On Mon, Dec 7, 2015 at 7:36 PM, Kamil Rytarowski <
Kamil.Rytarowski at 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 at 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
