Commit 3ff54efd authored by Srikar Dronamraju's avatar Srikar Dronamraju Committed by Ingo Molnar
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uprobes/core: Move insn to arch specific structure 



Few cleanups suggested by Ingo Molnar.

- Rename struct uprobe_arch_info to struct arch_uprobe.
- Move insn from struct uprobe to struct arch_uprobe.
- Make arch specific uprobe functions to accept struct arch_uprobe
  instead of  struct uprobe.
- Move struct uprobe to kernel/uprobes.c from include/linux/uprobes.h

Signed-off-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Josh Stone <jistone@redhat.com>
Link: http://lkml.kernel.org/r/20120222091602.15880.40249.sendpatchset@srdronam.in.ibm.com


[ Made various small improvements ]
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 96379f60

arch/x86/include/asm/uprobes.h

+3 −3
Original line number Diff line number Diff line
@@ -31,13 +31,13 @@ typedef u8 uprobe_opcode_t; 
#define UPROBES_BKPT_INSN		0xcc

#define UPROBES_BKPT_INSN_SIZE		   1



struct uprobe_arch_info {

struct arch_uprobe {

	u16				fixups;

	u8				insn[MAX_UINSN_BYTES];

#ifdef CONFIG_X86_64

	unsigned long			rip_rela_target_address;

#endif

};



struct uprobe;

extern int arch_uprobes_analyze_insn(struct mm_struct *mm, struct uprobe *uprobe);

extern int arch_uprobes_analyze_insn(struct mm_struct *mm, struct arch_uprobe *arch_uprobe);

#endif	/* _ASM_UPROBES_H */

arch/x86/kernel/uprobes.c

+30 −30
Original line number Diff line number Diff line
@@ -200,9 +200,9 @@ static bool is_prefix_bad(struct insn *insn) 
	return false;

}



static int validate_insn_32bits(struct uprobe *uprobe, struct insn *insn)

static int validate_insn_32bits(struct arch_uprobe *auprobe, struct insn *insn)

{

	insn_init(insn, uprobe->insn, false);

	insn_init(insn, auprobe->insn, false);



	/* Skip good instruction prefixes; reject "bad" ones. */

	insn_get_opcode(insn);
@@ -222,11 +222,11 @@ static int validate_insn_32bits(struct uprobe *uprobe, struct insn *insn) 


/*

 * Figure out which fixups post_xol() will need to perform, and annotate

 * uprobe->arch_info.fixups accordingly.  To start with,

 * uprobe->arch_info.fixups is either zero or it reflects rip-related

 * arch_uprobe->fixups accordingly.  To start with,

 * arch_uprobe->fixups is either zero or it reflects rip-related

 * fixups.

 */

static void prepare_fixups(struct uprobe *uprobe, struct insn *insn)

static void prepare_fixups(struct arch_uprobe *auprobe, struct insn *insn)

{

	bool fix_ip = true, fix_call = false;	/* defaults */

	int reg;
@@ -269,17 +269,17 @@ static void prepare_fixups(struct uprobe *uprobe, struct insn *insn) 
		break;

	}

	if (fix_ip)

		uprobe->arch_info.fixups |= UPROBES_FIX_IP;

		auprobe->fixups |= UPROBES_FIX_IP;

	if (fix_call)

		uprobe->arch_info.fixups |= UPROBES_FIX_CALL;

		auprobe->fixups |= UPROBES_FIX_CALL;

}



#ifdef CONFIG_X86_64

/*

 * If uprobe->insn doesn't use rip-relative addressing, return

 * If arch_uprobe->insn doesn't use rip-relative addressing, return

 * immediately.  Otherwise, rewrite the instruction so that it accesses

 * its memory operand indirectly through a scratch register.  Set

 * uprobe->arch_info.fixups and uprobe->arch_info.rip_rela_target_address

 * arch_uprobe->fixups and arch_uprobe->rip_rela_target_address

 * accordingly.  (The contents of the scratch register will be saved

 * before we single-step the modified instruction, and restored

 * afterward.)
@@ -297,7 +297,7 @@ static void prepare_fixups(struct uprobe *uprobe, struct insn *insn) 
 *  - There's never a SIB byte.

 *  - The displacement is always 4 bytes.

