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author | Julien Thierry <julien.thierry@arm.com> | 2019-06-11 10:38:10 +0100 |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2019-06-21 15:50:10 +0100 |
commit | bd82d4bd21880b7c4d5f5756be435095d6ae07b5 (patch) | |
tree | fdc4ec809f5d0991d9932cebddf7b5821f970f9d /arch/arm64/kernel | |
parent | 17ce302f3117e9518395847a3120c8a108b587b8 (diff) | |
download | linux-stable-bd82d4bd21880b7c4d5f5756be435095d6ae07b5.tar.gz linux-stable-bd82d4bd21880b7c4d5f5756be435095d6ae07b5.tar.bz2 linux-stable-bd82d4bd21880b7c4d5f5756be435095d6ae07b5.zip |
arm64: Fix incorrect irqflag restore for priority masking
When using IRQ priority masking to disable interrupts, in order to deal
with the PSR.I state, local_irq_save() would convert the I bit into a
PMR value (GIC_PRIO_IRQOFF). This resulted in local_irq_restore()
potentially modifying the value of PMR in undesired location due to the
state of PSR.I upon flag saving [1].
In an attempt to solve this issue in a less hackish manner, introduce
a bit (GIC_PRIO_IGNORE_PMR) for the PMR values that can represent
whether PSR.I is being used to disable interrupts, in which case it
takes precedence of the status of interrupt masking via PMR.
GIC_PRIO_PSR_I_SET is chosen such that (<pmr_value> |
GIC_PRIO_PSR_I_SET) does not mask more interrupts than <pmr_value> as
some sections (e.g. arch_cpu_idle(), interrupt acknowledge path)
requires PMR not to mask interrupts that could be signaled to the
CPU when using only PSR.I.
[1] https://www.spinics.net/lists/arm-kernel/msg716956.html
Fixes: 4a503217ce37 ("arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking")
Cc: <stable@vger.kernel.org> # 5.1.x-
Reported-by: Zenghui Yu <yuzenghui@huawei.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Wei Li <liwei391@huawei.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Pouloze <suzuki.poulose@arm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
-rw-r--r-- | arch/arm64/kernel/entry.S | 38 | ||||
-rw-r--r-- | arch/arm64/kernel/process.c | 2 | ||||
-rw-r--r-- | arch/arm64/kernel/smp.c | 8 |
3 files changed, 39 insertions, 9 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 6d5966346710..165da78815c5 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -258,6 +258,7 @@ alternative_else_nop_endif /* * Registers that may be useful after this macro is invoked: * + * x20 - ICC_PMR_EL1 * x21 - aborted SP * x22 - aborted PC * x23 - aborted PSTATE @@ -449,6 +450,24 @@ alternative_endif .endm #endif + .macro gic_prio_kentry_setup, tmp:req +#ifdef CONFIG_ARM64_PSEUDO_NMI + alternative_if ARM64_HAS_IRQ_PRIO_MASKING + mov \tmp, #(GIC_PRIO_PSR_I_SET | GIC_PRIO_IRQON) + msr_s SYS_ICC_PMR_EL1, \tmp + alternative_else_nop_endif +#endif + .endm + + .macro gic_prio_irq_setup, pmr:req, tmp:req +#ifdef CONFIG_ARM64_PSEUDO_NMI + alternative_if ARM64_HAS_IRQ_PRIO_MASKING + orr \tmp, \pmr, #GIC_PRIO_PSR_I_SET + msr_s SYS_ICC_PMR_EL1, \tmp + alternative_else_nop_endif +#endif + .endm + .text /* @@ -627,6 +646,7 @@ el1_dbg: cmp x24, #ESR_ELx_EC_BRK64 // if BRK64 cinc x24, x24, eq // set bit '0' tbz