sh: Provide diagnostic kernel stack checks (b99610fb) · Commits · 戴 / test

arch/sh/Kconfig.debug

+11 −0

Original line number	Diff line number	Diff line
		@@ -123,4 +123,15 @@ config SH64_SR_WATCH
		bool "Debug: set SR.WATCH to enable hardware watchpoints and trace"
		depends on SUPERH64

		config STACK_DEBUG
		bool "Enable diagnostic checks of the kernel stack"
		depends on FUNCTION_TRACER
		select DEBUG_STACKOVERFLOW
		default n
		help
		This option allows checks to be performed on the kernel stack
		at runtime. Saying Y here will add overhead to every function
		call and will therefore incur a major performance hit. Most
		users should say N.

		endmenu

arch/sh/kernel/asm-offsets.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -26,6 +26,7 @@ int main(void)
		DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
		DEFINE(TI_PRE_COUNT, offsetof(struct thread_info, preempt_count));
		DEFINE(TI_RESTART_BLOCK,offsetof(struct thread_info, restart_block));
		DEFINE(TI_SIZE, sizeof(struct thread_info));

		#ifdef CONFIG_HIBERNATION
		DEFINE(PBE_ADDRESS, offsetof(struct pbe, address));

arch/sh/lib/mcount.S

+85 −0

Original line number	Diff line number	Diff line
		@@ -9,6 +9,8 @@
		* for more details.
		*/
		#include <asm/ftrace.h>
		#include <asm/thread_info.h>
		#include <asm/asm-offsets.h>

		#define MCOUNT_ENTER() \
		mov.l r4, @-r15; \
		@@ -28,6 +30,55 @@
		rts; \
		mov.l @r15+, r4

		#ifdef CONFIG_STACK_DEBUG
		/*
		* Perform diagnostic checks on the state of the kernel stack.
		*
		* Check for stack overflow. If there is less than 1KB free
		* then it has overflowed.
		*
		* Make sure the stack pointer contains a valid address. Valid
		* addresses for kernel stacks are anywhere after the bss
		* (after _ebss) and anywhere in init_thread_union (init_stack).
		*/
		#define STACK_CHECK() \
		mov #(THREAD_SIZE >> 10), r0; \
		shll8 r0; \
		shll2 r0; \
		\
		/* r1 = sp & (THREAD_SIZE - 1) */ \
		mov #-1, r1; \
		add r0, r1; \
		and r15, r1; \
		\
		mov #TI_SIZE, r3; \
		mov #(STACK_WARN >> 8), r2; \
		shll8 r2; \
		add r3, r2; \
		\
		/* Is the stack overflowing? */ \
		cmp/hi r2, r1; \
		bf stack_panic; \
		\
		/* If sp > _ebss then we're OK. */ \
		mov.l .L_ebss, r1; \
		cmp/hi r1, r15; \
		bt 1f; \
		\
		/* If sp < init_stack, we're not OK. */ \
		mov.l .L_init_thread_union, r1; \
		cmp/hs r1, r15; \
		bf stack_panic; \
		\
		/* If sp > init_stack && sp < _ebss, not OK. */ \
		add r0, r1; \
		cmp/hs r1, r15; \
		bt stack_panic; \
		1:
		#else
		#define STACK_CHECK()
		#endif /* CONFIG_STACK_DEBUG */

		.align 2
		.globl _mcount
		.type _mcount,@function
		@@ -41,6 +92,8 @@ mcount:
		tst r0, r0
		bf ftrace_stub
		#endif
		STACK_CHECK()

		MCOUNT_ENTER()

		#ifdef CONFIG_DYNAMIC_FTRACE
		@@ -73,6 +126,8 @@ ftrace_caller:
		tst r0, r0
		bf ftrace_stub

		STACK_CHECK()

		MCOUNT_ENTER()

		.globl ftrace_call
		@@ -100,6 +155,36 @@ ftrace_stub:
		rts
		nop

		#ifdef CONFIG_STACK_DEBUG
		.globl stack_panic
		stack_panic:
		mov.l .Ldump_stack, r0
		jsr @r0
		nop

		mov.l .Lpanic, r0
		jsr @r0
		mov.l .Lpanic_s, r4

		rts
		nop

		.align 2
		.Lfunction_trace_stop:
		.long function_trace_stop
		.L_ebss:
		.long _ebss
		.L_init_thread_union:
		.long init_thread_union
		.Lpanic:
		.long panic
		.Lpanic_s:
		.long .Lpanic_str
		.Ldump_stack:
		.long dump_stack

		.section .rodata
		.align 2
		.Lpanic_str:
		.string "Stack error"
		#endif /* CONFIG_STACK_DEBUG */

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