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Commit 37b6cb47 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 fixes and cleanups from Oleg Nesterov:

  "Any probed jmp/call can kill the application, see the changelog in 11/15."

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parents b3d5fc3c 6cc5e7ff

arch/x86/include/asm/uprobes.h

+14 −2
Original line number Diff line number Diff line
@@ -33,15 +33,27 @@ typedef u8 uprobe_opcode_t; 
#define UPROBE_SWBP_INSN		0xcc

#define UPROBE_SWBP_INSN_SIZE		   1



struct uprobe_xol_ops;



struct arch_uprobe {

	u16				fixups;

	union {

		u8			insn[MAX_UINSN_BYTES];

		u8			ixol[MAX_UINSN_BYTES];

	};



	u16				fixups;

	const struct uprobe_xol_ops	*ops;



	union {

#ifdef CONFIG_X86_64

		unsigned long			rip_rela_target_address;

#endif

		struct {

			s32	offs;

			u8	ilen;

			u8	opc1;

		}				branch;

	};

};



struct arch_uprobe_task {

arch/x86/kernel/uprobes.c

+349 −202

File changed.

Preview size limit exceeded, changes collapsed.

kernel/events/uprobes.c

+9 −22
Original line number Diff line number Diff line
@@ -60,8 +60,6 @@ static struct percpu_rw_semaphore dup_mmap_sem; 


/* Have a copy of original instruction */

#define UPROBE_COPY_INSN	0

/* Can skip singlestep */

#define UPROBE_SKIP_SSTEP	1



struct uprobe {

	struct rb_node		rb_node;	/* node in the rb tree */
@@ -491,12 +489,9 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset) 
	uprobe->offset = offset;

	init_rwsem(&uprobe->register_rwsem);

	init_rwsem(&uprobe->consumer_rwsem);

	/* For now assume that the instruction need not be single-stepped */

	__set_bit(UPROBE_SKIP_SSTEP, &uprobe->flags);



	/* add to uprobes_tree, sorted on inode:offset */

	cur_uprobe = insert_uprobe(uprobe);



	/* a uprobe exists for this inode:offset combination */

	if (cur_uprobe) {

		kfree(uprobe);
@@ -1628,20 +1623,6 @@ bool uprobe_deny_signal(void) 
	return true;

}



/*

 * Avoid singlestepping the original instruction if the original instruction

 * is a NOP or can be emulated.

 */

static bool can_skip_sstep(struct uprobe *uprobe, struct pt_regs *regs)

{

	if (test_bit(UPROBE_SKIP_SSTEP, &uprobe->flags)) {

		if (arch_uprobe_skip_sstep(&uprobe->arch, regs))

			return true;

		clear_bit(UPROBE_SKIP_SSTEP, &uprobe->flags);

	}

	return false;

}



static void mmf_recalc_uprobes(struct mm_struct *mm)

{

	struct vm_area_struct *vma;
@@ -1868,13 +1849,13 @@ static void handle_swbp(struct pt_regs *regs) 


	handler_chain(uprobe, regs);



	if (can_skip_sstep(uprobe, regs))

	if (arch_uprobe_skip_sstep(&uprobe->arch, regs))

		goto out;



	if (!pre_ssout(uprobe, regs, bp_vaddr))

		return;



	/* can_skip_sstep() succeeded, or restart if can't singlestep */

	/* arch_uprobe_skip_sstep() succeeded, or restart if can't singlestep */

out:

	put_uprobe(uprobe);

}
@@ -1886,10 +1867,11 @@ static void handle_swbp(struct pt_regs *regs) 
static void handle_singlestep(struct uprobe_task *utask, struct pt_regs *regs)

{

	struct uprobe *uprobe;

	int err = 0;



	uprobe = utask->active_uprobe;

	if (utask->state == UTASK_SSTEP_ACK)

		arch_uprobe_post_xol(&uprobe->arch, regs);

		err = arch_uprobe_post_xol(&uprobe->arch, regs);

	else if (utask->state == UTASK_SSTEP_TRAPPED)

		arch_uprobe_abort_xol(&uprobe->arch, regs);

	else
@@ -1903,6 +1885,11 @@ static void handle_singlestep(struct uprobe_task *utask, struct pt_regs *regs) 
	spin_lock_irq(&current->sighand->siglock);

	recalc_sigpending(); /* see uprobe_deny_signal() */

	spin_unlock_irq(&current->sighand->siglock);



	if (unlikely(err)) {

		uprobe_warn(current, "execute the probed insn, sending SIGILL.");

		force_sig_info(SIGILL, SEND_SIG_FORCED, current);

	}

}



/*