From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>,
Nicholas Piggin <npiggin@gmail.com>
Subject: [RFC PATCH 26/27] powerpc/64s/exception: treat NIA below __end_interrupts as soft-masked
Date: Sun, 15 Sep 2019 11:28:12 +1000 [thread overview]
Message-ID: <20190915012813.29317-27-npiggin@gmail.com> (raw)
In-Reply-To: <20190915012813.29317-1-npiggin@gmail.com>
The scv instruction causes an interrupt which can enter the kernel with
MSR[EE]=1, thus allowing interrupts to hit at any time. These must not
be taken as normal interrupts, because they come from MSR[PR]=0 context,
and yet the kernel stack is not yet set up and r13 is not set to the
PACA).
Treat this as a soft-masked interrupt regardless of the soft masked
state. This does not affect behaviour yet, because currently all
interrupts are taken with MSR[EE]=0.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/exceptions-64s.S | 34 +++++++++++++++++++++++++---
1 file changed, 31 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 1bccc869ebd3..07e00f690730 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -492,10 +492,33 @@ DEFINE_FIXED_SYMBOL(\name\()_common_virt)
.endif /* IVIRT */
.endm
+#define LOAD_IMM(reg, expr) \
+ lis reg,(expr)@highest; \
+ ori reg,reg,(expr)@higher; \
+ rldicr reg,reg,32,31; \
+ oris reg,reg,(expr)@__AS_ATHIGH; \
+ ori reg,reg,(expr)@l
+
.macro __GEN_COMMON_BODY name
.if IMASK
+ .if ! ISTACK
+ .error "No support for masked interrupt to use custom stack"
+ .endif
+
+ /* If coming from user, skip soft-mask tests. */
+ andi. r10,r12,MSR_PR
+ bne 2f
+
+ /* Kernel code running below __end_interrupts is implicitly
+ * soft-masked */
+ LOAD_HANDLER(r10, __end_interrupts)
+ cmpd r11,r10
+ li r10,IMASK
+ blt- 1f
+
+ /* Test the soft mask state against our interrupt's bit */
lbz r10,PACAIRQSOFTMASK(r13)
- andi. r10,r10,IMASK
+1: andi. r10,r10,IMASK
/* Associate vector numbers with bits in paca->irq_happened */
.if IVEC == 0x500 || IVEC == 0xea0
li r10,PACA_IRQ_EE
@@ -526,7 +549,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_virt)
.if ISTACK
andi. r10,r12,MSR_PR /* See if coming from user */
- mr r10,r1 /* Save r1 */
+2: mr r10,r1 /* Save r1 */
subi r1,r1,INT_FRAME_SIZE /* alloc frame on kernel stack */
beq- 100f
ld r1,PACAKSAVE(r13) /* kernel stack to use */
@@ -2771,7 +2794,8 @@ masked_interrupt:
ld r10,PACA_EXGEN+EX_R10(r13)
ld r11,PACA_EXGEN+EX_R11(r13)
ld r12,PACA_EXGEN+EX_R12(r13)
- /* returns to kernel where r13 must be set up, so don't restore it */
+ ld r13,PACA_EXGEN+EX_R13(r13)
+ /* May return to masked low address where r13 is not set up */
.if \hsrr
HRFI_TO_KERNEL
.else
@@ -2930,6 +2954,10 @@ EXC_COMMON_BEGIN(ppc64_runlatch_on_trampoline)
USE_FIXED_SECTION(virt_trampolines)
/*
+ * All code below __end_interrupts is treated as soft-masked. If
+ * any code runs here with MSR[EE]=1, it must then cope with pending
+ * soft interrupt being raised (i.e., by ensuring it is replayed).