x24, #0, el1_inv // EL1 only + gic_prio_kentry_setup tmp=x3 mrs x0, far_el1 mov x2, sp // struct pt_regs bl do_debug_exception @@ -644,12 +664,10 @@ ENDPROC(el1_sync) .align 6 el1_irq: kernel_entry 1 + gic_prio_irq_setup pmr=x20, tmp=x1 enable_da_f #ifdef CONFIG_ARM64_PSEUDO_NMI -alternative_if ARM64_HAS_IRQ_PRIO_MASKING - ldr x20, [sp, #S_PMR_SAVE] -alternative_else_nop_endif test_irqs_unmasked res=x0, pmr=x20 cbz x0, 1f bl asm_nmi_enter @@ -679,8 +697,9 @@ alternative_else_nop_endif #ifdef CONFIG_ARM64_PSEUDO_NMI /* - * if IRQs were disabled when we received the interrupt, we have an NMI - * and we are not re-enabling interrupt upon eret. Skip tracing. + * When using IRQ priority masking, we can get spurious interrupts while + * PMR is set to GIC_PRIO_IRQOFF. An NMI might also have occurred in a + * section with interrupts disabled. Skip tracing in those cases. */ test_irqs_unmasked res=x0, pmr=x20 cbz x0, 1f @@ -809,6 +828,7 @@ el0_ia: * Instruction abort handling */ mrs x26, far_el1 + gic_prio_kentry_setup tmp=x0 enable_da_f #ifdef CONFIG_TRACE_IRQFLAGS bl trace_hardirqs_off @@ -854,6 +874,7 @@ el0_sp_pc: * Stack or PC alignment exception handling */ mrs x26, far_el1 + gic_prio_kentry_setup tmp=x0 enable_da_f #ifdef CONFIG_TRACE_IRQFLAGS bl trace_hardirqs_off @@ -888,6 +909,7 @@ el0_dbg: * Debug exception handling */ tbnz x24, #0, el0_inv // EL0 only + gic_prio_kentry_setup tmp=x3 mrs x0, far_el1 mov x1, x25 mov x2, sp @@ -909,7 +931,9 @@ ENDPROC(el0_sync) el0_irq: kernel_entry 0 el0_irq_naked: + gic_prio_irq_setup pmr=x20, tmp=x0 enable_da_f + #ifdef CONFIG_TRACE_IRQFLAGS bl trace_hardirqs_off #endif @@ -931,6 +955,7 @@ ENDPROC(el0_irq) el1_error: kernel_entry 1 mrs x1, esr_el1 + gic_prio_kentry_setup tmp=x2 enable_dbg mov x0, sp bl do_serror @@ -941,6 +966,7 @@ el0_error: kernel_entry 0 el0_error_naked: mrs x1, esr_el1 + gic_prio_kentry_setup tmp=x2 enable_dbg mov x0, sp bl do_serror @@ -965,6 +991,7 @@ work_pending: */ ret_to_user: disable_daif + gic_prio_kentry_setup tmp=x3 ldr x1, [tsk, #TSK_TI_FLAGS] and x2, x1, #_TIF_WORK_MASK cbnz x2, work_pending @@ -981,6 +1008,7 @@ ENDPROC(ret_to_user) */ .align 6 el0_svc: + gic_prio_kentry_setup tmp=x1 mov x0, sp bl el0_svc_handler b ret_to_user diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 3767fb21a5b8..58efc3727778 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -94,7 +94,7 @@ static void __cpu_do_idle_irqprio(void) * be raised. */ pmr = gic_read_pmr(); - gic_write_pmr(GIC_PRIO_IRQON); + gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET); __cpu_do_idle(); diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index bb4b3f07761a..4deaee3c2a33 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -192,11 +192,13 @@ static void init_gic_priority_masking(void) WARN_ON(!(cpuflags & PSR_I_BIT)); - gic_write_pmr(GIC_PRIO_IRQOFF); - /* We can only unmask PSR.I if we can take aborts */ - if (!(cpuflags & PSR_A_BIT)) + if (!(cpuflags & PSR_A_BIT)) { + gic_write_pmr(GIC_PRIO_IRQOFF); write_sysreg(cpuflags & ~PSR_I_BIT, daif); + } else { + gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET); + } } /* |