ARM: 6199/1: Add kprobe-based event tracer (e513f8bf) · Commits · 戴 / test

arch/arm/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -24,6 +24,7 @@ config ARM
		select HAVE_KERNEL_LZMA
		select HAVE_PERF_EVENTS
		select PERF_USE_VMALLOC
		select HAVE_REGS_AND_STACK_ACCESS_API
		help
		The ARM series is a line of low-power-consumption RISC chip designs
		licensed by ARM Ltd and targeted at embedded applications and

arch/arm/include/asm/ptrace.h

+36 −0

Original line number	Diff line number	Diff line
		@@ -184,6 +184,42 @@ extern unsigned long profile_pc(struct pt_regs *regs);
		#define predicate(x) ((x) & 0xf0000000)
		#define PREDICATE_ALWAYS 0xe0000000

		/*
		* kprobe-based event tracer support
		*/
		#include <linux/stddef.h>
		#include <linux/types.h>
		#define MAX_REG_OFFSET (offsetof(struct pt_regs, ARM_ORIG_r0))

		extern int regs_query_register_offset(const char *name);
		extern const char *regs_query_register_name(unsigned int offset);
		extern bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr);
		extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
		unsigned int n);

		/**
		* regs_get_register() - get register value from its offset
		* @regs: pt_regs from which register value is gotten
		* @offset: offset number of the register.
		*
		* regs_get_register returns the value of a register whose offset from @regs.
		* The @offset is the offset of the register in struct pt_regs.
		* If @offset is bigger than MAX_REG_OFFSET, this returns 0.
		*/
		static inline unsigned long regs_get_register(struct pt_regs *regs,
		unsigned int offset)
		{
		if (unlikely(offset > MAX_REG_OFFSET))
		return 0;
		return (unsigned long )((unsigned long)regs + offset);
		}

		/* Valid only for Kernel mode traps. */
		static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
		{
		return regs->ARM_sp;
		}

		#endif /* __KERNEL__ */

		#endif /* __ASSEMBLY__ */

arch/arm/kernel/ptrace.c

+96 −0

Original line number	Diff line number	Diff line
		@@ -52,6 +52,102 @@
		#define BREAKINST_THUMB 0xde01
		#endif

		struct pt_regs_offset {
		const char *name;
		int offset;
		};

		#define REG_OFFSET_NAME(r) \
		{.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)}
		#define REG_OFFSET_END {.name = NULL, .offset = 0}

		static const struct pt_regs_offset regoffset_table[] = {
		REG_OFFSET_NAME(r0),
		REG_OFFSET_NAME(r1),
		REG_OFFSET_NAME(r2),
		REG_OFFSET_NAME(r3),
		REG_OFFSET_NAME(r4),
		REG_OFFSET_NAME(r5),
		REG_OFFSET_NAME(r6),
		REG_OFFSET_NAME(r7),
		REG_OFFSET_NAME(r8),
		REG_OFFSET_NAME(r9),
		REG_OFFSET_NAME(r10),
		REG_OFFSET_NAME(fp),
		REG_OFFSET_NAME(ip),
		REG_OFFSET_NAME(sp),
		REG_OFFSET_NAME(lr),
		REG_OFFSET_NAME(pc),
		REG_OFFSET_NAME(cpsr),
		REG_OFFSET_NAME(ORIG_r0),
		REG_OFFSET_END,
		};

		/**
		* regs_query_register_offset() - query register offset from its name
		* @name: the name of a register
		*
		* regs_query_register_offset() returns the offset of a register in struct
		* pt_regs from its name. If the name is invalid, this returns -EINVAL;
		*/
		int regs_query_register_offset(const char *name)
		{
		const struct pt_regs_offset *roff;
		for (roff = regoffset_table; roff->name != NULL; roff++)
		if (!strcmp(roff->name, name))
		return roff->offset;
		return -EINVAL;
		}

		/**
		* regs_query_register_name() - query register name from its offset
		* @offset: the offset of a register in struct pt_regs.
		*
		* regs_query_register_name() returns the name of a register from its
		* offset in struct pt_regs. If the @offset is invalid, this returns NULL;
		*/
		const char *regs_query_register_name(unsigned int offset)
		{
		const struct pt_regs_offset *roff;
		for (roff = regoffset_table; roff->name != NULL; roff++)
		if (roff->offset == offset)
		return roff->name;
		return NULL;
		}

		/**
		* regs_within_kernel_stack() - check the address in the stack
		* @regs: pt_regs which contains kernel stack pointer.
		* @addr: address which is checked.
		*
		* regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
		* If @addr is within the kernel stack, it returns true. If not, returns false.
		*/
		bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
		{
		return ((addr & ~(THREAD_SIZE - 1)) ==
		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
		}

		/**
		* regs_get_kernel_stack_nth() - get Nth entry of the stack
		* @regs: pt_regs which contains kernel stack pointer.
		* @n: stack entry number.
		*
		* regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
		* is specified by @regs. If the @n th entry is NOT in the kernel stack,
		* this returns 0.
		*/
		unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
		{
		unsigned long addr = (unsigned long )kernel_stack_pointer(regs);
		addr += n;
		if (regs_within_kernel_stack(regs, (unsigned long)addr))
		return *addr;
		else
		return 0;
		}

		/*
		* this routine will get a word off of the processes privileged stack.
		* the offset is how far from the base addr as stored in the THREAD.

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