 ` Burakov, Anatoly [this message]
2019-03-29 16:35 ` [dpdk-stable] " Hunt, David
2019-03-29 16:39 ` [dpdk-stable] [PATCH v2] " David Hunt
2019-03-29 17:56 ` Burakov, Anatoly
2019-04-01 20:24 ` [dpdk-stable] [dpdk-dev] " Thomas Monjalon
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