From ad315455d396a1cbcb2f9fdd687b7e1b26b789e7 Mon Sep 17 00:00:00 2001 From: Boqun Feng Date: Tue, 29 Dec 2015 12:18:46 +0800 Subject: sparse: Add __private to privatize members of structs In C programming language, we don't have a easy way to privatize a member of a structure. However in kernel, sometimes there is a need to privatize a member in case of potential bugs or misuses. Fortunately, the noderef attribute of sparse is a way to privatize a member, as by defining a member as noderef, the address-of operator on the member will produce a noderef pointer to that member, and if anyone wants to dereference that kind of pointers to read or modify the member, sparse will yell. Based on this, __private modifier and related operation ACCESS_PRIVATE() are introduced, which could help detect undesigned public uses of private members of structs. Here is an example of sparse's output if it detect an undersigned public use: | kernel/rcu/tree.c:4453:25: warning: incorrect type in argument 1 (different modifiers) | kernel/rcu/tree.c:4453:25: expected struct raw_spinlock [usertype] *lock | kernel/rcu/tree.c:4453:25: got struct raw_spinlock [noderef] * Also, this patch improves compiler.h a little bit by adding comments for "#else" and "#endif". Signed-off-by: Boqun Feng Signed-off-by: Paul E. McKenney --- scripts/checkpatch.pl | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'scripts') diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 0147c91fa549..874132b26d23 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -269,7 +269,8 @@ our $Sparse = qr{ __init_refok| __kprobes| __ref| - __rcu + __rcu| + __private }x; our $InitAttributePrefix = qr{__(?:mem|cpu|dev|net_|)}; our $InitAttributeData = qr{$InitAttributePrefix(?:initdata\b)}; -- cgit v1.2.3