[Deepin-Kernel-SIG] [linux 6.6-y] 修复 ARM64 架构下 HAOC 启用时可能出现的休眠后崩溃问题 #878
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Reviewer's GuideThis PR adds synchronization barriers and restructures ASID management by shifting the IEE ASID into TTBR0 and restoring the kernel’s use of TTBR1, refactors the IEE SIP handler to handle new context-switch flags, updates the kernel MM path to segregate user and IEE ASIDs, and cleans up legacy initialization code to prevent resume-from-suspend crashes and eliminate conflicts with KPTI. Sequence Diagram for Updated IEE Context SwitchsequenceDiagram
participant Kernel as cpu_do_switch_mm
participant IEE_SIP as iee_rwx_gate
participant IEE_SI as iee_si_handler
participant CPU_Regs as CPU Registers
Kernel->>IEE_SIP: Call iee_rwx_gate(IEE_SI_CONTEXT_SWITCH, ttbr1_with_user_ASID, ttbr0_base_pgd)
IEE_SIP->>CPU_Regs: Modify TCR_EL1.A1 = 0 (selects TTBR0 for ASID lookup)
IEE_SIP->>IEE_SI: Call iee_si_handler(IEE_SI_CONTEXT_SWITCH, ttbr1_with_user_ASID, ttbr0_base_pgd)
IEE_SI->>CPU_Regs: Write ttbr1_with_user_ASID to TTBR1_EL1
IEE_SI->>CPU_Regs: Write (ttbr0_base_pgd | IEE_ASID) to TTBR0_EL1
IEE_SI-->>IEE_SIP: Return
IEE_SIP->>IEE_SIP: Execute ISB instruction
IEE_SIP->>CPU_Regs: Modify TCR_EL1.A1 = 1 (selects TTBR1 for user ASID lookup)
IEE_SIP-->>Kernel: Return
Sequence Diagram for IEE SIP Call with ISB SynchronizationsequenceDiagram
participant Caller as Kernel Code
participant IEE_SIP as iee_rwx_gate
participant IEE_SI as iee_si_handler
participant CPU_Regs as CPU Registers
Caller->>IEE_SIP: Call iee_rwx_gate(flag, args...)
IEE_SIP->>CPU_Regs: Modify TCR_EL1.A1 = 0 (Enter IEE Mode)
IEE_SIP->>IEE_SI: Call iee_si_handler(flag, args...)
IEE_SI->>CPU_Regs: Perform register write (e.g., TTBR0_EL1)
IEE_SI-->>IEE_SIP: Return from handler
IEE_SIP->>IEE_SIP: Execute ISB instruction (Synchronization Fix)
IEE_SIP->>CPU_Regs: Modify TCR_EL1.A1 = 1 (Exit IEE Mode)
IEE_SIP-->>Caller: Return from gate
Updated Class Diagram for IEE ASID Kernel ComponentsclassDiagram
direction TB
class IEE_SI_Flags {
<<enumeration>>
+IEE_SI_SET_SCTLR
+IEE_SI_SET_VBAR
+IEE_SI_SET_TTBR0
+IEE_SI_CONTEXT_SWITCH
+IEE_SI_CONTEXT_SWITCH_PRE_INIT
}
class `iee_si_handler()` {
+unsigned long iee_si_handler(int flag, ...)
+void iee_si_check_ttbr0()
}
`iee_si_handler()` ..> IEE_SI_Flags : uses
class `cpu_do_switch_mm()` {
+void cpu_do_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm)
}
class `iee_setup_asid()` {
+void iee_setup_asid()
}
class `iee_rwx_gate()` {
<<Assembly>>
+void iee_rwx_gate(int flag, ...)
}
class `asids_update_limit()` {
+int asids_update_limit()
}
class `asids_init()` {
+int asids_init()
}
`cpu_do_switch_mm()` --> `iee_rwx_gate()` : calls
`iee_rwx_gate()` --> `iee_si_handler()` : calls
File-Level Changes
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changed the title
community inclusion category: bugfix -------------------------------- Fix 2 bugs: Bug 1: Crash upon resume from suspend. This issue occurred due to missing the proper use of the ISB (Instruction Synchronization Barrier) instruction after writing to the TTBR0 register via the IEE SIP interface. The absence of ISB prevented the modification from immediately taking effect, causing errors in subsequent code accessing addresses within the TTBR0 range. The problem was fixed by adding an ISB instruction in the IEE SIP gate. Bug 2: IEE ASID usage incompatible with KPTI. When Kernel Page Table Isolation (KPTI) was enabled along with HAOC initialization, conflicts in the Translation Lookaside Buffer (TLB) due to ASID handling incompatibility led to hangs during initialization. To resolve this, the modifications by IEE to the original ARM kernel ASID handling logic were reverted. Now, the storage of the IEE ASID has been shifted from TTBR1 to TTBR0, while the kernel continues to use TTBR1 to store user ASIDs. Fixes: 6d2d4fa ("HAOC: Add support for AArch64 Isolated Execution Environment(IEE).") Signed-off-by: Lyu Jinglin <[email protected]> Signed-off-by: Liu Zhehui <[email protected]>
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/ok-to-test |
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Pull Request Overview
This PR fixes two ARM64 HAOC issues: a suspend-resume crash due to missing ISB after TTBR0 updates, and a KPTI conflict by reverting ASID handling in TTBR1 and moving the IEE ASID into TTBR0. It refactors context-switch paths, updates SI handler logic, and cleans up legacy initialization code.
