[PATCH v2 01/11] uprobes: Introduce get_uprobe()

From: Oleg Nesterov
Date: Mon Jul 06 2015 - 21:24:20 EST


Cosmetic. Add the new trivial helper, get_uprobe(). It matches
put_uprobe() we already have and we can simplify a couple of its
users.

Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
---
kernel/events/uprobes.c | 39 ++++++++++++++++++++-------------------
1 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index cb346f2..a9847b4 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -366,6 +366,18 @@ set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long v
return uprobe_write_opcode(mm, vaddr, *(uprobe_opcode_t *)&auprobe->insn);
}

+static struct uprobe *get_uprobe(struct uprobe *uprobe)
+{
+ atomic_inc(&uprobe->ref);
+ return uprobe;
+}
+
+static void put_uprobe(struct uprobe *uprobe)
+{
+ if (atomic_dec_and_test(&uprobe->ref))
+ kfree(uprobe);
+}
+
static int match_uprobe(struct uprobe *l, struct uprobe *r)
{
if (l->inode < r->inode)
@@ -393,10 +405,8 @@ static struct uprobe *__find_uprobe(struct inode *inode, loff_t offset)
while (n) {
uprobe = rb_entry(n, struct uprobe, rb_node);
match = match_uprobe(&u, uprobe);
- if (!match) {
- atomic_inc(&uprobe->ref);
- return uprobe;
- }
+ if (!match)
+ return get_uprobe(uprobe);

if (match < 0)
n = n->rb_left;
@@ -432,10 +442,8 @@ static struct uprobe *__insert_uprobe(struct uprobe *uprobe)
parent = *p;
u = rb_entry(parent, struct uprobe, rb_node);
match = match_uprobe(uprobe, u);
- if (!match) {
- atomic_inc(&u->ref);
- return u;
- }
+ if (!match)
+ return get_uprobe(u);

if (match < 0)
p = &parent->rb_left;
@@ -472,12 +480,6 @@ static struct uprobe *insert_uprobe(struct uprobe *uprobe)
return u;
}

-static void put_uprobe(struct uprobe *uprobe)
-{
- if (atomic_dec_and_test(&uprobe->ref))
- kfree(uprobe);
-}
-
static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset)
{
struct uprobe *uprobe, *cur_uprobe;
@@ -1039,14 +1041,14 @@ static void build_probe_list(struct inode *inode,
if (u->inode != inode || u->offset < min)
break;
list_add(&u->pending_list, head);
- atomic_inc(&u->ref);
+ get_uprobe(u);
}
for (t = n; (t = rb_next(t)); ) {
u = rb_entry(t, struct uprobe, rb_node);
if (u->inode != inode || u->offset > max)
break;
list_add(&u->pending_list, head);
- atomic_inc(&u->ref);
+ get_uprobe(u);
}
}
spin_unlock(&uprobes_treelock);
@@ -1437,7 +1439,7 @@ static int dup_utask(struct task_struct *t, struct uprobe_task *o_utask)
return -ENOMEM;

*n = *o;
- atomic_inc(&n->uprobe->ref);
+ get_uprobe(n->uprobe);
n->next = NULL;

*p = n;
@@ -1565,8 +1567,7 @@ static void prepare_uretprobe(struct uprobe *uprobe, struct pt_regs *regs)
orig_ret_vaddr = utask->return_instances->orig_ret_vaddr;
}

- atomic_inc(&uprobe->ref);
- ri->uprobe = uprobe;
+ ri->uprobe = get_uprobe(uprobe);
ri->func = instruction_pointer(regs);
ri->orig_ret_vaddr = orig_ret_vaddr;
ri->chained = chained;
--
1.5.5.1

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