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linux-next/include/linux/uprobes.h
Oleg Nesterov 3ab6796617 uprobes: Teach uprobe_copy_process() to handle CLONE_VFORK
uprobe_copy_process() does nothing if the child shares ->mm with
the forking process, but there is a special case: CLONE_VFORK.
In this case it would be more correct to do dup_utask() but avoid
dup_xol(). This is not that important, the child should not unwind
its stack too much, this can corrupt the parent's stack, but at
least we need this to allow to ret-probe __vfork() itself.

Note: in theory, it would be better to check task_pt_regs(p)->sp
instead of CLONE_VFORK, we need to dup_utask() if and only if the
child can return from the function called by the parent. But this
needs the arch-dependant helper, and I think that nobody actually
does clone(same_stack, CLONE_VM).

Reported-by: Martin Cermak <mcermak@redhat.com>
Reported-by: David Smith <dsmith@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-10-29 18:02:55 +01:00

185 lines
5.4 KiB
C

#ifndef _LINUX_UPROBES_H
#define _LINUX_UPROBES_H
/*
* User-space Probes (UProbes)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (C) IBM Corporation, 2008-2012
* Authors:
* Srikar Dronamraju
* Jim Keniston
* Copyright (C) 2011-2012 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
*/
#include <linux/errno.h>
#include <linux/rbtree.h>
struct vm_area_struct;
struct mm_struct;
struct inode;
#ifdef CONFIG_ARCH_SUPPORTS_UPROBES
# include <asm/uprobes.h>
#endif
#define UPROBE_HANDLER_REMOVE 1
#define UPROBE_HANDLER_MASK 1
#define MAX_URETPROBE_DEPTH 64
enum uprobe_filter_ctx {
UPROBE_FILTER_REGISTER,
UPROBE_FILTER_UNREGISTER,
UPROBE_FILTER_MMAP,
};
struct uprobe_consumer {
int (*handler)(struct uprobe_consumer *self, struct pt_regs *regs);
int (*ret_handler)(struct uprobe_consumer *self,
unsigned long func,
struct pt_regs *regs);
bool (*filter)(struct uprobe_consumer *self,
enum uprobe_filter_ctx ctx,
struct mm_struct *mm);
struct uprobe_consumer *next;
};
#ifdef CONFIG_UPROBES
enum uprobe_task_state {
UTASK_RUNNING,
UTASK_SSTEP,
UTASK_SSTEP_ACK,
UTASK_SSTEP_TRAPPED,
};
/*
* uprobe_task: Metadata of a task while it singlesteps.
*/
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;
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;
/*
* 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 uprobes_state {
struct xol_area *xol_area;
};
extern int __weak set_swbp(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr);
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 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);
extern void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc);
extern int uprobe_mmap(struct vm_area_struct *vma);
extern void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end);
extern void uprobe_start_dup_mmap(void);
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);
extern bool uprobe_deny_signal(void);
extern bool arch_uprobe_skip_sstep(struct arch_uprobe *aup, struct pt_regs *regs);
extern void uprobe_clear_state(struct mm_struct *mm);
#else /* !CONFIG_UPROBES */
struct uprobes_state {
};
static inline int
uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc)
{
return -ENOSYS;
}
static inline int
uprobe_apply(struct inode *inode, loff_t offset, struct uprobe_consumer *uc, bool add)
{
return -ENOSYS;
}
static inline void
uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc)
{
}
static inline int uprobe_mmap(struct vm_area_struct *vma)
{
return 0;
}
static inline void
uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
}
static inline void uprobe_start_dup_mmap(void)
{
}
static inline void uprobe_end_dup_mmap(void)
{
}
static inline void
uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm)
{
}
static inline void uprobe_notify_resume(struct pt_regs *regs)
{
}
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)
{
}
static inline void uprobe_copy_process(struct task_struct *t, unsigned long flags)
{
}
static inline void uprobe_clear_state(struct mm_struct *mm)
{
}
#endif /* !CONFIG_UPROBES */
#endif /* _LINUX_UPROBES_H */