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authorMasami Hiramatsu <mhiramat@redhat.com>2008-03-04 14:29:44 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-03-04 16:35:19 -0800
commitb2a5cd6938879b5bcfef0a73c28fea84c49519c2 (patch)
treee2039a9f7a4766dbea703c6ed32db881863efc1d
parent1913130553aa231644eb4e955b1a2c533fe33d17 (diff)
downloadkernel-b2a5cd6938879b5bcfef0a73c28fea84c49519c2.tar.gz
kprobes: fix a null pointer bug in register_kretprobe()
Fix a bug in regiseter_kretprobe() which does not check rp->kp.symbol_name == NULL before calling kprobe_lookup_name. For maintainability, this introduces kprobe_addr helper function which resolves addr field. It is used by register_kprobe and register_kretprobe. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/kprobes.c43
1 files changed, 26 insertions, 17 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index e6a61dcbc578..fcfb580c3afc 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -498,27 +498,36 @@ static int __kprobes in_kprobes_functions(unsigned long addr)
return 0;
}
+/*
+ * If we have a symbol_name argument, look it up and add the offset field
+ * to it. This way, we can specify a relative address to a symbol.
+ */
+static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p)
+{
+ kprobe_opcode_t *addr = p->addr;
+ if (p->symbol_name) {
+ if (addr)
+ return NULL;
+ kprobe_lookup_name(p->symbol_name, addr);
+ }
+
+ if (!addr)
+ return NULL;
+ return (kprobe_opcode_t *)(((char *)addr) + p->offset);
+}
+
static int __kprobes __register_kprobe(struct kprobe *p,
unsigned long called_from)
{
int ret = 0;
struct kprobe *old_p;
struct module *probed_mod;
+ kprobe_opcode_t *addr;
- /*
- * If we have a symbol_name argument look it up,
- * and add it to the address. That way the addr
- * field can either be global or relative to a symbol.
- */
- if (p->symbol_name) {
- if (p->addr)
- return -EINVAL;
- kprobe_lookup_name(p->symbol_name, p->addr);
- }
-
- if (!p->addr)
+ addr = kprobe_addr(p);
+ if (!addr)
return -EINVAL;
- p->addr = (kprobe_opcode_t *)(((char *)p->addr)+ p->offset);
+ p->addr = addr;
if (!kernel_text_address((unsigned long) p->addr) ||
in_kprobes_functions((unsigned long) p->addr))
@@ -721,12 +730,12 @@ int __kprobes register_kretprobe(struct kretprobe *rp)
int ret = 0;
struct kretprobe_instance *inst;
int i;
- void *addr = rp->kp.addr;
+ void *addr;
if (kretprobe_blacklist_size) {
- if (addr == NULL)
- kprobe_lookup_name(rp->kp.symbol_name, addr);
- addr += rp->kp.offset;
+ addr = kprobe_addr(&rp->kp);
+ if (!addr)
+ return -EINVAL;
for (i = 0; kretprobe_blacklist[i].name != NULL; i++) {
if (kretprobe_blacklist[i].addr == addr)