diff options
| -rw-r--r-- | net/core/sysctl_net_core.c | 38 |
1 files changed, 27 insertions, 11 deletions
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index b60fac380cec..cb8d32e5c14e 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -51,29 +51,45 @@ int sysctl_devconf_inherit_init_net __read_mostly; EXPORT_SYMBOL(sysctl_devconf_inherit_init_net); #if IS_ENABLED(CONFIG_NET_FLOW_LIMIT) || IS_ENABLED(CONFIG_RPS) -static void dump_cpumask(void *buffer, size_t *lenp, loff_t *ppos, - struct cpumask *mask) +static int dump_cpumask(void *buffer, size_t *lenp, loff_t *ppos, + struct cpumask *mask) { - char kbuf[128]; + char *kbuf; int len; if (*ppos || !*lenp) { *lenp = 0; - return; + return 0; + } + + /* CPUs are displayed as a hex bitmap + a comma between each groups of 8 + * nibbles (except the last one which has a newline instead). + * Guesstimate the buffer size at the group granularity level. + */ + len = min(DIV_ROUND_UP(nr_cpumask_bits, 32) * (8 + 1), *lenp); + kbuf = kmalloc(len, GFP_KERNEL); + if (!kbuf) { + *lenp = 0; + return -ENOMEM; } - len = min(sizeof(kbuf) - 1, *lenp); len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask)); if (!len) { *lenp = 0; - return; + goto free_buf; } - if (len < *lenp) - kbuf[len++] = '\n'; + /* scnprintf writes a trailing null char not counted in the returned + * length, override it with a newline. + */ + kbuf[len++] = '\n'; memcpy(buffer, kbuf, len); *lenp = len; *ppos += len; + +free_buf: + kfree(kbuf); + return 0; } #endif @@ -117,8 +133,8 @@ static int rps_default_mask_sysctl(const struct ctl_table *table, int write, if (err) goto done; } else { - dump_cpumask(buffer, lenp, ppos, - net->core.rps_default_mask ? : cpu_none_mask); + err = dump_cpumask(buffer, lenp, ppos, + net->core.rps_default_mask ? : cpu_none_mask); } done: @@ -247,7 +263,7 @@ write_unlock: } rcu_read_unlock(); - dump_cpumask(buffer, lenp, ppos, mask); + ret = dump_cpumask(buffer, lenp, ppos, mask); } done: |