 */

static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, struct insn *insn)

static void handle_riprel_insn(struct mm_struct *mm, struct arch_uprobe *auprobe, struct insn *insn)

{

	u8 *cursor;

	u8 reg;
@@ -305,7 +305,7 @@ static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, stru 
	if (mm->context.ia32_compat)

		return;



	uprobe->arch_info.rip_rela_target_address = 0x0;

	auprobe->rip_rela_target_address = 0x0;

	if (!insn_rip_relative(insn))

		return;
@@ -315,7 +315,7 @@ static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, stru 
	 * we want to encode rax/rcx, not r8/r9.

	 */

	if (insn->rex_prefix.nbytes) {

		cursor = uprobe->insn + insn_offset_rex_prefix(insn);

		cursor = auprobe->insn + insn_offset_rex_prefix(insn);

		*cursor &= 0xfe;	/* Clearing REX.B bit */

	}
@@ -324,7 +324,7 @@ static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, stru 
	 * displacement.  Beyond the displacement, for some instructions,

	 * is the immediate operand.

	 */

	cursor = uprobe->insn + insn_offset_modrm(insn);

	cursor = auprobe->insn + insn_offset_modrm(insn);

	insn_get_length(insn);



	/*
@@ -341,18 +341,18 @@ static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, stru 
		 * is NOT the register operand, so we use %rcx (register

		 * #1) for the scratch register.

		 */

		uprobe->arch_info.fixups = UPROBES_FIX_RIP_CX;

		auprobe->fixups = UPROBES_FIX_RIP_CX;

		/* Change modrm from 00 000 101 to 00 000 001. */

		*cursor = 0x1;

	} else {

		/* Use %rax (register #0) for the scratch register. */

		uprobe->arch_info.fixups = UPROBES_FIX_RIP_AX;

		auprobe->fixups = UPROBES_FIX_RIP_AX;

		/* Change modrm from 00 xxx 101 to 00 xxx 000 */

		*cursor = (reg << 3);

	}



	/* Target address = address of next instruction + (signed) offset */

	uprobe->arch_info.rip_rela_target_address = (long)insn->length + insn->displacement.value;

	auprobe->rip_rela_target_address = (long)insn->length + insn->displacement.value;



	/* Displacement field is gone; slide immediate field (if any) over. */

	if (insn->immediate.nbytes) {
@@ -362,9 +362,9 @@ static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, stru 
	return;

}



static int validate_insn_64bits(struct uprobe *uprobe, struct insn *insn)

static int validate_insn_64bits(struct arch_uprobe *auprobe, struct insn *insn)

{

	insn_init(insn, uprobe->insn, true);

	insn_init(insn, auprobe->insn, true);



	/* Skip good instruction prefixes; reject "bad" ones. */

	insn_get_opcode(insn);
@@ -381,42 +381,42 @@ static int validate_insn_64bits(struct uprobe *uprobe, struct insn *insn) 
	return -ENOTSUPP;

}



static int validate_insn_bits(struct mm_struct *mm, struct uprobe *uprobe, struct insn *insn)

static int validate_insn_bits(struct mm_struct *mm, struct arch_uprobe *auprobe, struct insn *insn)

{

	if (mm->context.ia32_compat)

		return validate_insn_32bits(uprobe, insn);

	return validate_insn_64bits(uprobe, insn);

		return validate_insn_32bits(auprobe, insn);

	return validate_insn_64bits(auprobe, insn);

}

#else /* 32-bit: */

static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, struct insn *insn)

static void handle_riprel_insn(struct mm_struct *mm, struct arch_uprobe *auprobe, struct insn *insn)

{

	/* No RIP-relative addressing on 32-bit */

}



static int validate_insn_bits(struct mm_struct *mm, struct uprobe *uprobe, struct insn *insn)

static int validate_insn_bits(struct mm_struct *mm, struct arch_uprobe *auprobe, struct insn *insn)

{

	return validate_insn_32bits(uprobe, insn);

	return validate_insn_32bits(auprobe, insn);

}

#endif /* CONFIG_X86_64 */



/**

 * arch_uprobes_analyze_insn - instruction analysis including validity and fixups.

 * @mm: the probed address space.

 * @uprobe: the probepoint information.

 * @arch_uprobe: the probepoint information.

