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authorMark Rutland2021-06-07 10:46:20 +0100
committerWill Deacon2021-06-07 11:35:56 +0100
commit8168f098867f6584295ea408c683f61e945c6ff1 (patch)
tree5f39f2af949795d16569adfc0a6b88762369c9c9 /arch
parentafd05e28c9115d01f01d934962634789d069d3fe (diff)
arm64: entry: split bad stack entry
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> Link: https://lore.kernel.org/r/20210607094624.34689-17-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/exception.h4
-rw-r--r--arch/arm64/kernel/entry-common.c11
-rw-r--r--arch/arm64/kernel/traps.c6
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!");