[PATCH v4 16/20] arm64: entry: split bad stack entry
From: Mark Rutland <mark.rutland@arm.com>
Date: 2021-06-07 10:23:57
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
We'd like to keep all the entry sequencing in entry-common.c, as this will allow us to ensure this is 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> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Joey Gouly <joey.gouly@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org> --- arch/arm64/include/asm/exception.h | 4 ++++ arch/arm64/kernel/entry-common.c | 11 +++++++++++ arch/arm64/kernel/traps.c | 6 +----- 3 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h
index ad30a5a1d2bf..0113b9242b67 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);
@@ -73,4 +75,6 @@ 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 ce5c8af91d31..efe95edf10c0 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c@@ -699,3 +699,14 @@ UNHANDLED(el0t, 32, irq) UNHANDLED(el0t, 32, fiq) UNHANDLED(el0t, 32, error) #endif /* CONFIG_COMPAT */ + +#ifdef CONFIG_VMAP_STACK +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); +} +#endif /* CONFIG_VMAP_STACK */
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 47d423f7ac81..af941996eb5f 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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