 * Return 0 on success or a -ve number on error.

 */

int arch_uprobes_analyze_insn(struct mm_struct *mm, struct uprobe *uprobe)

int arch_uprobes_analyze_insn(struct mm_struct *mm, struct arch_uprobe *auprobe)

{

	int ret;

	struct insn insn;



	uprobe->arch_info.fixups = 0;

	ret = validate_insn_bits(mm, uprobe, &insn);

	auprobe->fixups = 0;

	ret = validate_insn_bits(mm, auprobe, &insn);

	if (ret != 0)

		return ret;



	handle_riprel_insn(mm, uprobe, &insn);

	prepare_fixups(uprobe, &insn);

	handle_riprel_insn(mm, auprobe, &insn);

	prepare_fixups(auprobe, &insn);



	return 0;

}

include/linux/uprobes.h

+2 −21
Original line number Diff line number Diff line
@@ -29,12 +29,6 @@ 
struct vm_area_struct;

#ifdef CONFIG_ARCH_SUPPORTS_UPROBES

#include <asm/uprobes.h>

#else



typedef u8 uprobe_opcode_t;

struct uprobe_arch_info {};



#define MAX_UINSN_BYTES 4

#endif



/* flags that denote/change uprobes behaviour */
@@ -56,22 +50,9 @@ struct uprobe_consumer { 
	struct uprobe_consumer *next;

};



struct uprobe {

	struct rb_node		rb_node;	/* node in the rb tree */

	atomic_t		ref;

	struct rw_semaphore	consumer_rwsem;

	struct list_head	pending_list;

	struct uprobe_arch_info arch_info;

	struct uprobe_consumer	*consumers;

	struct inode		*inode;		/* Also hold a ref to inode */

	loff_t			offset;

	int			flags;

	u8			insn[MAX_UINSN_BYTES];

};



#ifdef CONFIG_UPROBES

extern int __weak set_bkpt(struct mm_struct *mm, struct uprobe *uprobe, unsigned long vaddr);

extern int __weak set_orig_insn(struct mm_struct *mm, struct uprobe *uprobe, unsigned long vaddr, bool verify);

extern int __weak set_bkpt(struct mm_struct *mm, struct arch_uprobe *auprobe, unsigned long vaddr);

extern int __weak set_orig_insn(struct mm_struct *mm, struct arch_uprobe *auprobe, unsigned long vaddr, bool verify);

extern bool __weak is_bkpt_insn(uprobe_opcode_t *insn);

extern int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *consumer);

extern void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *consumer);

kernel/events/uprobes.c

+26 −12
Original line number Diff line number Diff line
@@ -65,6 +65,18 @@ struct vma_info { 
	loff_t			vaddr;

};



struct uprobe {

	struct rb_node		rb_node;	/* node in the rb tree */

	atomic_t		ref;

	struct rw_semaphore	consumer_rwsem;

	struct list_head	pending_list;

	struct uprobe_consumer	*consumers;

	struct inode		*inode;		/* Also hold a ref to inode */

	loff_t			offset;

	int			flags;

	struct arch_uprobe	arch;

};



/*

 * valid_vma: Verify if the specified vma is an executable vma

 * Relax restrictions while unregistering: vm_flags might have
@@ -180,7 +192,7 @@ bool __weak is_bkpt_insn(uprobe_opcode_t *insn) 
/*

 * write_opcode - write the opcode at a given virtual address.

 * @mm: the probed process address space.

 * @uprobe: the breakpointing information.

 * @arch_uprobe: the breakpointing information.

 * @vaddr: the virtual address to store the opcode.

 * @opcode: opcode to be written at @vaddr.

 *
@@ -190,13 +202,14 @@ bool __weak is_bkpt_insn(uprobe_opcode_t *insn) 
 * For mm @mm, write the opcode at @vaddr.

 * Return 0 (success) or a negative errno.

