From: Ingo Molnar Date: Thu, 12 May 2011 21:00:28 +0000 (+0200) Subject: vsprintf: Turn kptr_restrict off by default X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=411f05f123cbd7f8aa1edcae86970755a6e2a9d9;p=linux-beck.git vsprintf: Turn kptr_restrict off by default kptr_restrict has been triggering bugs in apps such as perf, and it also makes the system less useful by default, so turn it off by default. This is how we generally handle security features that remove functionality, such as firewall code or SELinux - they have to be configured and activated from user-space. Distributions can turn kptr_restrict on again via this line in /etc/sysctrl.conf: kernel.kptr_restrict = 1 ( Also mark the variable __read_mostly while at it, as it's typically modified only once per bootup, or not at all. ) Signed-off-by: Ingo Molnar Acked-by: David S. Miller Signed-off-by: Linus Torvalds --- diff --git a/lib/vsprintf.c b/lib/vsprintf.c index bc0ac6b333dc..dfd60192bc2e 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -797,7 +797,7 @@ char *uuid_string(char *buf, char *end, const u8 *addr, return string(buf, end, uuid, spec); } -int kptr_restrict = 1; +int kptr_restrict __read_mostly; /* * Show a '%p' thing. A kernel extension is that the '%p' is followed