cbc91f71b5
Uprobes has a callback (uprobe_munmap()) in the unmap path to
maintain the uprobes count.
In the exit path this callback gets called in unlink_file_vma().
However by the time unlink_file_vma() is called, the pages would
have been unmapped (in unmap_vmas()) and the task->rss_stat counts
accounted (in zap_pte_range()).
If the exiting process has probepoints, uprobe_munmap() checks if
the breakpoint instruction was around before decrementing the probe
count.
This results in a file backed page being reread by uprobe_munmap()
and hence it does not find the breakpoint.
This patch fixes this problem by moving the callback to
unmap_single_vma(). Since unmap_single_vma() may not unmap the
complete vma, add start and end parameters to uprobe_munmap().
This bug became apparent courtesy of commit c3f0327f8e
("mm: add rss counters consistency check").
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com>
Cc: Linux-mm <linux-mm@kvack.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120411103527.23245.9835.sendpatchset@srdronam.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
166 lines
4.9 KiB
C
166 lines
4.9 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
|
|
|
|
/* flags that denote/change uprobes behaviour */
|
|
|
|
/* Have a copy of original instruction */
|
|
#define UPROBE_COPY_INSN 0x1
|
|
|
|
/* Dont run handlers when first register/ last unregister in progress*/
|
|
#define UPROBE_RUN_HANDLER 0x2
|
|
/* Can skip singlestep */
|
|
#define UPROBE_SKIP_SSTEP 0x4
|
|
|
|
struct uprobe_consumer {
|
|
int (*handler)(struct uprobe_consumer *self, struct pt_regs *regs);
|
|
/*
|
|
* filter is optional; If a filter exists, handler is run
|
|
* if and only if filter returns true.
|
|
*/
|
|
bool (*filter)(struct uprobe_consumer *self, struct task_struct *task);
|
|
|
|
struct uprobe_consumer *next;
|
|
};
|
|
|
|
#ifdef CONFIG_UPROBES
|
|
enum uprobe_task_state {
|
|
UTASK_RUNNING,
|
|
UTASK_BP_HIT,
|
|
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 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;
|
|
atomic_t count;
|
|
};
|
|
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, bool verify);
|
|
extern bool __weak is_swbp_insn(uprobe_opcode_t *insn);
|
|
extern int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc);
|
|
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_free_utask(struct task_struct *t);
|
|
extern void uprobe_copy_process(struct task_struct *t);
|
|
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 __weak arch_uprobe_skip_sstep(struct arch_uprobe *aup, struct pt_regs *regs);
|
|
extern void uprobe_clear_state(struct mm_struct *mm);
|
|
extern void uprobe_reset_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 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_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)
|
|
{
|
|
}
|
|
static inline void uprobe_clear_state(struct mm_struct *mm)
|
|
{
|
|
}
|
|
static inline void uprobe_reset_state(struct mm_struct *mm)
|
|
{
|
|
}
|
|
#endif /* !CONFIG_UPROBES */
|
|
#endif /* _LINUX_UPROBES_H */
|