Files
linux/arch/arm64/include/asm/spectre.h
shechenglong 7f16357378 arm64: proton-pack: Fix hard lockup due to print in scheduler context
Relocate the printk() calls from spectre_v4_mitigations_off() and
spectre_v2_mitigations_off() into setup_system_capabilities() function,
preventing hard lockups caused by printk calls in scheduler context:

  | _raw_spin_lock_nested+168
  | ttwu_queue+180 (rq_lock(rq, &rf); 2nd acquiring the rq->__lock)
  | try_to_wake_up+548
  | wake_up_process+32
  | __up+88
  | up+100
  | __up_console_sem+96
  | console_unlock+696
  | vprintk_emit+428
  | vprintk_default+64
  | vprintk_func+220
  | printk+104
  | spectre_v4_enable_task_mitigation+344
  | __switch_to+100
  | __schedule+1028 (rq_lock(rq, &rf); 1st acquiring the rq->__lock)
  | schedule_idle+48
  | do_idle+388
  | cpu_startup_entry+44
  | secondary_start_kernel+352

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: shechenglong <shechenglong@xfusion.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-11-07 14:49:12 +00:00

124 lines
3.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Interface for managing mitigations for Spectre vulnerabilities.
*
* Copyright (C) 2020 Google LLC
* Author: Will Deacon <will@kernel.org>
*/
#ifndef __ASM_SPECTRE_H
#define __ASM_SPECTRE_H
#define BP_HARDEN_EL2_SLOTS 4
#define __BP_HARDEN_HYP_VECS_SZ ((BP_HARDEN_EL2_SLOTS - 1) * SZ_2K)
#ifndef __ASSEMBLY__
#include <linux/smp.h>
#include <asm/percpu.h>
#include <asm/cpufeature.h>
#include <asm/virt.h>
/* Watch out, ordering is important here. */
enum mitigation_state {
SPECTRE_UNAFFECTED,
SPECTRE_MITIGATED,
SPECTRE_VULNERABLE,
};
struct pt_regs;
struct task_struct;
/*
* Note: the order of this enum corresponds to __bp_harden_hyp_vecs and
* we rely on having the direct vectors first.
*/
enum arm64_hyp_spectre_vector {
/*
* Take exceptions directly to __kvm_hyp_vector. This must be
* 0 so that it used by default when mitigations are not needed.
*/
HYP_VECTOR_DIRECT,
/*
* Bounce via a slot in the hypervisor text mapping of
* __bp_harden_hyp_vecs, which contains an SMC call.
*/
HYP_VECTOR_SPECTRE_DIRECT,
/*
* Bounce via a slot in a special mapping of __bp_harden_hyp_vecs
* next to the idmap page.
*/
HYP_VECTOR_INDIRECT,
/*
* Bounce via a slot in a special mapping of __bp_harden_hyp_vecs
* next to the idmap page, which contains an SMC call.
*/
HYP_VECTOR_SPECTRE_INDIRECT,
};
typedef void (*bp_hardening_cb_t)(void);
struct bp_hardening_data {
enum arm64_hyp_spectre_vector slot;
bp_hardening_cb_t fn;
};
DECLARE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
/* Called during entry so must be __always_inline */
static __always_inline void arm64_apply_bp_hardening(void)
{
struct bp_hardening_data *d;
if (!alternative_has_cap_unlikely(ARM64_SPECTRE_V2))
return;
d = this_cpu_ptr(&bp_hardening_data);
if (d->fn)
d->fn();
}
enum mitigation_state arm64_get_spectre_v2_state(void);
bool has_spectre_v2(const struct arm64_cpu_capabilities *cap, int scope);
void spectre_v2_enable_mitigation(const struct arm64_cpu_capabilities *__unused);
bool has_spectre_v3a(const struct arm64_cpu_capabilities *cap, int scope);
void spectre_v3a_enable_mitigation(const struct arm64_cpu_capabilities *__unused);
enum mitigation_state arm64_get_spectre_v4_state(void);
bool has_spectre_v4(const struct arm64_cpu_capabilities *cap, int scope);
void spectre_v4_enable_mitigation(const struct arm64_cpu_capabilities *__unused);
void spectre_v4_enable_task_mitigation(struct task_struct *tsk);
enum mitigation_state arm64_get_meltdown_state(void);
enum mitigation_state arm64_get_spectre_bhb_state(void);
bool is_spectre_bhb_affected(const struct arm64_cpu_capabilities *entry, int scope);
extern bool __nospectre_bhb;
u8 get_spectre_bhb_loop_value(void);
bool is_spectre_bhb_fw_mitigated(void);
void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *__unused);
bool try_emulate_el1_ssbs(struct pt_regs *regs, u32 instr);
void spectre_v4_patch_fw_mitigation_enable(struct alt_instr *alt, __le32 *origptr,
__le32 *updptr, int nr_inst);
void smccc_patch_fw_mitigation_conduit(struct alt_instr *alt, __le32 *origptr,
__le32 *updptr, int nr_inst);
void spectre_bhb_patch_loop_mitigation_enable(struct alt_instr *alt, __le32 *origptr,
__le32 *updptr, int nr_inst);
void spectre_bhb_patch_fw_mitigation_enabled(struct alt_instr *alt, __le32 *origptr,
__le32 *updptr, int nr_inst);
void spectre_bhb_patch_loop_iter(struct alt_instr *alt,
__le32 *origptr, __le32 *updptr, int nr_inst);
void spectre_bhb_patch_wa3(struct alt_instr *alt,
__le32 *origptr, __le32 *updptr, int nr_inst);
void spectre_bhb_patch_clearbhb(struct alt_instr *alt,
__le32 *origptr, __le32 *updptr, int nr_inst);
void spectre_print_disabled_mitigations(void);
#endif /* __ASSEMBLY__ */
#endif /* __ASM_SPECTRE_H */