 */

static int write_opcode(struct mm_struct *mm, struct uprobe *uprobe,

static int write_opcode(struct mm_struct *mm, struct arch_uprobe *auprobe,

			unsigned long vaddr, uprobe_opcode_t opcode)

{

	struct page *old_page, *new_page;

	struct address_space *mapping;

	void *vaddr_old, *vaddr_new;

	struct vm_area_struct *vma;

	struct uprobe *uprobe;

	loff_t addr;

	int ret;
@@ -216,6 +229,7 @@ static int write_opcode(struct mm_struct *mm, struct uprobe *uprobe, 
	if (!valid_vma(vma, is_bkpt_insn(&opcode)))

		goto put_out;



	uprobe = container_of(auprobe, struct uprobe, arch);

	mapping = uprobe->inode->i_mapping;

	if (mapping != vma->vm_file->f_mapping)

		goto put_out;
@@ -326,7 +340,7 @@ static int is_bkpt_at_addr(struct mm_struct *mm, unsigned long vaddr) 
 * For mm @mm, store the breakpoint instruction at @vaddr.

 * Return 0 (success) or a negative errno.

 */

int __weak set_bkpt(struct mm_struct *mm, struct uprobe *uprobe, unsigned long vaddr)

int __weak set_bkpt(struct mm_struct *mm, struct arch_uprobe *auprobe, unsigned long vaddr)

{

	int result;
@@ -337,7 +351,7 @@ int __weak set_bkpt(struct mm_struct *mm, struct uprobe *uprobe, unsigned long v 
	if (result)

		return result;



	return write_opcode(mm, uprobe, vaddr, UPROBES_BKPT_INSN);

	return write_opcode(mm, auprobe, vaddr, UPROBES_BKPT_INSN);

}



/**
@@ -351,7 +365,7 @@ int __weak set_bkpt(struct mm_struct *mm, struct uprobe *uprobe, unsigned long v 
 * Return 0 (success) or a negative errno.

 */

int __weak

set_orig_insn(struct mm_struct *mm, struct uprobe *uprobe, unsigned long vaddr, bool verify)

set_orig_insn(struct mm_struct *mm, struct arch_uprobe *auprobe, unsigned long vaddr, bool verify)

{

	if (verify) {

		int result;
@@ -363,7 +377,7 @@ set_orig_insn(struct mm_struct *mm, struct uprobe *uprobe, unsigned long vaddr, 
		if (result != 1)

			return result;

	}

	return write_opcode(mm, uprobe, vaddr, *(uprobe_opcode_t *)uprobe->insn);

	return write_opcode(mm, auprobe, vaddr, *(uprobe_opcode_t *)auprobe->insn);

}



static int match_uprobe(struct uprobe *l, struct uprobe *r)
@@ -593,13 +607,13 @@ static int copy_insn(struct uprobe *uprobe, struct vm_area_struct *vma, unsigned 


	/* Instruction at the page-boundary; copy bytes in second page */

	if (nbytes < bytes) {

		if (__copy_insn(mapping, vma, uprobe->insn + nbytes,

		if (__copy_insn(mapping, vma, uprobe->arch.insn + nbytes,

				bytes - nbytes, uprobe->offset + nbytes))

			return -ENOMEM;



		bytes = nbytes;

	}

	return __copy_insn(mapping, vma, uprobe->insn, bytes, uprobe->offset);

	return __copy_insn(mapping, vma, uprobe->arch.insn, bytes, uprobe->offset);

}



static int install_breakpoint(struct mm_struct *mm, struct uprobe *uprobe,
@@ -625,23 +639,23 @@ static int install_breakpoint(struct mm_struct *mm, struct uprobe *uprobe, 
		if (ret)

			return ret;



		if (is_bkpt_insn((uprobe_opcode_t *)uprobe->insn))

		if (is_bkpt_insn((uprobe_opcode_t *)uprobe->arch.insn))

			return -EEXIST;



		ret = arch_uprobes_analyze_insn(mm, uprobe);

		ret = arch_uprobes_analyze_insn(mm, &uprobe->arch);

		if (ret)

			return ret;



		uprobe->flags |= UPROBES_COPY_INSN;

	}

	ret = set_bkpt(mm, uprobe, addr);

	ret = set_bkpt(mm, &uprobe->arch, addr);



	return ret;

}



static void remove_breakpoint(struct mm_struct *mm, struct uprobe *uprobe, loff_t vaddr)

{

	set_orig_insn(mm, uprobe, (unsigned long)vaddr, true);

	set_orig_insn(mm, &uprobe->arch, (unsigned long)vaddr, true);

}



static void delete_uprobe(struct uprobe *uprobe)

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