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

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Pull uprobes fixes + cleanups from Oleg Nesterov.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar
2012-09-19 17:03:07 +02:00
parent bea8f35421 baedbf02b1
commit d0616c1775
7 changed files with 171 additions and 43 deletions
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99
kernel/events/uprobes.c
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@@ -411,11 +411,10 @@ static struct uprobe *__find_uprobe(struct inode *inode, loff_t offset)
static struct uprobe *find_uprobe(struct inode *inode, loff_t offset)
{
struct uprobe *uprobe;
unsigned long flags;
spin_lock_irqsave(&uprobes_treelock, flags);
spin_lock(&uprobes_treelock);
uprobe = __find_uprobe(inode, offset);
spin_unlock_irqrestore(&uprobes_treelock, flags);
spin_unlock(&uprobes_treelock);
return uprobe;
}
@@ -462,12 +461,11 @@ static struct uprobe *__insert_uprobe(struct uprobe *uprobe)
*/
static struct uprobe *insert_uprobe(struct uprobe *uprobe)
{
unsigned long flags;
struct uprobe *u;
spin_lock_irqsave(&uprobes_treelock, flags);
spin_lock(&uprobes_treelock);
u = __insert_uprobe(uprobe);
spin_unlock_irqrestore(&uprobes_treelock, flags);
spin_unlock(&uprobes_treelock);
/* For now assume that the instruction need not be single-stepped */
uprobe->flags |= UPROBE_SKIP_SSTEP;
@@ -686,7 +684,9 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
set_bit(MMF_HAS_UPROBES, &mm->flags);
ret = set_swbp(&uprobe->arch, mm, vaddr);
if (ret && first_uprobe)
if (!ret)
clear_bit(MMF_RECALC_UPROBES, &mm->flags);
else if (first_uprobe)
clear_bit(MMF_HAS_UPROBES, &mm->flags);
return ret;
@@ -695,6 +695,11 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
static void
remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr)
{
/* can happen if uprobe_register() fails */
if (!test_bit(MMF_HAS_UPROBES, &mm->flags))
return;
set_bit(MMF_RECALC_UPROBES, &mm->flags);
set_orig_insn(&uprobe->arch, mm, vaddr);
}
@@ -705,11 +710,9 @@ remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vad
*/
static void delete_uprobe(struct uprobe *uprobe)
{
unsigned long flags;
spin_lock_irqsave(&uprobes_treelock, flags);
spin_lock(&uprobes_treelock);
rb_erase(&uprobe->rb_node, &uprobes_tree);
spin_unlock_irqrestore(&uprobes_treelock, flags);
spin_unlock(&uprobes_treelock);
iput(uprobe->inode);
put_uprobe(uprobe);
atomic_dec(&uprobe_events);
@@ -897,7 +900,8 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *
}
mutex_unlock(uprobes_hash(inode));
put_uprobe(uprobe);
if (uprobe)
put_uprobe(uprobe);
return ret;
}
@@ -967,7 +971,6 @@ static void build_probe_list(struct inode *inode,
struct list_head *head)
{
loff_t min, max;
unsigned long flags;
struct rb_node *n, *t;
struct uprobe *u;
@@ -975,7 +978,7 @@ static void build_probe_list(struct inode *inode,
min = vaddr_to_offset(vma, start);
max = min + (end - start) - 1;
spin_lock_irqsave(&uprobes_treelock, flags);
spin_lock(&uprobes_treelock);
n = find_node_in_range(inode, min, max);
if (n) {
for (t = n; t; t = rb_prev(t)) {
@@ -993,7 +996,7 @@ static void build_probe_list(struct inode *inode,
atomic_inc(&u->ref);
}
}
spin_unlock_irqrestore(&uprobes_treelock, flags);
spin_unlock(&uprobes_treelock);
}
/*
@@ -1030,6 +1033,25 @@ int uprobe_mmap(struct vm_area_struct *vma)
return 0;
}
static bool
vma_has_uprobes(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
loff_t min, max;
struct inode *inode;
struct rb_node *n;
inode = vma->vm_file->f_mapping->host;
min = vaddr_to_offset(vma, start);
max = min + (end - start) - 1;
spin_lock(&uprobes_treelock);
n = find_node_in_range(inode, min, max);
spin_unlock(&uprobes_treelock);
return !!n;
}
/*
* Called in context of a munmap of a vma.
*/
@@ -1041,10 +1063,12 @@ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned lon
if (!atomic_read(&vma->vm_mm->mm_users)) /* called by mmput() ? */
return;
if (!test_bit(MMF_HAS_UPROBES, &vma->vm_mm->flags))
if (!test_bit(MMF_HAS_UPROBES, &vma->vm_mm->flags) ||
test_bit(MMF_RECALC_UPROBES, &vma->vm_mm->flags))
return;
/* TODO: unmapping uprobe(s) will need more work */
if (vma_has_uprobes(vma, start, end))
set_bit(MMF_RECALC_UPROBES, &vma->vm_mm->flags);
}
/* Slot allocation for XOL */
@@ -1150,8 +1174,11 @@ void uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm)
{
newmm->uprobes_state.xol_area = NULL;
if (test_bit(MMF_HAS_UPROBES, &oldmm->flags))
if (test_bit(MMF_HAS_UPROBES, &oldmm->flags)) {
set_bit(MMF_HAS_UPROBES, &newmm->flags);
/* unconditionally, dup_mmap() skips VM_DONTCOPY vmas */
set_bit(MMF_RECALC_UPROBES, &newmm->flags);
}
}
/*
@@ -1369,6 +1396,25 @@ static bool can_skip_sstep(struct uprobe *uprobe, struct pt_regs *regs)
return false;
}
static void mmf_recalc_uprobes(struct mm_struct *mm)
{
struct vm_area_struct *vma;
for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (!valid_vma(vma, false))
continue;
/*
* This is not strictly accurate, we can race with
* uprobe_unregister() and see the already removed
* uprobe if delete_uprobe() was not yet called.
*/
if (vma_has_uprobes(vma, vma->vm_start, vma->vm_end))
return;
}
clear_bit(MMF_HAS_UPROBES, &mm->flags);
}
static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
{
struct mm_struct *mm = current->mm;
@@ -1390,11 +1436,24 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
} else {
*is_swbp = -EFAULT;
}
if (!uprobe && test_and_clear_bit(MMF_RECALC_UPROBES, &mm->flags))
mmf_recalc_uprobes(mm);
up_read(&mm->mmap_sem);
return uprobe;
}
void __weak arch_uprobe_enable_step(struct arch_uprobe *arch)
{
user_enable_single_step(current);
}
void __weak arch_uprobe_disable_step(struct arch_uprobe *arch)
{
user_disable_single_step(current);
}
/*
* Run handler and ask thread to singlestep.
* Ensure all non-fatal signals cannot interrupt thread while it singlesteps.
@@ -1441,7 +1500,7 @@ static void handle_swbp(struct pt_regs *regs)
utask->state = UTASK_SSTEP;
if (!pre_ssout(uprobe, regs, bp_vaddr)) {
user_enable_single_step(current);
arch_uprobe_enable_step(&uprobe->arch);
return;
}
@@ -1477,10 +1536,10 @@ static void handle_singlestep(struct uprobe_task *utask, struct pt_regs *regs)
else
WARN_ON_ONCE(1);
arch_uprobe_disable_step(&uprobe->arch);
put_uprobe(uprobe);
utask->active_uprobe = NULL;
utask->state = UTASK_RUNNING;
user_disable_single_step(current);
xol_free_insn_slot(current);
spin_lock_irq(&current->sighand->siglock);