Commit 09897d78 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge branch 'uprobes/core' of... 

Merge branch 'uprobes/core' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc

 into perf/core

Pull uprobes cleanups from Oleg Nesterov.

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parents e98a6e59 ad439356

arch/powerpc/include/asm/uprobes.h

+2 −3
Original line number Diff line number Diff line
@@ -36,9 +36,8 @@ typedef ppc_opcode_t uprobe_opcode_t; 


struct arch_uprobe {

	union {

		u8	insn[MAX_UINSN_BYTES];

		u8	ixol[MAX_UINSN_BYTES];

		u32	ainsn;

		u32	insn;

		u32	ixol;

	};

};

arch/powerpc/kernel/uprobes.c

+1 −1
Original line number Diff line number Diff line
@@ -186,7 +186,7 @@ bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs) 
	 * emulate_step() returns 1 if the insn was successfully emulated.

	 * For all other cases, we need to single-step in hardware.

	 */

	ret = emulate_step(regs, auprobe->ainsn);

	ret = emulate_step(regs, auprobe->insn);

	if (ret > 0)

		return true;

include/linux/uprobes.h

+20 −32
Original line number Diff line number Diff line
@@ -26,16 +26,13 @@ 


#include <linux/errno.h>

#include <linux/rbtree.h>

#include <linux/types.h>



struct vm_area_struct;

struct mm_struct;

struct inode;

struct notifier_block;



#ifdef CONFIG_ARCH_SUPPORTS_UPROBES

# include <asm/uprobes.h>

#endif



#define UPROBE_HANDLER_REMOVE		1

#define UPROBE_HANDLER_MASK		1
@@ -60,6 +57,8 @@ struct uprobe_consumer { 
};



#ifdef CONFIG_UPROBES

#include <asm/uprobes.h>



enum uprobe_task_state {

	UTASK_RUNNING,

	UTASK_SSTEP,
@@ -72,35 +71,28 @@ enum uprobe_task_state { 
 */

struct uprobe_task {

	enum uprobe_task_state		state;

	struct arch_uprobe_task		autask;



	struct return_instance		*return_instances;

	unsigned int			depth;

	struct uprobe			*active_uprobe;



	unsigned long			xol_vaddr;

	union {

		struct {

			struct arch_uprobe_task	autask;

			unsigned long		vaddr;

		};



/*

 * On a breakpoint hit, thread contests for a slot.  It frees the

 * slot after singlestep. Currently a fixed number of slots are

 * allocated.

 */

struct xol_area {

	wait_queue_head_t 	wq;		/* if all slots are busy */

	atomic_t 		slot_count;	/* number of in-use slots */

	unsigned long 		*bitmap;	/* 0 = free slot */

	struct page 		*page;

		struct {

			struct callback_head	dup_xol_work;

			unsigned long		dup_xol_addr;

		};

	};



	/*

	 * We keep the vma's vm_start rather than a pointer to the vma

	 * itself.  The probed process or a naughty kernel module could make

	 * the vma go away, and we must handle that reasonably gracefully.

	 */

	unsigned long 		vaddr;		/* Page(s) of instruction slots */

	struct uprobe			*active_uprobe;

	unsigned long			xol_vaddr;



	struct return_instance		*return_instances;

	unsigned int			depth;

};



struct xol_area;



struct uprobes_state {

	struct xol_area		*xol_area;

};
@@ -109,6 +101,7 @@ extern int __weak set_swbp(struct arch_uprobe *aup, struct mm_struct *mm, unsign 
extern int __weak set_orig_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr);

extern bool __weak is_swbp_insn(uprobe_opcode_t *insn);

extern bool __weak is_trap_insn(uprobe_opcode_t *insn);

extern unsigned long __weak uprobe_get_swbp_addr(struct pt_regs *regs);

extern int uprobe_write_opcode(struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t);

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

extern int uprobe_apply(struct inode *inode, loff_t offset, struct uprobe_consumer *uc, bool);
@@ -120,7 +113,6 @@ extern void uprobe_end_dup_mmap(void); 
extern void uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm);

extern void uprobe_free_utask(struct task_struct *t);

extern void uprobe_copy_process(struct task_struct *t, unsigned long flags);

extern unsigned long __weak uprobe_get_swbp_addr(struct pt_regs *regs);

extern int uprobe_post_sstep_notifier(struct pt_regs *regs);

extern int uprobe_pre_sstep_notifier(struct pt_regs *regs);

extern void uprobe_notify_resume(struct pt_regs *regs);
@@ -176,10 +168,6 @@ static inline bool uprobe_deny_signal(void) 
{

	return false;

}

static inline unsigned long uprobe_get_swbp_addr(struct pt_regs *regs)

{

	return 0;

}

static inline void uprobe_free_utask(struct task_struct *t)

{

}

kernel/events/uprobes.c

+43 −17
Original line number Diff line number Diff line
@@ -73,6 +73,17 @@ struct uprobe { 
	struct inode		*inode;		/* Also hold a ref to inode */

	loff_t			offset;

	unsigned long		flags;



	/*

	 * The generic code assumes that it has two members of unknown type

	 * owned by the arch-specific code:

	 *

	 * 	insn -	copy_insn() saves the original instruction here for

	 *		arch_uprobe_analyze_insn().

