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128 lines
2.4 KiB
128 lines
2.4 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright IBM Corp. 2016 |
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* Author(s): Martin Schwidefsky <[email protected]> |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/syscalls.h> |
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#include <linux/signal.h> |
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#include <linux/mm.h> |
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#include <linux/slab.h> |
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#include <asm/guarded_storage.h> |
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#include "entry.h" |
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void guarded_storage_release(struct task_struct *tsk) |
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{ |
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kfree(tsk->thread.gs_cb); |
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kfree(tsk->thread.gs_bc_cb); |
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} |
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static int gs_enable(void) |
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{ |
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struct gs_cb *gs_cb; |
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if (!current->thread.gs_cb) { |
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gs_cb = kzalloc(sizeof(*gs_cb), GFP_KERNEL); |
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if (!gs_cb) |
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return -ENOMEM; |
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gs_cb->gsd = 25; |
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preempt_disable(); |
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__ctl_set_bit(2, 4); |
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load_gs_cb(gs_cb); |
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current->thread.gs_cb = gs_cb; |
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preempt_enable(); |
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} |
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return 0; |
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} |
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static int gs_disable(void) |
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{ |
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if (current->thread.gs_cb) { |
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preempt_disable(); |
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kfree(current->thread.gs_cb); |
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current->thread.gs_cb = NULL; |
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__ctl_clear_bit(2, 4); |
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preempt_enable(); |
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} |
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return 0; |
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} |
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static int gs_set_bc_cb(struct gs_cb __user *u_gs_cb) |
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{ |
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struct gs_cb *gs_cb; |
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gs_cb = current->thread.gs_bc_cb; |
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if (!gs_cb) { |
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gs_cb = kzalloc(sizeof(*gs_cb), GFP_KERNEL); |
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if (!gs_cb) |
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return -ENOMEM; |
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current->thread.gs_bc_cb = gs_cb; |
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} |
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if (copy_from_user(gs_cb, u_gs_cb, sizeof(*gs_cb))) |
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return -EFAULT; |
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return 0; |
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} |
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static int gs_clear_bc_cb(void) |
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{ |
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struct gs_cb *gs_cb; |
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gs_cb = current->thread.gs_bc_cb; |
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current->thread.gs_bc_cb = NULL; |
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kfree(gs_cb); |
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return 0; |
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} |
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void gs_load_bc_cb(struct pt_regs *regs) |
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{ |
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struct gs_cb *gs_cb; |
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preempt_disable(); |
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clear_thread_flag(TIF_GUARDED_STORAGE); |
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gs_cb = current->thread.gs_bc_cb; |
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if (gs_cb) { |
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kfree(current->thread.gs_cb); |
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current->thread.gs_bc_cb = NULL; |
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__ctl_set_bit(2, 4); |
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load_gs_cb(gs_cb); |
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current->thread.gs_cb = gs_cb; |
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} |
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preempt_enable(); |
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} |
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static int gs_broadcast(void) |
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{ |
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struct task_struct *sibling; |
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read_lock(&tasklist_lock); |
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for_each_thread(current, sibling) { |
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if (!sibling->thread.gs_bc_cb) |
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continue; |
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if (test_and_set_tsk_thread_flag(sibling, TIF_GUARDED_STORAGE)) |
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kick_process(sibling); |
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} |
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read_unlock(&tasklist_lock); |
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return 0; |
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} |
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SYSCALL_DEFINE2(s390_guarded_storage, int, command, |
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struct gs_cb __user *, gs_cb) |
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{ |
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if (!MACHINE_HAS_GS) |
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return -EOPNOTSUPP; |
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switch (command) { |
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case GS_ENABLE: |
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return gs_enable(); |
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case GS_DISABLE: |
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return gs_disable(); |
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case GS_SET_BC_CB: |
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return gs_set_bc_cb(gs_cb); |
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case GS_CLEAR_BC_CB: |
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return gs_clear_bc_cb(); |
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case GS_BROADCAST: |
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return gs_broadcast(); |
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default: |
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return -EINVAL; |
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} |
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}
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