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From: Mark Rutland <mark.rutland@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: catalin.marinas@arm.com, james.morse@arm.com,
	mark.rutland@arm.com, maz@kernel.org, will@kernel.org,
	joey.gouly@arm.com
Subject: [PATCH v2 15/19] arm64: entry: split bad stack entry
Date: Wed, 19 May 2021 13:38:58 +0100	[thread overview]
Message-ID: <20210519123902.2452-16-mark.rutland@arm.com> (raw)
In-Reply-To: <20210519123902.2452-1-mark.rutland@arm.com>

We'd like to keep all the entry sequencing in entry-common.c, as this
will allow us to ensure this is all consistent, and free from any
unsound instrumentation.

Currently handle_bad_stack() performs the NMI entry sequence in traps.c.
Let's split the low-level entry sequence from the reporting, moving the
former to entry-common.c and keeping the latter in traps.c. To make it
clear that reporting function never returns, it is renamed to
panic_bad_stack().

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
---
 arch/arm64/include/asm/exception.h | 4 ++++
 arch/arm64/kernel/entry-common.c   | 9 +++++++++
 arch/arm64/kernel/traps.c          | 6 +-----
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h
index 40a3a20dca1c..952402ca9533 100644
--- a/arch/arm64/include/asm/exception.h
+++ b/arch/arm64/include/asm/exception.h
@@ -31,6 +31,8 @@ static inline u32 disr_to_esr(u64 disr)
 	return esr;
 }
 
+asmlinkage void handle_bad_stack(struct pt_regs *regs);
+
 asmlinkage void el1t_64_sync_handler(struct pt_regs *regs);
 asmlinkage void el1t_64_irq_handler(struct pt_regs *regs);
 asmlinkage void el1t_64_fiq_handler(struct pt_regs *regs);
@@ -74,4 +76,6 @@ void do_el0_svc(struct pt_regs *regs);
 void do_el0_svc_compat(struct pt_regs *regs);
 void do_ptrauth_fault(struct pt_regs *regs, unsigned int esr);
 void do_serror(struct pt_regs *regs, unsigned int esr);
+
+void panic_bad_stack(struct pt_regs *regs, unsigned int esr, unsigned long far);
 #endif	/* __ASM_EXCEPTION_H */
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index 6f1caec913a9..801c7d479d47 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -104,6 +104,15 @@ void noinstr arm64_exit_nmi(struct pt_regs *regs)
 	__nmi_exit();
 }
 
+asmlinkage void noinstr handle_bad_stack(struct pt_regs *regs)
+{
+	unsigned int esr = read_sysreg(esr_el1);
+	unsigned long far = read_sysreg(far_el1);
+
+	arm64_enter_nmi(regs);
+	panic_bad_stack(regs, esr, far);
+}
+
 static void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs)
 {
 	if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs))
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 7def18ff02e2..4d157d2d8f67 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -763,15 +763,11 @@ void bad_el0_sync(struct pt_regs *regs, int reason, unsigned int esr)
 DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack)
 	__aligned(16);
 
-asmlinkage void noinstr handle_bad_stack(struct pt_regs *regs)
+void panic_bad_stack(struct pt_regs *regs, unsigned int esr, unsigned long far)
 {
 	unsigned long tsk_stk = (unsigned long)current->stack;
 	unsigned long irq_stk = (unsigned long)this_cpu_read(irq_stack_ptr);
 	unsigned long ovf_stk = (unsigned long)this_cpu_ptr(overflow_stack);
-	unsigned int esr = read_sysreg(esr_el1);
-	unsigned long far = read_sysreg(far_el1);
-
-	arm64_enter_nmi(regs);
 
 	console_verbose();
 	pr_emerg("Insufficient stack space to handle exception!");
-- 
2.11.0


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  parent reply	other threads:[~2021-05-19 13:11 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-19 12:38 [PATCH v2 00/19] arm64: entry: migrate more code to C Mark Rutland
2021-05-19 12:38 ` [PATCH v2 01/19] arm64: remove redundant local_daif_mask() in bad_mode() Mark Rutland
2021-05-21 10:39   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 02/19] arm64: entry: unmask IRQ+FIQ after EL0 handling Mark Rutland
2021-05-25 16:45   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 03/19] arm64: entry: convert SError handlers to C Mark Rutland
2021-05-25 13:38   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 04/19] arm64: entry: move arm64_preempt_schedule_irq to entry-common.c Mark Rutland
2021-05-21 11:00   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 05/19] arm64: entry: move preempt logic to C Mark Rutland
2021-05-25 12:50   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 06/19] arm64: entry: add a call_on_irq_stack helper Mark Rutland
2021-05-19 14:46   ` Mark Rutland
2021-05-19 12:38 ` [PATCH v2 07/19] arm64: entry: convert IRQ+FIQ handlers to C Mark Rutland
2021-05-21 13:19   ` Joey Gouly
2021-05-21 15:23     ` Mark Rutland
2021-05-19 12:38 ` [PATCH v2 08/19] arm64: entry: organise entry handlers consistently Mark Rutland
2021-05-21 16:04   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 09/19] arm64: entry: organise entry vectors consistently Mark Rutland
2021-05-21 16:07   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 10/19] arm64: entry: consolidate EL1 exception returns Mark Rutland
2021-05-21 16:22   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 11/19] arm64: entry: move bad_mode() to entry-common.c Mark Rutland
2021-05-21 16:46   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 12/19] arm64: entry: improve bad_mode() Mark Rutland
2021-05-21 17:02   ` Joey Gouly
2021-05-21 17:10     ` Mark Rutland
2021-05-19 12:38 ` [PATCH v2 13/19] arm64: entry: template the entry asm functions Mark Rutland
2021-05-21 17:16   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 14/19] arm64: entry: handle all vectors with C Mark Rutland
2021-05-21 15:59   ` Joey Gouly
2021-05-21 16:41     ` Mark Rutland
2021-05-19 12:38 ` Mark Rutland [this message]
2021-05-25 11:25   ` [PATCH v2 15/19] arm64: entry: split bad stack entry Joey Gouly
2021-05-19 12:38 ` [PATCH v2 16/19] arm64: entry: split SDEI entry Mark Rutland
2021-05-25 11:49   ` Joey Gouly
2021-05-19 12:39 ` [PATCH v2 17/19] arm64: entry: make NMI entry/exit functions static Mark Rutland
2021-05-21 17:21   ` Joey Gouly
2021-05-19 12:39 ` [PATCH v2 18/19] arm64: entry: don't instrument entry code with KCOV Mark Rutland
2021-05-19 12:39 ` [PATCH v2 19/19] arm64: idle: don't instrument idle " Mark Rutland

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