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From: David Marchand <david.marchand@6wind.com>
To: Kamil Rytarowski <Kamil.Rytarowski@caviumnetworks.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v3 2/2] eal/linux: Add support for handling built-in kernel modules
Date: Mon, 7 Dec 2015 21:45:10 +0100	[thread overview]
Message-ID: <CALwxeUv-GK_VhQyNjYjJ47NJrSyi=EAJn9hab5TCJGi1kEX8oQ@mail.gmail.com> (raw)
In-Reply-To: <1449513365-22282-2-git-send-email-Kamil.Rytarowski@caviumnetworks.com>

On Mon, Dec 7, 2015 at 7:36 PM, Kamil Rytarowski <
Kamil.Rytarowski@caviumnetworks.com> wrote:

> Currently rte_eal_check_module() detects Linux kernel modules via reading
> /proc/modules. Built-in ones aren't listed there and therefore they are not
> being found by the script.
>
> Add support for checking built-in modules with parsing the sysfs files
>
> This commit obsoletes the /proc/modules parsing approach.
>
> Signed-off-by: Kamil Rytarowski <Kamil.Rytarowski@caviumnetworks.com>
> ---
>  lib/librte_eal/linuxapp/eal/eal.c | 32 +++++++++++++++++---------------
>  1 file changed, 17 insertions(+), 15 deletions(-)
>
> diff --git a/lib/librte_eal/linuxapp/eal/eal.c
> b/lib/librte_eal/linuxapp/eal/eal.c
> index 635ec36..539188f 100644
> --- a/lib/librte_eal/linuxapp/eal/eal.c
> +++ b/lib/librte_eal/linuxapp/eal/eal.c
> @@ -52,6 +52,8 @@
>  #if defined(RTE_ARCH_X86_64) || defined(RTE_ARCH_I686)
>  #include <sys/io.h>
>  #endif
> +#include <sys/types.h>
> +#include <sys/stat.h>
>
>  #include <rte_common.h>
>  #include <rte_debug.h>
> @@ -901,27 +903,27 @@ int rte_eal_has_hugepages(void)
>  int
>  rte_eal_check_module(const char *module_name)
>  {
> -       char mod_name[30]; /* Any module names can be longer than 30
> bytes? */
> -       int ret = 0;
> -       int n;
> +       char sysfs_mod_name[PATH_MAX];
> +       struct stat st;
>
>         if (NULL == module_name)
>                 return -1;
>
> -       FILE *fd = fopen("/proc/modules", "r");
> -       if (NULL == fd) {
> -               RTE_LOG(ERR, EAL, "Open /proc/modules failed!"
> -                       " error %i (%s)\n", errno, strerror(errno));
> +       /* Check if there is sysfs mounted */
> +       if (stat("/sys/module", &st) != 0) {
> +               RTE_LOG(DEBUG, EAL, "Open /sys/module failed: %s\n",
> +                       strerror(errno));
>                 return -1;
>         }
>

Not sure making a difference between /sys/module and /sys/module/XXX
presence really helps, but this is the same philosophy as how it was done
before...
So, ok let's go with this.



> -       while (!feof(fd)) {
> -               n = fscanf(fd, "%29s %*[^\n]", mod_name);
> -               if ((n == 1) && !strcmp(mod_name, module_name)) {
> -                       ret = 1;
> -                       break;
> -               }
> +
> +       /* A module might be built-in, therefore try sysfs */
> +       snprintf(sysfs_mod_name, PATH_MAX, "/sys/module/%s", module_name);
> +       if (stat(sysfs_mod_name, &st) != 0) {
> +               RTE_LOG(DEBUG, EAL, "Open %s failed! error %i (%s)\n",
> +                       sysfs_mod_name, errno, strerror(errno));
> +               return 0;
>         }
>

Please, add a check on snprintf return value.
Even if this can't happen, if snprintf fails, stat would access a truncated
or uninitialized (when < 0) path.

With this fixed, you can add my ack.


Thanks.

-- 
David Marchand

  reply	other threads:[~2015-12-07 20:45 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1449499771-31466-1-git-send-email-Kamil.Rytarowski@caviumnetworks.com>
2015-12-07 16:57 ` [dpdk-dev] [PATCH v2 1/2] tools: " Kamil Rytarowski
2015-12-07 16:57   ` [dpdk-dev] [PATCH v2 2/2] eal/linux: " Kamil Rytarowski
2015-12-07 17:14     ` David Marchand
2015-12-07 18:36   ` [dpdk-dev] [PATCH v3 1/2] tools: " Kamil Rytarowski
2015-12-07 18:36     ` [dpdk-dev] [PATCH v3 2/2] eal/linux: " Kamil Rytarowski
2015-12-07 20:45       ` David Marchand [this message]
2015-12-07 20:55       ` Stephen Hemminger
2015-12-08  7:25         ` Panu Matilainen
2015-12-08 13:08           ` Kamil Rytarowski
2015-12-08 15:33     ` [dpdk-dev] [PATCH v4 1/2] tools: " Kamil Rytarowski
2015-12-08 15:33       ` [dpdk-dev] [PATCH v4 2/2] eal/linux: " Kamil Rytarowski
2015-12-09  7:30         ` Panu Matilainen
2015-12-09 13:28           ` Kamil Rytarowski
2015-12-09 13:19       ` [dpdk-dev] [PATCH v5 1/2] tools: " Kamil Rytarowski
2015-12-09 13:19         ` [dpdk-dev] [PATCH v5 2/2] eal/linux: " Kamil Rytarowski
2015-12-09 16:38           ` Stephen Hemminger
2015-12-09 16:45             ` Kamil Rytarowski
2016-01-18 14:22           ` Yuanhan Liu
2016-01-19 16:38             ` Kamil Rytarowski
2015-12-16 14:14         ` [dpdk-dev] [PATCH v5 1/2] tools: " Kamil Rytarowski
2016-01-18  9:26           ` Kamil Rytarowski
2016-01-18 14:21         ` Yuanhan Liu
2016-01-19 16:34           ` Kamil Rytarowski
2016-01-18 14:32         ` Thomas Monjalon
2016-01-19 16:35           ` Kamil Rytarowski
2016-01-26 15:12             ` Thomas Monjalon
2016-01-28 11:16               ` Kamil Rytarowski
2016-01-20  9:48         ` [dpdk-dev] [PATCH v6 " krytarowski
2016-01-20  9:48           ` [dpdk-dev] [PATCH v6 2/2] eal/linux: " krytarowski
2016-01-26  9:31           ` [dpdk-dev] [PATCH v6 1/2] tools: " Kamil Rytarowski
2016-01-26 15:23           ` Thomas Monjalon
2016-01-28 11:17             ` Kamil Rytarowski
2016-01-28 11:22               ` Panu Matilainen
2016-01-28 12:54                 ` Kamil Rytarowski
2016-01-28 13:52               ` Thomas Monjalon
2016-01-28 15:33                 ` Kamil Rytarowski
2016-01-28 13:13           ` [dpdk-dev] [PATCH v7 " krytarowski
2016-01-28 13:13             ` [dpdk-dev] [PATCH v7 2/2] eal/linux: " krytarowski
2016-02-09 14:56               ` Thomas Monjalon
2016-02-09 16:07                 ` Kamil Rytarowski
2016-01-29  7:21             ` [dpdk-dev] [PATCH v7 1/2] tools: " Yuanhan Liu
2016-02-08 22:14               ` Kamil Rytarowski

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