	 *

	 *	ixol -	potentially modified instruction to execute out of

	 *		line, copied to xol_area by xol_get_insn_slot().

	 */

	struct arch_uprobe	arch;

};
@@ -85,6 +96,29 @@ struct return_instance { 
	struct return_instance	*next;		/* keep as stack */

};



/*

 * Execute out of line area: anonymous executable mapping installed

 * by the probed task to execute the copy of the original instruction

 * mangled by set_swbp().

 *

 * On a breakpoint hit, thread contests for a slot.  It frees the

 * slot after singlestep. Currently a fixed number of slots are

 * allocated.

 */

struct xol_area {

	wait_queue_head_t 	wq;		/* if all slots are busy */

	atomic_t 		slot_count;	/* number of in-use slots */

	unsigned long 		*bitmap;	/* 0 = free slot */

	struct page 		*page;



	/*

	 * We keep the vma's vm_start rather than a pointer to the vma

	 * itself.  The probed process or a naughty kernel module could make

	 * the vma go away, and we must handle that reasonably gracefully.

	 */

	unsigned long 		vaddr;		/* Page(s) of instruction slots */

};



/*

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

 * Relax restrictions while unregistering: vm_flags might have
@@ -330,7 +364,7 @@ int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned 
int __weak

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

{

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

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

}



static int match_uprobe(struct uprobe *l, struct uprobe *r)
@@ -529,8 +563,8 @@ static int copy_insn(struct uprobe *uprobe, struct file *filp) 
{

	struct address_space *mapping = uprobe->inode->i_mapping;

	loff_t offs = uprobe->offset;

	void *insn = uprobe->arch.insn;

	int size = MAX_UINSN_BYTES;

	void *insn = &uprobe->arch.insn;

	int size = sizeof(uprobe->arch.insn);

	int len, err = -EIO;



	/* Copy only available bytes, -EIO if nothing was read */
@@ -569,7 +603,7 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file, 
		goto out;



	ret = -ENOTSUPP;

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

	if (is_trap_insn((uprobe_opcode_t *)&uprobe->arch.insn))

		goto out;



	ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, vaddr);
@@ -1264,7 +1298,7 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe) 


	/* Initialize the slot */

	copy_to_page(area->page, xol_vaddr,

			uprobe->arch.ixol, sizeof(uprobe->arch.ixol));

			&uprobe->arch.ixol, sizeof(uprobe->arch.ixol));

	/*

	 * We probably need flush_icache_user_range() but it needs vma.

	 * This should work on supported architectures too.
@@ -1403,12 +1437,10 @@ static void uprobe_warn(struct task_struct *t, const char *msg) 


static void dup_xol_work(struct callback_head *work)

{

	kfree(work);



	if (current->flags & PF_EXITING)

		return;



	if (!__create_xol_area(current->utask->vaddr))

	if (!__create_xol_area(current->utask->dup_xol_addr))

		uprobe_warn(current, "dup xol area");

}
@@ -1419,7 +1451,6 @@ void uprobe_copy_process(struct task_struct *t, unsigned long flags) 
{

	struct uprobe_task *utask = current->utask;

	struct mm_struct *mm = current->mm;

	struct callback_head *work;

	struct xol_area *area;



	t->utask = NULL;
@@ -1441,14 +1472,9 @@ void uprobe_copy_process(struct task_struct *t, unsigned long flags) 
	if (mm == t->mm)

		return;



	/* TODO: move it into the union in uprobe_task */

	work = kmalloc(sizeof(*work), GFP_KERNEL);

	if (!work)

		return uprobe_warn(t, "dup xol area");



	t->utask->vaddr = area->vaddr;

	init_task_work(work, dup_xol_work);

	task_work_add(t, work, true);

	t->utask->dup_xol_addr = area->vaddr;

	init_task_work(&t->utask->dup_xol_work, dup_xol_work);

	task_work_add(t, &t->utask->dup_xol_work, true);

}



/*