mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
synced 2025-09-04 10:33:13 +00:00
cbbcfb94c5
Mark Rutland noticed that the task parameter is ignored and
'current' is being used instead. Since this is usually
what its passed, it hasn't yet been causing problems but likely
will as the code gets more testing.
But, once this is fixed, it creates a new bug in copy_thread_gcs()
since the gcs_el_mode isn't yet set for the task before its being
checked. Move gcs_alloc_thread_stack() after the new task's
gcs_el0_mode initialization to avoid this.
Fixes: fc84bc5378 ("arm64/gcs: Context switch GCS state for EL0")
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250719043740.4548-2-jeremy.linton@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
108 lines
2.1 KiB
C
108 lines
2.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2023 ARM Ltd.
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*/
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#ifndef __ASM_GCS_H
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#define __ASM_GCS_H
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#include <asm/types.h>
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#include <asm/uaccess.h>
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struct kernel_clone_args;
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struct ksignal;
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static inline void gcsb_dsync(void)
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{
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asm volatile(".inst 0xd503227f" : : : "memory");
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}
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static inline void gcsstr(u64 *addr, u64 val)
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{
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register u64 *_addr __asm__ ("x0") = addr;
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register long _val __asm__ ("x1") = val;
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/* GCSSTTR x1, x0 */
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asm volatile(
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".inst 0xd91f1c01\n"
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:
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: "rZ" (_val), "r" (_addr)
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: "memory");
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}
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static inline void gcsss1(u64 Xt)
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{
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asm volatile (
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"sys #3, C7, C7, #2, %0\n"
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:
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: "rZ" (Xt)
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: "memory");
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}
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static inline u64 gcsss2(void)
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{
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u64 Xt;
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asm volatile(
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"SYSL %0, #3, C7, C7, #3\n"
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: "=r" (Xt)
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:
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: "memory");
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return Xt;
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}
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#define PR_SHADOW_STACK_SUPPORTED_STATUS_MASK \
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(PR_SHADOW_STACK_ENABLE | PR_SHADOW_STACK_WRITE | PR_SHADOW_STACK_PUSH)
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#ifdef CONFIG_ARM64_GCS
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static inline bool task_gcs_el0_enabled(struct task_struct *task)
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{
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return task->thread.gcs_el0_mode & PR_SHADOW_STACK_ENABLE;
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}
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void gcs_set_el0_mode(struct task_struct *task);
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void gcs_free(struct task_struct *task);
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void gcs_preserve_current_state(void);
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unsigned long gcs_alloc_thread_stack(struct task_struct *tsk,
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const struct kernel_clone_args *args);
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static inline int gcs_check_locked(struct task_struct *task,
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unsigned long new_val)
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{
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unsigned long cur_val = task->thread.gcs_el0_mode;
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cur_val &= task->thread.gcs_el0_locked;
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new_val &= task->thread.gcs_el0_locked;
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if (cur_val != new_val)
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return -EBUSY;
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return 0;
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}
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#else
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static inline bool task_gcs_el0_enabled(struct task_struct *task)
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{
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return false;
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}
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static inline void gcs_set_el0_mode(struct task_struct *task) { }
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static inline void gcs_free(struct task_struct *task) { }
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static inline void gcs_preserve_current_state(void) { }
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static inline unsigned long gcs_alloc_thread_stack(struct task_struct *tsk,
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const struct kernel_clone_args *args)
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{
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return -ENOTSUPP;
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}
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static inline int gcs_check_locked(struct task_struct *task,
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unsigned long new_val)
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{
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return 0;
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}
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#endif
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#endif
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