+ *
* The __end_interrupts marker must be past the out-of-line (OOL)
* handlers, so that they are copied to real address 0x100 when running
* a relocatable kernel. This ensures they can be reached from the short
--
2.23.0
next prev parent reply other threads:[~2019-09-15 2:23 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-15 1:27 [RFC PATCH 00/27] current interrupt series plus scv syscall Nicholas Piggin
2019-09-15 1:27 ` [RFC PATCH 01/27] powerpc/64s/exception: Introduce INT_DEFINE parameter block for code generation Nicholas Piggin
2019-09-15 1:27 ` [RFC PATCH 02/27] powerpc/64s/exception: Add GEN_COMMON macro that uses INT_DEFINE parameters Nicholas Piggin
2019-09-15 1:27 ` [RFC PATCH 03/27] powerpc/64s/exception: Add GEN_KVM " Nicholas Piggin
2019-09-15 1:27 ` [RFC PATCH 04/27] powerpc/64s/exception: Expand EXC_COMMON and EXC_COMMON_ASYNC macros Nicholas Piggin
2019-09-15 1:27 ` [RFC PATCH 05/27] powerpc/64s/exception: Move all interrupt handlers to new style code gen macros Nicholas Piggin
2019-09-15 1:27 ` [RFC PATCH 06/27] powerpc/64s/exception: Remove old INT_ENTRY macro Nicholas Piggin
2019-09-15 1:27 ` [RFC PATCH 07/27] powerpc/64s/exception: Remove old INT_COMMON macro Nicholas Piggin
2019-09-15 1:27 ` [RFC PATCH 08/27] powerpc/64s/exception: Remove old INT_KVM_HANDLER Nicholas Piggin
2019-09-15 1:27 ` [RFC PATCH 09/27] powerpc/64s/exception: Add ISIDE option Nicholas Piggin
2019-09-15 1:27 ` [RFC PATCH 10/27] powerpc/64s/exception: move real->virt switch into the common handler Nicholas Piggin
2019-09-15 1:27 ` [RFC PATCH 11/27] powerpc/64s/exception: move soft-mask test to common code Nicholas Piggin
2019-09-15 1:27 ` [RFC PATCH 12/27] powerpc/64s/exception: move KVM " Nicholas Piggin
2019-09-15 1:27 ` [RFC PATCH 13/27] powerpc/64s/exception: remove confusing IEARLY option Nicholas Piggin
2019-09-15 1:28 ` [RFC PATCH 14/27] powerpc/64s/exception: remove the SPR saving patch code macros Nicholas Piggin
2019-09-15 1:28 ` [RFC PATCH 15/27] powerpc/64s/exception: trim unused arguments from KVMTEST macro Nicholas Piggin
2019-09-15 1:28 ` [RFC PATCH 16/27] powerpc/64s/exception: hdecrementer avoid touching the stack Nicholas Piggin
2019-09-15 1:28 ` [RFC PATCH 17/27] powerpc/64s/exception: re-inline some handlers Nicholas Piggin
2019-09-15 1:28 ` [RFC PATCH 18/27] powerpc/64s/exception: Clean up SRR specifiers Nicholas Piggin
2019-09-15 1:28 ` [RFC PATCH 19/27] powerpc/64s/exception: add more comments for interrupt handlers Nicholas Piggin
2019-09-15 1:28 ` [RFC PATCH 20/27] powerpc/64s/exception: only test KVM in SRR interrupts when PR KVM is supported Nicholas Piggin
2019-09-15 1:28 ` [RFC PATCH 21/27] powerpc/64s/exception: soft nmi interrupt should not use ret_from_except Nicholas Piggin
2019-09-15 1:28 ` [RFC PATCH 22/27] powerpc/64: system call remove non-volatile GPR save optimisation Nicholas Piggin
2019-09-15 1:28 ` [RFC PATCH 23/27] powerpc/64: system call implement the bulk of the logic in C Nicholas Piggin
2019-10-02 8:21 ` Michal Suchánek
2019-10-02 3:10 ` Nicholas Piggin
2019-09-15 1:28 ` [RFC PATCH 24/27] powerpc/64s: interrupt return " Nicholas Piggin
2019-10-02 8:20 ` Michal Suchánek
2019-09-15 1:28 ` [RFC PATCH 25/27] powerpc/64s/exception: remove lite interrupt return Nicholas Piggin
2019-09-15 1:28 ` Nicholas Piggin [this message]
2019-09-15 1:28 ` [RFC PATCH 27/27] powerpc/64s: system call support for scv/rfscv instructions Nicholas Piggin
2019-10-02 8:21 ` Michal Suchánek
2019-10-02 8:20 ` [RFC PATCH 00/27] current interrupt series plus scv syscall Michal Suchánek
2019-10-02 3:13 ` Nicholas Piggin
2019-10-30 12:55 ` Michal Suchánek
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