- Add ISB in IEE SIP gate and adjust TCR.A1 toggling for proper barrier and isolation.
- Move IEE ASID storage to TTBR0 and revert conflicting kernel ASID logic in TTBR1.
- Refactor SI handler (
iee-si.c), MMU init (iee-mmu.c), and init routines to streamline ASID setup and remove legacy data paths.
Reviewed Changes
Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.
Show a summary per file
| File | Description |
|---|---|
| arch/arm64/mm/context.c | Refactored ASID assignment in cpu_do_switch_mm for IEE/KPTI |
| arch/arm64/kernel/haoc/iee/iee-si.c | Rewrote SI handler, added TTBR0 consistency check and PTRP path |
| arch/arm64/kernel/haoc/iee/iee-si-gate.S | Added isb after gate entry and flipped TCR.A1 setup/teardown |
| arch/arm64/kernel/haoc/iee/iee-mmu.c | Updated TCR mask operations for IEE TCR initialization |
| arch/arm64/kernel/haoc/iee/iee-init.c | Simplified ASID setup, removed legacy init-data |
| arch/arm64/kernel/haoc/iee/iee-gate.S | Adjusted TCR.A1 bit toggling in protected RW gate |
| arch/arm64/include/asm/mmu_context.h | Applied IEE ASID in TTBR helpers under CONFIG_IEE |
| arch/arm64/include/asm/haoc/iee-si.h | Added IEE_SI_CONTEXT_SWITCH_PRE_INIT enum flag |
| arch/arm64/include/asm/haoc/iee-asm.h | Updated comment and moved IEE_ASID definition to TTBR0 usage |
Comments suppressed due to low confidence (3)
arch/arm64/kernel/haoc/iee/iee-init.c:45
- The original implementation cleared TCR.A1 (
write_sysreg(tcr_el1 & ~TCR_A1)) after loading the IEE ASID. That write was removed here, so TCR.A1 may remain set and prevent the TTBR0 ASID change from taking effect. Restore the TCR.A1-clear write to ensure the ASID switch happens correctly.
write_sysreg(ttbr0, ttbr0_el1);
arch/arm64/kernel/haoc/iee/iee-si-gate.S:44
- [nitpick] The comment above still describes setting
TCR_A1with OR, but this line clears it. Please update the comment to reflect thatTCR_A1is being cleared here to avoid confusion.
bic x12, x12, #TCR_A1
arch/arm64/kernel/haoc/iee/iee-gate.S:53
- [nitpick] The preceding comment indicates OR-ing
TCR_A1, but this line actually clears it. Consider updating the comment block to match the new behavior and maintain clarity.
bic x12, x12, #TCR_A1
| @@ -77,6 +102,11 @@ unsigned long __iee_si_code iee_si_handler(int flag, ...) | |||
| return 0; | |||
| } | |||
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| static inline void iee_si_setup_data(void) | |||
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The function iee_si_setup_data initializes iee_si_reserved_pg_dir but is never called. This means TTBR0 consistency checks will use an uninitialized value and always trigger errors. Consider invoking it early (for example in iee_si_init) before any SI operations.
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测试通过 |
I indeed did not set nr_pinned_asids, but this doesn't seem to significantly impact the kernel's normal operation. This variable appears to only affect the refresh rate of ASIDs. If necessary, we will submit a new patch to fix this. |
HAOC: Fix conflict between IEE and KPTI while modifying ASID
community inclusion
category: bugfix
Fix 2 bugs:
Bug 1: Crash upon resume from suspend.
This issue occurred due to missing the proper use of the ISB (Instruction Synchronization Barrier) instruction after writing to the TTBR0 register via the IEE SIP interface. The absence of ISB prevented the modification from immediately taking effect, causing errors in subsequent code accessing addresses within the TTBR0 range. The problem was fixed by adding an ISB instruction in the IEE SIP gate.
Bug 2: IEE ASID usage incompatible with KPTI.
When Kernel Page Table Isolation (KPTI) was enabled along with HAOC initialization, conflicts in the Translation Lookaside Buffer (TLB) due to ASID handling incompatibility led to hangs during initialization. To resolve this, the modifications by IEE to the original ARM kernel ASID handling logic were reverted. Now, the storage of the IEE ASID has been shifted from TTBR1 to TTBR0, while the kernel continues to use TTBR1 to store user ASIDs.
Fixes: 6d2d4fa ("HAOC: Add support for AArch64 Isolated Execution Environment(IEE).")
Summary by Sourcery
Fix suspend-resume crash under ARM64 HAOC by adding an ISB after TTBR0 updates, and restore kernel ASID handling to avoid TLB hangs with KPTI by moving the IEE ASID into TTBR0 and reverting conflicting logic, while refactoring IEE context-switch and initialization code for consistency.
Bug Fixes:
Enhancements: