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![Joel Granados](/assets/img/avatar_default.png)
This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) Remove the sentinel from ctl_table arrays. Reduce by one the values used to compare the size of the adjusted arrays. Signed-off-by: Joel Granados <j.granados@samsung.com>
54 lines
1.5 KiB
C
54 lines
1.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef LINUX_PID_SYSCTL_H
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#define LINUX_PID_SYSCTL_H
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#include <linux/pid_namespace.h>
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#if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
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static int pid_mfd_noexec_dointvec_minmax(struct ctl_table *table,
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int write, void *buf, size_t *lenp, loff_t *ppos)
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{
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struct pid_namespace *ns = task_active_pid_ns(current);
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struct ctl_table table_copy;
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int err, scope, parent_scope;
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if (write && !ns_capable(ns->user_ns, CAP_SYS_ADMIN))
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return -EPERM;
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table_copy = *table;
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/* You cannot set a lower enforcement value than your parent. */
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parent_scope = pidns_memfd_noexec_scope(ns->parent);
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/* Equivalent to pidns_memfd_noexec_scope(ns). */
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scope = max(READ_ONCE(ns->memfd_noexec_scope), parent_scope);
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table_copy.data = &scope;
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table_copy.extra1 = &parent_scope;
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err = proc_dointvec_minmax(&table_copy, write, buf, lenp, ppos);
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if (!err && write)
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WRITE_ONCE(ns->memfd_noexec_scope, scope);
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return err;
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}
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static struct ctl_table pid_ns_ctl_table_vm[] = {
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{
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.procname = "memfd_noexec",
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.data = &init_pid_ns.memfd_noexec_scope,
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.maxlen = sizeof(init_pid_ns.memfd_noexec_scope),
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.mode = 0644,
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.proc_handler = pid_mfd_noexec_dointvec_minmax,
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.extra1 = SYSCTL_ZERO,
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.extra2 = SYSCTL_TWO,
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},
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};
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static inline void register_pid_ns_sysctl_table_vm(void)
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{
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register_sysctl("vm", pid_ns_ctl_table_vm);
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}
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#else
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static inline void register_pid_ns_sysctl_table_vm(void) {}
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#endif
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#endif /* LINUX_PID_SYSCTL_H */
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