diff options
Diffstat (limited to 'arch/arm64/kernel/proton-pack.c')
| -rw-r--r-- | arch/arm64/kernel/proton-pack.c | 26 |
1 files changed, 7 insertions, 19 deletions
diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c index bfce41c2a53b..fca9cc6f5581 100644 --- a/arch/arm64/kernel/proton-pack.c +++ b/arch/arm64/kernel/proton-pack.c @@ -521,10 +521,13 @@ bool has_spectre_v4(const struct arm64_cpu_capabilities *cap, int scope) return state != SPECTRE_UNAFFECTED; } -static int ssbs_emulation_handler(struct pt_regs *regs, u32 instr) +bool try_emulate_el1_ssbs(struct pt_regs *regs, u32 instr) { - if (user_mode(regs)) - return 1; + const u32 instr_mask = ~(1U << PSTATE_Imm_shift); + const u32 instr_val = 0xd500401f | PSTATE_SSBS; + + if ((instr & instr_mask) != instr_val) + return false; if (instr & BIT(PSTATE_Imm_shift)) regs->pstate |= PSR_SSBS_BIT; @@ -532,19 +535,11 @@ static int ssbs_emulation_handler(struct pt_regs *regs, u32 instr) regs->pstate &= ~PSR_SSBS_BIT; arm64_skip_faulting_instruction(regs, 4); - return 0; + return true; } -static struct undef_hook ssbs_emulation_hook = { - .instr_mask = ~(1U << PSTATE_Imm_shift), - .instr_val = 0xd500401f | PSTATE_SSBS, - .fn = ssbs_emulation_handler, -}; - static enum mitigation_state spectre_v4_enable_hw_mitigation(void) { - static bool undef_hook_registered = false; - static DEFINE_RAW_SPINLOCK(hook_lock); enum mitigation_state state; /* @@ -555,13 +550,6 @@ static enum mitigation_state spectre_v4_enable_hw_mitigation(void) if (state != SPECTRE_MITIGATED || !this_cpu_has_cap(ARM64_SSBS)) return state; - raw_spin_lock(&hook_lock); - if (!undef_hook_registered) { - register_undef_hook(&ssbs_emulation_hook); - undef_hook_registered = true; - } - raw_spin_unlock(&hook_lock); - if (spectre_v4_mitigations_off()) { sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_DSSBS); set_pstate_ssbs(1); |